Online Certificate Status Protocol (OCSP) Nonce Extension
RFC 8954
Document | Type |
RFC - Proposed Standard
(November 2020; No errata)
Updates RFC 6960
|
|
---|---|---|---|
Author | Mohit Sahni | ||
Last updated | 2020-11-19 | ||
Replaces | draft-msahni-lamps-ocsp-nonce | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html xml pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Russ Housley | ||
Shepherd write-up | Show (last changed 2020-05-18) | ||
IESG | IESG state | RFC 8954 (Proposed Standard) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Roman Danyliw | ||
Send notices to | Russ Housley <housley@vigilsec.com> | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) M. Sahni, Ed. Request for Comments: 8954 Palo Alto Networks Updates: 6960 November 2020 Category: Standards Track ISSN: 2070-1721 Online Certificate Status Protocol (OCSP) Nonce Extension Abstract This document specifies the updated format of the Nonce extension in the Online Certificate Status Protocol (OCSP) request and response messages. OCSP is used 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. This document updates RFC 6960. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8954. Copyright Notice Copyright (c) 2020 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 extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction 1.1. Terminology 2. OCSP Extensions 2.1. Nonce Extension 3. Security Considerations 3.1. Replay Attack 3.2. Nonce Collision 4. IANA Considerations 5. Changes to Appendix B of RFC 6960 5.1. Changes to Appendix B.1 OCSP in ASN.1 - 1998 Syntax 5.2. Changes to Appendix B.2 OCSP in ASN.1 - 2008 Syntax 6. References 6.1. Normative References 6.2. Informative References Author's Address 1. Introduction This document updates the usage and format of the Nonce extension in OCSP request and response messages. This extension was previously defined in Section 4.4.1 of [RFC6960]. [RFC6960] does not mention any minimum or maximum length of the nonce in the Nonce extension. Lacking limits on the length of the nonce in the Nonce extension, OCSP responders that follow [RFC6960] may be vulnerable to various attacks, like Denial-of-Service attacks [RFC4732] or chosen-prefix attacks (to get a desired signature), and possible evasions using the Nonce extension data. This document specifies a lower limit of 1 and an upper limit of 32 for the length of the nonce in the Nonce extension. This document updates [RFC6960]. 1.1. Terminology 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]. [RFC6960] also defines the standard extensions for OCSP messages based on the extension model employed in X.509 version 3 certificates (see [RFC5280]). This document only specifies the new format for the Nonce extension and does not change the specifications of any of the other standard extensions defined in [RFC6960]. 2.1. Nonce Extension This section replaces the entirety of Section 4.4.1 of [RFC6960], 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 32 octets. A server MUST reject any OCSP request that has a nonce in the Nonce extension with a length of either 0 octets or more than 32 octets with the malformedRequest OCSPResponseStatus, as described in Section 4.2.1 of [RFC6960]. The value of the nonce MUST be generated using a cryptographicallyShow full document text