Online Certificate Status Protocol (OCSP) Nonce Extension
draft-ietf-lamps-ocsp-nonce-update-07

Internet Engineering Task Force                           H. Sharma, Ed.
Internet-Draft                                              Netskope Inc
Obsoletes: 8954 (if approved)                                 6 May 2024
Updates: 6960 (if approved)                                             
Intended status: Standards Track                                        
Expires: 7 November 2024

       Online Certificate Status Protocol (OCSP) Nonce Extension
                 draft-ietf-lamps-ocsp-nonce-update-07

Abstract

   RFC 8954 imposed the size constraints on the optional Nonce extension
   for the Online Certificate Status Protocol (OCSP).  OCSP is used for
   checking the status of a certificate, and the Nonce extension is used
   to cryptographically bind an OCSP response message to a particular
   OCSP request message.

   Some environments use cryptographic algorithms that generate a Nonce
   value that is longer than 32 octets.  This document updates the
   maximum allowed length of Nonce to 128 octets.  This document also
   modifies Nonce section to clearly define the encoding format and
   values distinctively for an easier implementation and understanding.
   This document obsoletes RFC 8954 and provides updated ASN.1 modules
   for OCSP, updates RFC 6960.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on 7 November 2024.

Copyright Notice

   Copyright (c) 2024 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   2
   2.  OCSP Extensions . . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Nonce Extension . . . . . . . . . . . . . . . . . . . . .   3
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
     3.1.  Replay Attack . . . . . . . . . . . . . . . . . . . . . .   4
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .   5
   References  . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     Normative References  . . . . . . . . . . . . . . . . . . . . .   5
     Informative References  . . . . . . . . . . . . . . . . . . . .   6
   Appendix A.  ASN.1 Modules  . . . . . . . . . . . . . . . . . . .   6
     A.1.  OCSP in ASN.1 - 1998 Syntax . . . . . . . . . . . . . . .   6
     A.2.  OCSP in ASN.1 - 2008 Syntax . . . . . . . . . . . . . . .  10
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   Nonce extension was previously defined in Section 4.4.1 of [RFC6960]
   and updated in [RFC8954].  [RFC8954] limits the maximum Nonce length
   to 32 octets.  To support cryptographic algorithms that generate a
   Nonce that is longer than 32 octets, this document updates the
   maximum allowed size of the Nonce to 128 octets.  In addition, this
   document recommends that the OCSP client and responder use a Nonce
   with a minimum length of 32 octets.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

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2.  OCSP Extensions

   The message formats for OCSP requests and responses are defined in
   [RFC6960] and Nonce extension was updated in [RFC8954].  [RFC6960]
   also defines the standard extensions for OCSP messages based on the
   extension model employed in X.509 version 3 certificates (see
   [RFC5280]).  [RFC8954] replaces this section to limit the minimum and
   maximum length for the Nonce value.  This document extends the
   maximum allowed nonce length to 128 octets and does not change the
   specifications of any of the other standard extensions defined in
   [RFC6960].

2.1.  Nonce Extension

   The Nonce cryptographically binds a request and a response to prevent
   replay attacks.  The Nonce is included as one of the
   requestExtensions in requests; in responses, it would be included as
   one of the responseExtensions.  In both the request and the response,
   the Nonce will be identified by the object identifier id-pkix-ocsp-
   nonce, while the extnValue is the encoded value of Nonce.  If the
   Nonce extension is present, then the length of the Nonce MUST be at
   least 1 octet and can be up to 128 octets.

   An OCSP client that implements this document MUST use a minimum
   length of 32 octets for Nonce in the Nonce extension.  [RFC8954]
   compliant implementations will be unable to process nonces generated
   per the new specification with sizes in excess of the limit of 32
   octets that was specified in [RFC8954].

