<?xml version="1.0" encoding="utf-8"?>
<?xml-model href="rfc7991bis.rnc"?>  <!-- Required for schema validation and schema-aware editing -->
<!-- <?xml-stylesheet type="text/xsl" href="rfc2629.xslt" ?> -->
<!-- This third-party XSLT can be enabled for direct transformations in XML processors, including most browsers --> encoding="UTF-8"?>

<!DOCTYPE rfc [
  <!ENTITY nbsp    "&#160;">
  <!ENTITY zwsp   "&#8203;">
  <!ENTITY nbhy   "&#8209;">
  <!ENTITY wj     "&#8288;">
]>
<!-- If further character entities are required then they should be added to the DOCTYPE above.
     Use of an external entity file is not recommended. -->

<rfc xmlns:xi="http://www.w3.org/2001/XInclude"  category="std"  consensus="true" docName="draft-ietf-lamps-ocsp-nonce-update-11"  number="9654" tocInclude="true" sortRefs="true" symRefs="true" ipr="trust200902"  obsoletes="8954"  updates="6960"  submissionType="IETF" xml:lang="en"  version="3">

  <front>
    <title abbrev="draft-ietf-lamps-ocsp-nonce-update-11">Online abbrev="OCSP Nonce Extension">Online Certificate Status Protocol (OCSP) Nonce Extension</title>
    <!--  [REPLACE/DELETE] abbrev. The abbreviated title is required if the full title is longer than 39 characters -->
    <seriesInfo name="Internet-Draft" value="draft-ietf-lamps-ocsp-nonce-update-11"/> name="RFC" value="9654"/>
    <author fullname="Himanshu Sharma" initials="H" role="editor" surname="Sharma">
      <!-- [CHECK]
             * initials should not include an initial for the surname
             * role="editor" is optional -->
    <!-- Can have more than one author -->

    <!-- all of the following elements are optional -->
      <organization>Netskope Inc</organization>
      <address>
        <postal>
          <!-- Reorder these if your country does things differently -->
          <street>2445 Augustine Dr 3rd floor</street>
          <city>Santa Clara</city>
          <region>California</region>
          <code>95054</code>
          <country>USA</country>
          <!-- Uses two letter country code -->
          <country>United States of America</country>
        </postal>
        <email>himanshu@netskope.com</email>
        <uri>www.netskope.com</uri>
      </address>
    </author>

    <date month="August" year="2024"/>
    <!-- On draft subbmission:
         * If only the current year is specified, the current day and month will be used.
         * If the month and year are both specified and are the current ones, the current day will
           be used
         * If the year is not the current one, it is necessary to specify at least a month and day="1" will be used.
    -->

    <area>General</area>
    <workgroup>Internet Engineering Task Force</workgroup>
    <!-- "Internet Engineering Task Force" is fine for individual submissions.  If this element is
          not present, the default is "Network Working Group", which is used by the RFC Editor as
          a nod to the history of the RFC Series. -->

    <keyword>Online Certificate Status Protocol (OCSP) Nonce Extension</keyword>
    <!-- [REPLACE/DELETE]. Multiple allowed.  Keywords are incorporated into HTML output files for
         use by search engines. -->

    <area>SEC</area>
    <workgroup>lamps</workgroup>

<keyword>OCSP</keyword>
<keyword>Nonce</keyword>
<keyword>backward compatibility</keyword>

    <abstract>
        <t>
            RFC 8954 imposed the size constraints on the
            optional Nonce extension for the Online Certificate Status Protocol (OCSP).
            OCSP is used for checking to check the status of a certificate, and the Nonce extension
            is used to cryptographically bind an OCSP response message to a particular
            OCSP request message.
        </t>
        <t>
            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 the "Nonce" section of RFC 6960 to clearly define and differentiate the encoding format and values distinctively for an easier implementation and understanding.
   This document obsoletes RFC 8954 and provides 8954, which includes updated ASN.1 modules
   for OCSP, and updates RFC 6960.
        </t>
    </abstract>

