S/MIME
Network Working Group                                 D.Pinkas (Bull SAS)
INTERNET-DRAFT                                 N.Pope (Thales eSecurity)
Expires May 2008                         J.Ross (Security and Standards)                                          D. Pinkas
Request for Comments: 5126                                      Bull SAS
Obsoletes: RFC 3126                                        November 2007
Intended status:                                                  N. Pope
Category: Informational                                 Thales eSecurity
                                                                 J. Ross
                                                  Security and Standards
                                                           February 2008

               CMS Advanced Electronic Signatures (CAdES)
                    <draft-ietf-smime-cades-07.txt>

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Copyright Notice

Copyright (C) The IETF Trust (2007). this
   memo is unlimited.

Abstract

   This document defines the format of an electronic signature that can
   remain valid over long periods.  This includes evidence as to its
   validity even if the signer or verifying party later attempts to deny
   (i.e., repudiates) the validity of the signature.

   The format can be considered as an extension to RFC 3852 [4] and RFC 2634 [5],
   2634, where, when appropriate, additional signed and unsigned
   attributes have been defined.

   The contents of this Informational RFC amounts amount to a transposition of
   the ETSI TS Traffic Sector (TS) 101 733 V.1.7.4 (CMS Advanced Electronic
   Signatures - -- CAdES) [TS101733] and is technically equivalent to it.

The technical contents of this specification are maintained by ETSI.
The ETSI TS and further updates are available free of charge at :
http://www.etsi.org/WebSite/Standards/StandardsDownload.aspx

Table of Contents

   1. Introduction                                                      6 ....................................................6
   2. Scope                                                             6 ...........................................................6
   3. Definitions and abbreviations                                     8
3.1 Abbreviations ...................................8
      3.1. Definitions                                                      8
3.2 ................................................8
      3.2. Abbreviations                                                   11 .............................................11
   4. Overview                                                         12
4.1 .......................................................12
      4.1. Major parties                                                   12
4.2  Signatures policies                                             14
4.3 Parties .............................................13
      4.2. Signature Policies ........................................14
      4.3. Electronic signature formats                                    14
4.3.1 Signature Formats ..............................15
           4.3.1. CAdES Basic Electronic Signature (CAdES-BES)                  14
4.3.2 .......15
           4.3.2. CAdES Explicit Policy Policy-based Electronic
                  Signatures (CAdES-EPES)      17
4.4 ............................18
      4.4. Electronic signature formats Signature Formats with validation data               18
4.4.1 Validation Data .........19
           4.4.1. Electronic Signature with Time Time-stamp (CAdES-T)                      19
4.4.2 .....20
           4.4.2. ES with Complete validation data references Validation Data References
                  (CAdES-C)         20
4.4.3 ..........................................21
           4.4.3. Extended electronic signature formats                         22
4.4.4 Electronic Signature Formats ..............23
                  4.4.3.1. EXtended Long Electronic Signature
                           (CAdES-X Long) ............................24
                  4.4.3.2. EXtended Electronic Signature with
                           Time Type 1 ...............................25
                  4.4.3.3. EXtended Electronic Signature with
                           Time Type 2 ...............................26
                  4.4.3.4. EXtended Long Electronic Signature
                           with Time (CAdES-X Long ...................27
           4.4.4. Archival Electronic Signature (CAdES-A)                       26
4.5 ............27
      4.5. Arbitration                                                     27
4.6 ...............................................28
      4.6. Validation process                                              28 Process ........................................29
   5. Electronic signature attributes                                  29
5.1 Signature Attributes ................................30
      5.1. General syntax                                                  29
5.2 Syntax ............................................30
      5.2. Data content type                                               29
5.3 Content Type .........................................30
      5.3. Signed-data content type                                        29
5.4 Content Type ..................................30
      5.4. SignedData type                                                 29
5.5 Type ...........................................31
      5.5. EncapsulatedContentInfo type                                    30
5.6 Type ..............................31
      5.6. SignerInfo type                                                 30
5.6.1 Type ...........................................31
           5.6.1. Message digest calculation process                            31
5.6.2 Digest Calculation Process .................32
           5.6.2. Message signature generation process                          31
5.6.3 Signature Generation Process ...............32
           5.6.3. Message signature verification process                        31
5.7 Signature Verification Process .............32
      5.7. Basic ES mandatory present attributes                           31
5.7.1  Content type                                                  31
5.7.2 Mandatory Present Attributes .....................32
           5.7.1. content-type .......................................32
           5.7.2. Message digest                                                32
5.7.3 Digest .....................................33
           5.7.3. Signing certificate reference attribute                       32
5.8 Certificate Reference Attributes ...........33
                  5.7.3.1. ESS signing-certificate Attribute
                           Definition ................................34
                  5.7.3.2. ESS signing-certificate-v2
                           Attribute Definition ......................34
                  5.7.3.3. Other signing-certificate
                           Attribute Definition ......................35
      5.8. Additional mandatory attributes Mandatory Attributes for Explicit
           Policy-based Electronic Signatures                                           34
5.8.1  Signature policy identifier                                   34
5.9 ........................36
           5.8.1. signature-policy-identifier ........................36
      5.9. CMS imported optional attributes                                36
5.9.1  Signing time                                                  36
5.9.2  Countersignature                                              36
5.10  ESS imported optional attributes                               37
5.10.1  Content reference attribute                                  37
5.10.2  Content identifier attribute                                 37
5.10.3  Content hints attribute                                      37

5.11 Imported Optional Attributes ..........................38
           5.9.1. signing-time .......................................38
           5.9.2. countersignature ...................................39
      5.10. ESS-Imported Optional Attributes .........................39
           5.10.1. content-reference Attribute .......................39
           5.10.2. content-identifier Attribute ......................39
           5.10.3. content-hints Attribute ...........................40
      5.11. Additional optional attributes defined Optional Attributes Defined in the present document 38
5.11.1  Commitment type indication attribute                         38
5.11.2  Signer location attribute                                    40
5.11.3  Signer attributes attribute                                  40
5.11.4  Content time-stamp                                           41
5.12
            Present Document .........................................40
           5.11.1. commitment-type-indication Attribute ..............41
           5.11.2. signer-location Attribute .........................43
           5.11.3. signer-attributes Attribute .......................43
           5.11.4. content-time-stamp ................................44
      5.12. Support for multiple signatures                                41
5.12.1 Multiple Signatures ..........................44
           5.12.1. Independent signatures                                       41
5.12.2 Signatures ............................44
           5.12.2. Embedded signatures                                          42 Signatures ...............................45
   6. Additional Electronic Signature validation attributes            42
6.1  Electronic Signature Time-stamped Validation Attributes ..........45
      6.1. signature time-stamp Attribute (CAdES-T)                     43
6.1.1  Signature time- stamp attribute definition                    44
6.2  Complete validation reference data (CAdES-C)                    44
6.2.1  Complete certificate references attribute definition          45
6.2.2 ..................47
           6.1.1. signature-time-stamp Attribute Definition ..........47
      6.2. Complete Revocation Validation Data References attribute definition           45
6.2.3 (CAdES-C) .............48
           6.2.1. complete-certificate-references Attribute certificate references attribute definition         47
6.2.4
                  Definition .........................................48
           6.2.2. complete-revocation-references Attribute revocation references attribute definition          48
6.3
                  Definition .........................................49
           6.2.3. attribute-certificate-references Attribute
                  Definition .........................................51
           6.2.4. attribute-revocation-references Attribute
                  Definition .........................................52
      6.3. Extended validation data Validation Data (CAdES-X)                              48
6.3.1  Time-stamped validation data ........................52
           6.3.1. Time-Stamped Validation Data (CAdES-X Type
                  1 or Type 2)       48
6.3.2 .......................................53
           6.3.2. Long validation data Validation Data (CAdES-X Long, CAdES-X
                  Long Type 1 or 2) 48
6.3.3  Certificate values attribute definition                       49
6.3.4  Revocation values attribute definition                        50
6.3.5  CAdES-C time-stamp attribute definition                       51
6.3.6  Time-stamped certificates and crls references attribute
       definition                                                    52
6.4  Archive validation data                                         53
6.4.1 ..................................53
           6.3.3. certificate-values Attribute Definition ............54
           6.3.4. revocation-values Attribute Definition .............54
           6.3.5. CAdES-C-time-stamp Attribute Definition ............56
           6.3.6. time-stamped-certs-crls-references
                  Attribute Definition ...............................57
      6.4. Archive time-stamp attribute definition                       53 Validation Data ...................................58
           6.4.1. archive-time-stamp Attribute Definition ............58
   7. Other standard data structures                                   55
7.1  Public-key certificate format                                   55
7.2 Standard Data Structures .................................60
      7.1. Public Key Certificate revocation list format                              55
7.3 Format .............................60
      7.2. Certificate Revocation List Format ........................60
      7.3. OCSP response format                                            55
7.4  Time-stamp token format                                         55
7.5 Response Format ......................................60
      7.4. Time-Stamp Token Format ...................................60
      7.5. Name and attribute formats                                      55
7.6 Attribute certificate                                           56 Formats ................................60
      7.6. AttributeCertificate ......................................61
   8. Conformance requirements                                         56
8.1 Requirements .......................................61
      8.1. CAdES-Basic Electronic Signature (CAdES-BES)                    56
8.2 ..............62
      8.2. CAdES-Explicit Policy-based Electronic Signature                57
8.3 ..........63
      8.3. Verification using time-stamping                                57
8.4 Using Time-Stamping ..........................63
      8.4. Verification using secure records                               58 Using Secure Records .........................63
   9.  IANA Considerations                                              58

10. References                                                      58
10.1 .....................................................64
      9.1. Normative references                                           58
10.2 References ......................................64
      9.2. Informative references                                         59

11.  Authors' addresses                                              62

12.  Acknowledgments                                                 62 References ....................................65
   Annex A (normative): ASN.1 definitions                               63
A.1 Definitions ............................69
           A.1. Signature format definitions using Format Definitions Using
                X.208 ASN.1 syntax           63
A.2 Syntax ...................................69
           A.2. Signature format definitions using Format Definitions Using
                X.680 ASN.1 syntax           71 Syntax ...................................77
   Annex B (informative): Extended forms Forms of Electronic Signatures       80
B.1 ....86
           B.1. Extended forms Forms of validation data                               80
B.1.1 Validation Data ....................86
                B.1.1. CAdES-X Long                                                  81
B.1.2 ..................................87
                B.1.2. CAdES-X Type 1                                                82
B.1.3 ................................88
                B.1.3. CAdES-X Type 2                                                83
B.1.4 ................................90
                B.1.4. CAdES-X Long Type 1 and CAdES-X Long Type 2                   85
B.2  Timestamp extensions                                            86
B.3 ...91
           B.2. Time-Stamp Extensions ................................93
           B.3. Archive validation data Validation Data (CAdES-A)                               87
B.4 ....................94
           B.4. Example validation sequence                                     89
B.5 Validation Sequence ..........................97
           B.5. Additional optional features                                    94 Optional Features ........................102
   Annex C (informative):General description                            95
C.1 (informative): General Description .......................103
           C.1. The signature policy                                            95
C.2 Signature Policy ................................103
           C.2. Signed information                                              96
C.3 Information ..................................104
           C.3. Components of an electronic signature                           96
C.3.1 Electronic Signature ...............104
                C.3.1. Reference to the signature policy                             96
C.3.2 Signature Policy ............104
                C.3.2. Commitment type indication                                    97
C.3.3 Type Indication ...................105
                C.3.3. Certificate identifier Identifier from the signer                        97
C.3.4 Signer .......106
                C.3.4. Role attributes                                               98
C.3.4.1 Attributes ..............................106
                       C.3.4.1.  Claimed role                                                98
C.3.4.2 Role .......................107
                       C.3.4.2.  Certified role                                              99
C.3.5 Role .....................107
                C.3.5. Signer location                                               99
C.3.6 Location ..............................108
                C.3.6. Signing time                                                  99
C.3.7  Content format                                               100
C.3.8 Time .................................108
                C.3.7. Content hints                                                100
C.3.9 Format ...............................108
                C.3.8. content-hints ................................109
                C.3.9. Content cross referencing                                    100
C.4 Cross-Referencing ....................109
           C.4. Components of validation data                                  100
C.4.1 Validation Data .......................109
                C.4.1. Revocation status information                                100
C.4.1.1 Status Information ................109
                       C.4.1.1. CRL information                                            101
C.4.1.2 Information .....................110
                       C.4.1.2. OCSP information                                           101
C.4.2 Information ....................110
                C.4.2. Certification path                                           102
C.4.3 Path ...........................111
                C.4.3. Time-stamping for long life Long Life of signatures                    102
C.4.4 Signatures ....111
                C.4.4. Time-stamping for long life Long Life of signature Signature
                       before CA key
       compromises                                                  103
C.4.4.1 Compromises ....................113
                        C.4.4.1. Time-stamping the ES with complete validation data         104
C.4.4.2  Time-stamping certificates
                                 Complete Validation Data ...........113
                        C.4.4.2. Time-Stamping Certificates and revocation information
         references                                                 105
C.4.5
                                 Revocation Information References ..114
                C.4.5. Time-stamping for archive Archive of signature                       106
C.4.6 Signature .......115
                C.4.6. Reference to additional data                                 107
C.4.7  Time-stamping Additional Data .................116
                C.4.7. Time-Stamping for mutual recognition                         107
C.4.8 Mutual Recognition .........116
                C.4.8. TSA key compromise                                           108
C.5 Key Compromise ...........................117
           C.5. Multiple signatures                                            108 Signatures .................................118
   Annex D (informative):Data protocols (informative): Data Protocols to interoperate Interoperate with TSPs      109
D.1 ..118
           D.1. Operational protocols                                          109
D.1.1 Protocols ...............................118
                D.1.1. Certificate retrieval                                        109
D.1.2 Retrieval ........................118
                D.1.2. CRL retrieval                                                109
D.1.3  OnLine certificate status                                    109
D.1.4  Time-stamping                                                109

D.2 Retrieval ................................118
                D.1.3. Online Certificate Status ....................119
                D.1.4. Time-Stamping ................................119
           D.2. Management protocols                                           109
D.2.1 Protocols ................................119
                D.2.1. Request for certificate revocation                           109 Certificate Revocation ...........119
   Annex E (informative): Security Considerations                      110
E.1 ...................119
           E.1. Protection of private key                                      110
E.2 Private Key ...........................119
           E.2. Choice of algorithms                                           110 Algorithms ................................119
   Annex F (informative): Example structured contents Structured Contents and MIME         111
F.1 ......120
           F.1. General description                                            111
F.2 Description .................................120
                F.1.1. Header information                                             111
F.3 Information ...........................120
                F.1.2. Content encoding                                               113
F.4  Multi-part content                                             113
F.5 Encoding .............................121
                F.1.3. Multi-Part Content ...........................121
           F.2. S/MIME                                                         113 ..............................................122
                F.2.1. Using application/pkcs7-mime .................123
                F.2.2. Using application/pkcs7-signature ............124
   Annex G (informative): Relationship to the European Directive
                          and EESSI                                    115
G.1 .................................125
           G.1. Introduction                                                   116
G.2 ........................................125
           G.2. Electronic signatures Signatures and the directive                        116
G.3 Directive .............126
           G.3. ETSI electronic signature formats Electronic Signature Formats and the directive            117
G.4 Directive .127
           G.4. EESSI standards Standards and classes Classes of electronic signature            117
G.4.1 Electronic Signature .127
                G.4.1. Structure of EESSI standardization                           117
G.4.2 Standardization ...........127
                G.4.2. Classes of electronic signatures                             118
G.4.3 Electronic Signatures .............128
                G.4.3. EESSI classes Classes and the ETSI electronic signature format       118 Electronic
                       Signature Format .............................128
   Annex H (informative): APIs for the generation Generation and verification Verification
                          of electronic signatures tokens              118
H.1 Electronic Signatures Tokens ...........129
           H.1. Data framing                                                   119
H.2 Framing ........................................129
           H.2. IDUP-GSS-APIs defined Defined by the IETF                              120
H.3 ...................131
           H.3. CORBA security interfaces defined Security Interfaces Defined by the OMG                   121 ........132
   Annex I (informative):Cryptographic algorithms                      123
I.1 (informative): Cryptographic Algorithms ..................133
           I.1. Digest algorithms                                              123
I.1.1 Algorithms ...................................133
                I.1.1. SHA-1                                                        123
I.1.2 ........................................133
                I.1.2. General                                                      123
I.2 ......................................133
           I.2. Digital signature algorithms                                   124
I.2.1 Signature Algorithms ........................134
                I.2.1. DSA                                                          124
I.2.2 ..........................................134
                I.2.2. RSA                                                          124
I.2.3 ..........................................135
                I.2.3. General                                                      125 ......................................135
   Annex J (informative): Guidance on naming                           127
J.1 Naming ........................137
           J.1. Allocation of names                                            127
J.2 Names .................................137
           J.2. Providing access Access to registration information                   127
J.3 Registration Information ........138
           J.3. Naming schemes                                                 128
J.3.1 Schemes ......................................138
                J.3.1. Naming schemes Schemes for individual citizens                       128
J.3.2 Individual Citizens .......138
                J.3.2. Naming schemes Schemes for employees Employees of an organization              128

Annex K (informative): Changes from the previous version            130

Full Copyright Statement                                            131
Intellectual Property                                               131
Acknowledgements                                                    132
                       Organization .................................139

1.  Introduction

   This document is intended to cover electronic signatures for various
   types of transactions, including business transactions (e.g. (e.g.,
   purchase requisition, contract, and invoice applications) where long term
   long-term validity of such signatures is important.  This includes
   evidence as to its validity even if the signer or verifying party
   later attempts to deny (i.e., repudiates, repudiates; see ISO/IEC 10181-5
   [ISO10181-5]) the validity of the signature).

Thus signature.

   Thus, the present document can be used for any transaction between an
   individual and a company, between two companies, between an
   individual and a governmental body, etc.  The present document is
   independent of any environment. It environment; it can be applied to any environment e.g. environment,
   e.g., smart cards,
GSM SIM Global System for Mobile Communication Subscriber
   Identity Module (GSM SIM) cards, special programs for electronic
   signatures, etc.

   The European Directive on a community framework for Electronic
   Signatures defines an electronic signature as: "Data in electronic
   form which is attached to or logically associated with other
   electronic data and which serves as a method of authentication".

   An electronic signature signature, as used in the present document document, is a form
   of advanced electronic signature signature, as defined in the Directive.

2.  Scope

   The scope of the present document covers Electronic Signature Formats electronic signature formats
   only.  The aspects of Electronic Signature Policies are defined in
   RFC 3125 [RFC3125] and in ETSI TR 102 272 [TR102272].

   The present document defines a number of Electronic Signature Formats,
including electronic signature
   formats, including electronic signatures that can remain valid over
   long periods.  This includes evidence as to its validity even if the
   signer or verifying party later attempts to deny (repudiates) the
   validity of the electronic signature.

   The present document specifies use of trusted service providers (e.g. Trusted Service Providers
   (e.g., Time-Stamping Authorities), Authorities) and the data that needs to be
   archived
(e.g. cross certificates (e.g., cross-certificates and revocation lists) to meet the
   requirements of long term long-term electronic signatures.

   An electronic signature signature, as defined by the present document document, can be
   used for arbitration in case of a dispute between the signer and
   verifier, which may occur at some later time, even years later.

   The present document includes the concept of signature policies that
   can be used to establish technical consistency when validating
   electronic signatures signatures, but it does not mandate their use.

   The present document is based on the use of public key cryptography
   to produce digital signatures, supported by public key certificates.
   The present document also specifies the use of time-stamping and time-
marking
   time-marking services to prove the validity of a signature long after
   the normal lifetime of critical elements of an electronic signature.  It
   This document also, as an option, defines ways to provide very
   long-term protection against key compromise or weakened algorithms.

   The present document builds on existing standards that are widely
   adopted. This includes:  These include:

      - RFC 3852 [4] [4]: "Cryptographic Message Syntax (CMS)";

      - ISO/IEC 9594-8/ITU-T Recommendation X.509 [1]: "Information
        technology - Open Systems Interconnection - The Directory:
        Authentication framework";

      - RFC 3280 [2] [2]: "Internet X.509 Public Key Infrastructure (PKIX)
        Certificate and CRL Certificate Revocation List (CRL) Profile";

      - RFC 3161 [7] [7]: "Internet X.509 Public Key Infrastructure
        Time-Stamp
      Protocol". Protocol (TSP)".

      NOTE: See section Section 11 for a full set of references.

   The present document describes formats for advanced electronic
   signatures using ASN.1 (Abstract Syntax Notation 1) [14].  ASN.1 is
   encoded using X.690 [16].

   These formats are based on CMS (Cryptographic Message Syntax) defined
   in RFC 3852 [4].  These electronic signatures are thus called CAdES,
   for "CMS Advanced Electronic Signatures".

   Another document, TS 101 903 [TS101903], describes formats for XML
   advanced electronic signatures (XAdES) built on XMLDSIG [XMLDSIG].

   In addition, the present document identifies other documents that
   define formats for Public Key Certificates, Attribute Certificates,
   and Certificate Revocation Lists and supporting protocols, including, including
   protocols for use of by trusted third parties to support the operation
   of electronic signature creation and validation.

   Informative annexes include:

      - illustrations of extended forms of extended Electronic Signatures Signature formats
        that protect against various vulnerabilities and examples of
        validation processes (Annex B);

      - descriptions and explanations of some of the concepts used in
        the present document, giving a rationale for normative parts of
        the present document (Annex C);

      - information on protocols to interoperate with Trusted Service
        Providers (Annex D);

      - guidance on naming (Annex E);

      - an example structured content and MIME (Annex F);

      - the relationship between the present document and the directive
        on electronic signature and associated standardization
        initiatives (Annex G);

      - APIs to support the generation and the verification of electronic
        signatures (Annex H);

      - cryptographic algorithms that may be used (Annex I); and

      - changes from the previous version naming schemes (see Annex J).

3

3.  Definitions and abbreviations

3.1 Abbreviations

3.1.  Definitions

   For the purposes of the present document, the following terms and
   definitions apply:

   Arbitrator: an arbitrator entity may be used to arbitrate a dispute
   between a signer and verifier when there is a disagreement on the
   validity of a digital signature.

   Attribute Authority (AA): an authority which that assigns privileges by
   issuing attribute certificates.

   Authority certificate: Certificate: a certificate issued to an authority (e.g. (e.g.,
   either to a certification authority or to an attribute authority).

   Attribute Authority Revocation List (AARL): a revocation list
   containing a list of references to certificates issued to AAs, AAs that
   are no longer considered valid by the issuing authority.

   Attribute Certificate Revocation List (ACRL): a revocation list
   containing a list of references to attribute certificates that are no
   longer considered valid by the issuing authority.

   Certification Authority Revocation List (CARL): a revocation list
   containing a list of public-key public key certificates issued to certification
authorities,
   authorities that are no longer considered valid by the certificate
   issuer.

   Certification Authority (CA): an authority trusted by one or more
   users to create and assign public key certificates, optionally certificates; optionally, the
   certification authority may create the users' keys.

      NOTE: See ITU-T Recommendation X.509 [1].

   Certificate Revocation List (CRL): a signed list indicating a set of
   public key certificates that are no longer considered valid by the
   certificate issuer.

   Digital signature: Signature: data appended to, or a cryptographic
   transformation of, a data unit that allows a recipient of the data
   unit to prove the source and integrity of the data unit and protect
   against forgery, e.g. e.g., by the recipient.

      NOTE: See ISO 7498-2 [ISO7498-2].

   Electronic signature: Signature: data in electronic form which are that is attached to or
   logically associated with other electronic data and which serve that serves as a
   method of authentication.

      NOTE: See Directive 1999/93/EC of the European Parliament and of
      the Council of 13 December 1999 on a Community framework for
      electronic signatures [EU Directive]. [EUDirective].

   Enhanced electronic signatures: Electronic Signatures: electronic signatures enhanced by
   complementing the baseline requirements with additional data, such as
time tamp
   time-stamp tokens and certificate revocation data, to address
   commonly recognized threats.

   Explicit Policy-based Electronic Signature (EPES): an electronic
   signature where the signature policy is explicitly specified that
   shall be used to validate it.

   Grace period: Period: a time period which that permits the certificate revocation
   information to propagate through the revocation process to relying
   parties.

   Initial verification: Verification: a process performed by a verifier done after an
   electronic signature is generated in order to capture additional
   information that could make it valid for long term long-term verification.

   Public Key Certificate (PKC): public keys of a user, together with
   some other information, rendered unforgeable by encipherment with the
   private key of the certification authority which that issued it.

      NOTE: See ITU-T Recommendation X.509 [1].

   Rivest-Shamir-Adleman (RSA): an asymmetric cryptography algorithm
   based on the difficulty to factor very large numbers, numbers using a key
   pair: a private key and a public key.

   Signature policy: Policy: a set of rules for the creation and validation of
   an electronic signature, signature that defines the technical and procedural
   requirements for electronic signature creation and validation, in
   order to meet a particular business need, and under which the
   signature can be determined to be valid.

   Signature policy issuer: Policy Issuer: an entity that defines and issues a
   signature policy.

   Signature validation policy: Validation Policy: part of the signature policy which that
   specifies the technical requirements on the signer in creating a
   signature and verifier when validating a signature.

   Signer: an entity that creates an electronic signature.

   Subsequent Verification: a process performed by a verifier to assess
   the signature validity.

      NOTE: It Subsequent verification may be done even years after the
      electronic signature was produced by the signer and completed by
      the Initial
       Verification initial verification, and it might not need to capture more
      data than those captured at the time of initial verification.

   Time-Stamp token: Token: a data object that binds a representation of a
   datum to a particular time, thus establishing evidence that the datum
   existed before that time.

   Time-Mark: information in an audit trail from a Trusted Service
   Provider that binds a representation of a datum to a particular time,
   thus establishing evidence that the datum existed before that time.

   Time-Marking Authority: a trusted third party that creates records in
   an audit trail in order to indicate that a datum existed before a
   particular point in time.

   Time-Stamping Authority (TSA): a trusted third party that creates time-
stamp
   time-stamp tokens in order to indicate that a datum existed at a
   particular point in time.

   Time-Stamping Unit (TSU): a set of hardware and software which that is
   managed as a unit and has a single time-stamp token signing key
   active at a time.

   Trusted Service Provider (TSP): an entity that helps to build trust
   relationships by making available or providing some information upon
   request.

   Validation data: Data: additional data that may be used by a verifier of
   electronic signatures to determine that the signature is valid.

   Valid electronic signature: Electronic Signature: an electronic signature which that passes
   validation.

   Verifier: an entity that verifies evidence.

      NOTE 1: See ISO/IEC 13888-1 [ISO13888-1].

      NOTE 2: Within the context of the present document document, this is an
      entity that validates an electronic signature.

3.2

3.2.  Abbreviations

   For the purposes of the present document, the following abbreviations
   apply:

   AA           Attribute Authority
   AARL         Attribute Authority Revocation List
   ACRL         Attribute Certificate Revocation List
   API          Application Program Interface
   ASCII        American Standard Code for Information Interchange
   ASN.1        Abstract Syntax Notation 1
   CA           Certification Authority
   CAD          Card Accepting Device
   CAdES        CMS Advanced Electronic Signature
   CAdES-A      CAdES with Archive validation data
   CAdES-BES    CAdES Basic Electronic Signature
   CAdES-C      CAdES with Complete validation data
   CAdES-EPES   CAdES Explicit Policy Electronic Signature
   CAdES-T      CAdES with Time-stamp
   CAdES-X      CAdES with eXtended validation data
   CAdES-X Long CAdES with EXtended Long validation data
   CARL         Certification Authority Revocation List
   CMS          Cryptographic Message Syntax
   CRL          Certificate Revocation List
   CWA          CEN (European Committee for Standardization) Workshop
                Agreement
   DER          Distinguished Encoding Rules (for ASN.1)
   DSA          Digital Signature Algorithm
   EDIFACT      Electronic Data Interchange For Administration,
                Commerce and Transport
   EESSI        European Electronic Signature Standardization
                Initiative
   EPES         Explicit Policy-based Electronic Signature
   ES           Electronic Signature
   ESS          Enhanced Security Services (enhances CMS)
   IDL          Interface Definition Language
   MIME         Multipurpose Internet Mail Extensions
   OCSP         Online Certificate Status Provider
   OID          Object IDentifier
   PKC          Public Key Certificate
   PKIX         Public Key Infrastructure using X.509
                (IETF Working Group)
   RSA          Rivest-Shamir-Adleman
   SHA-1        Secure Hash Algorithm 1
   TSA          Time-Stamping Authority
   TSP          Trusted Service Provider
   TST          Time-Stamp Token
   TSU          Time-Stamping Unit
   URI          Uniform Resource Identifier
   URL          Uniform Resource Locator
   XML         eXtended Mark up          Extensible Markup Language
   XMLDSIG      XML-Signature Syntax and Processing

4

4.  Overview

   The present document defines a number of Electronic Signature (ES)
   formats that build on CMS (RFC 3852 [4]) by adding signed and
   unsigned attributes.

   This section section:

      - provides an introduction to the major parties involved
(section
        (Section 4.1),
      - provides the concept of Signature Policies (section signature policies (Section 4.2),

      - provides an overview of the various ES formats (section (Section 4.3),

      - introduces the concept of validation data data, and provides an
        overview of formats that incorporate validation data (section
        (Section 4.4), and

      - presents relevant considerations on arbitration (section
        (Section 4.5) and for the validation process (section (Section 4.6).

   The formal specifications of the attributes are specified in sections Sections
   5 and 6, annexes 6; Annexes C and D provide rationale for the definitions of the
   different ES forms.

4.1

4.1.  Major parties Parties

   The major parties involved in a business transaction supported by
   electronic signatures signatures, as defined in the present document document, are:

      - the Signer; signer;
      - the Verifier; verifier;
      - Trusted Service Providers (TSP); and
      - the Arbitrator. arbitrator.

   The signer is the entity that creates the electronic signature.  When
   the signer digitally signs over data using the prescribed format,
   this represents a commitment on behalf of the signing entity to the
   data being signed.

   The verifier is the entity that validates the electronic signature, signature;
   it may be a single entity or multiple entities.

   The Trusted Service Providers (TSPs) are one or more entities that
   help to build trust relationships between the signer and verifier.
   They support the signer and verifier by means of supporting services
   including: user certificates, cross-certificates, time-stamp tokens,
   CRLs, ARLs, and OCSP responses.  The following TSPs are used to
   support the functions defined in the present document:

      - Certification Authorities;
      - Registration Authorities;
      - CRL Issuers;
      - OCSP Responders;
      - Repository Authorities (e.g. (e.g., a Directory);
      - Time-Stamping Authorities;
      - Time-Marking Authorities; and
      - Signature Policy Issuers.

   Certification Authorities provide users with public key certificates
   and with a revocation service.

   Registration Authorities allow the identification and registration of
   entities before a CA generates certificates.

   Repository Authorities publish CRLs issued by CAs, signature policies
   issued by Signature Policy Issuers Issuers, and optionally public key
   certificates.

   Time-Stamping Authorities attest that some data was formed before a
   given trusted time.

   Time-Marking Authorities record that some data was formed before a
   given trusted time.

   Signature Policy Issuers define the signature policies to be used by
   signers and verifiers.

   In some cases cases, the following additional TSPs are needed:

      - Attribute Authorities.

   Attributes Authorities provide users with attributes linked to public
   key certificates.

   An Arbitrator is an entity that arbitrates in disputes between a
   signer and a verifier.

4.2 Signatures policies

4.2.  Signature Policies

   The present document includes the concept of signature policies that
   can be used to establish technical consistency when validating
   electronic signatures.

   When a comprehensive signature policy used by the verifier is either
   explicitly indicated by the signer or implied by the data being
   signed, then a consistent result can be obtained when validating an
   electronic signature.

   When the signature policy being used by the verifier is neither
   indicated by the signer nor can be derived from other data, or the
   signature policy is incomplete incomplete, then verifiers, including
   arbitrators, may obtain different results when validating an
   electronic signature.  Therefore, comprehensive signature policies
   that ensure consistency of signature validation are recommended from
   both the signers signer's and
verifiers verifier's point of view.