   An OCSP responder that implements this document MUST reject any OCSP
   request that has a Nonce with a length of either 0 octets or more
   than 128 octets, with the malformedRequest OCSPResponseStatus as
   described in Section 4.2.1 of [RFC6960].  Responders, supporting the
   Nonce extension, MUST accept Nonce lengths of at least 16 octets and
   MAY choose to ignore the Nonce extension for requests where the
   length of the Nonce is less than 16 octets or more than 32 octets.

   The value of the Nonce MUST be generated using a cryptographically
   strong pseudorandom number generator (see [RFC4086]).  The minimum
   Nonce length of 1 octet is defined to provide backward compatibility
   with older clients that follow [RFC6960].

   id-pkix-ocsp           OBJECT IDENTIFIER ::= { id-ad-ocsp }
   id-pkix-ocsp-nonce     OBJECT IDENTIFIER ::= { id-pkix-ocsp 2 }
   Nonce ::= OCTET STRING(SIZE(1..128))

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   Example of an encoded OCSP Nonce extension with 32 octet Nonce in
   hexadecimal format.

   30 2f 06 09 2b 06 01 05 05 07 30 01 02 04 22 04
   20 dd 49 d4 07 2c 44 9d a1 c3 17 bd 1c 1b df fe
   db e1 50 31 2e c4 cd 0a dd 18 e5 bd 6f 84 bf 14
   c8

   Here is the decoded version of the above example.
   Offset, Length and Object Identifier are in decimal.

   Offset  Length
   0       47    : SEQUENCE {
   2       9     :   OBJECT IDENTIFIER ocspNonce (1 3 6 1 5 5 7 48 1 2)
   13      34    :   OCTET STRING, encapsulates {
   15      32    :     OCTET STRING
                 :       DD 49 D4 07 2C 44 9D A1 C3 17 BD 1C 1B DF FE DB
                 :       E1 50 31 2E C4 CD 0A DD 18 E5 BD 6F 84 BF 14 C8
                 :     }
                 :  }

3.  Security Considerations

   The security considerations of OCSP, in general, are described in
   [RFC6960].  During the interval in which the previous OCSP response
   for a certificate is not expired but the responder has a changed
   status for that certificate, a copy of that OCSP response can be used
   to indicate that the status of the certificate is still valid.
   Including a client's nonce value in the OCSP response makes sure that
   the response is the latest response from the server and not an old
   copy.

3.1.  Replay Attack

   The Nonce extension is used to avoid replay attacks.  Since the OCSP
   responder may choose not to send the Nonce extension in the OCSP
   response even if the client has sent the Nonce extension in the
   request [RFC5019], an on-path attacker can intercept the OCSP request
   and respond with an earlier response from the server without the
   Nonce extension.  This can be mitigated by configuring the server to
   use a short time interval between the thisUpdate and nextUpdate
   fields in the OCSP response.

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4.  IANA Considerations

   For the ASN.1 Module in Appendix A.1, IANA is requested to assign an
   object identifier (OID) for the module identifier to replace TBD1.
   The OID for the module should be allocated in the "SMI Security for
   PKIX Module Identifier" registry (1.3.6.1.5.5.7.0), and the
   Description for the new OID should be set to "id-mod-ocsp-2024-88".

   For the ASN.1 Module in Appendix A.2, IANA is requested to assign an
   object identifier (OID) for the module identifier to replace TBD2.
   The OID for the module should be allocated in the "SMI Security for
   PKIX Module Identifier" registry (1.3.6.1.5.5.7.0), and the
   Description for the new OID should be set to "id-mod-ocsp-2024-08".

Acknowledgements

   The authors of this document wish to thank Mohit Sahni for his work
   to produce [RFC8954].

   The authors wish to thank Russ Housley, Corey Bonnell, Michael
   StJohns and Carl Wallace for the feedback and suggestions.

References

Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC4086]  Eastlake 3rd, D., Schiller, J., and S. Crocker,
              "Randomness Requirements for Security", BCP 106, RFC 4086,
              DOI 10.17487/RFC4086, June 2005,
              <https://www.rfc-editor.org/info/rfc4086>.