  </front>

  <middle>

    <section>
      <name>Introduction</name>
        <t>
            The Nonce extension was previously defined in Section 4.4.1 of <xref target="RFC6960"/>. target="RFC6960" sectionFormat="of" section="4.4.1"/>.
                The Nonce cryptographically binds an OCSP request and a response. It guarantees the freshness of an OCSP response and to avoid avoids replay attacks.
            This extension was updated in <xref target="RFC8954"/>.  <xref target="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 requester and responder use a
                Nonce with a minimum length of 32 octets.
        </t>
      <section>
        <name>Requirements Language</name>
        <t>The
        <t>
    The key words "MUST", "MUST NOT", "REQUIRED", "SHALL",
          "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT
          RECOMMENDED", "MAY", "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>",
    "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>",
    "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>",
    "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
    "<bcp14>MAY</bcp14>", and "OPTIONAL" "<bcp14>OPTIONAL</bcp14>" in this document are to be
    interpreted as described in BCP 14 BCP&nbsp;14 <xref target="RFC2119"/> <xref
    target="RFC8174"/> when, and only when, they appear in all capitals, as
    shown here.</t> here.
        </t>
      </section>
    </section>

    <section>
      <name>OCSP Extensions</name>
      <t>
          The message formats for OCSP requests and responses are defined in
   <xref target="RFC6960"/> and the Nonce extension was updated in <xref target="RFC8954"/>.  <xref target="RFC6960"/>
   also defines the standard extensions for OCSP messages based on the
   extension model employed in X.509 version 3 certificates (see
   <xref target="RFC5280"/>).  <xref target="RFC8954"/> replaces this section <xref target="RFC6960" sectionFormat="of" section="4.4.1"/> 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 <xref target="RFC6960"/>.
      </t>
   <section>
   <name>Nonce Extension</name>
   <t>
       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 is included as
       one of the responseExtensions.  In both the request and the response,
       the Nonce will be is identified by the object identifier id-pkix-ocsp-
       nonce, 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 <bcp14>MUST</bcp14> be at
       least 1 octet and can be up to 128 octets. [RFC8954] Implementations compliant
       implementations with <xref target="RFC8954"/>
       will not be unable able to process nonces
       generated per the new specification with sizes in excess of the limit
       of 32 octets that was (32 octets) specified in [RFC8954]. <xref target="RFC8954"/>.
   </t>
   <t>
        An OCSP requester that implements the extension in this document MUST <bcp14>MUST</bcp14> use a minimum
       length of 32 octets for Nonce in the Nonce extension.
   </t>
   <t>
       An OCSP responder , supporting that supports the Nonce extension, MUST extension <bcp14>MUST</bcp14> accept Nonce lengths
   of at least 16 octets and up to and including 32 octets. Responder MAY A responder <bcp14>MAY</bcp14> choose to respond without the Nonce extension
   for requests where in which the length of the Nonce is in between 1 octet and
       15 octets or 33 octets and 128 octets.
   </t>
   <t>
       Responders,
       Responders that implements implement the extension in this document MUST <bcp14>MUST</bcp14> reject any OCSP
   request that has a Nonce with a length of either 0 octets or more greater
   than 128 octets, with the malformedRequest OCSPResponseStatus as
       described in Section 4.2.1 of [RFC6960]. <xref target="RFC6960" sectionFormat="of" section="4.2.1"/>.
   </t>
   <t>
       The value of the Nonce MUST <bcp14>MUST</bcp14> be generated using a cryptographically
       strong pseudorandom number generator (see <xref target="RFC4086"/>). The minimum
           Nonce length of 1 octet is defined to provide backward compatibility
           with older OCSP requester requesters that follow <xref target="RFC6960"/>.
       </t>
    <artwork><![CDATA[
    <sourcecode type="asn.1"><![CDATA[
id-pkix-ocsp           OBJECT IDENTIFIER ::= { id-ad-ocsp }
id-pkix-ocsp-nonce     OBJECT IDENTIFIER ::= { id-pkix-ocsp 2 }
Nonce ::= OCTET STRING(SIZE(1..128))
    ]]></artwork>
    <artwork><![CDATA[