   Further information on signature policies is provided in:

      - TR 102 038 [TR102038];
      - sections Sections 5.8.1, C.1 C.1, and C.3.1 of the present document;
      - RFC 3125 [RFC3125]; and
      - TR 102 272 [TR102272].

4.3

4.3.  Electronic signature formats Signature Formats

   The current document sectionprovides section provides an overview for two forms of CMS
   advanced electronic signature specified in the present document,
   namely, the CAdES Basic Electronic Signature (CAdES-BES) and the
   CAdES Explicit Policy-based Electronic Signature (CAdES-EPES).
   Conformance to the present document mandates that the signer creates create
   one of these formats.

4.3.1

4.3.1.  CAdES Basic Electronic Signature (CAdES-BES)

   A CAdES Basic Electronic Signature (CAdES-BES) (CAdES-BES), in accordance with
   the present document, contains:

      - The signed user data (e.g. (e.g., the signer's document) document), as defined
        in CMS (RFC 3852 [4]);

      - A collection of mandatory signed attributes attributes, as defined in CMS
        (RFC 3852 [4]) and in ESS (RFC 2634 [5]);

      - Additional mandatory signed attributes attributes, defined in the present
        document; and

      - The digital signature value computed on the user data and, when
        present, on the signed attributes, as defined in CMS (RFC 3852
        [4]).

   A CAdES Basic Electronic Signature (CAdES-BES) (CAdES-BES), in accordance with
   the present document document, may contain:

      - a collection of additional signed attributes; and

      - a collection of optional unsigned attributes.

   The mandatory signed attributes are:

      - Content-type.  It is defined in RFC 3852 [4] and specifies the
        type of the EncapsulatedContentInfo value being signed.  Details
        are provided in 5.7.1. Section 5.7.1 of the present document.
        Rationale for its inclusion is provided in section Annex C.3.7;
      - Message-digest.  It is defined in RFC 3852 [4] and specifies the
        message digest of the eContent OCTET STRING within
        encapContentInfo being signed.  Details are provided in section Section
        5.7.2;

      - ESS signing-certificate OR ESS signing-certificate v2. signing-certificate-v2.  The ESS
        signing-certificate attribute is defined in Enhanced Security
        Services (ESS), RFC 2634 [5] [5], and only allows for the use of
        SHA-1 as a digest algorithm.  The ESS signing-certificate signing-certificate-v2
        attribute V2 is defined in "ESS Update: Adding CertID Algorithm Agility"
        Agility", RFC 5035 [15], and allows for the use of any digest
        algorithm.  A CAdES-BES claiming compliance with the present
        document must include one of them.  Section 5.7.3 provides the
        details of these attributes.  Rationale for its inclusion is
        provided in
     section Annex C.3.3.

   Optional signed attributes may be added to the CAdES-BES, including
   optional signed attributes defined in CMS (RFC 3852 [4]), ESS (RFC
   2634
[5]) [5]), and the present document.  Listed below are optional
   attributes that are defined in section Section 5 and have a rational rationale
   provided in annex Annex C:

      - Signing-time: as defined in CMS (RFC 3852 [4]) [4]), indicates the
        time of the signature signature, as claimed by the signer.  Details and
        short rationale are provided in section 5.9.1. Section 5.9.1.  Annex C.3.6
        provides the rationale.

      - Content-hints content-hints: as defined in ESS (RFC 2634 [5]) [5]), provides
        information that describes the innermost signed content of a
        multi-layer message where one content is encapsulated in
        another.  Section 5.10.1 provides the specification details.  Section
        Annex C.3.8 provides the rationale.

      - Content-reference. content-reference: as defined in ESS (RFC 2634 [5]) [5]), can be
        incorporated as a way to link request and reply messages in an
        exchange between two parties.  Section 5.10.1 provides the
        specification details.  Section  Annex C.3.9 provides the rationale.

      - Content-identifier. content-identifier: as defined in ESS (RFC 2634 [5]) [5]), contains
        an identifier that may be used later on in the previous content-
     reference
        content-reference attribute.  Section 5.10.2 provides the
        specification details.  Section C.3.8 provides the rationale.

      - Commitment-type-indication.  This commitment-type-indication: this attribute is defined by the
        present document as a way to indicate the commitment endorsed by
        the signer when producing the signature.  Section 5.11.1
        provides the specification details.  Section  Annex C.3.2 provides the
        rationale.

      - Signer-location.  This signer-location: this attribute is defined by the present
        document.  It allows the signer to indicate the place where the
        signer purportedly produced the signature.  Section 5.11.2
        provides the specification details.  Section  Annex C.3.5 provides the
        rationale.

      - Signer-attributes.  This signer-attributes: this attribute is defined by the present
        document.  It allows a claimed or certified role to be
        incorporated into the signed information.  Section 5.11.3
        provides the specification details.  Section  Annex C.3.4 provides the
        rationale.

      - Content-time-stamp.  This content-time-stamp: this attribute is defined by the present
        document.  It allows a time-stamp token of the data to be signed
        to be incorporated into the signed information.  It provides
        proof of the existence of the data before the signature was
        created.  Section 5.11.4 provides the specification details.
     Section
        Annex C.3.6 provides the rationale.

   A CAdES-BES form can also incorporate instances of unsigned attributes
   attributes, as defined in CMS (RFC 3852 [4]) and ESS (RFC 2634 [5]).

      - CounterSignature, as defined in CMS (RFC 3852 [4]).  It [4]); it can be
        incorporated wherever embedded signatures (i.e. (i.e., a signature on
        a previous signature) are needed.  Section 5.9.2 provides the
        specification details.  Section  Annex C.5 in annex Annex C provides the
        rationale.

   The structure of the CAdES-BES is illustrated in figure Figure 1.

                +------Elect.Signature (CAdES-BES)------+
                |+----------------------------------- + |
                ||+---------+ +----------+            | |
                |||Signer's | |  Signed  |  Digital   | |
                |||Document | |Attributes| Signature  | |
                |||         | |          |            | |
                ||+---------+ +----------+            | |
                |+------------------------------------+ |
                +---------------------------------------+

                  Figure 1: Illustration of a CAdES-BES

   The signer's conformance requirements of a CAdES-BES are defined in
section
   Section 8.1.

      NOTE: The CAdES-BES is the minimum format for an electronic
      signature to be generated by the signer.  On its own, it does not
      provide enough information for it to be verified in the longer
      term.  For example, revocation information issued by the relevant
      certificate status information issuer needs to be available for long term
      long-term validation (see section Section 4.4.2).

   The CAdES-BES satisfies the legal requirements for electronic
signatures
   signatures, as defined in the European Directive on electronic
signatures, Electronic
   Signatures, (see annex Annex C for further discussion on the relationship
   of the present document to the Directive).  It provides basic
   authentication and integrity protection.

   The semantics of the signed data of a CAdES-BES or its context may
   implicitly indicate a signature policy to the verifier.
   Specification of the contents of signature policies is outside the
   scope of the present document.  However, further information on
   signature policies is provided in TR 102 038 [TR102038], RFC 3125 [RFC3125]
   [RFC3125], and sections Sections 5.8.1, C.1 C.1, and C.3.1 of the present
   document.

4.3.2

4.3.2.  CAdES Explicit Policy Policy-based Electronic Signatures (CAdES-EPES)

   A CAdES Explicit Policy-based Electronic Signature (CAdES-EPES) (CAdES-EPES), in
   accordance with the present document, extends the definition of an
   electronic signature to conform to the identified signature policy.

   A CAdES Explicit Policy-based Electronic Signature (CAdES-EPES)
   incorporates a signed attribute (signature-policy-identifier) (sigPolicyID attribute) indicating that a signature policy that is mandatory to use to validate
the signature and specifies explicitly
   the signature policy that shall be used. used to validate the electronic
   signature.  This signed attribute is protected by the signature.  The
   signature may also have other signed attributes required to conform
   to the mandated signature policy.

   Section 5.7.3 provides the details on the specification of signature-
policy-identifier
   signature-policy-identifier attribute.  Section  Annex C.1 provides a short
   rationale.  Specification of the contents of signature policies is
   outside the scope of the present document.

   Further information on signature policies is provided in TR 102 038
   [TR102038] and sections Sections 5.8.1, C.1 C.1, and C.3.1 of the present
   document.

   The structure of the CAdES-EPES is illustrated in figure Figure 2.

          +------------- Elect.Signature (CAdES-EPES) ---------------+
          |                                                          |
          |+-------------------------------------------------------+ |
          || +-----------+                                         | |
          || |           |   +---------------------------+         | |
          || |           |   |   +----------+            |         | |
          || | Signer's  |   |   |Signature | Signed     | Digital | |
          || | Document  |   |   |Policy ID | Attributes |Signature| |
          || |           |   |   +----------+            |         | |
          || |           |   +---------------------------+         | |
          || +-----------+                                         | |
          |+-------------------------------------------------------+ |
          |                                                          |
          +----------------------------------------------------------+

                   Figure 2: Illustration of a CAdES-EPES

   The signer's conformance requirements of CAdES-EPES are defined in
section
   Section 8.2.

4.4

4.4.  Electronic signature formats Signature Formats with validation data Validation Data

   Validation of an electronic signature signature, in accordance with the present
document
   document, requires additional data needed to validate the electronic
   signature.  This additional data is called validation data; data, and
   includes:

      - Public Key Certificates (PKCs);

      - revocation status information for each PKC;

      - trusted time-stamps applied to the digital signature or signature, otherwise
        a time-
     mark time-mark shall be available in an audit log; and log.

      - when appropriate, the details of a signature policy to be used
        to verify the electronic signature.

   The validation data may be collected by the signer and/or the
   verifier.  When the signature-policy-identifier signed attribute is
   present, it shall meet the requirements of the signature policy.

   Validation data includes CA certificates as well as revocation status
   information in the form of Certificate Revocation Lists (CRLs) or
   certificate status information (OCSP) provided by an on-line online service.
   Validation data also includes evidence that the signature was created
   before a particular point in time time; this may be either a time-stamp
   token or time-mark.

   The present document defines unsigned attributes able to contain
   validation data that can be added to CAdES-BES and CAdES-EPES CAdES-EPES,
   leading to electronic signature formats that include validation data.  Sections
   The sections below summarize these formats and their most relevant
   characteristics.

4.4.1

4.4.1.  Electronic Signature with Time Time-stamp (CAdES-T)

Electronic Signature

   An electronic signature with Time (CAdES-T) time (CAdES-T), in accordance with the
   present
document document, is when there exits trusted time associated with
   the ES.

   The trusted time may be provided by:

      - the signature-time-stamp a time-stamp attribute as an unsigned attribute added to the ES;
        and

      - A time mark a time-mark of the ES provided by a trusted service provider. Trusted Service Provider.

   The signature-time-stamp time-stamp attribute contains a time-stamp token of the
   electronic signature value.  Section 6.1.1 provides the specification
   details.  Section  Annex C.4.3 in provides the rationale.

   A time-mark provided by a Trusted Service would have a similar effect
   to the signature-time-stamp attribute attribute, but in this case case, no attribute
   is added to the ES ES, as it is the responsibility of the TSP to provide
   evidence of a time mark time-mark when required to do so.  The management of
   time marks is outside the scope of the present document.

   Trusted time provides the initial steps towards providing long term long-term
   validity.  Electronic signatures with the time stamp time-stamp attribute
   forming the CAdES-T is are illustrated in figure Figure 3.

   +-------------------------------------------------CAdES-T ---------+
   |+------ CAdES-BES or CAdES-EPES -------+                          |
   ||+-----------------------------------+ | +----------------------+ |
   |||+---------+ +----------+           | | |                      | |
   ||||Signer's | |  Signed  |  Digital  | | | Signature-time-stamp | |
   ||||Document | |Attributes| Signature | | | attribute required   | |
   ||||         | |          |           | | | when using time      | |
   |||+---------+ +----------+           | | | stamps.              | |
   ||+-----------------------------------+ | |                      | |
   |+--------------------------------------+ | or the BES/EPES      | |
   |                                         | shall be time marked time-marked | |
   |                                         |                      | |
   |                                         | Management and       | |
   |                                         | provision of time    | |
   |                                         | mark is the          | |
   |                                         | responsibility of    | |
   |                                         | the TSP.             | |
   |                                         +----------------------+ |
   +------------------------------------------------------------------+

                Figure 3: Illustration of CAdES-T formats

      NOTE 1 : 1: A time stamp time-stamp token is added to the CAdES-BES or CAdES-EPES
      as an unsigned attribute.

      NOTE 2 :  Timestamp 2: Time-stamp tokens that may themselves include unsigned
      attributes required to validate the timestamp time-stamp token, such as the
      complete-certificate-references and complete-
           revocation-references attributes complete-revocation-references
      attributes, as defined by the present document.

4.4.2

4.4.2.  ES with Complete validation data references Validation Data References (CAdES-C)

   Electronic Signature with Complete validation data references (CAdES-C)
   (CAdES-C), in accordance with the present document document, adds to the
   CAdES-T the complete-certificate-references and
   complete-revocation-references
attributes attributes, as defined by the present
   document.  The complete-
certificate-references complete-certificate-references attribute contain contains
   references to all the certificates present in the certification path
   used for verifying the signature.  The complete-revocation-references
   attribute contains references to the CRLs and/or OCSP responses used
   for verifying the signature.  Section 6.2 provides the specification
   details.  Storing the references allows the values of the
   certification path and the CRLs CRL's or OCSPs OCSP's responses to be stored
   elsewhere, reducing the size of a stored electronic signature format.

   Sections C.4.1 to C.4.2 provide rationale on the usage of validation
   data and when it is suitable to generate the CAdES-C form.
   Electronic signatures signatures, with the additional validation data forming
   the
CAdES-C CAdES-C, are illustrated in figure Figure 4.

   +------------------------- CAdES-C --------------------------------+
   |+----------------------------- CAdES-T ---------+                 |
   ||                                  +----------+ | +-------------+ |
   ||                                  |Timestamp | | |             | |
   ||                                  |attribute | | |             | |
   ||+- CAdES-BES or CAdES-EPES ------+|over      | | |             | |
   |||                                ||digital   | | | Complete    | |
   |||+---------++----------+         ||signature | | | certificate | |
   ||||Signer's ||  Signed  | Digital ||is        | | |     and     | |
   ||||Document ||Attributes|Signature||mandatory | | | revocation  | |
   ||||         ||          |         ||if is not | | | references  | |
   |||+---------++----------+         ||timemarked| | |             | |
   ||+--------------------------------++----------+ | |             | |
   |+-----------------------------------------------+ +-------------+ |
   +------------------------------------------------------------------+

             Figure 4: Illustration of CAdES-C format

      NOTE 1: The complete certificate and revocation references are
      added to the CAdES-T as an unsigned attribute.

      NOTE 2: As a minimum, the signer will provide the CAdES-BES or or,
      when indicating that the signature conforms to an explicit signing
         policy
      policy, the CAdES-EPES.

      NOTE 3: To reduce the risk of repudiating signature creation, the
      trusted time indication needs to be as close as possible to the
      time the signature was created.  The signer or a TSP could provide
      the CAdES-T, CAdES-T; if not not, the verifier should create the CAdES-T on
      first receipt of an electronic signature because the CAdES-T
      provides independent evidence of the existence of the signature
      prior to the trusted time indication.

      NOTE 4: An A CAdES-T trusted time indications indication must be created before a
      certificate has been revoked or expired.

      NOTE 5: The signer and TSP could provide the CAdES-C, CAdES-C to minimize
      this risk risk, and when the signer does not provide the CAdES-C, the
      verifier should create the CAdES-C when the required component of
      revocation and validation data become available, available; this may require
      a grace period.

      NOTE 6: A grace period permits certificate revocation information
      to propagate through the revocation processes.  This period could
      extend from the time an authorized entity requests certificate
         revocation,
      revocation to when the information is available for the relying
      party to use.  In order to make sure that the certificate was not
      revoked at the time the signature was time-marked or time-stamped,
      verifiers should wait until the end of the grace period.  A
      signature policy may define specific values for grace periods.

   An illustration of a grace period is provided in figure Figure 5.

               +<--------------Grace Period --------->+
   ----+-------+-------+--------+---------------------+----------+
       ^       ^       ^        ^                     ^          ^
       |       |       |        |                     |          |
       |       |       |        |                     |          |
   Signature   |     First      |                   Second       |
    creation   |   revocation   |                  revocation    |
     time      |     status     |                    status      |
               |    checking    |                  checking      |
               |                |                                |
           Time-stamp      Certification                       Build
              or              path                            CAdES-C
           time-mark      construction
             over          & verification
           signature

               Figure 5: Illustration of a grace period

      NOTE 7: CWA 14171 [CWA14171] specifies a signature validation
      process using CAdES-T, CAdES-C CAdES-C, and a grace period.  Annex B
      provides example validation processes.  Section  Annex C.4 provides
      additional information about applying grace periods during the
      validation process.

   The verifier's conformance requirements are defined in section Section 8.3
   for
time stamped CAdES-C time-stamped CAdES-C, and section Section 8.4 for time marked time-marked CAdES-C.
   The present document only defines conformance requirements for the
   verifier up to an ES with complete Complete validation data (CAdES-C).  This
   means that none of the extended and archive forms of Electronic Signature electronic
   signatures, as defined in sections Sections 4.4.3 to 4.4.4) 4.4.4, need to be
   implemented to achieve conformance to the present document.

4.4.3

4.4.3.  Extended electronic signature formats Electronic Signature Formats

   CAdES-C can be extended by adding unsigned attributes to the
   electronic signature.  The present document defines various unsigned
   attributes that are applicable for very long term long-term verification, and
   for preventing some disaster situations which that are discussed in annex Annex
   C.  Annex B provides the details of the various extended formats, all
   the required unsigned attributes for each type type, and how they can be
   used within the electronic signature validation process.  The
   sections below give an overview of the various forms of extended
   signature formats in the present document.

4.4.3.1

4.4.3.1.  EXtended Long Electronic Signature (CAdES-X Long)

   Extended Long format (CAdES-X Long) Long), in accordance with the present
document
   document, adds to the CAdES-C format the certificate-values and revocation-values attributes.
   attributes to the CAdES-C format.  The first one contains the whole
   certificate path required for verifying the signature; the second one
   contains the CRLs and/OCSP responses required for the validation of
   the signature.  This provides a known repository of certificate and
   revocation information required to validate an a CAdES-C and prevents
   such information from getting lost.  Sections 6.3.3 and 6.3.4 give
   specification details.  Section  Annex B.1.1 gives details on the production
   of the format.  Sections  Annexes C4.1 to C.4.2 provide the rationale.

   The structure of the CAdES-X Long format is illustrated in figure Figure 6.

   +----------------------- CAdES-X-Long -----------------------------+
   |+------------------------------------ CadES-C --+                 |
   ||                                  +----------+ | +-------------+ |
   ||+------ CAdES -------------------+|Timestamp | | |             | |
   |||                                ||  over    | | | Complete    | |
   |||+---------++----------+         ||digital   | | | certificate | |
   ||||Signer's ||  Signed  | Digital ||signature | | |     and     | |
   ||||Document ||Attributes|Signature||          | | | revocation  | |
   ||||         ||          |         ||Optional  | | |    data     | |
   |||+---------++----------+         ||when      | | |             | |
   ||+--------------------------------+|timemarked| | |             | |
   ||                                  +----------+ | |             | |
   ||                               +-------------+ | +-------------+ |
   ||                               | Complete    | |                 |
   ||                               | certificate | |                 |
   ||                               | and         | |                 |
   ||                               | revocation  | |                 |
   ||                               | references  | |                 |
   ||                               +-------------+ |                 |
   |+-----------------------------------------------+                 |
   |                                                                  |
   +------------------------------------------------------------------+

                  Figure 6: Illustration of CAdES-X-Long

4.4.3.2

4.4.3.2.  EXtended Electronic Signature with Time Type 1
          (CAdES-X Type 1)

   Extended format with time type 1 (CAdES-X Type 1) 1), in accordance with
   the present document document, adds to the CAdES-C format the CAdES-C-time-stamp attribute, whose
   content is a time-stamp token on the CAdES-C itself. itself, to the CAdES-C
   format.

   This provides an integrity and trusted time protection over all the
   elements and references.  It may protect the certificates, CRLs CRLs, and
   OCSP responses in case of a later compromise of a CA key, CRL key key, or
   OCSP issuer key.  Section 6.3.5 provides the specification details.

Section

   Annex B.1.2 gives details on the production of the time-stamping
   process.  Sections  Annex C.4.4.1 provides the rationale.

   The structure of the CAdES-X Type 1 format is illustrated in figure Figure
   7.

  +----------------------- CAdES-X-Type 1 ------------------------------+
  |+-------------------------------------- CAdES-C -----+               |
  ||                                    +-------------+ | +-----------+ |
  ||+--------- CAdES ------------------+| Timestamp   | | |           | |
  |||                                  || over        | | |           | |
  |||+---------++----------+           || digital     | | |           | |
  ||||Signer's ||  Signed  |  Digital  || signature   | | | Timestamp | |
  ||||Document ||Attributes| Signature ||             | | |   over    | |
  ||||         ||          |           || Optional    | | | CAdES-C   | |
  |||+---------++----------+           || when        | | |           | |
  ||+----------------------------------+| time-marked | | |           | |
  ||                                    +-------------+ | |           | |
  ||                                    +-------------+ | +-----------+ |
  ||                                    | Complete    | |               |
  ||                                    | certificate | |               |
  ||                                    | and         | |               |
  ||                                    | revocation  | |               |
  ||                                    | references  | |               |
  ||                                    +-------------+ |               |
  |+----------------------------------------------------+               |
  +---------------------------------------------------------------------+

                  Figure 7: Illustration of CAdES-X Type  1

4.4.3.3

4.4.3.3.  EXtended Electronic Signature with Time Type 2
          (CAdES-X Type 2)

   Extended format with time type 2 (CAdES-X Type 2) 2), in accordance with
   the present document document, adds to the CAdES-C format the CAdES-C-time-
stamped-certs-crls-references
   CAdES-C-time-stamped-certs-crls-references attribute, whose content
   is a time-stamp token on the certification path and revocation
   information references.  This provides an integrity and trusted time
   protection over all the references.

   It may protect the certificates, CRLs and OCSP responses in case of a
   later compromise of a CA key, CRL key or OCSP issuer key.

   Both CAdES-X Type 1 and CAdES-X Type 2 counter the same threats threats, and
   the usage of one or the other depends on the environment.  Section
   6.3.5 provides the specification details.  Section  Annex B.1.3 gives details
   on the production of the time-stamping process.  Section  Annex C.4.4.2
   provides the rationale.

   The structure of the CAdES-X Type 2 format is illustrated in figure Figure
   8.

+------------------------- CAdES-X-Type 2 ----------------------------+
|+----------------------------------------CAdES-C ---+                |
||                                     +------------+|                |
||+----- CAdES -----------------------+| Timmestamp Timestamp  ||                |
|||                                   || over       ||                |
|||+---------+ +----------+           || digital    || +-------------+|
||||Signer's | |  Signed  |  Digital  || signature  || | Time-stamp  ||
||||Document | |Attributes| signature ||            || | only over   ||
||||         | |          |           || optional   || | complete    ||
|||+---------+ +----------+           || when       || | certificate ||
||+-----------------------------------+| timemarked || |    and      ||
||                                     +------------+| | revocation  ||
||                                   +-------------+ | | references  ||
||                                   | Complete    | | +-------------+|
||                                   | certificate | |                |
||                                   | and         | |                |
||                                   | revocation  | |                |
||                                   | references  | |                |
||                                   +-------------+ |                |
|+---------------------------------------------------+                |
+---------------------------------------------------------------------+

                  Figure 8: Illustration of CAdES-X Type 2

4.4.3.4

4.4.3.4.  EXtended Long Electronic Signature with Time (CAdES-X Long
          Type 1 or 2)

   Extended Long with Time (CAdES-X Long Type 1 or 2) 2), in accordance
   with the present document document, is a combination of CAdES-X Long and one
   of the two former types (CAdES-X Type 1 and CAdES-X Type 2).  Section  Annex
   B.1.4 gives details on the production of the time-stamping process.  Section
C4.8
   Annex C.4.8 in annex Annex C provides the rationale.

   The structure of the CAdES-X Long Type 1 and CAdES-X Long Type 2. 2
   format is illustrated in figure Figure 9.

   +------------------ CAdES-X Long Type 1 or 2 -----------------------+
   |                                                   +--------------+|
   |+-------------------------------------- CAdES-C --+|+------------+||
   ||                                                 ||| Timestamp  |||
   ||+------- CAdES --------------------++----------+ |||   over     |||
   |||                                  ||Timestamp | |||  CAdES-C   |||
   |||                                  ||over      | ||+------------+||
   |||+---------++----------+           ||digital   | ||      OR      ||
   ||||Signer's ||  Signed  | Digital   ||signature | ||+------------+||
   ||||Document ||Attributes| signature ||          | ||| Timestamp  |||
   ||||         ||          |           ||Optional  | ||| only over  |||
   |||+---------++----------+           ||when      | ||| complete   |||
   ||+----------------------------------+|timemarked| ||| certificate|||
   ||                                    +----------+ |||    and     |||
   ||                                                 ||| Revocation |||
   ||                                 +-------------+ ||| References |||
   ||                                 | Complete    | ||+------------+||
   ||                                 | certificate | |+--------------+|
   ||                                 | and         | | +------------+ |
   ||                                 | revocation  | | | Complete   | |
   ||                                 | references  | | |certificate | |
   ||                                 +-------------+ | |   and      | |
   |+-------------------------------------------------+ |revocation  | |
   |                                                    |  value     | |
   |                                                    +------------+ |
   +-------------------------------------------------------------------+

     Figure 9: Illustration of CAdES-X Long Type 1 and CAdES Long Type 2

4.4.4

4.4.4.  Archival Electronic Signature (CAdES-A)

   Archival Form (CAdES-A) (CAdES-A), in accordance with the present document document,
   builds on a CAdES-X Long or a CAdES-X Long Type 1 or 2 by adding one
   or more archive-time-stamp attributes.  This form is used for
   archival of long-
term long-term signatures.  Successive time-stamps protect the
   whole material against vulnerable hashing algorithms or the breaking
   of the cryptographic material or algorithms.  Section 6.4 contains
   the specification details.  Sections C.4.5 and C.4.8 provide the
   rationale.

   The structure of the CAdES-A form is illustrated in figure Figure 10.

  +---------------------------CAdES-A ---------------------------------+
  |+----------------------------------------------------+              |
  ||                                    +--------------+| +----------+ |
  ||+----------------------CAdES-C ----+|+------------+|| |          | |
  |||                     +----------+ ||| Timestamp  ||| |          | |
  |||+---- CAdES-BES ----+|Timestamp | |||    over    ||| |          | |
  ||||    or CAdeS-EPES  ||  over    | |||   CAdES-C  ||| |  Archive | |
  ||||                   ||digital   | ||+------------+|| |          | |
  ||||                   ||signature | ||      or      || |Timestamp | |
  ||||                   ||          | ||+------------+|| |          | |
  ||||                   ||Optional  | ||| Timestamp  ||| |          | |
  ||||                   ||when      | ||| only over  ||| |          | |
  ||||                   ||Timemarked| ||| complete   ||| |          | |
  |||+-------------------+|          | ||| certificate||| +----------+ |
  |||                     +----------+ |||    and     |||              |
  |||                  +-------------+ ||| revocation |||              |
  |||                  | Complete    | ||| references |||              |
  |||                  | certificate | ||+------------+||              |
  |||                  | and         | |+--------------+|              |
  |||                  | revocation  | | +------------+ |              |
  |||                  | references  | | |  Complete  | |              |
  |||                  +-------------+ | |certificate | |              |
  |||                                  | |    and     | |              |
  ||+----------------------------------+ |revocation  | |              |
  ||                                     |  values    | |              |
  ||                                     +------------+ |              |
  |+----------------------------------------------------+              |
  +--------------------------------------------------------------------+

                     Figure 10: Illustration of CAdES-A

4.5

4.5.  Arbitration

   The CAdES-C may be used for arbitration should there be a dispute
   between the signer and verifier, provided that:

      - the arbitrator knows where to retrieve the signer's certificate
        (if not already present), all the cross-certificates and the
        required CRLs, ACRLs ACRLs, or OCSP responses referenced in the
        CAdES-C;
      - when time-stamping in the CAdES-T is being used, the certificate
        from the TSU that has issued the time-stamp token in the CAdES-T
        format is still within its validity period;

      - when time-stamping in the CAdES-T is being used, the certificate
        from the TSU that has issued the time-stamp token in the CAdES-T
        format is not revoked at the time of arbitration;

      - when time-marking in the CAdES-T is being used, a reliable audit
        trail from the Time-Marking Authority is available for
        examination regarding the time;

      - none of the private keys corresponding to the certificates used
        to verify the signature chain have ever been compromised;

      - the cryptography used at the time the CAdES-C was built has not
        been broken at the time the arbitration is performed; and

      - If if the signature policy can be explicit explicitly or implicitly identified
        identified, then an arbitrator is able to determine the rules
        required to validate the electronic signature.

4.6 Validation process

The

4.6.  Validation Process

   The validation process validates an electronic signature, signature; the output
   status of the validation process can be:

      - invalid;

      - incomplete validation; or

      - valid.

   An Invalid invalid response indicates that either the signature format is
   incorrect or that the digital signature value fails verification (e.g.
   (e.g., the integrity check on the digital signature value fails fails, or
   any of the certificates on which the digital signature verification
   depends is known to be invalid or revoked).

   An Incomplete Validation incomplete validation response indicates that the signature
   validation status is currently unknown.  In the case of incomplete
   validation, additional information may be made available to the
   application or user, thus allowing them to decide what to do with the
   electronic signature.  In the case of incomplete validation, the
   electronic signature may be checked again at some later time when
   additional information becomes available.

      NOTE: For example; example, an incomplete validation may be because all the
      required certificates are not available or the grace period is not
      completed.

   A Valid valid response indicates that the signature has passed verification
   verification, and it complies with the signature validation policy.

   Example validation sequences are illustrated in annex Annex B.

5

5.  Electronic signature attributes Signature Attributes

   This section builds upon the existing Cryptographic Message Syntax
   (CMS), as defined in RFC 3852 [4], and Enhanced Security Services
   (ESS), as defined in RFC 2634 [5].  The overall structure of an
   Electronic Signature is as defined in CMS.  The Electronic Signature
   (ES) uses attributes defined in CMS, ESS ESS, and the present document.
   The present document defines ES attributes which that it uses and that are
   not defined elsewhere.

   The mandated set of attributes and the digital signature value is
   defined as the minimum Electronic Signature (ES) required by the
   present document.  A signature policy may mandate that other signed
   attributes are be present.

5.1

5.1.  General syntax Syntax

   The general syntax of the ES is as defined in CMS (RFC 3852 [4]).

      NOTE: CMS defines content types for id-data, id-signedData, id-
       envelopedData,
      id-envelopedData, id-digestedData, id-encryptedData, and id-
       authenticatedData.
      id-authenticatedData.  Although CMS permits other documents to
      define other content types, the ASN.1 type defined should not be a
      CHOICE type.  The present document does not define other content
      types.

5.2

5.2.  Data content type Content Type

   The data content type of the ES is as defined in CMS (RFC 3852 [4]).

      NOTE: If the content type is id-data, it is recommended that the
      content is be encoded using MIME MIME, and that the MIME type is used to
      identify the presentation format of the data.  See annex Annex F.1 for
      an example of using MIME to identify the encoding type.

5.3

5.3.  Signed-data content type Content Type

   The signed-data Signed-data content type of the ES is as defined in CMS (RFC 3852
   [4]).

5.4

5.4.  SignedData type Type

   The syntax of the SignedData of the ES is as defined in CMS (RFC 3852
   [4]).

   The fields of type SignedData have the meanings are as defined in CMS (RFC 3852 [4]).

   The identification of a signer's certificate used to create the
   signature is always signed (see section Section 5.7.3).  The validation
   policy may specify requirements for the presence of certain
   certificates.  The degenerate
case case, where there are no signers signers, is
   not valid in the present document.

5.5

5.5.  EncapsulatedContentInfo type Type

   The syntax of the EncapsulatedContentInfo type ES is as defined in
   CMS (RFC 3852 [4]).