   [RFC5019]  Deacon, A. and R. Hurst, "The Lightweight Online
              Certificate Status Protocol (OCSP) Profile for High-Volume
              Environments", RFC 5019, DOI 10.17487/RFC5019, September
              2007, <https://www.rfc-editor.org/info/rfc5019>.

   [RFC5280]  Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
              Housley, R., and W. Polk, "Internet X.509 Public Key
              Infrastructure Certificate and Certificate Revocation List
              (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
              <https://www.rfc-editor.org/info/rfc5280>.

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   [RFC6960]  Santesson, S., Myers, M., Ankney, R., Malpani, A.,
              Galperin, S., and C. Adams, "X.509 Internet Public Key
              Infrastructure Online Certificate Status Protocol - OCSP",
              RFC 6960, DOI 10.17487/RFC6960, June 2013,
              <https://www.rfc-editor.org/info/rfc6960>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8954]  Sahni, M., Ed., "Online Certificate Status Protocol (OCSP)
              Nonce Extension", RFC 8954, DOI 10.17487/RFC8954, November
              2020, <https://www.rfc-editor.org/info/rfc8954>.

Informative References

   [RFC5912]  Hoffman, P. and J. Schaad, "New ASN.1 Modules for the
              Public Key Infrastructure Using X.509 (PKIX)", RFC 5912,
              DOI 10.17487/RFC5912, June 2010,
              <https://www.rfc-editor.org/info/rfc5912>.

   [Errata5891]
              RFC Errata, Erratum ID 5891, RFC 6960,
              <https://www.rfc-editor.org/errata/eid5891>.

Appendix A.  ASN.1 Modules

   This section includes the ASN.1 modules for OCSP and replaces the
   entirity of Section 5 of [RFC8954].  It addresses Errata id 5891
   [Errata5891] as well.

   Appendix A.1 includes an ASN.1 module that conforms to the 1998
   version of ASN.1 for all syntax elements of OCSP.  This module
   replaces the modules Appendix B.1 of [RFC6960].

   Appendix A.2 includes an ASN.1 module, corresponding to the module
   present in A.1, that conforms to the 2008 version of ASN.1.  This
   module replaces the modules in Section 4 of [RFC5912] and
   Appendix B.2 of [RFC6960].  Although a 2008 ASN.1 module is provided,
   the module in Appendix A.1 remains the normative module as per the
   policy of the PKIX working group.

A.1.  OCSP in ASN.1 - 1998 Syntax

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OCSP-2024-88
      {iso(1) identified-organization(3) dod(6) internet(1)
      security(5) mechanisms(5) pkix(7) id-mod(0)
      id-mod-ocsp-2024-88(TBD1)}

DEFINITIONS EXPLICIT TAGS ::=

BEGIN

IMPORTS

   -- PKIX Certificate Extensions
      AuthorityInfoAccessSyntax, CRLReason, GeneralName
      FROM PKIX1Implicit88 { iso(1) identified-organization(3)
           dod(6) internet(1) security(5) mechanisms(5) pkix(7)
           id-mod(0) id-pkix1-implicit(19) }

      Name, CertificateSerialNumber, Extensions,
      id-kp, id-ad-ocsp, Certificate, AlgorithmIdentifier
      FROM PKIX1Explicit88 { iso(1) identified-organization(3)
           dod(6) internet(1) security(5) mechanisms(5) pkix(7)
           id-mod(0) id-pkix1-explicit(18) };

OCSPRequest ::= SEQUENCE {
   tbsRequest              TBSRequest,
   optionalSignature   [0] EXPLICIT Signature OPTIONAL }

TBSRequest ::= SEQUENCE {
   version             [0] EXPLICIT Version DEFAULT v1,
   requestorName       [1] EXPLICIT GeneralName OPTIONAL,
   requestList             SEQUENCE OF Request,
   requestExtensions   [2] EXPLICIT Extensions OPTIONAL }