   Example
    ]]></sourcecode>

<t>The following is an example of an encoded OCSP Nonce extension with 32 octet a 32-octet Nonce in
   hexadecimal format. format.</t>

    <artwork><![CDATA[
   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
]]></artwork>

<t>
   Here is the decoded version of the above example.
   Offset, Length Length, and Object Identifier are in decimal.
</t>
<artwork><![CDATA[
   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
                 :  }
                 : }
    ]]></artwork>
    </section>
    </section>
    <section>
        <name>Security Considerations</name>
        <t>The security considerations of OCSP, in general, are described in
   <xref target="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 requester's nonce value in the OCSP response makes sure ensures that
   the response is the latest most recent response from the server and not an old
       copy.</t>
        <section>
            <name>Replay Attack</name>
            <t>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 requester has sent the Nonce extension in the
   request <xref target="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.</t>
        </section>
    </section>
    <section anchor="IANA">
      <name>IANA Considerations</name>
      <t>
          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 modules in the "SMI Security for PKIX
          Module Identifier" registry (1.3.6.1.5.5.7.0), Appendixes <xref target="asn-1998" format="counter"/> and the Description
          for the new OID should be set to "id-mod-ocsp-2024-88".
      </t>
      <t>
          For the ASN.1 Module in Appendix A.2,
<xref target="asn-2008" format="counter"/>, IANA is requested to assign an
          object identifier (OID) for the module identifier to replace TBD2. The
          OID for has assigned the module should be allocated following
          object identifiers (OIDs) 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". (1.3.6.1.5.5.7.0): </t>

<table anchor="iana-tab">
  <name></name>
  <thead>
    <tr>
      <th>Value</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>111</td>
      <td>id-mod-ocsp-2024-88</td>
    </tr>
    <tr>
      <td>112</td>
      <td>id-mod-ocsp-2024-08</td>
    </tr>
  </tbody>
</table>
    </section>
    <section anchor="Acknowledgements" numbered="false">
      <name>Acknowledgements</name>
      <t>
          The authors of this document wish to thank Mohit Sahni for his work to produce <xref target="RFC8954"/>.
      </t>
      <t>
          The authors wish to thank Russ Housley, Corey Bonnell,
          Michael StJohns and Carl Wallace for the feedback and suggestions.

      </t>
    </section>
    <!-- NOTE: The Acknowledgements and Contributors sections are at the end of this template -->

  </middle>

  <back>
    <references>
      <name>References</name>
      <references>
        <name>Normative References</name>

        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4086.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5019.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5280.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6960.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8954.xml"/>
        <!-- The recommended and simplest way to include a well known reference -->

    </references>
    <references>
        <name>Informative References</name>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5912.xml"/>

<reference anchor="Errata5891" target="https://www.rfc-editor.org/errata/eid5891" quoteTitle="false"> anchor="Err5891" quote-title="false" target="https://www.rfc-editor.org/errata/eid5891">
   <front>
      <title>Erratum ID 5891</title>
      <author>
              <organization showOnFrontPage="true">RFC
         <organization>RFC Errata</organization>
      </author>
   </front>
   <refcontent>RFC 6960</refcontent>
</reference>