   For the purpose of long term validation long-term validation, as defined by the present
   document, it is advisable that either the eContent is present, or the
   data which that is signed is archived in such as way as to preserve any
   data encoding.  It is important that the OCTET STRING used to
   generate the signature remains the same every time either the
   verifier or an arbitrator validates the signature.

      NOTE: The eContent is optional in CMS :

          - When it is present, this allows the signed data to be
            encapsulated in the SignedData structure, which then
            contains both the signed data and the signature.  However,
            the signed data may only be accessed by a verifier able to
            decode the ASN.1 encoded SignedData structure.

          - When it is missing, this allows the signed data to be sent
            or stored separately from the signature signature, and the SignedData
            structure only contains the signature.  It is is, in the case
            of signature the signature, only that the data which that is signed that needs to
            be stored and distributed in such as way as to preserve any
            data encoding.

   The degenerate case where there are no signers is not valid in the
   present document.

5.6

5.6.  SignerInfo type Type

   The syntax of the SignerInfo type ES is as defined in CMS (RFC 3852
   [4]).

   Per-signer information is represented in the type SignerInfo.  In the
   case of multiple independent signatures (see section Annex B.5), there is an
   instance of this field for each signer.

   The fields of type SignerInfo have the meanings defined in CMS (RFC
   3852 [4]) [4]), but the signedAttrs field shall contain the following
   attributes:

      - content-type content-type, as defined in section Section 5.7.1; and

      - message-digest message-digest, as defined in section Section 5.7.2;

      - signing-certificate signing-certificate, as defined in section Section 5.7.3.

5.6.1

5.6.1.  Message digest calculation process Digest Calculation Process

   The message digest calculation process is as defined in CMS (RFC 3852
   [4]).

5.6.2

5.6.2.  Message signature generation process Signature Generation Process

   The input to the message signature generation process is as defined
   in CMS (RFC 3852 [4]).

5.6.3

5.6.3.  Message signature verification process Signature Verification Process

   The procedures for message signature verification are defined in CMS
   (RFC 3852 [4]) and enhanced in the present document: the input to the
   signature verification process must be the signer's public key key, which
   shall be verified as correct using the signing certificate reference
   attribute containing a reference to the signing certificate, i.e. i.e.,
   when SigningCertificateV2 from RFC 5035 [16] or SigningCertificate
   from ESS [5] is used, the public key from the first certificate
   identified in the sequence of certificate identifiers from
   SigningCertificate must be the key used to verify the digital
   signature.

5.7

5.7.  Basic ES mandatory present attributes Mandatory Present Attributes

   The following attributes shall be present with the signed-data
   defined by the present document.  The attributes are defined in CMS
   (RFC 3852 [4]).

5.7.1 Content type

5.7.1.  content-type

   The content-type attribute indicates the type of the signed content.
   The syntax of the content-type attribute type is as defined in CMS
   (RFC 3852 [4]) section Section 11.1.

   Note 1 :

      NOTE 1: As stated in RFC 3852 [4] , the content-type attribute
      must have its value (i.e. (i.e., ContentType) equal to the eContentType
      of the EncapsulatedContentInfo value being signed.

   Note 2 :

      NOTE 2: For implementations supporting signature generation, if
      the content-type attribute is id-data, then it is recommended that
      the eContent be encoded using MIME.  For implementations
      supporting signature verification, if the signed data (i.e. (i.e.,
      eContent) is MIME-encoded, then the OID of the content-type
      attribute must be id-data.  In both cases, the MIME
      content-type(s) must be used to identify the presentation format
      of the data.  See Annex F for further details about the use of
      MIME.

5.7.2

5.7.2.  Message digest Digest

   The syntax of the message-digest attribute type of the ES is as
   defined in CMS (RFC 3852 [4]).

5.7.3

5.7.3.  Signing certificate reference attributes Certificate Reference Attributes

   The Signing certificate reference attributes are supported by using
   either the ESS signing-certificate attribute or the ESS-signing-
certificate-v2
   ESS-signing-certificate-v2 attribute.

   These attributes shall contain a reference to the signer's certificate,
   certificate; they are designed to prevent the simple substitution and re-issue
   reissue attacks and to allow for a restricted set of certificates to
   be used in verifying a signature.  They have a compact form (much
   shorter than the full certificate) that allows to for a certificate to
   be unambiguously identified.

   One, and only one, of the following alternative attributes shall be
   present with the signedData signedData, defined by the present document. document:

      - The ESS signing-certificate attribute, defined in ESS [5], must
        be used if the SHA-1 hashing algorithm is used.

      - The ESS signing-certificate attribute v2, signing-certificate-v2 attribute, defined in "ESS
        Update: Adding CertID Algorithm Agility", RFC 5035 [15] [15], which
        shall be used when other hashing algorithms are to be used.

   The certificate to be used to verify the signature shall be
   identified in the sequence (i.e. (i.e., the certificate from the signer) signer),
   and the sequence shall not be empty.  The signature validation policy
   may mandate other certificates be present that may include all the
   certificates up to the trust anchor.

5.7.3.1

5.7.3.1.  ESS signing certificate attribute definition signing-certificate Attribute Definition

   The syntax of the signing-certificate attribute type of the ES is as
   defined in Enhanced Security Services (ESS), RFC 2634 [5] [5], and
   further qualified in the present document.

   The sequence of the policy information field is not used in the
   present document.

   The ESS signing-certificate attribute shall be a signed attribute.
   The encoding of the ESSCertID for this certificate shall include the
   issuerSerial field.

   If present, the issuerAndSerialNumber in SignerIdentifier field of
   the SignerInfo shall match the issuerSerial field present in
   ESSCertID.  In addition addition, the certHash from ESSCertID shall match the
   SHA-1 hash of the certificate.  The certificate identified shall be
   used during the signature verification process.  If the hash of the
   certificate does not match the certificate used to verify the
   signature, the signature shall be considered invalid.

      NOTE: Where an attribute certificate is used by the signer to
      associate a role, or other attributes of the signer, with the
      electronic signature, signature; this is placed in the signer-attributes
      attribute as defined in section Section 5.8.3.

5.7.3.2

5.7.3.2.  ESS signing certificate v2 attribute definition signing-certificate-v2 Attribute Definition

   The ESS signing-certificate v2 signing-certificate-v2 attribute is similar to the ESS
   signing-certificate defined above, except that this attribute can be
   used with hashing algorithms other than SHA-1.

   The syntax of the signing-certificate v2 signing-certificate-v2 attribute type of the ES is
   as defined in "ESS Update: Adding CertID Algorithm Agility", RFC 5035 [15]
   [15], and further qualified in the present document.

   The sequence of the policy information field is not used in the
   present document.

   This attribute shall be used in the same manner as defined above for
   the ESS signing-certificate attribute.

   The object identifier for this attribute is:
         id-aa-signingCertificateV2 OBJECT IDENTIFIER ::=
         { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
           smime(16) id-aa(2) 47 }
   If present, the issuerAndSerialNumber in SignerIdentifier field of
   the SignerInfo shall match the issuerSerial field present in
   ESSCertID.  In addition addition, the certHash from ESSCertID shall match the
   SHA-1 hash of the certificate.  The certificate identified shall be
   used during the signature verification process.  If the hash of the
   certificate does not match the certificate used to verify the
   signature, the signature shall be considered invalid.

 Note 1 :

      NOTE 1: Where an attribute certificate is used by the signer to
      associate a role, or other attributes of the signer, with the
      electronic signature, signature; this is placed in the signer-attributes
      attribute as defined in section Section 5.8.3.

 Note 2 :

      NOTE 2: RFC 3126 was using the other signing certificate signing-certificate attribute
      (see section Section 5.7.3.3) for the same purpose.  Its use is now
      deprecated, since this structure is simpler.

5.7.3.3

5.7.3.3.  Other signing certificate attribute definition signing-certificate Attribute Definition

   RFC 3126 was using the other signing certificate signing-certificate attribute as an
   alternative to the ESS signing-certificate when hashing algorithms
   other than SHA-1 were being used.  Its use is now deprecated, since
   the structure of the general-signing-certificate-v2 signing-certificate-v2 attribute is simpler.
   Its description is however still present in this version for
   backwards compatibility.

   id-aa-ets-otherSigCert OBJECT IDENTIFIER ::= { iso(1)
       member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
       smime(16) id-aa(2) 19 }

   The other-signing-certificate attribute value has the ASN.1 syntax
   OtherSigningCertificate:

   OtherSigningCertificate ::=  SEQUENCE {
       certs        SEQUENCE OF OtherCertID,
       policies     SEQUENCE OF PolicyInformation OPTIONAL
                    -- NOT USED IN THE PRESENT DOCUMENT }

   OtherCertID ::= SEQUENCE {
       otherCertHash            OtherHash,
       issuerSerial             IssuerSerial OPTIONAL }

   OtherHash ::= CHOICE {
       sha1Hash OtherHashValue,  -- This contains a SHA-1 hash
       otherHash OtherHashAlgAndValue}

   OtherHashValue ::= OCTET STRING
   OtherHashAlgAndValue ::= SEQUENCE {
       hashAlgorithm     AlgorithmIdentifier,
       hashValue         OtherHashValue }

5.8

5.8.  Additional mandatory attributes Mandatory Attributes for Explicit Policy-based
      Electronic Signatures

5.8.1 Signature policy identifier

5.8.1.  signature-policy-identifier

   The present document mandates that for CAdES-EPES CAdES-EPES, a reference to the
   signature policy is included in the signedData.  This reference is
   explicitly identified.  A signature policy defines the rules for
   creation and validation of an electronic signature, and is included
   as a signed attribute with every Explicit Policy-based Electronic
   Signature.  The signature-policy-identifier shall be a signed
   attribute.

   The following object identifier identifies the
   signature-policy-identifier attribute:

      id-aa-ets-sigPolicyId OBJECT IDENTIFIER ::= { iso(1)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
      smime(16) id-aa(2) 15 }

   signature-policy-identifier attribute values have ASN.1 type
   SignaturePolicyIdentifier:

      SignaturePolicyIdentifier ::= CHOICE {
           signaturePolicyId          SignaturePolicyId,
           signaturePolicyImplied     SignaturePolicyImplied
                                      -- not used in this version
   }

      SignaturePolicyId ::= SEQUENCE {
           sigPolicyId           SigPolicyId,
           sigPolicyHash         SigPolicyHash,
           sigPolicyQualifiers   SEQUENCE SIZE (1..MAX) OF
                                   SigPolicyQualifierInfo OPTIONAL}

      SignaturePolicyImplied ::= NULL
   The sigPolicyId field contains an object-identifier which that uniquely
   identifies a specific version of the signature policy.  The syntax of
   this field is as follows:

      SigPolicyId ::= OBJECT IDENTIFIER

   The sigPolicyHash field optionally contains the identifier of the
   hash algorithm and the hash of the value of the signature policy.
   The hashValue within the sigPolicyHash may be set to zero to indicate
   that the policy hash value is not known.

      NOTE: The use of zero policy the zero-policy hash value is to ensure backward backwards
      compatibility with earlier versions of the current document.  If
      hashValue is zero zero, then the hash value should not be checked
      against the calculated hash value of the signature policy.

   If the signature policy is defined using ASN.1, then the hash is
   calculated on the value without the outer type and length fields fields, and
   the hashing algorithm shall be as specified in the field
   sigPolicyHash.

   If the signature policy is defined using another structure, the type
   of structure and the hashing algorithm shall be either specified as
   part of the signature policy, or indicated using a signature policy
   qualifier.

      SigPolicyHash ::= OtherHashAlgAndValue

      OtherHashAlgAndValue ::= SEQUENCE {
         hashAlgorithm   AlgorithmIdentifier,
         hashValue       OtherHashValue }

      OtherHashValue ::= OCTET STRING

   A signature policy identifier Signature Policy Identifier may be qualified with other information
   about the qualifier.  The semantics and syntax of the qualifier is as
   associated with the object-identifier in the sigPolicyQualifierId
   field.  The general syntax of this qualifier is as follows:

      SigPolicyQualifierInfo ::= SEQUENCE {
           sigPolicyQualifierId  SigPolicyQualifierId,
           sigQualifier          ANY DEFINED BY sigPolicyQualifierId }
   The present document specifies the following qualifiers:

      - spuri: this contains the web URI or URL reference to the
        signature policy, and

      - sp-user-notice: this contains a user notice which that should be
        displayed whenever the signature is validated.

           sigpolicyQualifierIds defined in the present document:
           SigPolicyQualifierId ::= OBJECT IDENTIFIER

            id-spq-ets-uri OBJECT IDENTIFIER ::= { iso(1)
            member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
            smime(16) id-spq(5) 1 }

        SPuri ::= IA5String

            id-spq-ets-unotice OBJECT IDENTIFIER ::= { iso(1)
            member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
            smime(16) id-spq(5) 2 }

        SPUserNotice ::= SEQUENCE {
                noticeRef        NoticeReference OPTIONAL,
                explicitText     DisplayText OPTIONAL}

        NoticeReference ::= SEQUENCE {

                organization     DisplayText,
                noticeNumbers    SEQUENCE OF INTEGER }

        DisplayText ::= CHOICE {
                visibleString    VisibleString  (SIZE (1..200)),
                bmpString        BMPString      (SIZE (1..200)),
                utf8String       UTF8String     (SIZE (1..200)) }

5.9

5.9.  CMS imported optional attributes Imported Optional Attributes

   The following attributes may be present with the signed-data, signed-data; the
   attributes are defined in CMS (RFC 3852 [4]) and are imported into
   the present document.  Were appropriated  Where appropriate, the attributes are
   qualified and profiled by the present document.

5.9.1 Signing time

5.9.1.  signing-time

   The signing-time attribute specifies the time at which the signer
   claims to have performed the signing process.

   Signing-time attribute values for ES have the ASN.1 type SigningTime
   as defined in CMS (RFC 3852 [4]).

      NOTE: RFC 3852 [4] states that dates between 1 January 1, 1950 and 31
      December 31, 2049 (inclusive) must be encoded as UTCTime.  Any
      dates with year values before 1950 or after 2049 must be encoded
      as GeneralizedTime.

5.9.2 Countersignature

5.9.2.  countersignature

   The counterSignature countersignature attribute values for ES have ASN.1 type
CounterSignature
   CounterSignature, as defined in CMS (RFC 3852 [4]).  A counterSignature
   countersignature attribute shall be an unsigned attribute.

5.10 ESS imported optional attributes

5.10.  ESS-Imported Optional Attributes

   The following attributes may be present with the signed-data defined
   by the present document.  The attributes are defined in ESS and are
   imported into the present document and were appropriate appropriately qualified
   and profiled by the present document.

5.10.1 Content reference attribute

5.10.1.  content-reference Attribute

   The content-reference attribute is a link from one SignedData to
   another.  It may be used to link a reply to the original message to
   which it refers, or to incorporate by reference one SignedData into
   another.  The content-reference attribute shall be a signed
   attribute.

Content-reference

   content-reference attribute values for ES have ASN.1 type
ContentReference
   ContentReference, as defined in ESS (RFC 2634 [5]).

   The content-reference attribute shall be used as defined in ESS (RFC
   2634 [5]).

5.10.2 Content identifier attribute

5.10.2.  content-identifier Attribute

   The content-identifier attribute provides an identifier for the
   signed
content content, for use when a reference may be later required to
   that content, content; for example example, in the content reference content-reference attribute in
   other signed data sent later.  The content-identifier shall be a
   signed attribute.

   content-identifier attribute type values for of the ES have an ASN.1
   type
ContentIdentifier ContentIdentifier, as defined in ESS (RFC 2634 [5]).

   The minimal content-identifier attribute should contain a
   concatenation of user-specific identification information (such as a
   user name or public keying material identification information), a
   GeneralizedTime string, and a random number.

5.10.3 Content hints attribute

5.10.3.  content-hints Attribute

   The content-hints attribute provides information on the innermost
   signed content of a multi-layer message where one content is
   encapsulated in another.

   The syntax of the content-hints attribute type of the ES is as
   defined in ESS (RFC 2634 [5]).

   When used to indicate the precise format of the data to be presented
   to the user user, the following rules apply:

      - the contentType indicates the type of the associated content.
        It is an object identifier (i.e. (i.e., a unique string of integers)
        assigned by an authority that defines the content type; and

      - when the contentType is id-data, the contentDescription shall
        define the presentation format, format; the format may be defined by
        MIME types.

   When the format of the content is defined by MIME types types, the
   following rules apply:

      - the contentType shall be id-data id-data, as defined in CMS (RFC 3852
        [4]);

      - the contentDescription shall be used to indicate the encoding of
        the data data, in accordance with the rules defined RFC 2045 [6], [6]; see
     annex
        Annex F for an example of structured contents and MIME.

   NOTE 1: id-data OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840)
   rsadsi(113549) pkcs(1) pkcs7(7) 1 }

   NOTE 2: contentDescription is optional in ESS (RFC 2634 [5]).  It may
   be used to complement contentTypes defined elsewhere , elsewhere; such
   definitions are outside the scope of the present document.

5.11

5.11.  Additional optional attributes defined Optional Attributes Defined in the present document Present Document

   This section defines a number of attributes that may be used to
   indicate additional information to a verifier : verifier:

      a) the type of commitment from the signer, and/or

      b) the claimed location where the signature is performed, and/or
      c) claimed attributes or certified attributes of the signer,
         and/or

      d) a content time-stamp applied before the content was signed.

5.11.1 Commitment type indication attribute

5.11.1.  commitment-type-indication Attribute

   There may be situations where a signer wants to explicitly indicate
   to a verifier that by signing the data, it illustrates a type of
   commitment on behalf of the signer.  The commitment-type-indication
   attribute conveys such information.

   The commitment-type-indication attribute shall be a signed attribute.
   The commitment type may be:

      - defined as part of the signature policy, in which case case, the
        commitment type has precise semantics that is are defined as part
        of the signature policy; and

      - be a registered type, in which case case, the commitment type has
        precise semantics defined by registration, under the rules of
        the registration authority.  Such a registration authority may
        be a trading association or a legislative authority.

   The signature policy specifies a set of attributes that it
   "recognizes".  This "recognized" set includes all those commitment
   types defined as part of the signature policy policy, as well as any
   externally defined commitment types that the policy may choose to
   recognize.  Only recognized commitment types are allowed in this
   field.

   The following object identifier identifies the commitment-type-
indication
   commitment-type-indication attribute:

id-aa-ets-commitmentType OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 16}

commitment-type-indication attribute values have ASN.1 type
CommitmentTypeIndication.

CommitmentTypeIndication ::= SEQUENCE {
  commitmentTypeId CommitmentTypeIdentifier,
  commitmentTypeQualifier SEQUENCE SIZE (1..MAX) OF
                 CommitmentTypeQualifier OPTIONAL}

CommitmentTypeIdentifier ::= OBJECT IDENTIFIER

CommitmentTypeQualifier ::= SEQUENCE {
   commitmentTypeIdentifier   CommitmentTypeIdentifier,
   qualifier                  ANY DEFINED BY commitmentTypeIdentifier }

   The use of any qualifiers to the commitment type is outside the scope
   of the present document.

   The following generic commitment types are defined in the present
   document:

id-cti-ets-proofOfOrigin OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) cti(6) 1}

id-cti-ets-proofOfReceipt OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) cti(6) 2}

id-cti-ets-proofOfDelivery OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
cti(6) 3}

id-cti-ets-proofOfSender OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) cti(6) 4}

id-cti-ets-proofOfApproval OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
cti(6) 5}

id-cti-ets-proofOfCreation OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
cti(6) 6}

   These generic commitment types have the following meaning: meanings:

   Proof of origin indicates that the signer recognizes to have created,
approved
   approved, and sent the message.

   Proof of receipt indicates that signer recognizes to have received
   the content of the message.

   Proof of delivery indicates that the TSP providing that indication
   has delivered a message in a local store accessible to the recipient
   of the message.

   Proof of sender indicates that the entity providing that indication
   has sent the message (but not necessarily created it).

   Proof of approval indicates that the signer has approved the content
   of the message.

   Proof of creation indicates that the signer has created the message
   (but not necessarily approved, nor sent it).

5.11.2 Signer location attribute

5.11.2.  signer-location Attribute

   The signer-location attribute specifies a mnemonic for an address
   associated with the signer at a particular geographical (e.g. (e.g., city)
   location.  The mnemonic is registered in the country in which the
   signer is located and is used in the provision of the Public Telegram
   Service (according to ITU-T Recommendation F.1 [11]).

   The signer-location attribute shall be a signed attribute.  The
   following object identifier identifies the signer-location attribute:

id-aa-ets-signerLocation OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 17}

   Signer-location attribute values have ASN.1 type SignerLocation:
   SignerLocation ::= SEQUENCE { -- at least one of the following shall
   be
present present:

         countryName    [0]    DirectoryString OPTIONAL,
                               -- As used to name a Country in X.500
         localityName   [1]    DirectoryString OPTIONAL,
                               -- As used to name a locality in X.500
         postalAdddress [2]    PostalAddress OPTIONAL }

   PostalAddress ::= SEQUENCE SIZE(1..6) OF DirectoryString

5.11.3 Signer attributes attribute

5.11.3.  signer-attributes Attribute

   The signer-attributes attribute specifies additional attributes of
   the signer (e.g. (e.g., role).  It may be either:

      - claimed attributes of the signer; or

      - certified attributes of the signer.

   The signer-attributes attribute shall be a signed attribute.  The
   following object identifier identifies the signer-attribute
   attribute:

   id-aa-ets-signerAttr OBJECT IDENTIFIER ::= { iso(1) member-body(2)
       us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 18}
   signer-attributes values have ASN.1 type SignerAttribute:

   SignerAttribute ::= SEQUENCE OF CHOICE {
       claimedAttributes     [0]   ClaimedAttributes,
       certifiedAttributes   [1]   CertifiedAttributes }

   ClaimedAttributes ::= SEQUENCE OF Attribute

   CertifiedAttributes ::= AttributeCertificate
   -- as defined in RFC 3281 : 3281: see section Section 4.1.

      NOTE 1: Only a single signer-attributes can be used

      NOTE 2: The claimedAttributes and certifiedAttributes fields are
      as defined in ITU-T Recommendations X.501 [9] and X.509 [1].

5.11.4 Content time-stamp

5.11.4.  content-time-stamp

   The content-time-stamp attribute is an attribute which that is the time-
stamp
   time-stamp token of the signed data content before it is signed.  The
   content-time-stamp attribute shall be a signed attribute.

   The following object identifier identifies the content-time-stamp
   attribute:

   id-aa-ets-contentTimestamp OBJECT IDENTIFIER ::=
   { iso(1) member- body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
   smime(16) id-aa(2) 20}

Content-time-stamp

   content-time-stamp attribute values have ASN.1 type ContentTimestamp:
   ContentTimestamp ::= TimeStampToken

   The value of messageImprint of TimeStampToken (as described in RFC
   3161 [7]) shall be a hash of the value of the eContent field within
   encapContentInfo in the signedData.

   For further information and definition of TimeStampToken TimeStampToken, see
section Section
   7.4.

      NOTE: Content-time-stamp content-time-stamp indicates that the signed information was
      formed before the date included in the Content-time-stamp.

5.12 content-time-stamp.

5.12.  Support for multiple signatures

5.12.1 Multiple Signatures

5.12.1.  Independent signatures Signatures

   Multiple independent signatures (see section Annex B.5) are supported by
   independent SignerInfo from each signer.

   Each SignerInfo shall include all the attributes required under the
   present document and shall be processed independently by the
   verifier.

Note:

      NOTE: Independent signatures may be used to provide independent
      signatures from different parties with different signed
      attributes, or to provide multiple signatures from the same party
      using alternative signature algorithms algorithms, in which case the other
      attributes, excluding time values and signature policy
      information, will generally be the same.

5.12.2

5.12.2.  Embedded signatures Signatures

   Multiple embedded signatures (see section Annex C.5) are supported using the
   countersignature unsigned attribute (see section Section 5.9.2).  Each
   counter signature is carried in Countersignature countersignature held as an unsigned
   attribute to the SignerInfo to which the counter-signature is
   applied.

Note:

      NOTE: Counter signatures may be used to provide signatures from
      different parties with different signed attributes, or to provide
      multiple signatures from the same party using alternative
      signature
algorithms algorithms, in which case the other attributes,
      excluding time values and signature policy information, will
      generally be the same.

6

6.  Additional Electronic Signature validation attributes Validation Attributes

   This section specifies attributes that contain different types of
   validation data.  These attributes build on the electronic signature
   specified in section Section 5.  This includes:

      - Signature-time-stamp applied to the electronic signature value
        or a Time-Mark in an audit trail.  This is defined as the
        Electronic Signature with Time Time-stamp (CAdES-T); and

      - complete Complete validation data references which comprises that comprise the time-
     stamp time-stamp
        of the signature value (CAdES-T), plus references to all the
        certificates (complete-certificate-references) and revocation
        (complete-revocation-references) information used for full
        validation of the electronic signature.  This is defined as the
        Electronic Signature with Complete data references (CAdES-C).

      NOTE 1: Formats for CAdES-T are illustrated in section 4.4 Section 4.4, and
      the
         attribute attributes are defined in section Section 6.1.1.

      NOTE 2: Formats for CAdES-C are illustrated in section Section 4.4.  The
      required attributes for the CAdES-C signature format are defined
      in section Sections 6.2.1 to 6.2.2, 6.2.2; optional attributes are defined in sections
      Sections 6.2.3 and 6.2.4.

   In addition addition, the following optional eXtended extended forms of validation data
   are also defined, defined; see annex Annex B for an overview of the eXtended extended forms
   of validation data:

      - CAdES-X with time stamp: time-stamp: there are two types of time-stamp time-stamps used
        in extended validation data defined by the present document: document;

         - Type 1(CAdES-X Type 1): comprises a time-stamp over the ES
           with complete Complete validation data (CAdES-C); and

         - Type 2 (CAdES-X Type2): comprises a time-stamp over the
           certification path references and the revocation information
           references used to support the CAdES-C.

      NOTE 3: Formats for CAdES-X Type 1 and CAdES-X Type 2 are
      illustrated in sections Sections B.1.2 and B.1.3, respectively.

         - CAdES-X Long :comprises Long: comprises the complete Complete validation data
           references
     (CAdES-C) (CAdES-C), plus the actual values of all the
           certificates and revocation information used in the CAdES-C.

      NOTE 4: Formats for CAdES-X Long are illustrated in section Annex B.1.1.

         - CAdES-X Long Type 1 or CAdES-X Long Type 2: comprises an X-Time-
     Stamp
           X-Time-Stamp (Type 1 or Type 2) 2), plus the actual values of
           all the certificates and revocation information used in the
           CAdES-C as per CAdES-X Long.

   This section also specifies the data structures used in Archive
   validation data format (CAdES-A)of eXtended extended forms:

      - Archive form of electronic signature (CAdES-A) comprises comprises:

        - the
     complete Complete validation data references (CAdES-C),

        - the certificate and revocation values (as in a CAdES-X Long ), if present

        - any existing extended electronic signature timestamps time-stamps
          (CAdES-X Type 1 or CAdES-X Type 2), plus if present, and

        - the signed user data and an additional archive time-stamp
          applied over all that data.

        An archive time-
     stamp time-stamp may be repeatedly applied after long
        periods to maintain validity when electronic signature and
        time-stamping algorithms weaken.

   The additional data required to create the forms of electronic
   signature identified above is carried as unsigned attributes
   associated with an individual signature by being placed in the
   unsignedAttrs field of SignerInfo.  Thus  Thus, all the attributes defined
   in section Section 6 are unsigned attributes.

      NOTE 5: Where multiple signatures are to be supported, as
      described in section Section 5.12, each signature has a separate
      SignerInfo.  Thus, each signature requires its own unsigned
      attribute values to create CAdES-T, CAdES-C, etc.

      NOTE 6: the The optional attributes of the extended validation data
      are defined in sections Sections 6.3 and 6.4.

6.1 Electronic Signature Time-stamped

6.1.  signature time-stamp Attribute (CAdES-T)

   An Electronic Signature electronic signature with time-stamp is an electronic signature
   for which part, but not all, of the additional data required for
   validation is available (i.e. (i.e., some certificates and revocation
   information are
available available, but not all).

   The minimum structure time-stamp validation data is:

      - the Signature Time-stamp Attribute signature time-stamp attribute, as defined in section 6.1.1 Section 6.1.1,
        over the ES signature value.

6.1.1 Signature time- stamp attribute definition

6.1.1.  signature-time-stamp Attribute Definition

   The signature-time-stamp attribute is a TimeStampToken computed on
   the signature value for a specific signer.  It signer; it is an unsigned
   attribute.  Several instances of this attribute may occur with an
   electronic signature, from different TSAs.

   The following object identifier identifies the signature-time-stamp
   attribute:

   id-aa-signatureTimeStampToken OBJECT IDENTIFIER ::=
   { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
   smime(16) id-aa(2) 14}

   The signature-time-stamp attribute value has ASN.1 type
   SignatureTimeStampToken:

   SignatureTimeStampToken ::= TimeStampToken
   The value of the messageImprint field within TimeStampToken shall be
   a hash of the value of the signature field within SignerInfo for the
   signedData being time-stamped.

   For further information and definition of TimeStampToken TimeStampToken, see
section Section
   7.4.

      NOTE 1: In the case of multiple signatures signatures, it is possible to have a
      a:

      - TimeStampToken computed for each and all signers, signers; or

      - TimeStampToken computed on one signer's signature signature; and no

      - TimeStampToken on another signer's signature.

      NOTE 2: In the case of multiple signatures, several TSTs, issued
      by different TSAs, may be present within the same signerInfo (see
      RFC 3852 [4]).

6.2

6.2.  Complete validation reference data Validation Data References (CAdES-C)

   An electronic signature with complete Complete validation data references
   (CAdES-C) is an Electronic Signature electronic signature for which all the additional
   data required for validation (i.e. (i.e., all certificates and revocation
   information) is available.  This form is built on the CAdES-T form
   defined above.

   As a minimum, the complete Complete validation data shall include the
   following:

      - a time, which shall either be a signature-timestamp attribute,
        as defined in section Section 6.1.1, or a time mark time-mark operated by a Time-
     Marking
        Time-Marking Authority;

      - complete-certificate-references, as defined in section Section 6.2.1;

      - complete-revocation-references , complete-revocation-references, as defined in section Section 6.2.2.

6.2.1 Complete certificate references attribute definition

6.2.1.  complete-certificate-references Attribute Definition

   The complete-certificate-references attribute is an unsigned
   attribute.  It references the full set of CA certificates that have
   been used to validate an ES with Complete validation data up to (but
   not including) the signer's certificate.  Only a single instance of
   this attribute shall occur with an electronic signature.

      NOTE 1: The signer's certificate is referenced in the signing
      certificate attribute (see section Section 5.7.3).

id-aa-ets-certificateRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 21}

   The complete-certificate-references complete-certificate-referneces attribute value has the ASN.1
   syntax CompleteCertificateRefs.

   CompleteCertificateRefs ::=  SEQUENCE OF OtherCertID

   OtherCertID is defined in section Section 5.7.3.2.

   The IssuerSerial that shall be present in OtherCertID.  The certHash
   shall match the hash of the certificate referenced.

      NOTE 2: Copies of the certificate values may be held using the
      certificate-values attribute attribute, defined in section Section 6.3.3.

      This attribute may include references to the certification chain
      for any TSUs that provides time-stamp tokens.  In this
         case case, the
      unsigned attribute shall be added to the signedData of the
      relevant times tamp time-stamp token as an unsignedAttrs in the signerInfos
      field.

6.2.2 Complete Revocation References attribute definition

6.2.2.  complete-revocation-references Attribute Definition

   The complete-revocation-references attribute is an unsigned
   attribute.  Only a single instance of this attribute shall occur with
   an electronic signature.  It references the full set of the CRL, ACRL
   ACRL, or OCSP responses that have been used in the validation of the signer
   signer, and CA certificates used in ES with Complete validation data.

   This attribute can be used to illustrate indicates that the verifier has taken due diligence of to
   gather the available revocation information and then to information.  The references stored
   in this attribute can be
able used to retrieve that information when the referenced information,
   if not stored elsewhere. in the CMS structure, but somewhere else.