Signature ::= SEQUENCE {
   signatureAlgorithm      AlgorithmIdentifier,
   signature               BIT STRING,
   certs               [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL }

Version ::= INTEGER { v1(0) }

Nonce ::= OCTET STRING(SIZE(1..128))

Request ::= SEQUENCE {
   reqCert                     CertID,
   singleRequestExtensions [0] EXPLICIT Extensions OPTIONAL }

CertID ::= SEQUENCE {
   hashAlgorithm           AlgorithmIdentifier,

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   issuerNameHash          OCTET STRING, -- Hash of issuer's DN
   issuerKeyHash           OCTET STRING, -- Hash of issuer's public key
   serialNumber            CertificateSerialNumber }

OCSPResponse ::= SEQUENCE {
   responseStatus          OCSPResponseStatus,
   responseBytes       [0] EXPLICIT ResponseBytes OPTIONAL }

OCSPResponseStatus ::= ENUMERATED {
   successful          (0),  -- Response has valid confirmations
   malformedRequest    (1),  -- Illegal confirmation request
   internalError       (2),  -- Internal error in issuer
   tryLater            (3),  -- Try again later
                             -- (4) is not used
   sigRequired         (5),  -- Must sign the request
   unauthorized        (6)   -- Request unauthorized
}

ResponseBytes ::= SEQUENCE {
   responseType            OBJECT IDENTIFIER,
   response                OCTET STRING }

BasicOCSPResponse ::= SEQUENCE {
  tbsResponseData          ResponseData,
  signatureAlgorithm       AlgorithmIdentifier,
  signature                BIT STRING,
  certs                [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL }

ResponseData ::= SEQUENCE {
   version             [0] EXPLICIT Version DEFAULT v1,
   responderID             ResponderID,
   producedAt              GeneralizedTime, -- The format for
                                            -- GeneralizedTime is as
                                            -- specified in Section
                                            -- 4.1.2.5.2 of [RFC5280]
   responses               SEQUENCE OF SingleResponse,
   responseExtensions  [1] EXPLICIT Extensions OPTIONAL }

ResponderID ::= CHOICE {
   byName              [1] Name,
   byKey               [2] KeyHash }

KeyHash ::= OCTET STRING -- SHA-1 hash of responder's public key
                         -- (i.e., the SHA-1 hash of the value of the
                         -- BIT STRING subjectPublicKey [excluding
                         -- the tag, length, and number of unused
                         -- bits] in the responder's certificate)

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SingleResponse ::= SEQUENCE {
   certID                  CertID,
   certStatus              CertStatus,
   thisUpdate              GeneralizedTime,
   nextUpdate          [0] EXPLICIT GeneralizedTime OPTIONAL,
   singleExtensions    [1] EXPLICIT Extensions OPTIONAL }

CertStatus ::= CHOICE {
   good                [0] IMPLICIT NULL,
   revoked             [1] IMPLICIT RevokedInfo,
   unknown             [2] IMPLICIT UnknownInfo }

RevokedInfo ::= SEQUENCE {
   revocationTime          GeneralizedTime,
   revocationReason    [0] EXPLICIT CRLReason OPTIONAL }

UnknownInfo ::= NULL

ArchiveCutoff ::= GeneralizedTime

AcceptableResponses ::= SEQUENCE OF OBJECT IDENTIFIER

ServiceLocator ::= SEQUENCE {
   issuer                  Name,
   locator                 AuthorityInfoAccessSyntax }

CrlID ::= SEQUENCE {
    crlUrl               [0]     EXPLICIT IA5String OPTIONAL,
    crlNum               [1]     EXPLICIT INTEGER OPTIONAL,
    crlTime              [2]     EXPLICIT GeneralizedTime OPTIONAL }

PreferredSignatureAlgorithms ::= SEQUENCE OF PreferredSignatureAlgorithm

PreferredSignatureAlgorithm ::= SEQUENCE {
   sigIdentifier   AlgorithmIdentifier,
   certIdentifier  AlgorithmIdentifier OPTIONAL }

