Internet DRAFT - draft-hsharma-lamps-ocsp-nonce-update
draft-hsharma-lamps-ocsp-nonce-update
Internet Engineering Task Force H. Sharma, Ed.
Internet-Draft Netskope Inc
Updates: 8954 (if approved) 29 January 2024
Intended status: Standards Track
Expires: 1 August 2024
Online Certificate Status Protocol (OCSP) Nonce Extension
draft-hsharma-lamps-ocsp-nonce-update-06
Abstract
This document updates the Nonce extension section of RFC-8954. Nonce
extension is an optional extension for Online Certificate Status
Protocol (OCSP) request and response messages. 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 that is longer than 32 octets. This document
updates the maximum allowed length of Nonce to 128 octets.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 1 August 2024.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
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
and restrictions with respect to this document. Code Components
Sharma Expires 1 August 2024 [Page 1]
Internet-Draft draft-hsharma-lamps-ocsp-nonce-update-06 January 2024
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
2. OCSP Extensions . . . . . . . . . . . . . . . . . . . . . . . 2
2.1. Nonce Extension . . . . . . . . . . . . . . . . . . . . . 3
3. Security Considerations . . . . . . . . . . . . . . . . . . . 3
3.1. Replay Attack . . . . . . . . . . . . . . . . . . . . . . 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5. Changes to Appendix B of RFC 6960. . . . . . . . . . . . . . 4
5.1. Changes to Appendix B.1 OCSP in ASN.1 - 1998 Syntax . . . 4
5.2. Changes to Appendix B.2 OCSP in ASN.1 - 2008 Syntax . . . 4
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Normative References . . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
Nonce extension was previously defined in Section 4.4.1 of [RFC6960]
and updated in [RFC8954]. [RFC8954] enforces 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.
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 enforce 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
Sharma Expires 1 August 2024 [Page 2]
Internet-Draft draft-hsharma-lamps-ocsp-nonce-update-06 January 2024
[RFC6960].
2.1. Nonce Extension
This section replaces the entirety of Section 2.1 of [RFC8954], which
describes the OCSP 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 value of the 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 SHOULD use a minimum
length of 32 octets for Nonce in the Nonce extension. RFC
8954-compliant implementations will be unable to process nonces
generated per the new specification with sizes in excess of what was
permitted by RFC 8954.
OCSP resonder that implements this document MUST reject any OCSP
request that has a Nonce in the Nonce extension 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 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))
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
Sharma Expires 1 August 2024 [Page 3]
Internet-Draft draft-hsharma-lamps-ocsp-nonce-update-06 January 2024
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.
4. IANA Considerations
This memo includes no request to IANA.
5. Changes to Appendix B of RFC 6960.
This section updates the ASN.1 definitions of the OCSP Nonce
extension in Appendices B.1 and B.2 of [RFC6960]. Appendix B.1
defines OCSP using ASN.1 - 1998 Syntax; Appendix B.2 defines OCSP
using ASN.1 - 2008 Syntax.
5.1. Changes to Appendix B.1 OCSP in ASN.1 - 1998 Syntax
OLD Syntax:
The definition of OCSP Nonce extension is not provided in
Appendix B.1 of [RFC6960] for the ASN.1 - 1998 Syntax.
NEW Syntax:
Nonce ::= OCTET STRING(SIZE(1..128))
5.2. Changes to Appendix B.2 OCSP in ASN.1 - 2008 Syntax
OLD Syntax:
re-ocsp-nonce EXTENSION ::= { SYNTAX OCTET STRING IDENTIFIED
BY id-pkix-ocsp-nonce }
NEW Syntax:
re-ocsp-nonce EXTENSION ::= { SYNTAX OCTET STRING(SIZE(1..128))
IDENTIFIED BY id-pkix-ocsp-nonce }
Sharma Expires 1 August 2024 [Page 4]
Internet-Draft draft-hsharma-lamps-ocsp-nonce-update-06 January 2024
6. References
6.1. Normative References
[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>.
[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>.
[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>.
[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>.
[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>.
[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>.
[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>.
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
Sharma Expires 1 August 2024 [Page 5]