   The following object identifier identifies the complete-revocation-
references
   complete-revocation-references attribute:

id-aa-ets-revocationRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 22}
   The complete-revocation-references attribute value has the ASN.1
   syntax CompleteRevocationRefs:

   CompleteRevocationRefs ::=  SEQUENCE OF CrlOcspRef

   CrlOcspRef ::= SEQUENCE {
      crlids      [0]   CRLListID    OPTIONAL,
      ocspids     [1]   OcspListID   OPTIONAL,
      otherRev    [2]   OtherRevRefs OPTIONAL
   }

   CompleteRevocationRefs shall contain one CrlOcspRef for the signing-
certificate,
   signing-certificate, followed by one for each OtherCertID in the
   CompleteCertificateRefs attribute.  The second and subsequent
   CrlOcspRef fields shall be in the same order as the OtherCertID to
   which they relate.  At least one of CRLListID or OcspListID or
   OtherRevRefs should be present for all but the "trusted" CA of the
   certificate path.

CRLListID ::=  SEQUENCE {
    crls        SEQUENCE OF CrlValidatedID }

CrlValidatedID ::=  SEQUENCE {
     crlHash                   OtherHash,
     crlIdentifier             CrlIdentifier OPTIONAL }

CrlIdentifier ::= SEQUENCE {
    crlissuer                 Name,
    crlIssuedTime             UTCTime,
    crlNumber                 INTEGER OPTIONAL }

OcspListID ::=  SEQUENCE {
    ocspResponses        SEQUENCE OF OcspResponsesID }

OcspResponsesID ::=  SEQUENCE {
    ocspIdentifier              OcspIdentifier,
    ocspRepHash                 OtherHash    OPTIONAL
}

OcspIdentifier ::= SEQUENCE {
   ocspResponderID    ResponderID,
      -- As in OCSP response data
   producedAt         GeneralizedTime
   -- As in OCSP response data
}
   When creating a crlValidatedID, the crlHash is computed over the
   entire DER encoded CRL including the signature.  The crlIdentifier
   would normally be present unless the CRL can be inferred from other
   information.

   The crlIdentifier is to identify the CRL using the issuer name and
   the
CRL issued CRL-issued time, which shall correspond to the time thisUpdate
   contained in the issued CRL, and if present, the crlNumber.  The
   crlListID attribute is an unsigned attribute.  In the case that the
   identified CRL is a Delta CRL CRL, then references to the set of CRLs to
   provide a complete revocation list shall be included.

   The OcspIdentifier is to identify the OCSP response using the issuer
   name and the time of issue of the OCSP response response, which shall
   correspond to the time producedAt produced as contained in the issued OCSP
   response.  Since it may be needed to make the difference between two
   OCSP responses received within the same second, then the hash of the
   response contained in the OcspResponsesID may be needed to solve the
   ambiguity.

      NOTE 1: Copies of the CRL and OCSP responses values may be held
      using the revocation-values attribute defined in section Section 6.3.4.

      NOTE 2: It is recommended that this attribute is be used in
      preference to

         The the OtherRevocationInfoFormat specified in RFC 3852
      to
         Maintain backward maintain backwards compatibility with the earlier version of
      this specification.

   The syntax and semantics of other revocation references is are outside
   the scope of the present document.  The definition of the syntax of
   the other form of revocation information is as identified by
   OtherRevRefType.

   This attribute may include the references to the full set of the CRL,
ACRL
   ACRL, or OCSP responses that have been used to verify the
   certification chain for any TSUs that provides provide time-stamp tokens.  In
   this case case, the unsigned attribute shall be added to the signedData of
   the relevant
timestamp time-stamp token as an unsignedAttrs in the signerInfos
   field.

6.2.3

6.2.3.  attribute-certificate-references Attribute certificate references attribute definition Definition

   This attribute is only used when a user attribute certificate is
   present in the electronic signature.

   The attribute-certificate-references attribute is an unsigned
   attribute.  It references the full set of AA certificates that have
   been used to validate the attribute certificate.  Only a single
   instance of this attribute shall occur with an electronic signature.

   id-aa-ets-attrCertificateRefs OBJECT IDENTIFIER ::=
   { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
   smime(16) id-aa(2) 44}

   The attribute-certificate-references attribute value has the ASN.1
   syntax AttributeCertificateRefs:

   AttributeCertificateRefs ::=  SEQUENCE OF OtherCertID

   OtherCertID is defined in section Section 5.8.2.

      NOTE: Copies of the certificate values may be held using the
      certificate-values attribute defined in section Section 6.3.3.

6.2.4

6.2.4.  attribute-revocation-references Attribute revocation references attribute definition Definition

   This attribute is only used when a user attribute certificate is
   present in the electronic signature and when that attribute
   certificate can be revoked.

   The attribute-revocation-references attribute is an unsigned
   attribute.  Only a single instance of this attribute shall occur with
   an electronic signature.  It references the full set of the ACRL or
   OCSP responses that have been used in the validation of the attribute
   certificate.  This attribute can be used to illustrate that the
   verifier has taken due diligence of the available revocation
   information.

   The following object identifier identifies the attribute-revocation-
references
   attribute-revocation-references attribute:

   id-aa-ets-attrRevocationRefs OBJECT IDENTIFIER ::= { iso(1)
   member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
   id-aa(2) 45}

   The attribute-revocation-references attribute value has the ASN.1
   syntax AttributeRevocationRefs:

   AttributeRevocationRefs ::=  SEQUENCE OF CrlOcspRef

6.3

6.3.  Extended validation data Validation Data (CAdES-X)

   This section specifies a number of optional attributes that are used
   by extended forms of electronic signatures (see annex Annex B for an
   overview of these forms of validation data).

6.3.1 Time-stamped validation data

6.3.1.  Time-Stamped Validation Data (CAdES-X Type 1 or Type 2)

   The extended validation data may include one of the following
   additional attributes, forming a CAdES-X Time-Stamp validation data
   (CAdES-X Type 1 or CAdES-X Type 2), to provide additional protection
   against later CA compromise and provide integrity of the validation
   data used:

      - CAdES-C Time-stamp, as defined in section Section 6.3.5 (CAdES-X Type
        1); or

      - Time-Stamped Certificates and CRLs references, as defined in
     section
        Section 6.3.6 (CAdES-X Type 2).

6.3.2

6.3.2.  Long validation data Validation Data (CAdES-X Long, CAdES-X Long Type 1 or 2)

   The extended validation data may also include the following
   additional information, forming a CAdES-X Long, for use if later
   validation processes may not have access to this information:

      - certificate-values certificate-values, as defined in section Section 6.3.3; and

      - revocation-values revocation-values, as defined in section Section 6.3.4.

   The extended validation data may may, in addition to certificate-values
   and revocation-values as defined in sections Sections 6.3.3 and 6.3.4 6.3.4, include
   one of the following additional attributes, forming an a CAdES-X Long
   Type 1 or CAdES-X Long Type 2.

      - CAdES-C Time-stamp, as defined in section Section 6.3.3 (CAdES-X long
        Type 1); or

      - Time-Stamped Certificates and CRLs references, as defined in
     section
        Section 6.3.4 (CAdES-X Long Type 2).

   The CAdES-X Long Type 1 or CAdES-X Long Type 2 provide provides additional
   protection against later CA compromise and provide provides integrity of the
   validation data used.

      NOTE 1: The CAdES-X-Long signature provides long term long-term proof of the
      validity of the signature for as long as the CA keys, CRL Issuers keys
      keys, and OCSP responder keys are not compromised and are
      resistant to cryptographic attacks.

      NOTE 2: As long as the time stamp time-stamp data remains valid, the CAdES-X
      Long Type 1 and the CAdES-X Long Type 2 provides provide the following
      important property for long standing long-standing signatures; that having been
      found once to be valid, it shall continue to be so months or years
      later, long after the validity period of the certificates have has
      expired, or after the user key has been compromised.

6.3.3 Certificate values attribute definition

6.3.3.  certificate-values Attribute Definition

   This attribute may be used to contain the certificate information
   required for the following forms of eXtended Electronic Signature: extended electronic signature:
   CAdES-X Long , Long, ES X-Long Type 1 1, and CAdES-X Long Type 2, 2; see section Annex
   B.1.1 for an illustration of this form of electronic signature.

   The certificate-values attribute is an unsigned attribute.  Only a
   single instance of this attribute shall occur with an electronic
   signature.  It holds the values of certificates referenced in the
   complete-certificate-references attribute.

      NOTE: If an attribute certificate is used, it is not provided in
      this structure but shall be provided by the signer as a signer-
       attributes
      signer-attributes attribute (see section Section 5.11.3).

   The following object identifier identifies the certificate-values
   attribute:

   id-aa-ets-certValues OBJECT IDENTIFIER ::= { iso(1) member-body(2)
   us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 23}

   The certificate-values attribute value has the ASN.1 syntax
   CertificateValues.

   CertificateValues ::=  SEQUENCE OF Certificate

   Certificate is defined in section Section 7.1. (which is as defined in ITU-T
   Recommendation X.509 [1]. [1]).

   This attribute may include the certification information for any TSUs
   that have provided the time-stamp tokens tokens, if these certificates are
   not already included in the TSTs as part of the TSUs signatures.  In
   this
case case, the unsigned attribute shall be added to the signedData of
   the relevant timestamp time-stamp token.

6.3.4 Revocation values attribute definition

6.3.4.  revocation-values Attribute Definition

   This attribute is used to contain the revocation information required
   for the following forms of eXtended Electronic Signature: extended electronic signature: CAdES-X
   Long, ES X-Long Type 1 1, and CAdES-X Long Type 2, 2; see section Annex B.1.1 for
   an illustration of this form of electronic signature.

   The revocation-values attribute is an unsigned attribute.  Only a
   single instance of this attribute shall occur with an electronic
   signature.  It holds the values of CRLs and OCSP referenced in the
   complete-revocation-references attribute.

 NOTE :

      NOTE: It is recommended that this attribute is be used in preference
      to the OtherRevocationInfoFormat specified in RFC 3852 to maintain
        backward
      backwards compatibility with the earlier version of this
      specification.

   The following object identifier identifies the revocation-values
   attribute:

   id-aa-ets-revocationValues OBJECT IDENTIFIER ::= { iso(1)
   member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
   smime(16) id-aa(2) 24}

   The revocation-values attribute value has the ASN.1 syntax
   RevocationValues

   RevocationValues ::=  SEQUENCE {
      crlVals          [0] SEQUENCE OF CertificateList OPTIONAL,
      ocspVals         [1] SEQUENCE OF BasicOCSPResponse OPTIONAL,
      otherRevVals     [2] OtherRevVals OPTIONAL }

   OtherRevVals ::= SEQUENCE {
      OtherRevValType   OtherRevValType,
      OtherRevVals      ANY DEFINED BY OtherRevValType }

   OtherRevValType ::= OBJECT IDENTIFIER

   The syntax and semantics of the other revocation values
   (OtherRevVals)
is are outside the scope of the present document.

   The definition of the syntax of the other form of revocation
   information is as identified by OtherRevRefType.

   CertificateList is defined in section Section 7.2. (which is as defined in
   ITU-T Recommendation X.509 [1]).

   BasicOCSPResponse is defined in section Section 7.3. (which is as defined in
   RFC 2560 [3]).

   This attribute may include the values of revocation data including
   CRLs and OCSP OCSPs for any TSUs that have provided the time-stamp tokens tokens,
   if these certificates are not already included in the TSTs as part of
   the TSUs signatures.  In this case case, the unsigned attribute shall be
   added to the signedData of the relevant timestamp token.

6.3.5 CAdES-C time-stamp attribute definition token.

6.3.5.  CAdES-C-time-stamp Attribute Definition

   This attribute is used to protect against CA key compromise.

   This attribute is used for the time stamping time-stamping of the complete
   electronic signature (CAdES-C).  It is used in the following forms of eXtended
Electronic Signature;
   extended electronic signature; CAdES-X Type 1 and CAdES-X Long Type 1,
   1; see
section Annex B.1.2 for an illustration of this form of electronic
   signature.

   The CAdES-C-timestamp CAdES-C-time-stamp attribute is an unsigned attribute.  It is a
   time-stamp token of the hash of the electronic signature and the
   complete validation data (CAdES-C).  It is a special purpose special-purpose
   TimeStampToken Attribute which that time-stamps the CAdES-C.  Several
   instances of this attribute may occur with an electronic signature
   from different TSAs.

      NOTE 1: It is recommended that the attributes being time-stamped are
      be encoded in DER.  If DER is not employed employed, then the binary
      encoding of the ASN.1structures ASN.1 structures being time-stamped should be
      preserved to ensure that the recalculation of the data hash is
      consistent.

      NOTE 2: Each attribute is included in the hash with the attrType
      and attrValues (including type and length) but without the type
      and length of the outer SEQUENCE.

   The following object identifier identifies the CAdES-C-Timestamp
   attribute:

   id-aa-ets-escTimeStamp OBJECT IDENTIFIER ::= { iso(1) member-body(2)
   us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 25}

   The CAdES-C-timestamp attribute value has the ASN.1 syntax
   ESCTimeStampToken :

   ESCTimeStampToken ::= TimeStampToken

   The value of the messageImprint field within TimeStampToken shall be
   a hash of the concatenated values (without the type or length
   encoding for that value) of the following data objects:

      - OCTETSTRING of the SignatureValue field within SignerInfo;

      - signature-time-stamp, or a time mark time-mark operated by a Time-Marking
        Authority;

      - complete-certificate-references s attribute; and
      - complete-revocation-references attribute.

   For further information and definition of the TimeStampToken, see
clause
   Section 7.4.

6.3.6 Time-stamped certificates and crls references attribute
definition

6.3.6.  time-stamped-certs-crls-references Attribute Definition

   This attribute is used to protect against CA key compromise.  This
   attribute is used for the time stamping time-stamping certificate and revocation
   references.  It is used in the following forms of eXtended Electronic
Signature; extended electronic
   signature: CAdES-X Type 2 and CAdES-X Long Type 2, 2; see section Annex B.1.3
   for an illustration of this form of electronic signature.

   A time-stamped-certs-crls-references attribute is an unsigned
   attribute.  It is a time-stamp token issued for a list of referenced
   certificates and OCSP responses or/and and/or CRLs to protect against
   certain CA compromises.  Its syntax is as follows:

      NOTE 1: It is recommended that the attributes being time-stamped are
      be encoded in DER.  If DER is not employed employed, then the binary
      encoding of the ASN.1structures ASN.1 structures being time-stamped should be
      preserved to ensure that the recalculation of the data hash is
      consistent.

      NOTE 2: Each attribute is included in the hash with the attrType
      and attrValues (including type and length) but without the type
      and length of the outer SEQUENCE SEQUENCE.

   The following object identifier identifies the time-stamped-certs-crls-
references
   time-stamped-certs-crls-references attribute:

   id-aa-ets-certCRLTimestamp OBJECT IDENTIFIER ::=
   { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
   smime(16) id-aa(2) 26}

   The attribute value has the ASN.1 syntax TimestampedCertsCRLs : TimestampedCertsCRLs:

   TimestampedCertsCRLs ::= TimeStampToken

   The value of the messageImprint field within the TimeStampToken shall
   be a hash of the concatenated values (without the type or length
   encoding for that value) of the following data objects objects, as present in
   the ES with Complete validation data (CAdES-C):

      - complete-certificate-references attribute; and

      - complete-revocation-references attribute.

6.4

6.4.  Archive validation data Validation Data

   Where an electronic signature is required to last for a very long
   time, and a the time-stamp token on an electronic signature is in
   danger of being invalidated due to algorithm weakness or limits in
   the validity period of the TSA certificate, then it may be required to
   time-stamp the electronic signature several times.  When this is required
   required, an archive time-stamp attribute may be required for the
   archive form of the electronic signature (CAdES-A).  This archive
   time-stamp attribute may be repeatedly applied over a period of time.

6.4.1 Archive time-stamp attribute definition

6.4.1.  archive-time-stamp Attribute Definition

   The archive-time-stamp attribute is a time-stamp token of many of the
   elements of the signedData in the electronic signature.  If the
   certificate-values and revocation-values attributes are not present
   in the CAdES-BES or CAdES-EPES, then they shall be added to the
   electronic signature prior to computing the archive time-stamp token.

   The archive-time-stamp attribute is an unsigned attribute.  Several
   instances of this attribute may occur with an electronic signature
   both over time and from different TSUs.

   The following object identifier identifies the nested
   archive-time-stamp attribute:

   id-aa-ets-archiveTimestampV2  OBJECT IDENTIFIER ::=
   { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
   smime(16) id-aa(2) 48}

   Archive-time-stamp attribute values have the ASN.1 syntax
   ArchiveTimeStampToken

   ArchiveTimeStampToken ::= TimeStampToken

   The value of the messageImprint field within TimeStampToken shall be
   a hash of the concatenation of:

      - The the encapContentInfo element of the SignedData sequence;

      - If the eContent element of the encapContentInfo is omitted, any external content being protected by the signature; signature, if the
        eContent element of the encapContentInfo is omitted;

      - When present, the Certificates and crls elements of the SignedData sequence; and sequence,
        when present, and;

      - Together with all data elements in the SignerInfo sequence including all
        signed and unsigned attributes.

      NOTE 1: An alternative archiveTimestamp attribute, identified by
      an object identifier { iso(1) member-body(2) us(840)
      rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 27, is defined
      in prior versions of TS 101 733 [TS101733] and in RFC 3126.

      The archiveTimestamp attribute attribute, defined in versions of TS 101 733
      prior to 1.5.1 and in RFC 3126 3126, is not compatible with the
      attribute defined in the current document.  The archiveTimestamp attribute
      attribute, defined in versions 1.5.1 to 1.7.3 1.6.3 of TS 101 733 733, is
      compatible with the current document if the content is internal to
      encapContentInfo.  Unless the version of TS 101 733 employed by
      the signing party is known by all recipients, use of the
      archiveTimestamp attribute defined in prior versions of TS 101 733
      is deprecated.

      NOTE 2: Counter signatures held as countersignature attributes do
      not require independent archive time-stamps time-stamps, as they are protected
      by the archive time-stamp against the containing signedData SignedData
      structure.

      NOTE 3: Unless DER is used throughout, it is recommended that the
      binary encoding of the ASN.1 structures being time-stamped are be
      preserved when being archived to ensure that the recalculation of
      the data hash is consistent.

      NOTE 4: The hash is calculated over the concatenated data elements
      as
        received / stored received/stored, including the Type and Length encoding.

      NOTE 5: Whilst it is recommended that unsigned attributes are be DER
        encoded
      encoded, it cannot generally be so guaranteed except by prior
      arrangement.  Further  For further information and definition of
        TimeStampToken
      TimeStampToken, see section Section 7.4.  The timestamp should be created
      using stronger algorithms (or longer key lengths) than in the
      original electronic signatures and weak algorithm (key length)
      timestamps.

      NOTE 6: This form of ES also provides protection against a TSP key
      compromise.

   The ArchiveTimeStamp will be added as an unsigned attribute in the
   SignerInfo sequence.  For the validation of one ArchiveTimeStamp ArchiveTimeStamp, the
   data elements of the SignerInfo must be concatenated concatenated, excluding all
   later ArchivTimeStampToken attributes.

   Certificates and revocation information required to validate the
   ArchiveTimeStamp shall be provided by one of the following methods:

      - The TSU provides the information in the SignedData of the
        timestamp token;

      - Adding the complete-certificate-references attribute and the
        complete-revocation-references attribute of the TSP as an
        unsigned attribute within TimeStampToken, when the required
        information is store stored elsewhere; or

      - Adding the certificate-values attribute and the
        revocation-values attribute of the TSP as an unsigned attribute
        within TimeStampToken, when the required information is store stored
        elsewhere.

7

7.  Other standard data structures

7.1 Public-key certificate format Standard Data Structures

7.1.  Public Key Certificate Format

   The X.509 v3 certificate basis syntax is defined in ITU-T
   Recommendation X.509 [1].  A profile of the X.509 v3 certificate is
   defined in RFC 3280 [2].

7.2

7.2.  Certificate revocation list format Revocation List Format

   The X.509 v2 CRL syntax is defined in ITU-T Recommendation X.509 [1].
   A profile of the X.509 v2 CRL is defined in RFC 3280 [2].

7.3

7.3.  OCSP response format Response Format

   The format of an OCSP token is defined in RFC 2560 [3].

7.4 Time-stamp token format

7.4.  Time-Stamp Token Format

   The format of a TimeStampToken type is defined in RFC 3161 [7] and
   profiled in ETSI TS 101 861 [TS101861].

7.5

7.5.  Name and attribute formats Attribute Formats

   The syntax of the naming and other attributes is defined in ITU-T
   Recommendation X.509 [1].

Note:

      NOTE: The name used by the signer, held as the subject in the
      signer's certificate, is allocated and verified on registration
      with the Certification Authority, either directly or indirectly
      through a Registration Authority, before being issued with a
      Certificate.

   The present document places no restrictions on the form of the name.
   The subject's name may be a distinguished name, as defined in ITU-T
   Recommendation X.500 [12], held in the subject field of the
   certificate, or any other name form held in the subjectAltName
   certificate extension field field, as defined in ITU-T Recommendation X.509
   [1].  In the case that the subject has no distinguished name, the
   subject name can be an empty sequence and the subjectAltName
   extension shall be critical.

   All Certification Authorities, Attribute Authorities Authorities, and Time Stamping
   Time-Stamping Authorities shall use distinguished names in the
   subject field of their certificate.

   The distinguished name shall include identifiers for the organization
   providing the service and the legal jurisdiction (e.g. (e.g., country)
   under which it operates.

   Where a signer signs as an individual individual, but wishes to also identify
   him/herself as acting on behalf of an organization, it may be
   necessary to provide two independent forms of identification.  The
   first identity, with which is directly associated with the signing key key,
   identifies him/her as an individual.  The second, which is managed
   independently, identifies that person acting as part of the
   organization, possibly with a given role.  In this case case, one of the
   two identities is carried in the subject/subjectAltName field of the
   signer's certificate as described above.

   The present document does not specify the format of the signer's
   attribute that may be included in public key certificates.

 NOTE : Signer's

      NOTE: The signer's attribute may be supported by using a claimed
      role in the CMS signed attributes field or by placing an attribute
      certificate containing a certified role in the CMS signed
      attributes field, field; see section Section 7.6.

7.6 Attribute certificate

7.6.  AttributeCertificate

   The syntax of the AttributeCertificate type is defined in RFC 3281
   [13].

8.  Conformance requirements Requirements

   For implementations supporting signature generation, the present
   document defines conformance requirements for the generation of two
   forms of basic electronic signature, one of the two forms must be
   implemented.

   For implementations supporting signature verification, the present
   document defines conformance requirements for the verification of two
   forms of basic electronic signature, one of the two forms must be
   implemented.

   The present document only defines conformance requirements up to an
   ES with Complete validation data (CAdES-C).  This means that none of
   the extended and archive forms of Electronic Signature the electronic signature (CAdES-X,
   CAdES-A) need to be implemented to get conformance to the present
   document.

   On verification the inclusion of optional signed and unsigned
   attributes must be supported only to the extended extent that the signature is
   verifiable.  The semantics of optional attributes may be unsupported,
   unless specified otherwise by a signature policy.

8.1

8.1.  CAdES-Basic Electronic Signature (CAdES-BES)

   A system supporting CAdES-BES signers signers, according to the present
document
   document, shall, at a minimum, support generation of an electronic
   signature consisting of the following components:

      - The general CMS syntax and content type type, as defined in RFC 3852
        [4] (see sections Sections 5.1 and 5.2);

      - CMS SignedData SignedData, as defined in RFC 3852 [4] [4], with the version set
        to 3 and at least one SignerInfo shall be present (see sections Sections 5.3 to
        5.6);

         - The following CMS attributes attributes, as defined in RFC 3852 [4]:

         - content-type; this shall always be present (see section Section
           5.7.1); and

         - message-digest; this shall always be present (see section Section
           5.7.2).

      - One of the following attributes attributes, as defined in the present
        document:

         - signing-certificate: as defined in section Section 5.7.3.1; or
         - signing-certificate v2 : as defined in section Section 5.7.3.2.

   Note :

      NOTE: RFC 3126 was using the other signing certificate signing-certificate attribute
      (see section Section 5.7.3.3).  Its use is now deprecated, since the
      structure of the signing-certificate v2 attribute is simpler than
      the other signing certificate signing-certificate attribute.

8.2

8.2.  CAdES-Explicit Policy-based Electronic Signature

   A system supporting Policy-based signers signers, according to the present
document
   document, shall, at a minimum, support the generation of an
   electronic signature consisting of the previous components defined
   for the basic signer, plus:

      - The following attributes attributes, as defined in section Section 5.9:

         - signature-policy-identifier; this shall always be present
           (see
         section Section 5.8.1).

8.3

8.3.  Verification using time-stamping Using Time-Stamping

   A system supporting verifiers verifiers, according to the present document document,
   with time-stamping facilities shall, at a minimum, support:

      - verification of the mandated components of an electronic
        signature, as defined in section Section 8.1;

      - signature-time-stamp attribute, as defined in section Section 6.1.1;

      - complete-certificate-references, attribute complete-certificate-references attribute, as defined in
     section Section
        6.2.1;

      - complete-revocation-references attribute, as defined in
     section Section
        6.2.2;

      - Public Key Certificates, as defined in ITU-T Recommendation
        X.509 [1] (see section Section 8.1); and

      - either of:

         - Certificate Revocation Lists. Lists, as defined in ITU-T
           Recommendation X.509 [1] (see section Section 8.2); or

         - on-line Online Certificate Status Protocol, as defined in RFC 2560
           [3] (see section Section 8.3).

8.4

8.4.  Verification using secure records Using Secure Records

   A system supporting verifiers verifiers, according to the present document document,
   shall, at a minimum, support:

      - verification of the mandated components of an electronic
        signature, as defined in section Section 8.1;
      - complete-certificate-references attribute, as defined in
     section Section
        6.2.1;

      - complete-revocation-references attribute, as defined in
     section Section
        6.2.2;

      - a record of the electronic signature and the time when the
        signature was first validated using the referenced certificates certificates,
        and revocation information must be maintained maintained, such that records
        cannot be undetectable undetectably modified;

      - Public Key Certificates, as defined in ITU-T Recommendation
        X.509 [1] (see section Section 8.1); and

         - either of:

            - Certificate Revocation Lists. Lists, as defined in ITU-T
              Recommendation X.509 [1] (see section Section 8.2); or

            - on-line online Certificate Status Protocol, as defined in RFC 2560
              [3] (see section Section 8.3).

9. IANA Considerations

No IANA actions required.

10.  References

10.1

9.1.  Normative references References

   [1]    ITU-T Recommendation X.509 (2000)/ISO/IEC 9594-8 (2001):
          "Information technology - Open Systems Interconnection - The
          Directory: Authentication Public key and Attribute Certificate framework".

   [2]   IETF RFC 3280 (2002):    Housley, R., Polk, W., Ford, W., and D. Solo, "Internet X.509
          Public Key Infrastructure Certificate and Certificate
          Revocation List (CRL) Profile".

    [3]   IETF Profile", RFC 2560 (1999): 3280, April 2002.

   [3]    Myers, M., Ankney, R., Malpani, A., Galperin, S., and C.
          Adams, "X.509 Internet Public Key Infrastructure Online
          Certificate Status Protocol - OCSP".

    [4]   IETF OCSP", RFC 3852 (2004): 2560, June 1999.

   [4]    Housley, R., "Cryptographic Message Syntax (CMS)".

    [5]   IETF (CMS)", RFC 2634 (1999): 3852,
          July 2004.

   [5]    Hoffman, P., Ed., "Enhanced Security Services for
          S/MIME".

    [6]   IETF S/MIME", RFC 2045 (1996):
          2634, June 1999.

   [6]    Freed, N. and N. Borenstein, "Multipurpose Internet Mail
          Extensions (MIME) Part One: Format of Internet Message Bodies".

    [7]   IETF
          Bodies", RFC 3161 (2001): 2045, November 1996.

   [7]    Adams, C., Cain, P., Pinkas, D., and R. Zuccherato, "Internet
          X.509 Public Key Infrastructure Time-Stamp Protocol ". (TSP)",
          RFC 3161, August 2001.

   [8]    ITU-T Recommendation X.680 (1997): "Information technology -
          Abstract Syntax Notation One (ASN.1): Specification of basic
          notation".

   [9]    ITU-T Recommendation X.501 (2000)/ISO/IEC 9594-1 (2001):
          "Information technology - Open Systems Interconnection -
          Directory models ". models".

   [10]   IETF RFC 3370 (2002):   Housley, R., "Cryptographic Message Syntax (CMS)
          Algorithms". Algorithms",
          RFC 3370, August 2002.

   [11]   ITU-T Recommendation F.1: "Operational provisions for the
          international public telegram service".

   [12]   ITU-T Recommendation X.500: "Information technology - Open
          Systems Interconnection - The Directory: Overview of concepts,
          models and services".

   [13]   IETF RFC 3281 (2002):   Farrell, S. and R. Housley, "An Internet Attribute Certificate
          Profile for Authorization". Authorization", RFC 3281, April 2002.

   [14]   ITU-T Recommendation X.208 (1988): "Specification of Abstract
          Syntax Notation One (ASN.1)".

   [15]   IETF RFC 5035 (2007). ESS   Schaad, J., "Enhanced Security Services (ESS) Update: Adding
          CertID Algorithm
          Agility. Agility", RFC 5035, August 2007.

   [16]   ITU-T Recommendation X.690 (2002): "Information technology
          ASN.1 encoding rules: Specification of Basic Encoding Rules
          (BER), Canonical Encoding Rules (CER) and Distinguished
          Encoding Rules (DER)

10.2 (DER)".

9.2.  Informative references

    ETSI technical specifications can be downloaded free of charge
    via the Services and Products Download Area at:
    http://www.etsi.org/WebSite/Standards/StandardsDownload.aspx

   [EU Directive] References

   [EUDirective]  Directive 1999/93/EC of the European Parliament and of
                  the Council of 13 December 1999 on a Community community
                  framework for
   electronic signatures. Electronic Signatures.

   [TS101733]     ETSI Standard TS 101 733 V.1.7.3 (2005-06) Electronic
                  Signature Formats.

   [TS101861]     ETSI TS 101 861: "Time stamping profile".

   [TS101903]     ETSI TS 101 903: "XML Advanced Electronic Signatures
                  (XAdES)".

   [TR102038]     ETSI TR 102 038: "Electronic Signatures and
                  Infrastructures (ESI); XML format for signature
                  policies".

   [TR102272]     ETSI TR 102 272 V1.1.1 (2003-12). "Electronic
                  Signatures and Infrastructures (ESI); ASN.1 format for
                  signature policies".

   [RFC2479] IETF RFC 2479 (1998):      Adams, C., "Independent Data Unit Protection Generic
                  Security Service Application Program Interface
   (IDUP-GSS-API)".

   [RFC2743] IETF (IDUP-
                  GSS-API)", RFC 2743 (2000): 2479, December 1998.

   [RFC2743]      Linn, J., "Generic Security Service Application
                  Program Interface Version 2, Update 1

   [RFC3125] IETF 1", RFC 3125 (2000): 2743,
                  January 2000.

   [RFC3125]      Ross, J., Pinkas, D., and N. Pope, "Electronic
                  Signature Policies".

   [RFC3447] IETF Policies", RFC 3447 (2003): "PKCS 3125, September 2001.

   [RFC3447]      Jonsson, J. and B. Kaliski, "Public-Key Cryptography
                  Standards (PKCS) #1: RSA Cryptography Specifications
                  Version 2.1". 2.1", RFC 3447, February 2003.

   [RFC3494] IETF      Zeilenga, K., "Lightweight Directory Access Protocol
                  version 2 (LDAPv2) to Historic Status", RFC 3494 (2003): "Internet X.509 Public Key
   Infrastructure Operational Protocols - LDAPv2". 3494,
                  March 2003.

   [RFC3851] IETF RFC 3851 (2004): "SMIME      Ramsdell, B., Ed., "Secure/Multipurpose Internet Mail
                  Extensions (S/MIME) Version 3.1 Message
   Specification".

   [RFC4210] IETF
                  Specification", RFC 4210 (2005): 3851, July 2004.

   [RFC4210]      Adams, C., Farrell, S., Kause, T., and T. Mononen,
                  "Internet X.509 Public Key Infrastructure Certificate
                  Management Protocols".