-- Object Identifiers

id-kp-OCSPSigning            OBJECT IDENTIFIER ::= { id-kp 9 }
id-pkix-ocsp                 OBJECT IDENTIFIER ::= { id-ad-ocsp }
id-pkix-ocsp-basic           OBJECT IDENTIFIER ::= { id-pkix-ocsp 1 }
id-pkix-ocsp-nonce           OBJECT IDENTIFIER ::= { id-pkix-ocsp 2 }
id-pkix-ocsp-crl             OBJECT IDENTIFIER ::= { id-pkix-ocsp 3 }
id-pkix-ocsp-response        OBJECT IDENTIFIER ::= { id-pkix-ocsp 4 }
id-pkix-ocsp-nocheck         OBJECT IDENTIFIER ::= { id-pkix-ocsp 5 }

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id-pkix-ocsp-archive-cutoff  OBJECT IDENTIFIER ::= { id-pkix-ocsp 6 }
id-pkix-ocsp-service-locator OBJECT IDENTIFIER ::= { id-pkix-ocsp 7 }
id-pkix-ocsp-pref-sig-algs   OBJECT IDENTIFIER ::= { id-pkix-ocsp 8 }
id-pkix-ocsp-extended-revoke OBJECT IDENTIFIER ::= { id-pkix-ocsp 9 }

END

A.2.  OCSP in ASN.1 - 2008 Syntax

OCSP-2024-08
     {iso(1) identified-organization(3) dod(6) internet(1)
     security(5) mechanisms(5) pkix(7) id-mod(0)
     id-mod-ocsp-2024-08(TBD2)}

DEFINITIONS EXPLICIT TAGS ::=

BEGIN

IMPORTS

Extensions{}, EXTENSION
FROM PKIX-CommonTypes-2009 -- From [RFC5912]
   {iso(1) identified-organization(3) dod(6) internet(1) security(5)
   mechanisms(5) pkix(7) id-mod(0) id-mod-pkixCommon-02(57)}

AlgorithmIdentifier{}, DIGEST-ALGORITHM, SIGNATURE-ALGORITHM, PUBLIC-KEY
FROM AlgorithmInformation-2009 -- From [RFC5912]
   {iso(1) identified-organization(3) dod(6) internet(1) security(5)
   mechanisms(5) pkix(7) id-mod(0)
   id-mod-algorithmInformation-02(58)}

AuthorityInfoAccessSyntax, GeneralName, CrlEntryExtensions, CRLReason
FROM PKIX1Implicit-2009 -- From [RFC5912]
   {iso(1) identified-organization(3) dod(6) internet(1) security(5)
   mechanisms(5) pkix(7) id-mod(0) id-mod-pkix1-implicit-02(59)}

Name, CertificateSerialNumber, id-kp, id-ad-ocsp, Certificate
FROM PKIX1Explicit-2009 -- From [RFC5912]
   {iso(1) identified-organization(3) dod(6) internet(1) security(5)
   mechanisms(5) pkix(7) id-mod(0) id-mod-pkix1-explicit-02(51)}

sa-dsaWithSHA1, sa-rsaWithMD2, sa-rsaWithMD5, sa-rsaWithSHA1
FROM PKIXAlgs-2009 -- From [RFC5912]
   {iso(1) identified-organization(3) dod(6) internet(1) security(5)
   mechanisms(5) pkix(7) id-mod(0)
   id-mod-pkix1-algorithms2008-02(56)};

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OCSPRequest     ::=     SEQUENCE {
   tbsRequest                  TBSRequest,
   optionalSignature   [0]     EXPLICIT Signature OPTIONAL }

TBSRequest      ::=     SEQUENCE {
   version             [0] EXPLICIT Version DEFAULT v1,
   requestorName       [1] EXPLICIT GeneralName OPTIONAL,
   requestList             SEQUENCE OF Request,
   requestExtensions   [2] EXPLICIT Extensions {{re-ocsp-nonce |
                    re-ocsp-response, ...,
                    re-ocsp-preferred-signature-algorithms}} OPTIONAL }

