JOSE: Deprecate 'none' and 'RSA1_5'
draft-ietf-jose-deprecate-none-rsa15-00

Javascript Object Signing and Encryption                       N. Madden
Internet-Draft                                  Illuminated Security Ltd
Updates: 7518 (if approved)                              3 November 2024
Intended status: Standards Track                                        
Expires: 7 May 2025

                  JOSE: Deprecate 'none' and 'RSA1_5'
                draft-ietf-jose-deprecate-none-rsa15-00

Abstract

   This draft updates [RFC7518] to deprecate the JWS algorithm "none"
   and the JWE algorithm "RSA1_5".  These algorithms have known security
   weaknesses.

About This Document

   This note is to be removed before publishing as an RFC.

   The latest revision of this draft can be found at
   https://NeilMadden.github.io/jose-deprecate-none-rsa1_5/draft-ietf-
   jose-deprecate-none-rsa15.html.  Status information for this document
   may be found at https://datatracker.ietf.org/doc/draft-ietf-jose-
   deprecate-none-rsa15/.

   Discussion of this document takes place on the Javascript Object
   Signing and Encryption Working Group mailing list
   (mailto:jose@ietf.org), which is archived at
   https://mailarchive.ietf.org/arch/browse/jose/.  Subscribe at
   https://www.ietf.org/mailman/listinfo/jose/.

   Source for this draft and an issue tracker can be found at
   https://github.com/NeilMadden/jose-deprecate-none-rsa1_5.

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/.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  The 'none' algorithm  . . . . . . . . . . . . . . . . . .   3
     1.2.  The 'RSA1_5' algorithm  . . . . . . . . . . . . . . . . .   4
     1.3.  Guidance on deprecation . . . . . . . . . . . . . . . . .   4
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   5
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
     4.1.  JOSE Algorithm Deprecations . . . . . . . . . . . . . . .   5
     4.2.  Updated Review Instructions for Designated Experts  . . .   5
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     5.1.  Normative References  . . . . . . . . . . . . . . . . . .   6
     5.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   7
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   JSON Web Algorithms (JWA, [RFC7518]) introduced several standard
   algorithms for both JSON Web Signature (JWS) and JSON Web Encryption
   (JWE).  Many of these algorithms have stood the test of time and are
   still in widespread use.  However, some algorithms have proved to be
   difficult to implement correctly leading to exploitable
   vulnerabilities.  This draft deprecates two such algorithms:

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   *  The JWS "none" algorithm, which indicates that no security is
      applied to the message at all.

   *  The JWE "RSA1_5" algorithm, which indicates RSA encryption with
      PKCS#1 version 1.5 padding.

   Note that RSA signatures using PKCS#1 version 1.5 padding (RS256,
   RS384, and RS512) are unchanged by this specification and can still
   be used.

1.1.  The 'none' algorithm

   The "none" algorithm creates an Unsecured JWS, whose contents are
   completely unsecured as the name implies.  Despite strong guidance in
   the original RFC around not accepting Unsecured JWS by default, many
   implementations have had serious bugs due to accepting this
   algorithm.  In some cases, this has led to a complete loss of
   security as authenticity and integrity checking can be disabled by an
   adversary simply by changing the algorithm ("alg") header in the JWS.
   The website [howmanydays] tracks public vulnerabilities due to
   implementations mistakenly accepting the "none" algorithm.  It
   currently lists 12 reports, many of which have high impact ratings.
   The following is a partial list of issues known to have been caused
   by misuse of the "none" algorithm, with a Common Vulnerability
   Enumeration [CVE] identifier, and a Common Vulnerability Scoring
   System [CVSS] score indicating the severity of the impact:

   *  CVE-2018-1000531 (https://nvd.nist.gov/vuln/detail/CVE-
      2018-1000531) - CVSS: 7.5 (High)

   *  CVE-2017-10862 (https://nvd.nist.gov/vuln/detail/CVE-2017-10862) -
      CVSS: 5.3 (Medium)

   *  CVE-2022-23540 (https://nvd.nist.gov/vuln/detail/CVE-2022-23540) -
      CVSS: 7.6 (High)

   *  CVE-2020-15957 (https://nvd.nist.gov/vuln/detail/CVE-2020-15957) -
      CVSS: 7.5 (High)