   [RFC4346] IETF Protocol (CMP)", RFC 4346 (2006): 4210, September 2005.

   [RFC4346]      Dierks, T. and E. Rescorla, "The TLS Transport Layer
                  Security (TLS) Protocol Version 1.1".

   [RFC4523] IETF 1.1", RFC 4523 (2006): " Lightweight 4346, April
                  2006.

   [RFC4523]      Zeilenga, K., "Lightweight Directory Access Protocol (LDAP).
                  (LDAP) Schema Definitions for X.509 Certificates". Certificates", RFC
                  4523, June 2006.

   [ISO7498-2]    ISO 7498-2 (1989): "Information processing systems -
                  Open Systems Interconnection - Basic Reference Model -
                  Part 2: Security Architecture".

   [ISO9796-2]    ISO/IEC 9796-2 (2002): "Information technology -
                  Security techniques - Digital signature schemes giving
                  message recovery - Part 2: Integer factorization based
                  mechanisms".

   [ISO9796-4]    ISO/IEC 9796-4 (1998): "Digital signature schemes
                  giving message recovery - Part 4: Discrete logarithm
                  based mechanisms".

   [ISO10118-1]   ISO/IEC 10118-1 (2000): "Information technology -
                  Security techniques - Hash-functions - Part 1:
                  General".

   [ISO10118-2]   ISO/IEC 10118-2 (2000): "Information technology -
                  Security techniques - Hash-functions - Part 2:
                  Hash-functions using an n-bit block cipher algorithm".

   [ISO10118-3]   ISO/IEC 10118-3 (2004): "Information technology -
                  Security techniques - Hash-functions - Part 3:
                  Dedicated hash-functions".

   [ISO10118-4]   ISO/IEC 10118-4 (1998): "Information technology -
                  Security techniques - Hash-functions - Part 4: Hash-functions Hash-
                  functions using modular arithmetic".

   [ISO10181-5]   ISO/IEC 10181-5:  Security Frameworks in Open Systems.
                  Non-Repudiation Framework.  April 1997.

   [ISO13888-1]   ISO/IEC 13888-1 (2004): "IT security techniques -
                  Non-repudiation - Part 1: General".

   [ISO14888-1]   ISO/IEC 14888-1 (1998): "Information technology -
                  Security techniques - Digital signatures with appendix
                  - Part 1: General".

   [ISO14888-2]   ISO/IEC 14888-2 (1999): "Information technology -
                  Security techniques - Digital signatures with appendix
                  - Part 2: Identity-based mechanisms".

   [ISO14888-3]   ISO/IEC 14888-3 (1998): "Information technology -
                  Security techniques - Digital signatures with appendix
                  - Part 3: Certificate-based mechanisms".

   [ISO15946-2]   ISO/IEC 15946-2 (2002): "Information technology -
                  Security techniques - Cryptographic techniques based
                  on elliptic curves - Part 2: Digital signatures".

   [CWA14171]     CWA 14171 CEN Workshop Agreement: "General Guidelines
                  for Electronic Signature Verification".

   [XMLDSIG]      XMLDSIG: W3C/IETF Recommendation (February 2002):
                  "XML-Signature Syntax and Processing".

   [X9.30-1]      ANSI X9.30-1 (1997): "Public Key Cryptography for the
                  Financial Services Industry - Part 1: The Digital
                  Signature Algorithm (DSA)".

   [X9.30-2]      ANSI X9.30-2 (1997): "Public Key Cryptography for the
                  Financial Services Industry - Part 2: The Secure Hash
                  Algorithm (SHA-1)".

   [X9.31-1]      ANSI X9.31-1 (1997): "Public Key Cryptography Using
                  Reversible Algorithms for the Financial Services
                  Industry - Part 1: The RSA Signature Algorithm".

   [X9.31-2]      ANSI X9.31-2 (1996): "Public Key Cryptography Using
                  Reversible Algorithms for the Financial Services
                  Industry - Part 2: Hash Algorithms".

   [X9.62]        ANSI X9.62 (1998): "Public Key Cryptography for the
   Financial Services Industry - The Elliptic Curve Digital Signature
   Algorithm (ECDSA)".

   [P1363] IEEE P1363 (2000): "Standard Specifications for Public-Key
   Cryptography".

12. Authors' addresses

      Denis Pinkas
      Bull S.A.S.
      Rue Jean-Jaures
      78340 Les Clayes sous Bois CEDEX
      FRANCE
      EMail: Denis.Pinkas@bull.net

      Nick Pope
      Thales eSecurity
      Meadow View House
      Long Crendon
      Aylesbury
      Buck
      HP18 9EQ
      United Kingdom
      EMail: nick.pope@thales-esecurity.com

      John Ross

      Security & Standards Consultancy Ltd (1998): "Public Key Cryptography for the
                  Financial Services Industry - The Waterhouse Business Centre
      2 Cromer Way
      Chelmsford
      Essex
      CM1 2QE
      United Kingdom
      EMail: ross@secstan.com

13. Acknowledgments

Special thanks to Russ Housley Elliptic Curve
                  Digital Signature Algorithm (ECDSA)".

   [P1363]        IEEE P1363 (2000): "Standard Specifications for reviewing
                  Public-Key Cryptography".

   ETSI technical specifications can be downloaded free of charge via
   the document. Services and Products Download Area at:
   http://www.etsi.org/WebSite/Standards/StandardsDownload.aspx

Annex A (normative): ASN.1 definitions Definitions

   This annex provides a summary of all the ASN.1 syntax definitions for
   new syntax defined in the present document.

A.1

A.1.  Signature format definitions using Format Definitions Using X.208 ASN.1 syntax Syntax

      NOTE: The ASN.1 module defined in section Annex A.1 using syntax defined
      in ITU-T Recommendation X.208 [14] has precedence over that
      defined in section Annex A.2 in the case of any conflict.

ETS-ElectronicSignatureFormats-ExplicitSyntax88 { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-mod(0)
eSignature-explicit88(28)}

DEFINITIONS EXPLICIT TAGS ::=

BEGIN

-- EXPORTS All

IMPORTS

-- Cryptographic Message Syntax (CMS): RFC 3852

   ContentInfo, ContentType, id-data, id-signedData, SignedData,
   EncapsulatedContentInfo, SignerInfo, id-contentType,
   id-messageDigest, MessageDigest, id-signingTime, SigningTime,
   id-countersignature, Countersignature
      FROM CryptographicMessageSyntax2004
      { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) modules(0) cms-2004(24) }

-- ESS Defined attributes: ESS Update
-- RFC 5035 (Adding CertID Algorithm Agility)

   id-aa-signingCertificate, SigningCertificate, IssuerSerial,
   id-aa-contentReference, ContentReference, id-aa-contentIdentifier,
   ContentIdentifier, id-aa-signingCertificateV2
      FROM ExtendedSecurityServices-2006
        { iso(1) member-body(2) us(840) rsadsi(113549)
          pkcs(1) pkcs-9(9) smime(16) modules(0) id-mod-ess-2006(30) }

-- Internet X.509 Public Key Infrastructure - Certificate and CRL
-- Profile: RFC 3280

   Certificate, AlgorithmIdentifier, CertificateList, Name,
   DirectoryString, Attribute, BMPString, UTF8String
      FROM PKIX1Explicit88
      {iso(1) identified-organization(3) dod(6) internet(1)
      security(5) mechanisms(5) pkix(7) id-mod(0) id-pkix1-explicit(18)}
   GeneralNames, GeneralName, PolicyInformation
      FROM PKIX1Implicit88
      {iso(1) identified-organization(3) dod(6) internet(1) security(5)
       mechanisms(5) pkix(7) id-mod(0) id-pkix1-implicit (19)}

-- Internet Attribute Certificate Profile for Authorization - RFC 3281

   AttributeCertificate
      FROM PKIXAttributeCertificate {iso(1) identified-organization(3)
                dod(6) internet(1) security(5) mechanisms(5) pkix(7)
                id-mod(0) id-mod-attribute-cert(12)}

-- OCSP - RFC 2560

   BasicOCSPResponse, ResponderID
      FROM OCSP {iso(1) identified-organization(3) dod(6) internet(1)
      security(5) mechanisms(5) pkix(7) id-mod(0) id-mod-ocsp(14)}

-- Time Stamp Protocol RFC 3161

   TimeStampToken
      FROM PKIXTSP
      {iso(1) identified-organization(3) dod(6) internet(1) security(5)
      mechanisms(5) pkix(7) id-mod(0) id-mod-tsp(13)}

;

-- Definitions of Object Identifier arcs used in the present document
-- ==================================================================

-- OID used referencing electronic signature mechanisms based on
-- the present document for use with the IDUP Independent Data Unit
-- Protection (IDUP) API (see annex Annex D)

   id-etsi-es-IDUP-Mechanism-v1 OBJECT IDENTIFIER ::=
   { itu-t(0) identified-organization(4) etsi(0)
     electronic-signature-standard (1733) part1 (1) idupMechanism (4)
     etsiESv1(1) }

-- Basic ES CMS Attributes Defined in the present document
-- =======================================================

-- OtherSigningCertificate - deprecated
    id-aa-ets-otherSigCert OBJECT IDENTIFIER ::=
    { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-aa(2) 19 }

   OtherSigningCertificate ::=  SEQUENCE {
      certs        SEQUENCE OF OtherCertID,
      policies     SEQUENCE OF PolicyInformation OPTIONAL
                   -- NOT USED IN THE PRESENT DOCUMENT
   }

   OtherCertID ::= SEQUENCE {
      otherCertHash            OtherHash,
      issuerSerial             IssuerSerial OPTIONAL }

   OtherHash ::= CHOICE {
       sha1Hash     OtherHashValue,  -- This contains a SHA-1 hash
       otherHash    OtherHashAlgAndValue}

-- Policy ES Attributes Defined in the present document
-- ====================================================

-- Mandatory Basic Electronic Signature Attributes as above,
-- plus in addition.

-- Signature Policy Identifier Signature-policy-identifier attribute

   id-aa-ets-sigPolicyId OBJECT IDENTIFIER ::=
   { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
   smime(16) id-aa(2) 15 }

   SignaturePolicy ::= CHOICE {
      signaturePolicyId          SignaturePolicyId,
      signaturePolicyImplied     SignaturePolicyImplied
                                 --  not used in this version
   }

   SignaturePolicyId ::= SEQUENCE {
      sigPolicyId        SigPolicyId,
      sigPolicyHash      SigPolicyHash,
      sigPolicyQualifiers   SEQUENCE SIZE (1..MAX) OF
                                   SigPolicyQualifierInfo OPTIONAL
   }

   SignaturePolicyImplied ::= NULL

   SigPolicyId ::= OBJECT IDENTIFIER
   SigPolicyHash ::= OtherHashAlgAndValue

   OtherHashAlgAndValue ::= SEQUENCE {
      hashAlgorithm   AlgorithmIdentifier,
      hashValue       OtherHashValue }

   OtherHashValue ::= OCTET STRING

   SigPolicyQualifierInfo ::= SEQUENCE {
      sigPolicyQualifierId  SigPolicyQualifierId,
      sigQualifier          ANY DEFINED BY sigPolicyQualifierId }

   SigPolicyQualifierId ::=   OBJECT IDENTIFIER

   id-spq-ets-uri OBJECT IDENTIFIER ::=
   { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
   smime(16) id-spq(5) 1 }

   SPuri ::= IA5String

   id-spq-ets-unotice OBJECT IDENTIFIER ::=
   { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
   smime(16) id-spq(5) 2 }

   SPUserNotice ::= SEQUENCE {
       noticeRef        NoticeReference OPTIONAL,
       explicitText     DisplayText OPTIONAL}

   NoticeReference ::= SEQUENCE {
      organization     DisplayText,
      noticeNumbers    SEQUENCE OF INTEGER }

   DisplayText ::= CHOICE {
      visibleString    VisibleString  (SIZE (1..200)),
      bmpString        BMPString      (SIZE (1..200)),

      utf8String       UTF8String     (SIZE (1..200)) }

-- Optional Electronic Signature Attributes

-- Commitment Type Commitment-type attribute

id-aa-ets-commitmentType OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 16}

   CommitmentTypeIndication ::= SEQUENCE {
     commitmentTypeId CommitmentTypeIdentifier,
     commitmentTypeQualifier SEQUENCE SIZE (1..MAX) OF
            CommitmentTypeQualifier OPTIONAL}

   CommitmentTypeIdentifier ::= OBJECT IDENTIFIER

   CommitmentTypeQualifier ::= SEQUENCE {
      commitmentTypeIdentifier CommitmentTypeIdentifier,
      qualifier   ANY DEFINED BY commitmentTypeIdentifier }

id-cti-ets-proofOfOrigin OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) cti(6) 1}

id-cti-ets-proofOfReceipt OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) cti(6) 2}

id-cti-ets-proofOfDelivery OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) cti(6) 3}

id-cti-ets-proofOfSender OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) cti(6) 4}

id-cti-ets-proofOfApproval OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) cti(6) 5}

id-cti-ets-proofOfCreation OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) cti(6) 6}

-- Signer Location Signer-location attribute

id-aa-ets-signerLocation OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 17}

   SignerLocation ::= SEQUENCE {
       -- at least one of the following shall be present
       countryName    [0]   DirectoryString OPTIONAL,
          -- As used to name a Country in X.500
       localityName   [1]   DirectoryString OPTIONAL,
           -- As used to name a locality in X.500
       postalAdddress [2]   PostalAddress OPTIONAL }

   PostalAddress ::= SEQUENCE SIZE(1..6) OF DirectoryString

-- Signer Attributes Signer-attributes attribute

id-aa-ets-signerAttr OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 18}
   SignerAttribute ::= SEQUENCE OF CHOICE {
      claimedAttributes   [0] ClaimedAttributes,
      certifiedAttributes [1] CertifiedAttributes }

   ClaimedAttributes ::= SEQUENCE OF Attribute

   CertifiedAttributes ::= AttributeCertificate
   -- as defined in RFC 3281 : 3281: see section Section 4.1

-- Content Timestamp Content-time-stamp attribute

id-aa-ets-contentTimestamp OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 20}

   ContentTimestamp ::= TimeStampToken

-- Signature Timestamp Signature-time-stamp attribute

id-aa-signatureTimeStampToken OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 14}

SignatureTimeStampToken ::= TimeStampToken

-- Complete Certificate Refs. Complete-certificate-references attribute

id-aa-ets-certificateRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 21}

CompleteCertificateRefs ::=  SEQUENCE OF OtherCertID

-- Complete Revocation Refs Complete-revocation-references attribute

id-aa-ets-revocationRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 22}

   CompleteRevocationRefs ::=  SEQUENCE OF CrlOcspRef

   CrlOcspRef ::= SEQUENCE {
      crlids          [0] CRLListID   OPTIONAL,
      ocspids         [1] OcspListID  OPTIONAL,
      otherRev        [2] OtherRevRefs OPTIONAL
   }

   CRLListID ::=  SEQUENCE {
      crls        SEQUENCE OF CrlValidatedID}
   CrlValidatedID ::=  SEQUENCE {
      crlHash                   OtherHash,
      crlIdentifier             CrlIdentifier OPTIONAL}

   CrlIdentifier ::= SEQUENCE {
      crlissuer                 Name,
      crlIssuedTime             UTCTime,
      crlNumber                 INTEGER OPTIONAL }

   OcspListID ::=  SEQUENCE {
       ocspResponses        SEQUENCE OF OcspResponsesID}

   OcspResponsesID ::=  SEQUENCE {
       ocspIdentifier              OcspIdentifier,
       ocspRepHash                 OtherHash    OPTIONAL
   }

   OcspIdentifier ::= SEQUENCE {
      ocspResponderID      ResponderID,
      -- As in OCSP response data
      producedAt           GeneralizedTime
       -- As in OCSP response data
   }

   OtherRevRefs ::= SEQUENCE {
       otherRevRefType   OtherRevRefType,
       otherRevRefs      ANY DEFINED BY otherRevRefType
    }

   OtherRevRefType ::= OBJECT IDENTIFIER

-- Certificate Values Certificate-values attribute

id-aa-ets-certValues OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 23}

   CertificateValues ::=  SEQUENCE OF Certificate

-- Certificate Revocation Values Certificate-revocation-values attribute

id-aa-ets-revocationValues OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 24}

   RevocationValues ::=  SEQUENCE {
      crlVals           [0] SEQUENCE OF CertificateList OPTIONAL,
      ocspVals          [1] SEQUENCE OF BasicOCSPResponse OPTIONAL,
      otherRevVals      [2] OtherRevVals OPTIONAL}
   OtherRevVals ::= SEQUENCE {
       otherRevValType   OtherRevValType,
       otherRevVals      ANY DEFINED BY otherRevValType
   }

   OtherRevValType ::= OBJECT IDENTIFIER

-- CAdES-C Timestamp time-stamp attribute

id-aa-ets-escTimeStamp OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 25}

ESCTimeStampToken ::= TimeStampToken

-- Time-Stamped Certificates and CRLs

id-aa-ets-certCRLTimestamp OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 26}

TimestampedCertsCRLs ::= TimeStampToken

-- Archive Timestamp time-stamp attribute
id-aa-ets-archiveTimestampV2  OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 48}

ArchiveTimeStampToken ::= TimeStampToken

-- Attribute certificate references Attribute-certificate-references attribute

id-aa-ets-attrCertificateRefs OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 44}

AttributeCertificateRefs ::=  SEQUENCE OF OtherCertID

-- Attribute revocation references Attribute-revocation-references attribute

id-aa-ets-attrRevocationRefs OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 45}

AttributeRevocationRefs ::=  SEQUENCE OF CrlOcspRef

END

A.2

A.2.  Signature format definitions using Format Definitions Using X.680 ASN.1 syntax Syntax

      NOTE: The ASN.1 module defined in section Annex A.1 has precedence over
      that defined in section Annex A.2 using syntax defined in ITU-T
      Recommendation X.680 (1997) [8] in the case of any conflict.

ETS-ElectronicSignatureFormats-ExplicitSyntax97 { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-mod(0)
eSignature-explicit97(29)}

DEFINITIONS EXPLICIT TAGS ::=

BEGIN

-- EXPORTS All -

IMPORTS

-- Cryptographic Message Syntax (CMS): RFC 3852

   ContentInfo, ContentType, id-data, id-signedData, SignedData,
   EncapsulatedContentInfo, SignerInfo,
   id-contentType, id-messageDigest, MessageDigest, id-signingTime,
   SigningTime, id-countersignature, Countersignature
      FROM CryptographicMessageSyntax2004
      { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
       smime(16) modules(0) cms-2004(24) }

-- ESS Defined attributes: ESS Update
-- RFC 5035 (Adding CertID Algorithm Agility)

   id-aa-signingCertificate, SigningCertificate, IssuerSerial,
   id-aa-contentReference, ContentReference, id-aa-contentIdentifier,
   ContentIdentifier, id-aa-signingCertificateV2
      FROM ExtendedSecurityServices-2006
        { iso(1) member-body(2) us(840) rsadsi(113549)
          pkcs(1) pkcs-9(9) smime(16) modules(0) id-mod-ess-2006(30) }

-- Internet X.509 Public Key Infrastructure
-- Certificate and CRL Profile: RFC 3280

   Certificate, AlgorithmIdentifier, CertificateList, Name,
   Attribute

      FROM PKIX1Explicit88
      {iso(1) identified-organization(3) dod(6) internet(1)
      security(5) mechanisms(5) pkix(7) id-mod(0)
      id-pkix1-explicit(18)}
   GeneralNames, GeneralName, PolicyInformation
      FROM PKIX1Implicit88 {iso(1) identified-organization(3) dod(6)
      internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
      id-pkix1-implicit(19)}

-- Internet Attribute Certificate Profile for Authorization - RFC 3281

   AttributeCertificate
      FROM PKIXAttributeCertificate {iso(1) identified-organization(3)
      dod(6) internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
      id-mod-attribute-cert(12)}

-- OCSP RFC 2560

   BasicOCSPResponse, ResponderID
      FROM OCSP {iso(1) identified-organization(3) dod(6) internet(1)
      security(5) mechanisms(5) pkix(7) id-mod(0) id-mod-ocsp(14)}

-- RFC 3161 Internet X.509 Public Key Infrastructure
-- Time-Stamp Protocol

   TimeStampToken
      FROM PKIXTSP {iso(1) identified-organization(3) dod(6) internet(1)
      security(5) mechanisms(5) pkix(7) id-mod(0) id-mod-tsp(13)}

-- X.520

    DirectoryString {}
        FROM SelectedAttributeTypes
         {joint-iso-itu-t ds(5) module(1) selectedAttributeTypes(5) 4}

;

-- Definitions of Object Identifier arcs used in the present document
-- ==================================================================

-- OID used referencing electronic signature mechanisms based
-- on the present document for use with the IDUP API (see annex Annex D)

id-etsi-es-IDUP-Mechanism-v1 OBJECT IDENTIFIER ::=
{ itu-t(0) identified-organization(4) etsi(0)
electronic-signature-standard (1733) part1 (1) idupMechanism (4)
etsiESv1(1) }

-- Basic ES Attributes Defined in the present document
-- ===================================================

-- CMS Attributes defined in the present document

-- OtherSigningCertificate - deprecated

id-aa-ets-otherSigCert OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
smime(16) id-aa(2) 19 }

   OtherSigningCertificate ::=  SEQUENCE {
      certs        SEQUENCE OF OtherCertID,
      policies     SEQUENCE OF PolicyInformation OPTIONAL
                   -- NOT USED IN THE PRESENT DOCUMENT
   }

   OtherCertID ::= SEQUENCE {
      otherCertHash            OtherHash,
      issuerSerial             IssuerSerial OPTIONAL }

   OtherHash ::= CHOICE {
      sha1Hash OtherHashValue,      -- This contains a SHA-1 hash
      otherHash OtherHashAlgAndValue}

-- Policy ES Attributes Defined in the present document
-- ====================================================

-- Mandatory Basic Electronic Signature Attributes, plus in addition.
-- Signature Policy Identifier

id-aa-ets-sigPolicyId OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
smime(16) id-aa(2) 15 }

   SignaturePolicy ::= CHOICE {
      signaturePolicyId          SignaturePolicyId,
      signaturePolicyImplied     SignaturePolicyImplied
                              -- not used in this version
   }

   SignaturePolicyId ::= SEQUENCE {
      sigPolicyId           SigPolicyId,
      sigPolicyHash         SigPolicyHash,
      sigPolicyQualifiers   SEQUENCE SIZE (1..MAX) OF
                                 SigPolicyQualifierInfo OPTIONAL
   }

   SignaturePolicyImplied ::= NULL
   SigPolicyId ::= OBJECT IDENTIFIER

   SigPolicyHash ::= OtherHashAlgAndValue

   OtherHashAlgAndValue ::= SEQUENCE {
      hashAlgorithm   AlgorithmIdentifier,
      hashValue       OtherHashValue
   }

   OtherHashValue ::= OCTET STRING

   SigPolicyQualifierInfo ::= SEQUENCE {
      sigPolicyQualifierId       SIG-POLICY-QUALIFIER.&id
      ({SupportedSigPolicyQualifiers}),
      qualifier               SIG-POLICY-QUALIFIER.&Qualifier
                                ({SupportedSigPolicyQualifiers}
                                    {@sigPolicyQualifierId})OPTIONAL }

   SupportedSigPolicyQualifiers SIG-POLICY-QUALIFIER ::=
       { noticeToUser | pointerToSigPolSpec }

   SIG-POLICY-QUALIFIER ::= CLASS {
      &id             OBJECT IDENTIFIER UNIQUE,
      &Qualifier      OPTIONAL }
   WITH SYNTAX {
      SIG-POLICY-QUALIFIER-ID     &id
      [SIG-QUALIFIER-TYPE &Qualifier] }

   noticeToUser SIG-POLICY-QUALIFIER ::= {
      SIG-POLICY-QUALIFIER-ID id-spq-ets-unotice SIG-QUALIFIER-TYPE
      SPUserNotice }

   pointerToSigPolSpec SIG-POLICY-QUALIFIER ::= {
      SIG-POLICY-QUALIFIER-ID id-spq-ets-uri SIG-QUALIFIER-TYPE SPuri }

   id-spq-ets-uri OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-spq(5) 1 }

   SPuri ::= IA5String

   id-spq-ets-unotice OBJECT IDENTIFIER ::= { iso(1)
   member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
   smime(16) id-spq(5) 2 }

   SPUserNotice ::= SEQUENCE {
        noticeRef        NoticeReference OPTIONAL,
        explicitText     DisplayText OPTIONAL}
   NoticeReference ::= SEQUENCE {
        organization     DisplayText,
        noticeNumbers    SEQUENCE OF INTEGER }

   DisplayText ::= CHOICE {
        visibleString    VisibleString  (SIZE (1..200)),
        bmpString        BMPString      (SIZE (1..200)),
        utf8String       UTF8String     (SIZE (1..200)) }

-- Optional Electronic Signature Attributes

-- Commitment Type

  id-aa-ets-commitmentType OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 16}

   CommitmentTypeIndication ::= SEQUENCE {
      commitmentTypeId CommitmentTypeIdentifier,
      commitmentTypeQualifier SEQUENCE SIZE (1..MAX) OF
         CommitmentTypeQualifier OPTIONAL}

   CommitmentTypeIdentifier ::= OBJECT IDENTIFIER

   CommitmentTypeQualifier ::= SEQUENCE {
      commitmentQualifierId   COMMITMENT-QUALIFIER.&id,
      qualifier               COMMITMENT-QUALIFIER.&Qualifier OPTIONAL }

   COMMITMENT-QUALIFIER ::= CLASS {
      &id             OBJECT IDENTIFIER UNIQUE,
      &Qualifier      OPTIONAL }
   WITH SYNTAX {
      COMMITMENT-QUALIFIER-ID     &id
      [COMMITMENT-TYPE &Qualifier] }

id-cti-ets-proofOfOrigin OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) cti(6) 1}

id-cti-ets-proofOfReceipt OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) cti(6) 2}

id-cti-ets-proofOfDelivery OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
cti(6) 3}

id-cti-ets-proofOfSender OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) cti(6) 4}

id-cti-ets-proofOfApproval OBJECT IDENTIFIER ::=

{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) cti(6) 5}

id-cti-ets-proofOfCreation OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) cti(6) 6}

-- Signer Location

id-aa-ets-signerLocation OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 17}

   SignerLocation ::= SEQUENCE {
   -- at least one of the following shall be present
      countryName [0] DirectoryString{maxSize} OPTIONAL,
         -- as used to name a Country in X.520
      localityName [1] DirectoryString{maxSize} OPTIONAL,
         -- as used to name a locality in X.520
      postalAdddress [2] PostalAddress OPTIONAL }

   PostalAddress ::= SEQUENCE SIZE(1..6) OF DirectoryString{maxSize}
                    -- maxSize parametrization as specified in X.683

-- Signer Attributes

id-aa-ets-signerAttr OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 18}

   SignerAttribute ::= SEQUENCE OF CHOICE {
      claimedAttributes   [0] ClaimedAttributes,
      certifiedAttributes [1] CertifiedAttributes }

   ClaimedAttributes ::= SEQUENCE OF Attribute

   CertifiedAttributes ::= AttributeCertificate
   -- as defined in RFC 3281 : 3281: see section Section 4.1

-- Content Timestamp

id-aa-ets-contentTimestamp OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 20}
   ContentTimestamp ::= TimeStampToken

-- Signature Timestamp

id-aa-signatureTimeStampToken OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)

smime(16) id-aa(2) 14}

   SignatureTimeStampToken ::= TimeStampToken

-- Complete Certificate Refs.

id-aa-ets-certificateRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 21}

CompleteCertificateRefs ::=  SEQUENCE OF OtherCertID

-- Complete Revocation Refs

id-aa-ets-revocationRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 22}

   CompleteRevocationRefs ::=  SEQUENCE OF CrlOcspRef

   CrlOcspRef ::= SEQUENCE {
      crlids          [0] CRLListID   OPTIONAL,
      ocspids         [1] OcspListID  OPTIONAL,
      otherRev        [2] OtherRevRefs OPTIONAL
   }

   CRLListID ::=  SEQUENCE {
      crls        SEQUENCE OF CrlValidatedID
   }

   CrlValidatedID ::=  SEQUENCE {
      crlHash                   OtherHash,
      crlIdentifier             CrlIdentifier OPTIONAL   }

   CrlIdentifier ::= SEQUENCE {
       crlissuer                 Name,
       crlIssuedTime             UTCTime,
       crlNumber                 INTEGER OPTIONAL
   }

   OcspListID ::=  SEQUENCE {
       ocspResponses        SEQUENCE OF OcspResponsesID
   }

   OcspResponsesID ::=  SEQUENCE {
       ocspIdentifier              OcspIdentifier,

       ocspRepHash                 OtherHash    OPTIONAL
   }
   OcspIdentifier ::= SEQUENCE {
      ocspResponderID      ResponderID,
      -- As in OCSP response data
      producedAt           GeneralizedTime
      -- As in OCSP response data
   }

   OtherRevRefs ::= SEQUENCE {
      otherRevRefType   OTHER-REVOCATION-REF.&id,
      otherRevRefs      SEQUENCE OF OTHER-REVOCATION-REF.&Type
   }

OTHER-REVOCATION-REF ::= CLASS {
      &Type,
      &id   OBJECT IDENTIFIER UNIQUE }
   WITH SYNTAX {
      WITH SYNTAX &Type ID &id }

-- Certificate Values

id-aa-ets-certValues OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 23}

CertificateValues ::=  SEQUENCE OF Certificate

-- Certificate Revocation Values

id-aa-ets-revocationValues OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 24}

   RevocationValues ::=  SEQUENCE {
     crlVals           [0] SEQUENCE OF CertificateList OPTIONAL,
     ocspVals          [1] SEQUENCE OF BasicOCSPResponse OPTIONAL,

     otherRevVals      [2] OtherRevVals OPTIONAL
   }

   OtherRevVals ::= SEQUENCE {
      otherRevValType   OTHER-REVOCATION-VAL.&id,
      otherRevVals      SEQUENCE OF OTHER-REVOCATION-REF.&Type
   }

  OTHER-REVOCATION-VAL ::= CLASS {
      &Type,
      &id   OBJECT IDENTIFIER UNIQUE }
   WITH SYNTAX {
      WITH SYNTAX &Type ID &id }

-- CAdES-C Timestamp
id-aa-ets-escTimeStamp OBJECT IDENTIFIER ::= { iso(1) member-body(2)
us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 25}

   ESCTimeStampToken ::= TimeStampToken

-- Time-Stamped Certificates and CRLs

id-aa-ets-certCRLTimestamp OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 26}

   TimestampedCertsCRLs ::= TimeStampToken

-- Archive Timestamp

id-aa-ets-archiveTimestampV2  OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 48}

   ArchiveTimeStampToken ::= TimeStampToken

-- Attribute certificate references

id-aa-ets-attrCertificateRefs OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 44}

   AttributeCertificateRefs ::=  SEQUENCE OF OtherCertID

-- Attribute revocation references

id-aa-ets-attrRevocationRefs OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) id-aa(2) 45}

   AttributeRevocationRefs ::=  SEQUENCE OF CrlOcspRef

END

Annex B (informative): Extended forms Forms of Electronic Signatures

   Section 4 provides on an overview of the various formats of electronic
   signatures included in the present document.  This annex lists the
   attributes that need to be present in the various extended electronic
   signature formats and provide provides example validation sequences using the
   extended formats.

B.1

B.1.  Extended forms Forms of validation data Validation Data

   The complete Complete validation data (CAdES-C) described in section Section 4.3 and
   illustrated in figure Figure 3 may be extended to create Electronic Signatures electronic
   signatures with extended validation data.  Some Electronic Signatures electronic signature
   forms that include extended validation are explained below.

   An X-Long electronic signature (CAdES-X Long) is when the CAdES-C with the
   values of the certificates and revocation information are added to the CAdES-C. information.

   This form of Electronic Signature electronic signature can be useful when the verifier
   does not have direct access to the following information:

      - the signer's certificate;

      - all the CA certificates that make up the full certification
        path;

      - all the associated revocation status information, as referenced
        in the CAdES-C.