Signature       ::=     SEQUENCE {
   signatureAlgorithm   AlgorithmIdentifier
                            { SIGNATURE-ALGORITHM, {...}},
   signature            BIT STRING,
   certs            [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL }

Version  ::=  INTEGER  {  v1(0) }

Nonce ::= OCTET STRING(SIZE(1..128))

Request ::=     SEQUENCE {
   reqCert                    CertID,
   singleRequestExtensions    [0] EXPLICIT Extensions
                                      { {re-ocsp-service-locator,
                                             ...}} OPTIONAL }

CertID ::= SEQUENCE {
   hashAlgorithm            AlgorithmIdentifier
                                {DIGEST-ALGORITHM, {...}},
   issuerNameHash     OCTET STRING, -- Hash of issuer's DN
   issuerKeyHash      OCTET STRING, -- Hash of issuer's public key
   serialNumber       CertificateSerialNumber }

OCSPResponse ::= SEQUENCE {
  responseStatus         OCSPResponseStatus,
  responseBytes          [0] EXPLICIT ResponseBytes OPTIONAL }

OCSPResponseStatus ::= ENUMERATED {
   successful            (0), -- Response has valid confirmations
   malformedRequest      (1), -- Illegal confirmation request
   internalError         (2), -- Internal error in issuer
   tryLater              (3), -- Try again later
                              -- (4) is not used
   sigRequired           (5), -- Must sign the request

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   unauthorized          (6)  -- Request unauthorized
}

RESPONSE ::= TYPE-IDENTIFIER

ResponseSet RESPONSE ::= {basicResponse, ...}

ResponseBytes ::=       SEQUENCE {
   responseType        RESPONSE.
                           &id ({ResponseSet}),
   response            OCTET STRING (CONTAINING RESPONSE.
                           &Type({ResponseSet}{@responseType}))}

basicResponse RESPONSE ::=
   { BasicOCSPResponse IDENTIFIED BY id-pkix-ocsp-basic }

BasicOCSPResponse       ::= SEQUENCE {
  tbsResponseData      ResponseData,
  signatureAlgorithm   AlgorithmIdentifier{SIGNATURE-ALGORITHM,
                           {sa-dsaWithSHA1 | sa-rsaWithSHA1 |
                                sa-rsaWithMD5 | sa-rsaWithMD2, ...}},
  signature            BIT STRING,
  certs            [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL }

ResponseData ::= SEQUENCE {
  version              [0] EXPLICIT Version DEFAULT v1,
  responderID              ResponderID,
  producedAt               GeneralizedTime,
  responses                SEQUENCE OF SingleResponse,
  responseExtensions   [1] EXPLICIT Extensions
                              {{re-ocsp-nonce, ...,
                                re-ocsp-extended-revoke}} OPTIONAL }

ResponderID ::= CHOICE {
  byName   [1] Name,
  byKey    [2] KeyHash }

KeyHash ::= OCTET STRING -- SHA-1 hash of responder's public key
                        -- (excluding the tag and length fields)

SingleResponse ::= SEQUENCE {
  certID                       CertID,
  certStatus                   CertStatus,
  thisUpdate                   GeneralizedTime,
  nextUpdate           [0]     EXPLICIT GeneralizedTime OPTIONAL,
  singleExtensions     [1]     EXPLICIT Extensions{{re-ocsp-crl |
                                            re-ocsp-archive-cutoff |
                                            CrlEntryExtensions, ...}

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                                            } OPTIONAL }

CertStatus ::= CHOICE {
   good                [0]     IMPLICIT NULL,
   revoked             [1]     IMPLICIT RevokedInfo,
   unknown             [2]     IMPLICIT UnknownInfo }

RevokedInfo ::= SEQUENCE {
   revocationTime              GeneralizedTime,
   revocationReason    [0]     EXPLICIT CRLReason OPTIONAL }