    </references>
    </references>

    <section anchor="asn-modules" title="ASN.1 Modules">
    <t>
        This section includes the ASN.1 modules for OCSP and replaces the entirity of Section 5 entirety of <xref target="RFC8954"/>. target="RFC8954" sectionFormat="of" section="5"/>.
        It addresses Errata id ID 5891 <xref target="Errata5891"/> target="Err5891"/> as well.
    </t>
    <t>
        Appendix A.1
        <xref target="asn-1998"/> 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 module in <xref target="RFC6960"/>. target="RFC6960" sectionFormat="of" section="B.1"/>.
    </t>
    <t>
        Appendix A.2
        <xref target="asn-2008"/> includes an ASN.1 module, corresponding to the module
        present in A.1, <xref target="asn-1998"/>, that conforms to the 2008 version of ASN.1.  This module
        replaces the modules in Section 4 of <xref target="RFC5912"/> target="RFC5912" sectionFormat="of" section="4"/> and Appendix B.2 of
        <xref target="RFC6960"/>. target="RFC6960" sectionFormat="of" section="B.2"/>. Although a 2008 ASN.1 module is provided, the module in
        Appendix A.1
        <xref target="asn-1998"/> remains the normative module as per the policy of the PKIX working group. Working Group.
    </t>
    <section anchor="asn-1998" title="OCSP in ASN.1 - 1998 Syntax">
        <artwork><![CDATA[
        <sourcecode type="asn.1" markers="true"><![CDATA[
OCSP-2024-88
      {iso(1)
      { iso(1) identified-organization(3) dod(6) internet(1)
        security(5) mechanisms(5) pkix(7) id-mod(0)
      id-mod-ocsp-2024-88(TBD1)}
        id-mod-ocsp-2024-88(111) }

DEFINITIONS EXPLICIT TAGS ::=
BEGIN

IMPORTS

   -- PKIX Certificate Extensions
    AuthorityInfoAccessSyntax, CRLReason, GeneralName
    FROM PKIX1Implicit88 -- From [RFC5280]
    { 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 -- From [RFC5280]
    { 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)) STRING (SIZE(1..128))

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

CertID ::= SEQUENCE {
   hashAlgorithm   AlgorithmIdentifier,
   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
                           -- 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)

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 }
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
            ]]>
    </artwork>
    </sourcecode>
    </section>
    <section anchor="asn-2008" title="OCSP in ASN.1 - 2008 Syntax">
        <artwork><![CDATA[
        <sourcecode type="asn.1" markers="true"><![CDATA[
OCSP-2024-08
     {iso(1)
     { iso(1) identified-organization(3) dod(6) internet(1)
       security(5) mechanisms(5) pkix(7) id-mod(0)
     id-mod-ocsp-2024-08(TBD2)}
       id-mod-ocsp-2024-08(112) }

DEFINITIONS EXPLICIT TAGS ::=
BEGIN

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

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

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

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

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

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-nonce |
                    re-ocsp-response, ...,
                    re-ocsp-preferred-signature-algorithms}} 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)) STRING (SIZE(1..128))

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

CertID ::= SEQUENCE {
   hashAlgorithm   AlgorithmIdentifier
                                {DIGEST-ALGORITHM,
                       { 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
   unauthorized      (6)  -- Request unauthorized
}

RESPONSE ::= TYPE-IDENTIFIER

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

ResponseBytes ::= SEQUENCE {
   responseType        RESPONSE.
                           &id  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   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}}
                              {{ 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) and number
            -- of unused bits)

SingleResponse ::= SEQUENCE {
  certID                CertID,
  certStatus            CertStatus,
  thisUpdate            GeneralizedTime,
  nextUpdate        [0] EXPLICIT GeneralizedTime OPTIONAL,
  singleExtensions  [1] EXPLICIT Extensions{{re-ocsp-crl Extensions
                        {{ re-ocsp-crl |
                           re-ocsp-archive-cutoff |
                           CrlEntryExtensions, ...}
                                            }
                           ... }} 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, {...}},  AlgorithmIdentifier
                      { SIGNATURE-ALGORITHM, {...} },
   certIdentifier AlgorithmIdentifier{PUBLIC-KEY, 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
    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
            ]]>
    </artwork>
    </sourcecode>
    </section>
    </section>

    <section anchor="Acknowledgements" numbered="false">
      <name>Acknowledgements</name>
      <t>
          The authors of this document thank <contact fullname="Mohit Sahni"/> for his work to produce <xref target="RFC8954"/>.
      </t>
      <t>
          The authors also thank <contact fullname="Russ Housley"/>, <contact fullname="Corey Bonnell"/>,
          <contact fullname="Michael StJohns"/>, <contact fullname="Tomas Gustavsson"/>, and <contact fullname="Carl Wallace"/> for their feedback and suggestions.

      </t>
    </section>
</back>
</rfc>