   In some situations situations, additional time-stamps may be created and added
   to the Electronic Signatures as additional attributes.  For example:

      - time-stamping all the validation data as held with the ES (CAdES-
     C), (-
        CAdES-C), this eXtended validation data is called a CAdES-X Type
        1; or

      - time-stamping individual reference data as used for complete
        validation.  This form of eXtended validation data is called an
        CAdES-X Type 2.

      NOTE 1: The advantages/drawbacks for CAdES-X Type 1 and CAdES-X
      Type 2 are discussed in section Annex C.4.4.

   The above time-stamp forms can be useful when it is required to
   counter the risk that any CA keys used in the certificate chain may
   be compromised.

   A combination of the two formats above may be used.  This form of
   eXtended validation data is called an ES X-Long Type 1 or CAdES-X
   Long Type 2.  This form of Electronic Signature electronic signature can be useful when
   the verifier needs both the values and proof of when the validation
   data existed.

      NOTE 2: The advantages/drawbacks for CAdES-X long Type 1 and
      CAdES-X long Type 2 are discussed in section Annex C.4.6.

B.1.1

B.1.1.  CAdES-X Long

   An Electronic Signature electronic signature with the additional validation data forming
   the CAdES-X Long form (CAdES-X-Long)) (CAdES-X-Long) is illustrated in figure Figure B.1 and
   comprises the following:

      - CAdES-BES or CAdES-EPES CAdES-EPES, as defined in sections Sections 4.3 , 5.7 5.7, or
        5.8;

      - complete-certificate-references attribute attribute, as defined in section Section
        6.2.1;

      - complete-revocation-references attribute attribute, as defined in section Section
        6.2.2.

   The following attributes are required if a TSP is not providing a time-
mark
   time-mark of the ES:

      - signature-time-stamp attribute attribute, as defined in section Section 6.1.1.

   The following attributes are required if the full certificate values
   and revocation values are not already included in the CAdES-BES or
   CAdES-EPES:

      - certificate-values attribute attribute, as defined in section Section 6.3.3;

      - revocation-values attribute, as defined in section Section 6.3.4.

   If attributes certificates are used used, then the following attributes
   may be present:

      - attribute-certificate-references attribute attribute, defined in section Section
        6.2.3;

      - attribute-revocation-references attribute attribute, as defined in section Section
        6.2.4.

   Other unsigned attributes may be present, but are not required.

      NOTE: Attribute certificate and revocation references are only
      present if a user attribute certificate is present in the
      electronic signature, signature; see sections Sections 6.2.2 and 6.2.3.

+---------------------- CAdES-X-Long --------------------------------+
|+-------------------------------------- CAdES-C ---+                |
||                                     +----------+ | +-------------+|
||+----- CAdES-BES or CAdES-EPES ----+ |Timestamp | | |             ||
|||                                  | |over      | | | Complete    ||
|||+---------++----------++---------+| |digital   | | | certificate ||
||||         ||          ||         || |signature | | |    and      ||
||||Signer's ||  Signed  ||Digital  || |          | | | revocation  ||
||||Document ||Attributes||signature|| |Optional  | | |    data     ||
||||         ||          ||         || |when      | | |             ||
|||+---------++----------++---------+| |timemarked| | |             ||
||+----------------------------------+ +----------+ | |             ||
||                                     +-----------+| +-------------+|
||                                     |Complete   ||                |
||                                     |certificate||                |
||                                     |and        ||                |
||                                     |revocation ||                |
||                                     |references ||                |
||                                     +-----------+|                |
|+--------------------------------------------------+                |
|                                                                    |
+--------------------------------------------------------------------+

             Figure B.1 : B.1: Illustration of CAdES-X-Long

B.1.2

B.1.2.  CAdES-X Type 1

   An Electronic Signature electronic signature with the additional validation data forming
   the eXtended Validation Data validation data - Type 1 X is illustrated in figure Figure B.2
   and comprises the following:

      - the CAdES-BES or CAdES-EPES CAdES-EPES, as defined in sections Sections 4.2, 5.7 5.7, or
        5.8;

      - complete-certificate-references attribute attribute, as defined in section Section
        6.2.1;

      - complete-revocation-references attribute attribute, as defined in section Section
        6.2.2;

      - CAdES-C-Timestamp attribute, as defined in section Section 6.3.5.

   The following attributes are required if a TSP is not providing a time-
mark
   time-mark of the ES:

      - signature-time-stamp attribute attribute, as defined in section Section 6.1.1.

   If attributes certificates are used used, then the following attributes
   may be present:

      - attribute-certificate-references attribute attribute, defined in section Section
        6.2.3;

      - attribute-revocation-references attribute attribute, as defined in section Section
        6.2.4.

   Other unsigned attributes may be present, but are not required.

+------------------------ CAdES-X-Type 1 ----------------------------+
|+---------------------------------- CAdES-C ------+                 |
||                                    +----------+ | +-------------+ |
||+--- CAdES-BES or CAdES-EPES ------+|Timestamp | | |             | |
|||                                  ||over      | | |             | |
|||+---------++----------++---------+||digital   | | |             | |
||||Signer's ||  Signed  || Digital |||signature | | | Timestamp   | |
||||Document ||Attributes||signature|||          | | |    over     | |
||||         ||          ||         |||Optional  | | |   CAdES-C   | |
|||+---------++----------++---------+||when      | | |             | |
||+----------------------------------+|timemarked| | |             | |
||                                    +----------+ | |             | |
||                                    +-----------+| +-------------+ |
||                                    |Complete   ||                 |
||                                    |certificate||                 |
||                                    |   and     ||                 |
||                                    |revocation ||                 |
||                                    |references ||                 |
||                                    +-----------+|                 |
|+-------------------------------------------------+                 |
|                                                                    |
+--------------------------------------------------------------------+

               Figure B.2 : B.2: Illustration of CAdES-X Type 1

B.1.3

B.1.3.  CAdES-X Type 2

   An Electronic Signature electronic signature with the additional validation data forming
   the eXtended Validation Data - Type 2 X is illustrated in figure B.3. Figure B.3
   and comprises the following:

      - CAdES-BES or CAdES-EPES CAdES-EPES, as defined in sections Sections 4.2, 5.7 5.7, or
        5.8;

      - complete-certificate-references attribute attribute, as defined in section Section
        6.2.1;

      - complete-revocation-references attribute attribute, as defined in section Section
        6.2.2;

      - time-stamped-certs-crls-references attribute attribute, as defined in section
        Section 6.3.6.

   The following attributes are required if a TSP is not providing a time-
mark
   time-mark of the ES:

      - signature-time-stamp attribute attribute, as defined in section Section 6.1.1.

   If attributes certificates are used used, then the following attributes
   may be present:

      - attribute-certificate-references attribute attribute, defined in section Section
        6.2.3;

      - attribute-revocation-references attribute attribute, as defined in section Section
        6.2.4.

   Other unsigned attributes may be present, but are not required.

+----------------------- CAdES-X-Type 2 -----------------------------+
|+-------------------------------------- CAdES-C --+                 |
||                                    +----------+ |                 |
||+-- CAdES-BES or CAdES-EPES -------+|Timestamp | |                 |
|||                                  ||over      | |                 |
|||+---------++----------++---------+||digital   | | +-------------+ |
||||         ||          ||         |||Signature | | | Timestamp   | |
||||Signer's ||  Signed  || Digital |||          | | | only over   | |
||||Document ||Attributes||signature|||Optional  | | | Complete    | |
||||         ||          ||         |||when      | | | certificate | |
|||+---------++----------++---------+||Timemarked| | |    and      | |
||+----------------------------------++----------+ | | revocation  | |
||                                    +-----------+| | references  | |
||                                    |Complete   || +-------------+ |
||                                    |certificate||                 |
||                                    |and        ||                 |
||                                    |revocation ||                 |
||                                    |references ||                 |
||                                    +-----------+|                 |
|+-------------------------------------------------+                 |
|                                                                    |
+--------------------------------------------------------------------+

               Figure B.3 : B.3: Illustration of CAdES-X Type 2

B.1.4

B.1.4.  CAdES-X Long Type 1 and CAdES-X Long Type 2

   An Electronic Signature electronic signature with the additional validation data forming
   the CAdES-X Long Type 1 and CAdES-X Long Type 2 is illustrated in
figure
   Figure B.4 and comprises the following:

      - CAdES-BES or CAdES-EPES CAdES-EPES, as defined in sections Sections 4.3, 5.7 5.7, or
        5.8;

      - complete-certificate-references attribute attribute, as defined in section Section
        6.2.1;

      - complete-revocation-references attribute attribute, as defined in section Section
        6.2.2;

   The following attributes are required if a TSP is not providing a time-
mark
   time-mark of the ES:

      - signature-time-stamp attribute attribute, as defined in section Section 6.1.1.

   The following attributes are required if the full certificate values
   and revocation values are not already included in the CAdES-BES or
   CAdES-EPES:

      - certificate-values attribute attribute, as defined in section Section 6.3.3;

      - revocation-values attribute, as defined in section Section 6.3.4.

   If attributes certificates are used used, then the following attributes
   may be present:

      - attribute-certificate-references attribute attribute, defined in section Section
        6.2.3;

      - attribute-revocation-references attribute attribute, as defined in section Section
        6.2.4.

   Plus one of the following attributes is required:

      - CAdES-C-Timestamp attribute, as defined in section Section 6.3.5;

      - time-stamped-certs-crls-references attribute attribute, as defined in section
        Section 6.3.6.

   Other unsigned attributes may be present, but are not required.

   +---------------------- CAdES-X-Type 1 or 2 ------------------------+
   |                                                   +--------------+|
   |+-------------------------------------- CAdES-C --+|+------------+||
   ||                                    +----------+ ||| Timestamp  |||
   ||+-- CAdES-BES or CAdES-EPES -------+|Timestamp | |||    over    |||
   |||                                  ||over      | |||  CAdES-C   |||
   |||+---------++----------++---------+||digital   | | +------------+ |
   ||||         ||          ||         |||signature | ||      or      ||
   ||||Signer's ||  Signed  || Digital |||          | ||+------------+||
   ||||Document ||Attributes||Signature|||Optional  | ||| Timestamp  |||
   ||||         ||          ||         |||when      | ||| only over  |||
   |||+---------++----------++---------+||timemarked| ||| complete   |||
   ||+----------------------------------++----------+ ||| certificate|||
   ||                                                 |||    and     |||
   ||                                    +-----------+||| revocation |||
   ||                                    |Complete   |||| references |||
   ||                                    |certificate|||+------------+||
   ||                                    |and        ||+--------------+|
   ||                                    |revocation || +------------+ |
   ||                                    |references || |Complete    | |
   ||                                    +-----------+| |certificate | |
   |+-------------------------------------------------+ |   and      | |
   |                                                    |revocation  | |
   |                                                    |  values    | |
   |                                                    +------------+ |
   +-------------------------------------------------------------------+

             Figure B.4 : B.4: Illustration of CAdES-X Long Type 1
                         and CAdES-X Long Type 2

B.2 Timestamp extensions

B.2.  Time-Stamp Extensions

   Each instance of the time-stamp attribute may include include, as unsigned
   attributes in the signedData of the timestamp time-stamp, the following attribute
   attributes related to the TSU:

      - complete-certificate-references attribute of the TSU TSU, as defined
        in section Section 6.2.1;

      - complete-revocation-references attribute of the TSU TSU, as defined
        in
     section Section 6.2.2;

      - certificate-values attribute; attribute of the TSU TSU, as defined in section Section
        6.3.3;

      - revocation-values attribute, attribute of the TSU TSU, as defined in section Section
        6.3.4.

   Other unsigned attributes may be present, but are not required.

B.3

B.3.  Archive validation data Validation Data (CAdES-A)

   Before the algorithms, keys keys, and other cryptographic data used at the
   time the CAdES-C was built become weak and the cryptographic
   functions become vulnerable, or the certificates supporting previous
   time-stamps
expires, expire, the signed data, the CAdES-C CAdES-C, and any additional
   information
(i.e. (i.e., any CAdES-X) should be time-stamped.  If possible possible,
   this should use stronger algorithms (or longer key lengths) than in
   the original time-
stamp. time-stamp.  This additional data and time-stamp is
   called Archive
Validation Data validation data required for the ES Archive format
   (CAdES-A).  The Time-stamping process may be repeated every time the
   protection used to time-stamp a previous CAdES-A becomes weak.  An  A
   CAdES-A may thus bear multiple embedded time stamps. time-stamps.

   An example of an Electronic Signature electronic signature (ES), with the additional
   validation data for the CAdES-C and CAdES-X forming the CAdES-A is
   illustrated in figure Figure B.5.

+--------------------------- CAdES-A---------------------------------+
|+----------------------------------------------------+              |
||                                    +--------------+| +----------+ |
||+--------------------- CAdES-C ----+|+------------+|| |          | |
|||                     +----------+ ||| Timestamp  ||| |          | |
|||+-- CAdES-BES ------+|Timestamp | |||   over     ||| |          | |
||||   or CAdES-EPES   ||over      | |||  CAdES-C   ||| |  Archive | |
||||                   ||digital   | ||+------------+|| |          | |
||||                   ||signature | ||     or       || |Timestamp | |
||||                   ||          | ||+------------+|| |          | |
||||                   ||optional  | ||| Timestamp  ||| |          | |
||||                   ||when      | ||| only over  ||| |          | |
||||                   ||timemarked| ||| complete   ||| |          | |
|||+-------------------++----------+ ||| certificate||| +----------+ |
|||                                  |||    and     |||              |
|||                   +-------------+||| revocation |||              |
|||                   | Complete    |||| references |||              |
|||                   | certificate |||+------------+||              |
|||                   | and         ||+--------------+|              |
|||                   | revocation  || +------------+ |              |
|||                   | references  || |Complete    | |              |
|||                   +-------------+| |certificate | |              |
||+----------------------------------+ |   and      | |              |
||                                     |revocation  | |              |
||                                     |  values    | |              |
||                                     +------------+ |              |
|+----------------------------------------------------+              |
+--------------------------------------------------------------------+

                    Figure B.5 : B.5: Illustration of CAdES-A

   The CAdES-A comprises the following elements:

      - the CAdES-BES or CAdES-EPES CAdES-EPES, including their signed and unsigned
        attributes;

      - complete-certificate-references attribute attribute, as defined in section Section
        6.2.1;

      - complete-revocation-references attribute attribute, as defined in section Section
        6.2.2.

   The following attributes are required if a TSP is not providing a time-
mark
   time-mark of the ES:

      - signature-time-stamp attribute attribute, as defined in section Section 6.1.1.

   If attributes certificates are used used, then the following attributes
   may be present:

      - attribute-certificate-references attribute attribute, defined in section Section
        6.2.3;

      - attribute-revocation-references attribute attribute, as defined in section Section
        6.2.4.

   The following attributes are required if the full certificate values
   and revocation values are not already included in the CAdES-BES or
   CAdES-EPES:

      - certificate-values attribute attribute, as defined in section Section 6.3.3;

      - revocation-values attribute attribute, as defined in section Section 6.3.4.

   At least one of the following two attributes is required:

      - CAdES-C-Timestamp attribute attribute, as defined in section Section 6.3.5;

      - time-stamped-certs-crls-references attribute attribute, as defined in section
        Section 6.3.6.

   The following attribute is required:

      - archive-time-stamp attributes attributes, defined in section Section 6.4.1.

   Several instances of the archive-time-stamp attribute may occur with
   an electronic signature signature, both over time and from different TSUs.  The time-
stamp
   time-stamp should be created using stronger algorithms (or longer key
   lengths) than in the original electronic signatures or time-stamps.

   Other unsigned attributes of the ES may be present, but are not
   required.

   The archive timestamp archive-time-stamp will itself contain the certificate and
   revocation information required to validate the archive timestamp, archive-time-stamp;
   this may include the following unsigned attributes:

      - complete-certificate-references attribute of the TSU TSU, as defined
        in section Section 6.2.1;

      - complete-revocation-references attribute of the TSU TSU, as defined
        in
     section Section 6.2.2;

      - certificate-values attribute of the TSU TSU, as defined in section Section
        6.3.3;
      - revocation-values attribute of the TSU TSU, as defined in section Section
        6.3.4.

   Other unsigned attributes may be present, but are not required.

B.4

B.4.  Example validation sequence Validation Sequence

   As described earlier earlier, the signer or initial verifier may collect all
   the additional data that forms the electronic signature.  Figure B.6, B.6
   and the subsequent description, describes description describe how the validation process
   may build up a complete electronic signature over time.

+------------------------------------------ CAdES-C -------------+
|+------------------------------- CAdES-T ------+                |
||+-------------- CAdES ------------+           |                |
|||+--------------------++---------+|+---------+|  +-----------+ |
|||| ________           ||         |||Timestamp||  |Complete   | |
|||||Sign.Pol|          ||Digital  |||over     ||  |certificate| |
|||||  Id.   | Signed   ||signature|||digital  ||  |   and     | |
||||| option.|attributes||         |||signature||  |revocation | |
|||||________|          |+---------+|+---------+|  |references | |
|||+--------------------+           |    ^      |  +-----------+ |
||+---------------------------------+    |      |        ^       |
||                     1 |              /       |        |       |
|+---------------------- | ------------/--------+        |       |
+----------------------- | ---------- / --------------- / -------+
                         |           /2    ----3--------
      +----------+       |          /     /
      |          |       v         /     |
      | Signer's |      +---------------------+     +-------------+
      | document |----->| Validation Process  |---->|- Valid      |
      |          |      +---------------------+ 4   |- Invalid    |
      +----------+           |  ^       |  ^        |- Validation |
                             v  |       v  |        |  Incomplete |
                         +---------+ +--------+     +-------------+
                         |Signature| |Trusted |
                         | Policy  | |Service |
                         | Issuer  | |Provider|
                         +---------+ +--------+

       Figure B.6 : B.6: Illustration of a CAdES validation sequence

   Soon after receiving the Electronic Signature electronic signature (CAdES) from the signer
   (1), the digital signature value may be checked; the validation
   process shall at least add a time-stamp (2), unless the signer has
   provided one which is trusted by the verifier.  The validation
   process may also validate the electronic signature, signature using additional
   data (e.g. (e.g., certificates, CRL, etc.) provided by trusted service providers. Trusted Service
   Providers.  When applicable, the validation process will also need to
   conform to the requirements specified in a signature policy.  If the
   validation process is validation incomplete, then the output from
   this stage is the CAdES-T.

   To ascertain the validity status as Valid or Invalid and communicate
   that to the user (4) (4), all the additional data required to validate
   the
CAdES-C, CAdES-C must be available (e.g. (e.g., the complete certificate and
   revocation information).

   Once the data needed to complete validation data references (CAdES-C)
   is available available, then the validation process should:

      - obtain all the necessary additional certificate certificates and revocation
        status information;

      - complete all the validation checks on the ES, ES using the complete
        certificate and revocation information (if a time-stamp is not
        already present, this may be added at the same stage stage, combining
        the CAdES-T and CAdES-C process); processes);

      - record the complete certificate and revocation references (3);

      - indicate the validity status to the user (4).

   At the same time as the validation process creates the CAdES-C, the
   validation process may provide and/or record the values of
   certificates and revocation status information used in CAdES-C, CAdES-C (5).
   The end result is called the CAdES-X
Long (5). Long.

   This is illustrated in figure Figure B.7.

+----------------------------------------------------- CAdES-X Long -+
|+------------------------------- CAdES-C -------------+             |
||+-------------- CAdES ------------+                  |             |
|||+--------------------++---------+|+---------+       |+-----------+|
|||| ________           ||         |||Timestamp|       ||Complete   ||
|||||Sign.Pol|          ||Digital  |||over     |       ||certificate||
|||||  Id.   | Signed   ||signature|||digital  |       ||   and     ||
||||| option.|attributes||         |||signature|       ||revocation ||
|||||________|          ||         ||+---------+       ||  values   ||
|||+--------------------++---------+|  ^  +-----------+|+-----------+|
||+---------------------------------+  |  |Complete   ||      ^      |
||                         |           |  |certificate||      |      |
||                         |         2 |  |   and     ||      |      |
||                         |           |  |revocation ||      |      |
||                         |           |  |references ||      |      |
||                       1 |          /   +-----------+|      |      |
|+------------------------ | ------- / --------- ^-----+     /       |
+------------------------- | ------ / ---------- |--------- / -------+
                           |       /      ----- /  ------- /
      +----------+         |      /      /  3     /   5
      |          |         v     |      |        |
      | Signer's |      +--------------------+      +-----------+
      | document |----->| Validation Process |----->| - Valid   |
      |          |      +--------------------+  4   | - Invalid |
      +----------+          |  ^       |  ^         +-----------+
                            v  |       v  |
                        +---------+ +--------+
                        |Signature| |Trusted |
                        | Policy  | |Service |
                        | Issuer  | |Provider|
                        +---------+ +--------+

          Figure B.7 : B.7: Illustration of a CAdES validation sequence
                      with CAdES-X Long

   When the validation process creates the CAdES-C CAdES-C, it may also create
   extended forms of validation data.

   A first alternative is to time-stamp all data forming the CAdES-X
   Type
1 (6). 1.

   This is illustrated in figure Figure B.8.

+------------------------------------------------ CAdES-X Type 1 -----+
|+------------------------------- CAdES-C ------------------+         |
||+-------------- CAdES ------------+                       |         |
|||+--------------------++---------+|+---------++----------+|+-------+|
|||| ________           ||         |||Timestamp|| Complete |||       ||
|||||Sign.Pol|          ||Digital  |||over     ||  cert.   |||Time-  ||
|||||  Id.   | Signed   ||signature|||digital  ||   and    |||stamp  ||
||||| option.|attributes||         |||signature||  revoc.  ||| over  ||
|||||________|          |+---------+|+---------+|references|||CAdES-C||
|||+--------------------+           |    ^      |          |||       ||
||+---------------------------------+    |      +----------+|+-------+|
||                         |             |            ^     |    ^    |
||                       1 |            /             |     |    |    |
|+------------------------ | --------- / ----------- / -----+    |    |
+------------------------- | -------- / ----------- / --------- / ----+
                           |       2 /     ---3----            /
      +----------+         |        /    /   -----------5------
      |          |         v       |    |  /
      | Signer's |      +--------------------+       +-----------+
      | document |----->| Validation Process |-----> | - Valid   |
      |          |      +--------------------+  4    | - Invalid |
      +----------+          |  ^       |  ^          +-----------+
                            v  |       v  |
                        +---------+ +--------+
                        |Signature| |Trusted |
                        | Policy  | |Service |
                        | Issuer  | |Provider|
                        +---------+ +--------+

    Figure B.8  : B.8: Illustration of CAdES with eXtended Validation Data validation data
                CAdES-X Type 1

   Another alternative is to time-stamp the certificate and revocation
   information references used to validate the electronic signature (but
   not the signature) (6'); this (6).  The end result is called CAdES-X Type 2.

   This is illustrated in figure Figure B.9.

+-------------------------------------------- CAdES-X Type 2 --------+
|+------------------------------- CAdES-C -------------+             |
||+-------------- CAdES ------------+                  |             |
|||+--------------------++---------+|+---------+       |+-----------+|
|||| ________           ||         |||Timestamp|       ||Timestamp  ||
|||||Sign.Pol|          ||         |||over     |       ||   over    ||
|||||  Id.   | Signed   ||Digital  |||digital  |       ||complete   ||
||||| option.|attributes||signature|||signature|       ||certificate||
|||||________|          ||         |||         |       ||           ||
|||+--------------------++---------+|+---------+       ||   and     ||
||+---------------------------------+  ^  +-----------+||revocation ||
||                         |           |  |Complete   |||references ||
||                         |           |  |certificate||+-----------+|
||                         |           |  |   and     ||     ^       |
||                       1 |         2 |  |revocation ||     |       |
||                         |           |  |references ||     |       |
||                         |           |  +-----------+|     |       |
|+------------------------ | --------- | --- ^ --------+     |       |
|                          |           |   3 |              /        |
|                          |           |    /    ----------          |
|                          |          /    /    /   5   6                |
|                          |         /    /    /                     |
|                          |        /    /    /                      |
+------------------------- | ----- | -- | -- / ----------------------+
                           |       |    |   |
                           v       |    |   |
                        +--------------------+      +-----------+
                        | Validation Process |----->| - Valid   |
                        +--------------------+  4   | - Invalid |
                            |  ^       |  ^         +-----------+
                            v  |       v  |
                        +---------+ +--------+
                        |Signature| |Trusted |
                        | Policy  | |Service |
                        | Issuer  | |Provider|
                        +---------+ +--------+

   Figure B.9: Illustration of CAdES with eXtended Validation Data validation data
               CAdES-X Type 2

   Before the algorithms used in any of the electronic signatures become
   or are likely, likely to be compromised or rendered vulnerable in the future,
   it may be necessary to time-stamp the entire electronic signature,
   including all the values of the validation and user data as an ES
   with Archive Validation Data validation data (CAdES-A) (7).

An

   A CAdES-A is illustrated in figure Figure B.10.

+----------------------------- CAdES-A ---------------------------+
|                                                                 |
|  +-- CAdES-X Long Type 1 or 2  ----------+                      |
|  |                                       |   +------------+     |
|  |                                       |   |            |     |
|  |                                       |   |  Archive   |     |
|  |                                       |   | Time-stamp |     |
|  |                                       |   |            |     |
|  |                                       |   +------------+     |
|  +---------------------------------------+         ^            |
|  +----------+          ^   ^   ^   ^               |            |
|  |          |          |   |   |   |              /             |
|  | Signers' |          |   |   |   |             /              |
|  | Document |\         |   |   |   |            /               |
|  |          | \ 1    2 | 3 | 5 | 6 |         7 /                |
|  +----------+  \       |   |   |   |          /                 |
|                 \      |   |   |   |         /                  |
+----------------- \ --- | - | - | - | ------ / ------------------+
                    \    |   |   |   |       |
                     |   |   |   |   |       |
                     |   |   |   |   |       |
                     v   v   |   |   |       |
                 +-----------------------------+      +-----------+
                 |      Validation Process     |----->| - Valid   |
                 +-----------------------------+  4   | - Invalid |
                     |  ^       |  ^                  +-----------+
                     v  |       v  |
                 +---------+ +--------+
                 |Signature| |Trusted |
                 | Policy  | |Service |
                 | Issuer  | |Provider|
                 +---------+ +--------+

                 Figure B.10: Illustration of CAdES-A

B.5

B.5.  Additional optional features Optional Features

   The present document also defines additional optional features to:

      - indicate a commitment type being made by the signer;

      - indicate the claimed time when the signature was done;

      - indicate the claimed location of the signer;

      - indicate the claimed or certified role under which a signature
        was created;
      - support counter signatures;

      - support multiple signatures.

Annex C (informative):General description (informative): General Description

   This annex explains some of the concepts and provides the rational rationale
   for normative parts of the present document.

   The specification below includes a description of why and when the each
   component of an electronic signature is useful, with a brief
   description of the vulnerabilities and threats and the manner by
   which they are countered.

C.1

C.1.  The signature policy Signature Policy

   The signature policy is a set of rules for the creation and
   validation of an electronic signature, under which the signature can
   be determined to be valid.  A given legal/contractual context may
   recognize a particular signature policy as meeting its requirements.
   A signature policy may be issued, for example, by a party relying on
   the electronic signatures and selected by the signer for use with
   that relying party.  Alternatively, a signature policy may be
   established through an electronic trading association for use amongst
   its members.  Both the signer and verifier use the same signature
   policy.

   The signature policy may be explicitly identified or may be implied
   by the semantics of the data being signed and other external data data,
   like a contract being referenced referenced, which itself refers to a signature
   policy.  An explicit signature policy has a globally unique
   reference, which is bound to an electronic signature by the signer as
   part of the signature calculation.

   The signature policy needs to be available in human readable form so
   that it can be assessed to meet the requirements of the legal and
   contractual context in which it is being applied.  To facilitate the
   automatic processing of an electronic signature signature, the parts of the
   signature policy policy, which specifies specify the electronic rules for the creation
   and validation of the electronic signature signature, also needs need to be
   comprehensively defined and in a computer processable computer-processable form.

   The signature policy thus includes the following:

      - rules, which rules that apply to technical validation of a particular
        signature;
      - rules which that may be implied through adoption of Certificate
        Policies that apply to the electronic signature (e.g. (e.g., rules for
        ensuring the secrecy of the private signing key);

      - rules, which rules that relate to the environment used by the signer, e.g. e.g.,
        the use of an agreed CAD (Card Accepting Device) used in
        conjunction with a smart card.

   For example, the major rules required for technical validation can
   include:

      - recognized root keys or "top-level certification authorities", authorities";

      - acceptable certificate policies (if any), any);

      - necessary certificate extensions and values (if any), any);

      - the need for the revocation status for each component of the
        certification tree, tree;

      - acceptable TSAs (if time-
stamp time-stamp tokens are being used), used);

      - acceptable organizations for keeping the audit trails with
        time-marks (if time-marking is being used), used);

      - acceptable AAs (if any are being used).as well as used),and;

      - rules defining the components of the electronic signature that
        shall be provided by the signer with data required by the
        verifier when required to provide long
term long-term proof.

C.2

C.2.  Signed information Information

   The information being signed may be defined as a MIME-encapsulated
   message which that can be used to signal the format of the content in order
   to select the right display or application.  It can be composed of
   formatted data, free text text, or fields from an electronic form
   (e-form).  For example, the Adobe(tm) format "pdf" may be used or the eXtensible
   Mark up Language (XML). (XML) may be used.  Annex D defines how the content
   may be structured to indicate the type of signed data using MIME.

C.3

C.3.  Components of an electronic signature

C.3.1 Electronic Signature

C.3.1.  Reference to the signature policy Signature Policy

   When two independent parties want to evaluate an electronic
   signature, it is fundamental that they get the same result.  This
   requirement can be met using comprehensive signature policies that
   ensure consistency of signature validation.  Signature policies can
   be identified implicitly by the data being signed signed, or they can be
   explicitly identified using the CAdES-EPES form of electronic signature,
   signature; the CAdES-EPES mandates a consistent signature policy must
   be used by both the signer and verifier.

   By signing over the signature policy identifier Signature Policy Identifier in the CAdES-EPES CAdES-EPES,
   the signer explicitly indicates that he or she has applied the
   signature policy in creating the signature.

   In order to unambiguously identify the details of an explicit
   signature policy that is to be used to verify a CAdES-EPES CAdES-EPES, the signature
   signature, an
identifier identifier, and hash of the "Signature policy" shall be
   part of the signed data.  Additional information about the explicit
   policy (e.g. (e.g., web reference to the document) may be carried as
   "qualifiers" to the
signature policy identifier. Signature Policy Identifier.

   In order to unambiguously identify the authority responsible for
   defining an explicit signature policy policy, the "Signature policy" can be
   signed.

C.3.2

C.3.2.  Commitment type indication Type Indication

   The commitment type can be indicated in the electronic signature
   either:

      - explicitly using a "commitment type indication" in the
        electronic signature;

      - implicitly or explicitly from the semantics of the signed data.

   If the indicated commitment type is explicit using a "commitment type
   indication" in the electronic signature, acceptance of a verified
   signature implies acceptance of the semantics of that commitment
   type.  The semantics of explicit commitment types type indications may be
   subject to signer and verifier agreement, specified as part of the
   signature policy or registered for generic use across multiple
   policies.

   If a CAdES-EPES electronic signature format is used and the
   electronic signature includes a commitment type indication other than
   one of those recognized under the signature policy policy, the signature
   shall be treated as invalid.

   How commitment is indicated using the semantics of the data being
   signed is outside the scope of the present document.

      NOTE: Examples of commitment indicated through the semantics of
      the data being signed, signed are:

      - an explicit commitment made by the signer indicated by the type
        of data being signed over.  Thus, the data structure being
        signed can have an explicit commitment within the context of the
        application (e.g. (e.g., EDIFACT purchase order);

      - an implicit commitment which that is a commitment made by the signer
        because the data being signed over has specific semantics
     (meaning)
        (meaning), which is only interpretable by humans, (i.e. (i.e., free
        text).