UnknownInfo ::= NULL

ArchiveCutoff ::= GeneralizedTime

AcceptableResponses ::= SEQUENCE OF RESPONSE.&id({ResponseSet})

ServiceLocator ::= SEQUENCE {
   issuer    Name,
   locator   AuthorityInfoAccessSyntax }

CrlID ::= SEQUENCE {
   crlUrl               [0]     EXPLICIT IA5String OPTIONAL,
   crlNum               [1]     EXPLICIT INTEGER OPTIONAL,
   crlTime              [2]     EXPLICIT GeneralizedTime OPTIONAL }

PreferredSignatureAlgorithms ::= SEQUENCE OF PreferredSignatureAlgorithm

PreferredSignatureAlgorithm ::= SEQUENCE {
  sigIdentifier  AlgorithmIdentifier{SIGNATURE-ALGORITHM, {...}},
  certIdentifier AlgorithmIdentifier{PUBLIC-KEY, {...}} OPTIONAL
}

-- Certificate Extensions

ext-ocsp-nocheck EXTENSION ::= { SYNTAX NULL IDENTIFIED
                                BY id-pkix-ocsp-nocheck }

-- Request Extensions

re-ocsp-nonce EXTENSION ::= { SYNTAX Nonce
                             IDENTIFIED BY id-pkix-ocsp-nonce }

re-ocsp-response EXTENSION ::= { SYNTAX AcceptableResponses IDENTIFIED
                                BY id-pkix-ocsp-response }

re-ocsp-service-locator EXTENSION ::= { SYNTAX ServiceLocator
                                       IDENTIFIED BY

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                                       id-pkix-ocsp-service-locator }

re-ocsp-preferred-signature-algorithms EXTENSION ::= {
  SYNTAX PreferredSignatureAlgorithms
  IDENTIFIED BY id-pkix-ocsp-pref-sig-algs  }

-- Response Extensions

re-ocsp-crl EXTENSION ::= { SYNTAX CrlID IDENTIFIED BY
                               id-pkix-ocsp-crl }

re-ocsp-archive-cutoff EXTENSION ::= { SYNTAX ArchiveCutoff
                                      IDENTIFIED BY
                                      id-pkix-ocsp-archive-cutoff }

re-ocsp-extended-revoke EXTENSION ::= { SYNTAX NULL IDENTIFIED BY
                                       id-pkix-ocsp-extended-revoke }

-- Object Identifiers

id-kp-OCSPSigning            OBJECT IDENTIFIER ::= { id-kp 9 }
id-pkix-ocsp                 OBJECT IDENTIFIER ::= id-ad-ocsp
id-pkix-ocsp-basic           OBJECT IDENTIFIER ::= { id-pkix-ocsp 1 }
id-pkix-ocsp-nonce           OBJECT IDENTIFIER ::= { id-pkix-ocsp 2 }
id-pkix-ocsp-crl             OBJECT IDENTIFIER ::= { id-pkix-ocsp 3 }
id-pkix-ocsp-response        OBJECT IDENTIFIER ::= { id-pkix-ocsp 4 }
id-pkix-ocsp-nocheck         OBJECT IDENTIFIER ::= { id-pkix-ocsp 5 }
id-pkix-ocsp-archive-cutoff  OBJECT IDENTIFIER ::= { id-pkix-ocsp 6 }
id-pkix-ocsp-service-locator OBJECT IDENTIFIER ::= { id-pkix-ocsp 7 }
id-pkix-ocsp-pref-sig-algs   OBJECT IDENTIFIER ::= { id-pkix-ocsp 8 }
id-pkix-ocsp-extended-revoke OBJECT IDENTIFIER ::= { id-pkix-ocsp 9 }

END

Author's Address

   Himanshu Sharma (editor)
   Netskope Inc
   2445 Augustine Dr 3rd floor
   Santa Clara, California 95054
   United States of America
   Email: himanshu@netskope.com
   URI:   www.netskope.com

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