C.3.3

C.3.3.  Certificate identifier Identifier from the signer Signer

   In many real life environments real-life environments, users will be able to get from
   different CAs or even from the same CA, different certificates
   containing the same public key for different names.  The prime
   advantage is that a user can use the same private key for different
   purposes.  Multiple use of the private key is an advantage when a
   smart card is used to protect the private key, since the storage of a
   smart card is always limited.  When several CAs are involved, each
   different certificate may contain a different identity, e.g. e.g., as a national
   citizen of a nation or as an employee from a company.  Thus  Thus, when a
   private key is used for various purposes, the certificate is needed
   to clarify the context in which the private key was used when
   generating the signature.  Where there is the possibility that
   multiple private keys are used, it is necessary for the signer to
   indicate to the verifier the precise certificate to be used.

   Many current schemes simply add the certificate after the signed data
   and thus are vulnerable to substitution attacks.  If the certificate
   from the signer was simply appended to the signature and thus not
   protected by the signature, any one anyone could substitute one certificate by
another
   for another, and the message would appear to be signed by some one someone
   else.  In order to counter this kind of attack, the identifier of the
   signer has to be protected by the digital signature from the signer.

   In order to identify unambiguously identify the certificate to be used for the
   verification of the signature signature, an identifier of the certificate from
   the signer shall be part of the signed data.

C.3.4

C.3.4.  Role attributes Attributes

   While the name of the signer is important, the position of the signer
   within a company or an organization is of paramount importance as
   well.  Some information (i.e. (i.e., a contract) may only be valid if
   signed by a user in a particular role, e.g. e.g., a Sales Director.  In
   many cases cases, who the sales Director really is, is not that important important,
   but being sure that the signer is empowered by his company to be the
   Sales Director is fundamental.

   The present document defines two different ways for providing this
   feature:

      - by placing a claimed role name in the CMS signed attributes
        field;

      - by placing an attribute certificate containing a certified role
        name in the CMS signed attributes field.

      NOTE: Another possible approach would have been to use additional
      attributes containing the roles name(s) in the signer's identity certificate
      certificate.  However, it was decided not to follow this approach
      as it significantly complicates the management of certificates.
      For example example, by using separate certificates for the signer's
      identity and roles means new identity keys need not be issued if a
      user's role changes.

C.3.4.1

C.3.4.1.  Claimed role Role

   The signer may be trusted to state his own role without any
   certificate to corroborate this claim.  In claim; in which case case, the claimed
   role can be added to the signature as a signed attribute.

C.3.4.2

C.3.4.2.  Certified role Role

   Unlike public key certificates that bind an identifier to a public
   key, Attribute Certificates bind the identifier of a certificate to
   some attributes, like a role.  An Attribute Certificate is NOT issued
   by a CA but by an Attribute Authority (AA).  The Attribute Authority Authority,
   in most
cases cases, might be under the control of an organization or a
   company that is best placed to know which attributes are relevant for
   which individual.  The Attribute Authority may use or point to public
   key certificates issued by any CA, provided that the appropriate
   trust may be placed in that CA.  Attribute Certificates may have
   various periods of validity.  That period may be quite short, e.g. e.g.,
   one day.  While this requires that a new Attribute Certificate be
   obtained every day, valid for that day, this can be advantageous
   since revocation of such certificates may not be needed.  When
   signing, the signer will have to specify which Attribute Certificate
   it selects.  In order to do so, the Attribute Certificate will have
   to be included in the signed data in order to be protected by the
   digital signature from the signer.

   In order to identify unambiguously identify the attribute certificate(s) to be
   used for the verification of the signature signature, an identifier of the
   attribute certificate(s) from the signer shall be part of the signed
   data.

C.3.5

C.3.5.  Signer location Location

   In some transactions transactions, the purported location of the signer at the
   time he or she applies his signature may need to be indicated.  For
   this
reason reason, an optional location indicator shall be able to be
   included.

   In order to provide indication of the location of the signer at the
   time he or she applied his signature signature, a location attribute may be
   included in the signature.

C.3.6

C.3.6.  Signing time Time

   The present document provides the capability to include a claimed
   signing time as an attribute of an electronic signature.

   Using this attribute attribute, a signer may sign over a time which that is the
   claimed signing time.  When an ES with Time-stamp is created (CAdES-T)
   (CAdES-T), then either a trusted time stamp time-stamp is obtained and added to
   the ES or a trusted time mark time-mark exists in an audit trail.  When a
   verifier accepts a signature, the two times shall be within
   acceptable limits.

   A further optional attribute is defined in the present document to
timestamp
   time-stamp the content, content and to provide proof of the existence of the
   content, at the time indicated by the time-stamp token.

   Using this optional attribute attribute, a trusted secure time may be obtained
   before the document is signed and included under the digital
   signature.  This solution requires an on-line online connection to a trusted
   time-stamping service before generating the signature and may not
   represent the precise signing time, since it can be obtained in
   advance.  However, this optional attribute may be used by the signer
   to prove that the signed object existed before the date included in
   the time-stamp (see
section Section 5.11.4).

C.3.7

C.3.7.  Content format Format

   When presenting signed data to a human user user, it may be important that
   there is no ambiguity as to the presentation of the signed
   information to the relying party.  In order for the appropriate
   representation (text, sound sound, or video) to be selected by the relying
   party when data (as opposed to data which that has been further signed or
   encrypted) is encapsulated in the SignedData (indicated by the
   eContentType within EncapsulatedContentInfo being set to id-data),
   further typing information should be used to identify the type of
   document being signed.  This is generally achieved using the MIME
   content typing and encoding mechanism defined in RFC 2045 [6]).
   Further information on the use of MIME is given in Annex F.

C.3.8 Content hints

C.3.8.  content-hints

   The contents hints contents-hints attribute provides information on the innermost
   signed content of a multilayer multi-layer message where one content is
   encapsulated in another.  This may be useful if the signed data is
   itself encrypted.

C.3.9

C.3.9.  Content cross referencing Cross-Referencing

   When presenting a signed data is in related relation to another signed data,
   it may be important to identify the signed data to which it relates to. relates.
   The Content-reference content-reference and Content-identifier attributes content-identifier attributes, as defined
   in ESS (RFC 2634 [5]) [5]), provide the ability to link a request and
   reply messages in an exchange between two parties.
C.4

C.4.  Components of validation data

C.4.1 Validation Data

C.4.1.  Revocation status information Status Information

   A verifier will have to ascertain that the certificate of the signer
   was valid at the time of the signature.  This can be done by either:

      - using Certificate Revocation Lists (CRLs);

      - using responses from an on-line online certificate status server (for
     example;
        example, obtained through the OCSP protocol).

      NOTE 1: The time of the signature may not be know, known, so
      time-stamping or time-marking may be used to provide the time
      indication of when it was known that the signature existed.

      NOTE 2: When validating an electronic signature and checking
      revocation status information information, a "grace period" is required required, which
      needs to be suitably long enough to allow the involved authority
      to process a "last minute" "last-minute" revocation request and for the request
      to propagate through the revocation system.  This grace period is
      to be added to the time included with the
         timestamp time-stamp token or the time mark
      time-mark, and thus the revocation status information should be
      captured after the end of the grace period.

C.4.1.1

C.4.1.1.  CRL information Information

   When using CRLs to get revocation information, a verifier will have
   to make sure that he or she gets gets, at the time of the first verification
   verification, the appropriate certificate revocation information from
   the signer's CA.  This should be done as soon as possible to minimize
   the time delay between the generation and verification of the
   signature.  However, a "grace period" is required to allow CAs time
   to process revocation requests.

   For example, a revocation request may arrive at a CA just before
   issuing the next CRL CRL, and there may not enough time to include the
   revised revocation status information.  This involves checking that
   the signer certificate serial number is not included in the CRL.  The
   Either the signer, the initial verifier, or a subsequent verifier may
   obtain either this CRL.  If obtained by the signer, then it shall be
   conveyed to the verifier.  It may be convenient to archive the CRL
   for ease of subsequent verification or arbitration.  Alternatively,
   provided the CRL is archived elsewhere elsewhere, which is accessible for the
   purpose of arbitration, then the serial number of the CRL used may be
   archived together with the verified electronic signature as an a CAdES-C
   form.

   Even if the certificate serial number appears in the CRL with the
   status "suspended" (i.e. (i.e., on hold), the signature is not to be deemed
   as valid since a suspended certificate is not supposed to be used
   even by its rightful owner.

C.4.1.2

C.4.1.2.  OCSP information Information

   When using OCSP to get revocation information, a verifier will have
   to make sure that he or she gets gets, at the time of the first verification
   verification, an OCSP response that contains the status "valid".
   This should be done as soon as possible after the generation of the
   signature, still providing a "grace period" suitable enough to allow
   the involved authority to process a "last minute" "last-minute" revocation request request.
   The signer, the verifier verifier, or any other third party may fetch this
   OCSP response.  Since OCSP responses are transient and thus are not
   archived by any TSP TSP, including CA, it is the responsibility of every
   verifier to make sure that it is stored in a safe place.  The
   simplest way is to store them associated with the electronic
   signature.  An alternative would be to store them
in some storage so that they can
   then be easily retrieved, retrieved and incorporate references to them in the
   electronic signature itself as
an a CAdES-C form.

   In the same way as for the case of the CRL, it may happen that the
   certificate is declared as invalid but with the secondary status
   "suspended".  In such a case, the same comment as for the CRL
   applies.

C.4.2

C.4.2.  Certification path Path

   A verifier may have to ascertain that the certification path was
   valid, at the time of the signature, up to a trust point point, according
   to the:

      - naming constraints;
      - certificate policy constraints;
      - Signature Policy, signature policy, when applicable.

   Since the time of the signature cannot be known with certainty, an
   upper limit of it should be used as indicated by either the time stamp
   time-stamp or time mark. time-mark.

   In this case case, it will be necessary to capture all the certificates
   from the certification path, starting with those from the signer and
   ending up with those of the self-signed certificate from one trusted root,
   root; when applicable applicable, this may be specified as part of the Signature
   Policy.  In addition, it will be necessary to capture the Certificate
   Authority Revocation Lists (CARLs) to prove than that none of the CAs from
   the chain
was were revoked at the time of the signature.  Again, all this
   material may be incorporated in the electronic signature (ES X
   forms).  An alternative would be to store it in some storage this information so that they can it
   can be easily retrieved, retrieved and incorporate references to it in the
   electronic signature itself as a CAdES-C form.

C.4.3 Time-stamping

C.4.3.  Time-Stamping for long life Long Life of signatures Signatures

   An important property for long standing long-standing signatures is that a
   signature, having been found once to be valid, shall continue to be
   so months or years later.

   A signer, verifier verifier, or both may be required to provide provide, on request,
   proof that a digital signature was created or verified during the
   validity period of the all the certificates that make up the certificate
   path.  In this case, the signer, verifier verifier, or both will also be
   required to provide proof that the signer's certificate and all the
   CA certificates used to form a valid certification path were not
   revoked when the signature was created or verified.

   It would be quite unacceptable, unacceptable to consider a signature as invalid
   even if the keys or certificates were later compromised.  Thus  Thus, there
   is a need to be able to demonstrate that the signature keys was were
   valid at the time that the signature was created to provide long term long-term
   evidence of the validity of a signature.

   It could be the case that a certificate was valid at the time of the
   signature but revoked some time later.  In this event, evidence shall
   be provided that the document was signed before the signing key was
   revoked.  Time-stamping by a Time-Stamping Authority (TSA) can
   provide such evidence.  A time stamp time-stamp is obtained by sending the hash
   value of the given data to the TSA.  The returned "time-stamp" is a
   signed document that contains the hash value, the identity of the
   TSA, and the time of stamping.  This proves that the given data
   existed before the time of stamping.  Time-stamping a digital
   signature (by sending a hash of the signature to the TSA) before the
   revocation of the signer's private key, key provides evidence that the
   signature has had been created before the key certificate was revoked.

   If a recipient wants to hold a valid electronic signature signature, he will
   have to ensure that he has obtained a valid time stamp time-stamp for it, it before
   that key (and any key involved in the validation) is revoked.  The
   sooner the time-stamp is obtained after the signing time, the better.
   Any
time stamp time-stamp or time mark time-mark that is taken after the expiration date
   of any certificate in the certification path has no value in proving
   the validity of a signature.

   It is important to note that signatures may be generated "off-line"
   and time-stamped at a later time by anyone, for example example, by the
   signer or any recipient interested in the value of the signature.
   The time stamp time-stamp can thus be provided by the signer signer, together with the
   signed document, or obtained by the recipient following receipt of
   the signed document.

   The time stamp time-stamp is NOT a component of the Basic Electronic Signature,
   but it is the essential component of the ES with Time-stamp.

   It is required required, in the present document document, that if a signer's digital
   signature value is to be time-stamped, the Time-Stamp Token time-stamp token is issued
   by a trusted source, known as a Time-stamping Time-Stamping Authority.

   The present document requires that the signer's digital signature
   value
is be time-stamped by a trusted source before the electronic
   signature can become an ES with Complete validation data.  Acceptable
   TSAs may be specified in a Signature Validation Policy.

   This technique is referred to as CAdES-C in the present document.

   Should both the signer and verifier be required to time-stamp the
   signature value to meet the requirements of the signature policy, the
   signature policy may specify a permitted time delay between the two
time stamps.

C.4.4 Time-stamping
   time-stamps.

C.4.4.  Time-Stamping for long life Long Life of signature Signature before CA key
compromises

Time-stamped Key
        Compromises

   Time-stamped, extended electronic signatures are needed when there is
   a requirement to safeguard against the possibility of a CA key in the
   certificate chain ever being compromised.  A verifier may be required
   to provide provide, on request, proof that the certification path and the
   revocation information used a at the time of the signature were valid,
   even in the case where one of the issuing keys or OCSP responder keys
   is later compromised.

   The present document defines two ways of using time-stamps to protect
   against this compromise:

      - time-stamp the ES with Complete validation data, when an OCSP
        response is used to get the status of the certificate from the
        signer (CAdES-X Type 1).  This format is suitable to be used
        with an OCSP response response, and it offers the additional advantage to provide of
        providing an integrity protection over the whole data;

      - time-stamp only the certification path and revocation
        information references when a CRL is used to get the status of
        the certificate from the signer (CAdES-X Type2).  This format is
        suitable to be used with CRLs, since the time-stamped
        information may be used for more than one signature (when
        signers have their certificates issued by the same CA and when
        signatures can be checked using the same CRLs).

      NOTE: The signer, verifier verifier, or both may obtain the time-stamp.

C.4.4.1 Time-stamping

C.4.4.1.  Time-Stamping the ES with complete validation data Complete Validation Data (CAdES-X
          Type 1)

   When an OCSP response is used, it is necessary to time stamp time-stamp in
   particular that response in the case the key from the responder would
   be compromised.  Since the information contained in the OCSP response
   is user specific and time specific, an individual time stamp time-stamp is
   needed for every signature received.  Instead of placing the time stamp
   time-stamp only over the certification path references and the revocation
   information references, which include the OCSP response, the time stamp
   time-stamp is placed on the CAdES-C.  Since the certification path
   and revocation information references are included in the ES with
   Complete validation
data data, they are also protected.  For the same
   cryptographic price, this provides an integrity mechanism over the ES
   with Complete validation data.  Any modification can be immediately
   detected.  It should be noticed that other means of
   protecting/detecting the integrity of the ES with Complete Validation Data validation
   data exist and could be used.  Although the technique requires a time stamp
   time-stamp for every signature, it is well suited for individual
   users wishing to have an integrity protected integrity-protected copy of all the
   validated signatures they have received.

   By time-stamping the complete electronic signature, including the
   digital signature as well as the references to the certificates and
   revocation status information used to support validation of that
   signature, the time-stamp ensures that there is no ambiguity in the
   means of validating that signature.

   This technique is referred to as CAdES-X Type 1 in the present
   document.

      NOTE: Trust is achieved in the references by including a hash of
      the data being referenced.

   If it is desired for any reason to keep a copy of the additional data
   being referenced, the additional data may be attached to the
   electronic signature, in which case the electronic signature becomes an
   a CAdES-X Long Type 1 1, as defined by the present document.

An

   A CAdES-X Long Type 1 is simply the concatenation of an a CAdES-X Type 1
   1, with a copy of the additional data being referenced.

C.4.4.2 Time-stamping certificates

C.4.4.2.  Time-Stamping Certificates and revocation information
        references Revocation Information
          References (CAdES-X Type 2)

   Time-stamping each ES with Complete Validation Data validation data, as defined above
   above, may not be efficient, particularly when the same set of CA
   certificates and CRL information is used to validate many signatures.

   Time-stamping CA certificates will stop any attacker from issuing
   bogus CA certificates that could be claimed to exist before the CA
   key was compromised.  Any bogus time-stamped CA certificates will
   show that the certificate was created after the legitimate CA key was
   compromised.  In the same way, time-stamping CA CRLs, CRLs will stop any
   attacker from issuing bogus CA CRLs which that could be claimed to exist
   before the CA key was compromised.

   Time-stamping of commonly used certificates and CRLs can be done
   centrally, e.g. e.g., inside a company or by a service provider.  This
   method reduces the amount of data the verifier has to time-stamp, time-stamp; for example
   example, it could reduce be reduced to just one time stamp time-stamp per day (i.e. (i.e., in
   the case were where all the signers use the same CA CA, and the CRL applies
   for the whole day).  The information that needs to be time stamped time-stamped is
   not the actual certificates and CRLs CRLs, but the unambiguous references
   to those certificates and CRLs.

   This technique is referred to as CAdES-X Type 2 in the present
   document and requires the following:

      - all the CA certificates references and revocation information
        references (i.e. (i.e., CRLs) used in validating the CAdES-C are
        covered by one or more time-stamp.

Thus an time-stamps.

   Thus, a CAdES-C with a time-stamp signature value at time T1, T1 can be
   proved valid if all the CA and CRL references are time-stamped at
   time T1+.

C.4.5 Time-stamping

C.4.5.  Time-Stamping for archive Archive of signature Signature

   Advances in computing increase the probability of being able to break
   algorithms and compromise keys.  There is therefore a requirement to
   be able to protect electronic signatures against this possibility.

   Over a period of time time, weaknesses may occur in the cryptographic
   algorithms used to create an electronic signature (e.g. (e.g., due to the
   time available for crypto analysis, cryptoanalysis, or improvements in crypto
analytical
   cryptoanalytical techniques).  Before such weaknesses become likely,
   a verifier should take extra measures to maintain the validity of the
   electronic signature.  Several techniques could be used to achieve
   this goal goal, depending on the nature of the weakened cryptography.  In
   order to simplify matters, a single technique, technique called Archive
   validation data, covering all the cases cases, is being used in the present
   document.

   Archive validation data consists of the validation data and the
   complete certificate and revocation data, time stamped time-stamped together with
   the electronic signature.  The Archive validation data is necessary
   if the hash function and the crypto algorithms that were used to
   create the signature are no longer secure.  Also, if it cannot be
   assumed that the hash function used by the Time Stamping Time-Stamping Authority is
   secure, then nested time-stamps of the Archived Electronic Signature
   are required.

   The potential for a Trusted Service Provider (TSP) key compromise
   should be significantly lower than user keys, keys because TSP(s) are
   expected to use stronger cryptography and better key protection.  It
   can be expected that new algorithms (or old ones with greater key
   lengths) will be used.  In such a case, a sequence of time-stamps
   will protect against forgery.  Each time-stamp needs to be affixed
   before either the compromise of the signing key or of the cracking of
   the algorithms used by the TSA.  TSAs (Time-stamping (Time-Stamping Authorities)
   should have long keys
(e.g. (e.g., which at the time of drafting the
   present document was at least 2048 bits for the signing RSA
   algorithm) and/or a "good" or different algorithm.

   Nested time-stamps will also protect the verifier against key
   compromise or cracking the algorithm on the old electronic
   signatures.

   The process will need to be performed and iterated before the
   cryptographic algorithms used for generating the previous time stamp time-stamp
   are no longer secure.  Archive validation data may thus bear multiple
   embedded time stamps. time-stamps.

   This technique is referred to as CAdES-A in the present document.

C.4.6

C.4.6.  Reference to additional data Additional Data

   Using CAdES-X Type 1 or CAdES-X Type 2 extended validation data data,
   verifiers still needs need to keep track of all the components that were
   used to validate the signature, in order to be able to retrieve them
   again later on.  These components may be archived by an external source
   source, like a trusted service provider, Trusted Service Provider; in which case case, referenced
   information that is provided as part of the ES with Complete
   validation data (CAdES-C) is adequate.  The actual certificates and
   CRL information reference in the CAdES-C can be gathered when needed
   for arbitration.

   If references to additional data are not adequate, then the actual
   values of all the certificates and revocation information required
   may be part of the electronic signature.  This technique is referred
   to as CAdES-X Long Type 1 or CAdES-X Long Type 2 in the present
   document.

C.4.7 Time-stamping

C.4.7.  Time-Stamping for mutual recognition Mutual Recognition

   In some business scenarios scenarios, both the signer and the verifier need to
   time-stamp their own copy of the signature value.  Ideally  Ideally, the two
   time-stamps should be as close as possible to each other.

      EXAMPLE:  A contract is signed by two parties parties, A and B B,
      representing their respective organizations, organizations; to time-stamp the
      signer and verifier data data, two approaches are possible:

         - under the terms of the contract pre-defined contract, a predefined common
           "trusted" TSA may be used;
         - if both organizations run their own time-stamping services, A
           and B can have the transaction time-stamped by these two
           time-stamping services.

   In the latter case, the electronic signature will only be considered as
valid,
   valid if both time-stamps were obtained in due time (i.e. (i.e., there
   should not be a long delay between obtaining the two time-stamps).
   Thus, neither A nor B can repudiate the signing time indicated by
   their own time-stamping service.  Therefore, A and B do not need to
   agree on a common "trusted" TSA to get a valid transaction.

   It is important to note that signatures may be generated "off-line"
   and time-stamped at a later time by anyone, e.g. e.g., by the signer or
   any recipient interested in validating the signature.  The time-stamp
   over the signature from the signer can thus be provided by the signer
   signer, together with the signed document, and/or be obtained by the
   verifier following receipt of the signed document.

   The business scenarios may thus dictate that one or more of the long-
term
   long-term signature time-stamping methods describe described above be used.
   This may be part of a mutually agreed Signature Validation Policy which
   that is part of an agreed signature policy under which digital signature
   signatures may be used to support the business relationship between
   the two parties.

C.4.8

C.4.8.  TSA key compromise Key Compromise

   TSA servers should be built in such a way that once the private
   signature key is installed, there is minimal likelihood of compromise
   over as long as a possible period.  Thus  Thus, the validity period for the
   TSA's keys should be as long as possible.

   Both the CAdES-T and the CAdES-C contain at least one time stamp time-stamp over
   the signer's signature.  In order to protect against the compromise
   of the private signature key used to produce that time-stamp, the
   Archive validation data can be used when a different Time-Stamping
   Authority key is involved to produce the additional time-stamp.  If
   it is believed that the TSA key used in providing an earlier
   time-stamp may ever be compromised (e.g. (e.g., outside its validity
   period), then the CAdES-
A CAdES-A should be used.  For extremely long periods
   periods, this may be applied repeatedly using new TSA keys.

   This technique is referred to as a nested CAdES-A in the present
   document.

C.5

C.5.  Multiple signatures Signatures

   Some electronic signatures may only be valid if they bear more than
   one signature.  This is generally the case generally when a contract is signed
   between two parties.  The ordering of the signatures may or may not
   be important, i.e. i.e., one may or may not need to be applied before the
   other.

   Several forms of multiple and counter signatures need to be
   supported, which fall into two basic categories:

      - independent signatures;
      - embedded signatures.

   Independent signatures are parallel signatures where the ordering of
   the signatures is not important.  The capability to have more than
   one independent signature over the same data shall be provided.

   Embedded signatures are applied one after the other and are used
   where the order in which the signatures are applied is important.
   The capability to sign over signed data shall be provided.

   These forms are described in section Section 5.13.  All other multiple
   signature schemes, e.g. e.g., a signed document with a countersignature,
   double
countersignatures countersignatures, or multiple signatures, signatures can be reduced to
   one or more
occurrence occurrences of the above two cases.

Annex D (informative): Data protocols Protocols to interoperate Interoperate with TSPs

D.1

D.1.  Operational protocols Protocols

   The following protocols can be used by signers and verifiers to
   interoperate with Trusted Service Providers during the electronic
   signature creation and validation.

D.1.1

D.1.1.  Certificate retrieval Retrieval

   User certificates, CA certificate certificates, and cross-certificates can be
   retrieved from a repository using the Lightweight Directory Access
   Protocol as defined in as defined RFC 3494 (RFC3494], [RFC3494], with the schema defined in
   RFC 4523 [RFC4523].

D.1.2

D.1.2.  CRL retrieval Retrieval

   Certificate revocation lists, including authority revocation lists
   and partial CRL variants, can be retrieved from a repository using
   the Lightweight Directory Access Protocol Protocol, as defined in RFC 3494
   [RFC3494], with the schema defined in RFC 4523 [RFC4523].

D.1.3 OnLine certificate status

D.1.3.  Online Certificate Status

   As an alternative to the use of certificate revocation lists lists, the
   status of a certificate can be checked using the OnLine Online Certificate
   Status Protocol
(OCSP) (OCSP), as defined in RFC 2560 [3].

D.1.4 Time-stamping

D.1.4.  Time-Stamping

   The time-stamping service can be accessed using the Time-Stamping
   Protocol defined in RFC 3161 [7].

D.2

D.2.  Management protocols Protocols

   Signers and verifiers can use the following management protocols to
   manage the use of certificates.

D.2.1

D.2.1.  Request for certificate revocation Certificate Revocation

   Request for a certificate to be revoked can be made using the
   revocation request and response messages defined in RFC 4210
   [RFC4210].

Annex E (informative): Security considerations

E.1 Considerations

E.1.  Protection of private key Private Key

   The security of the electronic signature mechanism defined in the
   present document depends on the privacy of the signer's private key.

   Implementations should take steps to ensure that private keys cannot
   be compromised.

E.2

E.2.  Choice of algorithms Algorithms

   Implementers should be aware that cryptographic algorithms become
   weaker with time.  As new cryptoanalysis techniques are developed and
   computing performance improves, the work factor to break a particular
   cryptographic algorithm will reduce.  Therefore, cryptographic
   algorithm implementations should be modular modular, allowing new algorithms
   to be readily inserted.  That is, implementers should be prepared for
   the set of mandatory to implement mandatory-to-implement algorithms to change over time.

Annex F (informative): Example structured contents Structured Contents and MIME

F.1

F.1.  Use of MIME to encode data Encode Data

   The signed content may be structured as using MIME (Multipurpose
   Internet Mail Extensions - -- RFC 2045 [6]. [6]).  Whilst the MIME structure
   was initially developed for Internet e-mail, email, it has a number of
   features
which that make it useful to provide a common structure for
   encoding a range of electronic documents and other multi-media data (e.g.
   (e.g., photographs, video).  These features include:

      - it provides providing a means of signalling the type of "object" being
        carried (e.g. (e.g., text, image, ZIP file, application data);

      - it provides providing a means of associating a file name with an object;

      - it can associate associating several independent "objects" (e.g. objects (e.g., a document and
        image) to form a multi-part object;

      - it can handle handling  data encoded in text or binary and, if necessary,
     re-encode
        re-encoding the binary as text.

   When encoding a single object object, MIME consists of:

      - header information, followed by;

      - encoded content.

   This structure can be extended to support multi-part content.

F.1.1

F.1.1.  Header information Information

   A MIME header includes:

   MIME Version information: e.g.: e.g., MIME-Version: 1.0

   Content type information information, which includes information describing the
   content sufficient for it to be presented to a user or application
process
   process, as required.  This includes information on the "media type"
(e.g.
   (e.g., text, image, audio) or whether the data is for passing to a
   particular type of application.  In the case of text text, the content
   type includes information on the character set used, e.g. e.g.,
   Content-Type: text/plain; charset="us-ascii"

Content encoding charset="us-ascii".

   Content-encoding information, which defines how the content is
encoded.  (See
   encoded (see below about encoding supported by MIME).

   Other information about the content content, such as a description, description or an
   associated file name.

   An example MIME header for text object is:

   Mime-Version: 1.0
   Content-Type: text/plain; charset=ISO-8859-1
   Content-Transfer-Encoding: quoted-printable

   An example MIME header for a binary file containing a pdf document
   is:

   Content-Type: application/pdf
   Content-Transfer-Encoding: base64
   Content-Description: JCFV201.pdf
   Content-Disposition: filename="JCFV201.pdf"

F.1.2

F.1.2.  Content encoding Encoding

   MIME supports a range of mechanisms for encoding the both text and binary
   data.

   Text data can be carried transparently as lines of text data encoded
   in 7 7- or 8 bit 8-bit ASCII characters.  MIME also includes a
   "quoted-printable" encoding which that converts characters other than the
   basic ASCII into an ASCII sequence.

   Binary can either be carried:

      - transparently a 8 bit as 8-bit octets; or

      - converted to a basic set of characters using a system called
        Base64.

      NOTE: As there are some mail relays which that can only handle 7 bit 7-bit
      ASCII, Base64 encoding is usually used on the Internet.

F1.3 Multi-part content

F.1.3.  Multi-Part Content

   Several objects (e.g. (e.g., text and a file attachment) can be associated
   together using a special "multi-part" content type.  This is
   indicated by the content type "multipart" with an indication of the
   string to be used indicate indicating a separation between each part.

   In addition to a header for the overall multipart content, each part
   includes its own header information indicating the inner content type
   and encoding.

   An example of a multipart content is:

Mime-Version: 1.0
Content-Type: multipart/mixed; boundary="----
=_NextPart_000_01BC4599.98004A80"
Content-Transfer-Encoding: 7bit

------=_NextPart_000_01BC4599.98004A80
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit

Per your request, I've attached our proposal for the Java Card Version
2.0 API and the Java Card FAQ.

------=_NextPart_000_01BC4599.98004A80
Content-Type: application/pdf; name="JCFV201.pdf"
Content-Transfer-Encoding: base64
Content-Description: JCFV201.pdf
Content-Disposition: attachment; filename="JCFV201.pdf"

0M8R4KGxGuEAAAAAAAAAAAAAAAAAAAAAPgADAP7/CQAGAAAAAAAAAAAAAAACAAAAAgAAAAA
AAAAAEAAAtAAAAAEAAAD+////AAAAAAMAAAAGAAAA//////////////////////////////
//////////AANhAAQAYg==

------=_NextPart_000_01BC4599.98004A80--

   Multipart content can be nested.  So a set of associated objects (e.g.
   (e.g., HTML text and images) can be handled as a single attachment to
   another object (e.g. (e.g., text).

   The Content-Type from each part of the S/MIME message indicates the
   type of content.

F.2

F.2.  S/MIME

   The specific use of MIME to carry CMS (extended as defined in the
   present document) secured data is called S/MIME (see [RFC3851]).

   S/MIME carries electronic signatures as either:

      - an "application/pkcs7-mime" object with the CMS carried as a
        binary attachment (PKCS7 is the name of the early version of
        CMS).

        The signed data may be included in the SignedData, which itself
        may be included in a single S/MIME object.  See [RFC3851],
     section 3.4.2
        Section 3.4.2: "Signing Using application/pkcs7-mime with
        SignedData" and figure Figure F.1 hereafter.

   or

      - a "multipart/signed" object with the signed data and the
        signature encoded as separate MIME objects.

        The signed data is not included in the SignedData, and the CMS
        structure only includes the signature.  See [RFC3851],
     section 3.4.3 Section
        3.4.3: "Signing Using the multipart/signed Format" and
     figure Figure
        F.2 hereafter.

        +-------------++----------++-------------++------------+
        |             ||          ||             ||            |
        |   S/MIME    ||  CAdES   ||    MIME     ||  pdf file  |
        |             ||          ||             ||            |
        |Content-Type=||SignedData||Content-Type=||Dear MrSmith|
        |application/ || eContent ||application/ ||Received    |
        |pkcs7-mime   ||          ||pdf          ||  100 tins  |
        |             ||          ||             ||            |
        |smime-type=  ||     /|   ||       /|    ||  Mr.Jones  |
        |signed-data  ||    / -----+      / ------+            |
        |             ||    \ -----+      \ ------+            |
        |             ||     \|   ||       \|    |+------------+
        |             ||          |+-------------+
        |             |+----------+
        +-------------+

            Figure F.1 F.1: Signing Using application/pkcs7-mime

F.2.1

F.2.1.  Using application/pkcs7-mime

   This approach is similar to handling signed data as any other binary
   file attachment.

   An example of signed data encoded using this approach is:

   Content-Type: application/pkcs7-mime; smime-type=signed-data;
   Content-Transfer-Encoding: base64
   Content-Disposition: attachment; filename=smime.p7m

     567GhIGfHfYT6ghyHhHUujpfyF4f8HHGTrfvhJhjH776tbB9HG4VQbnj7
     77n8HHGT9HG4VQpfyF467GhIGfHfYT6rfvbnj756tbBghyHhHUujhJhjH
     HUujhJh4VQpfyF467GhIGfHfYGTrfvbnjT6jH7756tbB9H7n8HHGghyHh
     6YT64V0GhIGfHfQbnj75

F.2.1

F.2.2.  Using application/pkcs7-signature

   CMS also supports an alternative structure where the signature and
   data being protected are separate MIME objects carried within a
   single message.  In this case case, the signed data is not included in the
   SignedData, and the CMS structure only includes the signature.  See
   [RFC3851], section 3.4.3 Section 3.4.3: "Signing Using the multipart/signed Format"
   and figure Figure F.2 herafter. hereafter.

   An example of signed data encoded using this approach is:

   Content-Type: multipart/signed;
             protocol="application/pkcs7-signature";
             micalg=sha1; boundary=boundary42

          --boundary42
          Content-Type: text/plain

          This is a clear-signed message.

          --boundary42

   Content-Type: application/pkcs7-signature; name=smime.p7s
          Content-Transfer-Encoding: base64
          Content-Disposition: attachment; filename=smime.p7s

          ghyHhHUujhJhjH77n8HHGTrfvbnj756tbB9HG4VQpfyF467GhIGfHfYT6
          4VQpfyF467GhIGfHfYT6jH77n8HHGghyHhHUujhJh756tbB9HGTrfvbnj
          n8HHGTrfvhJhjH776tbB9HG4VQbnj7567GhIGfHfYT6ghyHhHUujpfyF4
          7GhIGfHfYT64VQbnj756

          --boundary42--

   With this second approach MIME approach, the signed data passes through the CMS
   process and is carried as part of a muliple parts multiple-parts signed MIME
structure
   structure, as illustrated in figure Figure F.2.  The CMS structure just
   holds the electronic signature.

   +---------------++----------++-------------++------------+
   |               ||          ||             ||            |
   |     MIME      ||  CAdES   ||    MIME     ||  pdf file  |
   |               ||          ||             ||            |
   |Content-Type=  ||SignedData||Content-Type=||Dear MrSmith|
   |multipart/     ||          ||application/ ||Received    |
   |signed         ||          ||pdf          ||  100 tins  |
   |        /|     ||          ||             ||            |
   |       / -------------------+        /|   ||  Mr.Jones  |
   |       \ -------------------+       / -----+            |
   |        \|     ||          ||       \ -----+            |
   |Content-Type=  ||          ||        \|   |+------------+
   |application/   ||          |+-------------+
   |pdf            ||          |
   |               ||          |
   |Content-Type=  ||          |
   |application/   ||          |
   |pkcs7-signature||          |
   |               ||          |
   |        /|     ||          |
   |       / -------+          |
   |       \ -------+          |
   |        \|     ||----------+
   |               |
   +---------------+

       Figure F.2. F.2: Signing Using application/pkcs7-signature

   This second approach (multipart/signed) has the advantage that the
   signed data can be decoded by any MIME compatible MIME-compatible system even if it
   does not recognize CMS encoded CMS-encoded electronic signatures.

Annex G (informative): Relationship to the European Directive and EESSI

G.1

G.1.  Introduction

   This annex provides an indication of the relationship between
   electronic signatures created under the present document and
   requirements under the European Parliament and Council Directive on a
   Community framework for electronic signatures.

      NOTE: Legal advice should be sought on the specific national
      legislation regarding use of electronic signatures.

   The present document is one of a set of standards being defined under
   the "European Electronic Signature Standardization Initiative"
   (EESSI) for electronic signature products and solutions compliant
   with the European Directive for electronic signatures.

G.2 Electronic signatures Signatures.

G.2.  Electronic Signatures and the directive Directive

   This directive defines electronic signatures as:

      - "data in electronic form which are attached to or logically
        associated with other electronic data and which serve as a
        method of authentication".

   The directive states that an electronic signature should not be
   denied "legal effectiveness and admissibility as evidence in legal
   proceedings" solely on the grounds that it is in electronic form.

   The directive identifies an electronic signature as having
   equivalence to a hand-written signature if it meets specific
   criteria:

      - it is an "advanced electronic signature" with the following
        properties:

         a) it is uniquely linked to the signatory;

         b) it is capable of identifying the signatory;

         c) it is created using means that the signatory can maintain
            under his sole control; and

         d) it is linked to the data to which it relates in such a
            manner that any subsequent change of the data is detectable.

      - it is based on a certificate which that meets detailed criteria given
        in annex Annex I to of the directive and is issued by a "certification-
     service-provider" which
        "certification-service-provider" that meets requirements given
        in annex Annex II to of the directive.  Such a certificate is referred to
        as a "qualified certificate";

      - it is created by a "device" "device", for which detailed criteria are
        given in
     annex Annex III to of the directive.  Such a device is referred
        to a "secure-signature-creation device"; device".

   This form of electronic signature is referred to as a "qualified
   electronic signature" in EESSI (see below).

G.3

G.3.  ETSI electronic signature formats Electronic Signature Formats and the directive Directive

   An electronic signature created in accordance with the present
   document is:

      a) considered to be an "electronic signature" under the terms of
         the Directive;

      b) considered to be an "advanced electronic signature" under the
         terms of the Directive;

      c) considered to be a "Qualified Electronic Signature" Signature", provided
         the additional requirements in annex Annex I, II II, and III of the
         Directive are met.  The requirements in annex Annex I, II II, and III of
         the Directive are outside the scope of the present document,
         and are subject to further standardization.

G.4

G.4.  EESSI standards Standards and classes Classes of electronic signature

G.4.1 Electronic Signature

G.4.1.  Structure of EESSI standardization Standardization

   EESSI looks at standards in several areas.  See the ETSI ESI ETSI, ESI, and
   CEN web sites for the latest list of standards and their versions versions:

      - use of X.509 public key certificates as qualified certificates;

      - security Management and Certificate Policy for CSPs Issuing
        Qualified Certificates;

      - security requirements for trustworthy systems used by CSPs
        Issuing Qualified Certificates;

      - security requirements for Secure Signature Creation Devices;

      - security requirements for Signature Creation Systems;

      - procedures for Electronic Signature Verification;

      - electronic signature syntax and encoding formats;

      - protocol to interoperate with a Time Stamping Time-Stamping Authority;

      - Policy requirements for Time-Stamping Authorities; and

      - XML electronic signature formats.

   Each of these standards addresses a range of requirements requirements, including
   the requirements of Qualified Electronic Signatures Signatures, as specified in
article
   Article 5.1 of the Directive.  However, some of them also address
   general requirements of electronic signatures for business and
   electronic commerce commerce, which all fall into the category of article Article 5.2
   of the Directive.  Such variation in the requirements may be
   identified either as different levels or different options.

G.4.2

G.4.2.  Classes of electronic signatures Electronic Signatures

   Since some of these standards address a range of requirements, it may
   be useful to identify a set of standards to address a specific
   business need.  Such a set of standards and their uses defines define a class
   of electronic signature.  The first class already identified is the
   qualified electronic signature, fulfilling the requirements of article
   Article 5.1 of the Directive.

   A limited number of "classes of electronic signatures" and
   corresponding profiles could be defined by EESSI, in close
co-operation
   cooperation with actors on the market (business, users, suppliers).
Need
   The need for such standards is envisaged, in addition to those for
   qualified electronic signatures, in areas such as:

      - different classes of electronic signatures with long term long-term
        validity;

      - electronic signatures for business transactions with limited
        value.

G.4.3

G.4.3.  EESSI classes Classes and the ETSI electronic signature format Electronic Signature Format

   The electronic signature format defined in the present document is
   applicable to the EESSI area "electronic signature and encoding
   formats".

   An electronic signature produced by a signer (see section Section 5 and
   conformance section Section 10.1) is applicable to the proposed class of
   electronic signature: "qualified electronic signatures fulfilling
   article 5.1".

   With the addition of validation data attributes by the verifier (see section Section 6 and
   conformance section Section 10.2) this would become applicable electronic
signatures adding long-term validity attributes to the qualified electronic signature. signature supports
   long-term validity.

Annex H (informative):APIs (informative): APIs for the generation Generation and verification Verification of
electronic signatures tokens
                       Electronic Signatures Tokens

   While the present document describes the data format of an electronic
   signature, the question is whether there exists exist APIs (Application
   Programming Interfaces) able to manipulate these structures.  At
   least two such APIs have been defined.  One defined; one set by the IETF and
   another set by the OMG (Object Management Group).

H.1

H.1.  Data framing Framing

   In order to be able to use either of these APIs, it will be necessary
   to frame the previously defined electronic signature data structures
   using a mechanism-independent token format.  Section 3.1 of RFC 2743
   [RFC2743] describes that framing specifies a mechanism-independent level of encapsulating
   representation for the initial token of a GSS-API context
   establishment sequence, incorporating an identifier of the mechanism
   type to be used on that context and enabling tokens to be interpreted
unambiguously.
   unabmiguously.

   In order to be processable by these APIs, all electronic signature
   data formats that are defined in the present document shall be framed
   following that description.

   The encoding format for the token tag is derived from ASN.1 and DER,
   but its concrete representation is defined directly in terms of
   octets rather than at the ASN.1 level level, in order to facilitate
   interoperable implementation without use of general ASN.1 processing
   code.  The token tag consists of the following elements, in order:

      1) 0x60 -- Tag for RFC 2743 SEQUENCE; indicates that constructed
         form, definite length encoding follows.

      2) Token length Token-length octets, specifying length of subsequent data (i.e.
         (i.e., the summed lengths of elements 3 to 5 in this list, and
         of the mechanism-defined token object following the tag).  This
         element comprises a variable number of octets:

         a) If the indicated value is less than 128, it shall be
            represented in a single octet with bit 8 (high order) set to
            "0" and the remaining bits representing the value.

         b) If the indicated value is 128 or more, it shall be
            represented in two or more octets, with bit 8 of the first
            octet set to "1" and the remaining bits of the first octet
            specifying the number of additional octets.  The subsequent
            octets carry the value, 8 bits per octet, with the most
            significant digit first.  The minimum number of octets shall
            be used to encode the length
        (i.e. (i.e., no octets representing
            leading zeros shall be included within the length encoding).

      3) 0x06 -- Tag for OBJECT IDENTIFIER.

      4) Object identifier length -- length (number of octets) of the
         encoded object identifier contained in element 5, encoded per
         rules as described in 2a) and 2b) above.

      5) object identifier octets -- variable number of octets, encoded
         per ASN.1 BER rules:

         - The first octet contains the sum of two values:

            (1) the top-level object identifier component, multiplied by
                40 (decimal); and

            (2) the second-level object identifier component.

                This special case is the only point within an object
                identifier encoding where a single octet represents
                contents of more than one component.

            - Subsequent octets, if required, encode successively-lower successively lower
              components in the represented object identifier.  A
              component's encoding may span multiple octets, encoding 7
              bits per octet (most significant bits first) and with bit
              8 set to "1" on all but the final octet in the component's
              encoding.  The minimum number of octets shall be used to
              encode each component (i.e. (i.e., no octets representing
              leading zeros shall be included within a component's
              encoding).

      NOTE: In many implementations, elements 3 to 5 may be stored and
      referenced as a contiguous string constant.

   The token tag is immediately followed by a mechanism-defined token
   object.  Note that no independent size specifier intervenes following
   the object identifier value to indicate the size of the mechanism-

defined
   mechanism-defined token object.

   Tokens conforming to the present document shall have the following
   OID in order to be processable by IDUP-APIs:

   id-etsi-es-IDUP-Mechanism-v1 OBJECT IDENTIFIER ::=
    { itu-t(0) identified-organization(4) etsi(0)
     electronic-signature-standard (1733) part1 (1) IDUPMechanism (4)
     etsiESv1(1) }

H.2

H.2.  IDUP-GSS-APIs defined Defined by the IETF

   The IETF CAT WG has produced produced, in December 1998 1998, an RFC (RFC 2479
   [RFC2479]) under the name of IDUP-GSS-API (Independent Data Unit
   Protection) able to handle the electronic signature data format
   defined in the present document.

   The IDUP-GSS-API includes support for non-repudiation services.

   It supports evidence generation, where "evidence" is information that
   either by itself, or when used in conjunction with other information,
   is used to establish proof about an event or action, as well a as
   evidence verification.

   IDUP supports various types of evidences.  All the types defined in
   IDUP are supported in the present document through the commitment type
   commitment-type parameter.

   Section 2.3.3 of IDUP describes the specific calls needed to handle
evidences
   evidence ("EV" calls).  The "EV" group of calls provides a simple,
   high-level interface to underlying IDUP mechanisms when application
   developers need to deal only with evidences but only evidence: not with encryption or
   integrity services.

   All generations and verification are performed according to the
   content of a NR policy that is referenced in the context.

   Get_token_details is used to return to an application the attributes that correspond to
   a given input token. token to an application.  Since IDUP-GSS- API IDUP-GSS-API tokens are
   meant to be opaque to the calling application, this function allows
   the application to determine information about the token without
   having to violate the opaqueness intention of IDUP.  Of primary
   importance is the mechanism type, which the application can then use
   as input to the IDUP_Establish_Env() call in order to establish the
   correct environment in which to have the token processed.

   Generate_token generates a non-repudiation token using the current
   environment.

   Verify_evidence verifies the evidence token using the current
   environment.  This operation returns a major_status code which that can be
   used to determine whether the evidence contained in a token is
   complete
(i.e. (i.e., can be successfully verified (perhaps years) later).
   If a token's evidence is not complete, the token can be passed to
   another
API: form_complete_pidu API, form_complete_pidu, to complete it.  This happens when a
   status "conditionally valid" is returned.  That status corresponds to
   the status "validation incomplete" of the present document.

   Form_complete_PIDU is used primarily when the evidence token itself
   does not contain all the data required for its verification verification, and it
   is anticipated that some of the data not stored in the token may
   become unavailable during the interval between generation of the
   evidence token and verification unless it is stored in the token.
   The Form_Complete_PIDU operation gathers the missing information and
   includes it in the token so that verification can be guaranteed to be
   possible at any future time.

H.3

H.3.  CORBA security interfaces defined Security Interfaces Defined by the OMG

   Non-repudiation interfaces have been defined in "CORBA Security", a
   document produced by the OMG (Object Management Group).  These
   interfaces are described in IDL (Interface Definition Language) and
   are optional.

   The handling of "tokens" supporting non-repudiation is done through
   the following interfaces:

      - set_NR_features specifies the features to apply to future
        evidence generation and verification operations;

      - get_NR_features returns the features which that will be applied to
        future evidence generation and verification operations;

      - generate_token generates a Non-repudiation non-repudiation token using the
        current Non-repudiation non-repudiation features;

      - verify_evidence verifies the evidence token using the current
     Non-repudiation
        non-repudiation features;

      - get_tokens_details returns information about an input Non-
     repudiation
        non-repudiation token.  The information returned depends upon
        the type of token;

      - form_complete_evidence is used when the evidence token itself
        does not contain all the data required for its verification, and
        it is anticipated that some of the data not stored in the token
        may become unavailable during the interval between generation of
        the evidence token and verification unless it is stored in the
        token.  The form_complete_evidence operation gathers the missing
        information and includes it in the token so that verification
        can be guaranteed to be possible at any future time.

      NOTE: The similarity between the two sets of APIs is noticeable.

Annex I (informative):Cryptographic algorithms (informative): Cryptographic Algorithms

   RFC 3370 [10] describes the conventions for using several
   cryptographic algorithms with the Crytographic Message Syntax (CMS).
   Only the hashing and signing algorithms are appropriate for use with
   the present document.

   Since the publication of RFC 3370 [10], MD5 has been broken.  This
   algorithm is no more longer considered as appropriate and has been deleted
   from the list of algorithms.

I.1

I.1.  Digest algorithms

I.1.1 Algorithms

I.1.1.  SHA-1

   The SHA-1 digest algorithm is defined in FIPS Pub 180-1.  The
   algorithm identifier for SHA-1 is:

sha-1 OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) oiw(14)
secsig(3) algorithm(2) 26 }

   The AlgorithmIdentifier parameters field is optional.  If present,
   the parameters field shall contain an ASN.1 NULL.  Implementations
   should accept SHA-1 AlgorithmIdentifiers with absent parameters as
   well as NULL parameters.  Implementations should generate SHA-1
   AlgorithmIdentifiers with NULL parameters.

I.1.2

I.1.2.  General

   The following is a selection of work that has been done in the area
   of digest algorithms or, as they are often called, hash functions:

      - ISO/IEC 10118-1 (1994) [ISO10118-1]: "Information technology -
        Security techniques - Hash-functions - Part 1: General". ISO/IEC
        10118-1 contains definitions and describes basic concepts.

      - ISO/IEC 10118-2 (1994) [ISO10118-2]: "Information technology -
        Security techniques - Hash-functions - Part 2: Hash-functions
        using an n-bit block cipher algorithm".  ISO/IEC 10118-2
        specifies two ways to construct a hash-function from a block
        cipher.

      - ISO/IEC 10118-3 (1997) [ISO10118-3]: "Information technology -
        Security techniques - Hash-functions - Part 3: Dedicated
        hash-functions".  ISO/IEC 10118-3 specifies the following
        dedicated hash-functions:

         - SHA-1 (FIPS 180-1);
         - RIPEMD-128;
         - RIPEMD-160.

      - ISO/IEC 10118-4 (1998) [ISO10118-4]: "Information technology -
        Security techniques - Hash-functions - Part 4: Hash-functions
        using modular arithmetic".

      - RFC 1320 (PS 1992): "The MD4 Message-Digest Algorithm".  RFC
        1320 specifies the hash-function MD4.  Today, MD4 is considered out-
     dated.
        outdated.

      - RFC 1321 (I 1992): "The MD5 Message-Digest Algorithm".  RFC 1321
        (informational) specifies the hash-unction hash-function MD5.  Today, MD5 is
        not recommended for new implementations.

      - FIPS Publication 180-1 (1995): "Secure Hash Standard".  FIPS
        180-1 specifies the Secure Hash Algorithm (SHA), dedicated hash-
        function developed for use with the DSA.  The original SHA SHA,
        published in 1993 1993, was slightly revised in 1995 and renamed
        SHA-1.

      - ANSI X9.30-2 (1997) [X9.30-2]: "Public Key Cryptography for the
        Financial Services Industry - Part 2: The Secure Hash Algorithm
        (SHA-1)".  X9.30-2 specifies the ANSI-Version of SHA-1.

      - ANSI X9.31-2 (1996) [X9.31-2]: "Public Key Cryptography Using
        Reversible Algorithms for the Financial Services Industry - Part
        2: Hash Algorithms".  X9.31-2 specifies hash algorithms.

I.2

I.2.  Digital signature algorithms

I.2.1 Signature Algorithms

I.2.1.  DSA

   The DSA signature algorithm is defined in FIPS Pub 186.  DSA is
   always used with the SHA-1 message digest algorithm.  The algorithm
   identifier for DSA is:

id-dsa-with-sha1 OBJECT IDENTIFIER ::=  { iso(1) member-body(2) us(840)
x9-57 (10040) x9cm(4) 3 }

   The AlgorithmIdentifier parameters field shall not be present.

I.2.2

I.2.2.  RSA

   The RSA signature algorithm is defined in RFC 3447 [RFC3447].  RFC
   3370 [10] specifies the use of the RSA signature algorithm with the
   SHA-1 algorithm.  The algorithm identifier for RSA with SHA-1 is:

   Sha1WithRSAEncryption OBJECT IDENTIFIER ::= { iso(1) member-body(2)
   us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 5 }

      NOTE: RFC 3370 [10] recommends that MD5 is not be used for new
      implementations.

I.2.3

I.2.3.  General

      The following is a selection of work that has been done in the
      area of digital signature mechanisms:

      - FIPS Publication 186 (1994): "Digital Signature Standard".
        NIST's Digital Signature Algorithm (DSA) is a variant of
        ElGamal's Discrete Logarithm based Logarithm-based digital signature mechanism.
        The DSA requires a 160-bit hash-function and mandates SHA-1.

      - IEEE P1363 (2000) [P1363]: "Standard Specifications for
     Public-Key Public-
        Key Cryptography".  IEEE P1363 contains mechanisms for digital
        signatures, key establishment, and encipherment based on three
        families of public-key public key schemes:

      - "Conventional" Discrete Logarithm (DL) based (DL)-based techniques, i.e. i.e.,
        Diffie-Hellman (DH) key agreement, Menezes-Qu-Vanstone (MQV) key
        agreement, the Digital Signature Algorithm (DSA), and
        Nyberg-Rueppel (NR) digital signatures;

      - Elliptic Curve (EC) based (EC)-based variants of the DL-mechanisms
        specified above, i.e. i.e., EC-DH, EC-MQV, EC-DSA, and EC-NR.  For
        elliptic curves, implementation options include mod p and
        characteristic 2 with polynomial or normal basis representation;

      - Integer Factoring (IF) based techniques (IF)-based techniques, including RSA
        encryption, RSA digital signatures, and RSA-based key transport.

      - ISO/IEC 9796-2 (1997) [ISO9796-2]: "Information technology -
        Security techniques - Digital signature schemes giving message
        recovery - Part 2: Mechanisms using a hash-function".  ISO/IEC
        9796-2 specifies digital signature mechanisms with partial
        message recovery that are also based on the RSA technique but
        make use of a hash-function.

      - ISO/IEC 9796-4 (1998) [ISO9796-4]: "Digital signature schemes
        giving message recovery - Part 4: Discrete logarithm based
        mechanisms".  ISO/IEC 9796-4 specifies digital signature
        mechanisms with partial message recovery that are based on
        Discrete Logarithm techniques.  The document includes the
        Nyberg-Rueppel scheme.

      - ISO/IEC 14888-1 [ISO14888-1]: "Digital signatures with appendix
        - Part 1: General".  ISO/IEC 14888-1 contains definitions and
        describes the basic concepts of digital signatures with
        appendix.

      - ISO/IEC 14888-2 [ISO14888-2]: "Digital signatures with appendix
        - Part 2: Identity-based mechanisms".  ISO/IEC 14888-2 specifies
        digital signature schemes with appendix that make use of
        identity-based keying material.  The document includes the
        zero-knowledge techniques of Fiat-Shamir and Guillou-Quisquater.

      - ISO/IEC 14888-3 [ISO14888-3]: "Digital signatures with appendix
        - Part 3: Certificate-based mechanisms".  ISO/IEC 14888-3
        specifies digital signature schemes with appendix that make use
        of certificate-based keying material.  The document includes
        five schemes:

         - DSA;
         - EC-DSA, an elliptic curve based curve-based analog of NIST's Digital
           Signature Algorithm;
         - Pointcheval-Vaudeney signatures;
         - RSA signatures;
         - ESIGN.

      - ISO/IEC 15946-2 (2002) [ISO15946-2]: "Cryptographic techniques
        based on elliptic curves - Part 2: Digital signatures",
        specifies digital signature schemes with appendix using elliptic
        curves.

      - The document includes two schemes:

        - EC-DSA, an elliptic curve based curve-based analog of NIST's Digital
          Signature Algorithm;

        - EC-AMV, an elliptic curve based curve-based analog of the Agnew-Muller-
          Vanstone signature algorithm.

      - ANSI X9.31-1 (1997) [X9.31-1]: "Public Key Cryptography Using
        Reversible Algorithms for the Financial Services Industry - Part
        1: The RSA Signature Algorithm".  ANSI X9.31-1 specifies a
        digital signature mechanism with appendix using the RSA
     public-key public
        key technique.

      - ANSI X9.30-1 (1997) [X9.30-1]: "Public Key Cryptography Using
        Irreversible Algorithms for the Financial Services Industry -
        Part 1: The Digital Signature Algorithm (DSA)".  ANSI X9.30-1
        specifies the DSA, NIST's Digital Signature Algorithm.

      - ANSI X9.62 (1998) [X9.62]: "Public Key Cryptography for the
        Financial Services Industry - The Elliptic Curve Digital
        Signature Algorithm (ECDSA)".  ANSI X9.62 specifies the Elliptic
        Curve Digital Signature Algorithm, an analog of NIST's Digital
        Signature Algorithm (DSA) using elliptic curves.  The appendices
        provide tutorial information on the underlying mathematics for
        elliptic curve cryptography and give many examples.

Annex J (informative): Guidance on naming

J.1 Naming

J.1.  Allocation of names Names

   The subject name shall be allocated through a registration scheme
   administered through a Registration Authority (RA) to ensure
   uniqueness.  This RA may be an independent body or a function carried
   out by the Certification Authority.

   In addition to ensuring uniqueness, the RA shall verify that the name
   allocated properly identifies the applicant and that authentication
   checks are carried out to protect against masquerade.

   The name allocated by an RA is based on registration information
   provided by, or relating to, the applicant (e.g. (e.g., his personal name,
   date of birth, residence address) and information allocated by the
   RA. Three variations commonly exist:

      - the name is based entirely on registration information information, which
        uniquely identifies the applicant (e.g. (e.g., "Pierre Durand (born
        on) July 6, 1956");

      - the name is based on registration information information, with the addition
        of qualifiers added by the registration authority to ensure
        uniqueness (e.g. (e.g., "Pierre Durand 12");

      - the registration information is kept private by the registration
        authority and the registration authority allocates a
        "pseudonym".

J.2

J.2.  Providing access Access to registration information Registration Information

   Under certain circumstances circumstances, it may be necessary for information used
   during registration, but not published in the certificate, to be made
   available to third parties (e.g. (e.g., to an arbitrator to resolve a
   dispute or for law enforcement).  This registration information is
   likely to include personal and sensitive information.

Thus

   Thus, the RA needs to establish a policy for:

         - whether the registration information should be disclosed;
         - to whom such information should be disclosed;
         - under what circumstances such information should be
           disclosed.

   This policy may be different whether the RA is being used only within
   a company or for public use.  The policy will have to take into
   account national legislation and in particular any data protection
   and privacy legislation.

   Currently, the provision of access to registration is a local matter
   for the RA.  However, if open access is required, standard protocols protocols,
   such as HTTP - -- RFC 2068 (Internet Web Access Protocol) Protocol), may be
   employed with the addition of security mechanisms necessary to meet
   the data protection requirements (e.g. (e.g., Transport Layer Security - --
   RFC 4346
[RFC4346] [RFC4346]) with client authentication).

J.3 authentication.

J.3.  Naming schemes

J.3.1 Schemes

J.3.1.  Naming schemes Schemes for individual citizens Individual Citizens

   In some cases cases, the subject name that is contained in a public key
   certificate may not be meaningful enough.  This may happen because of
   the existence of homonyms or because of the use of pseudonyms.  A
   distinction could be made if more attributes were present.  However,
   adding more attributes to a public key certificate placed in a public
   repository would be going against the privacy protection
   requirements.

   In any case case, the Registration Authority will get information at the
   time of registration registration, but not all that information will be placed in
   the certificate.  In order to achieve a balance between these two
   opposite
requirements requirements, the hash values of some additional attributes
   can be placed in a public key certificate.  When the certificate
   owner provides these additional attributes, then they can be
   verified.  Using biometrics attributes may unambiguously identify a
   person.  Example  Examples of biometrics attributes that can be used include:
   a picture or a manual signature from the certificate owner.

      NOTE: Using hash values protects privacy only if the possible
      inputs are large enough.  For example, using the hash of a
      person's social security number is generally not sufficient since
      it can easily be reversed.

   A picture can be used if the verifier once met the person and later
   on wants to verify that the certificate that he or she got relates to
   the person whom was met.  In such a case, at the first exchange exchange, the
   picture is sent sent, and the hash contained in the certificate may be
   used by the verifier to verify that it is the right person.  At the
   next exchange exchange, the picture does not need to be sent again.

   A manual signature may be used if a signed document has been received
   beforehand.  In such a case, at the first exchange exchange, the drawing of
   the manual signature is sent sent, and the hash contained in the
   certificate may be used by the verifier to verify that it is the
   right manual signature.  At the next exchange exchange, the manual signature
   does not need to be sent again.

J.3.2

J.3.2.  Naming schemes Schemes for employees Employees of an organization Organization

   The name of an employee within an organization is likely to be some
   combination of the name of the organization and the identifier of the
   employee within that organization.

   An organization name is usually a registered name, i.e. i.e., business or
   trading name used in day to day day-to-day business.  This name is registered by
   a Naming Authority, which guarantees that the organization's
   registered name is unambiguous and cannot be confused with another
   organization.

   In order to get more information about a given registered
   organization name, it is necessary to go back to a publicly available
   directory maintained by the Naming Authority.

   The identifier may be a name or a pseudonym (e.g. (e.g., a nickname or a an
   employee number).  When it is a name, it is supposed to be
   descriptive enough to unambiguously identify the person.  When it is
   a pseudonym, the certificate does not disclose the identity of the
   person.  However  However, it ensures that the person has been correctly
   authenticated at the time of registration and therefore may be
   eligible to some advantages implicitly or explicitly obtained through
   the possession of the certificate.  In either case, however, this can
   be insufficient because of the existence of homonyms.

   Placing more attributes in the certificate may be one solution, for
example
   example, by giving the organization unit of the person or the name of
   a city where the office is located.  However  However, the more information is
   placed in the certificate certificate, the more problems arise if there is a
   change in the organization structure or the place of work.  So this
   may not be the best solution.  An alternative is to provide more
   attributes (like the organization unit and the place of work) through
   access to a directory maintained by the company.  It is likely that that,
   at the time of
registration registration, the Registration Authority got more
   information than what was placed in the certificate, if such
   additional information is placed in a repository accessible only to
   the organization.

Annex K (informative): Changes from the previous version

   The title of the document has changed to be aligned with the title
   of XAdES (XML Advanced Electronic Signatures), the vocabulary used
   within the present document has been aligned with the vocabulary
   used in XAdES,

   If the hash of the signature policy is unknown, then, by
   convention, the sigPolicyHash shall be set

Acknowledgments

   Special thanks to all zeros.

   The OIDs from the ASN.1 modules have changed Russ Housley for reviewing the following
   reasons:

    - the OIDs of the ASN.1 modules of RFC 2560 and RFC 3161 have been
      included.

    - since RFC 2459 and RFC 3852 has been obsoleted by RFC 3280 and
      RFC 3852 respectively, there was the need to refer to the OIDs
      of the ASN.1 modules of RFC 3280 and RFC 3852, instead of the
      OIDs of the ASN.1 modules of RFC 2459 and RFC 3852.

    - other changes are related to the addition of the signing-
      certificate attribute, where the ESS signing-certificate
      attribute defined in RFC 2634 [5], shall be used if the SHA-1
      hashing algorithm is used, while the ESS signing-certificate
      attribute v2, defined in "ESS Update: Adding CertID Algorithm
      Agility RFC 5035 [15] shall be used when other hashing
      algorithms are to be used.

    - the definition of the Archive time-stamp attribute has been
      changed in section 6.4.1. to protect all signed and unsined
      attributes.  A new object identifier has been assigned to this
      attribute. document.

Authors' Addresses

   Denis Pinkas
   Bull SAS
   Rue Jean-Jaures
   78340 Les Clayes sous Bois CEDEX
   FRANCE
   EMail: Denis.Pinkas@bull.net

   Nick Pope
   Thales eSecurity
   Meadow View House
   Long Crendon
   Aylesbury
   Buck
   HP18 9EQ
   United Kingdom
   EMail: nick.pope@thales-esecurity.com

   John Ross
   Security & Standards Consultancy Ltd
   The Waterhouse Business Centre
   2 Cromer Way
   Chelmsford
   Essex
   CM1 2QE
   United Kingdom
   EMail: ross@secstan.com

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Acknowledgements

   Funding for the RFC Editor function is currently provided by the
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   Funding for the publication of the previous RFC has been provided
   by ETSI and the European Commission.