   *  CVE-2021-29500 (https://nvd.nist.gov/vuln/detail/CVE-2021-29500) -
      CVSS: 7.5 (High)

   *  CVE-2021-29451 (https://nvd.nist.gov/vuln/detail/CVE-2021-29451) -
      CVSS: 9.1 (Critical)

   *  CVE-2021-29455 (https://nvd.nist.gov/vuln/detail/CVE-2021-29455) -
      CVSS: 7.5 (High)

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   *  CVE-2021-22160 (https://nvd.nist.gov/vuln/detail/CVE-2021-22160) -
      CVSS: 9.8 (Critical)

   *  CVE-2021-32631 (https://nvd.nist.gov/vuln/detail/CVE-2021-32631) -
      CVSS: 6.5 (Medium)

   *  CVE-2023-29357 (https://nvd.nist.gov/vuln/detail/CVE-2023-29357) -
      CVSS: 9.8 (Critical)

   Many other vulnerabilities have been reported without an accompanying
   CVE, which we do not list here.

   Although there are some legitimate use-cases for Unsecured JWS, these
   are relatively few in number and can easily be satisfied by
   alternative means.  The small risk of breaking some of these use-
   cases is far outweighed by the improvement in security for the
   majority of JWS users who may be impacted by accidental acceptance of
   the "none" algorithm.

1.2.  The 'RSA1_5' algorithm

   The "RSA1_5" algorithm implements RSA encryption using PKCS#1 version
   1.5 padding [RFC8017].  This padding mode has long been known to have
   security issues, since at least Bleichenbacher's attack in 1998.  It
   was supported in JWE due to the wide deployment of this algorithm,
   especially in legacy hardware.  However, more secure replacements
   such as OAEP [RFC8017] or elliptic curve encryption algorithms are
   now widely available.  NIST has disallowed the use of this encryption
   mode for federal use since the end of 2023 [NIST.SP800-131Ar2] and a
   CFRG draft [I-D.irtf-cfrg-rsa-guidance] also deprecates this
   encryption mode for IETF protocols.  This document therefore also
   deprecates this algorithm for JWE.

1.3.  Guidance on deprecation

   Both of the algorithms listed above are deprecated for use in JWS and
   JWE.  JOSE library developers SHOULD deprecate support for these
   algorithms and commit to a timeline for removal.  Application
   developers SHOULD disable support for these algorithms by default.
   New specifications building on top of JOSE MUST NOT allow the use of
   either algorithm.

   The IANA algorithm registry distinguishes between algorithms that are
   "Deprecated" and those that are "Prohibited".  The algorithms
   identified in this document are to be marked as Deprecated only.
   Existing specifications and applictions that make use of these
   algorithms can continue to do so, but should consider adopting
   alternatives in future updates.

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2.  Conventions and Definitions

   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.

3.  Security Considerations

   No security issues are introduced by this specification.

4.  IANA Considerations

4.1.  JOSE Algorithm Deprecations

   The following changes are to be made to the IANA JOSE Web Signature
   and Encryption Algorithms registry:

   *  For the entry with Algorithm Name "none", update the JOSE
      Implementation Requirements to "Deprecated".

   *  For the entry with Algorithm Name "RSA1_5", update the JOSE
      Implementation Requirements to "Deprecated".

4.2.  Updated Review Instructions for Designated Experts

   The review instructions for the designated experts for the IANA "JSON
   Web Signature and Encryption Algorithms" registry [IANA.jose] in
   Section 7.1 of [RFC7518] are updated to add these additional review
   criteria:

   *  For JWS signature algorithms, only algorithms that are reasonably
      conjectured to meet the standard security goal of existential
      unforgeability under a chosen message attack (EUF-CMA) should be
      considered for approval.

   *  For JWE key management algorithms (specified with the "alg"
      header), only algorithms that are reasonably conjectured to meet
      the standard security goal of indistinguishability under an
      adaptive chosen ciphertext attack (IND-CCA2) should be considered
      for approval.

   *  For JWE content encryption methods (specified with the "enc"
      header), only algorithms that are reasonably conjectured to meet
      the standard security goal of authenticated encryption with
      associated data (AEAD) should be considered for approval.

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5.  References

5.1.  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/rfc/rfc2119>.

   [RFC7518]  Jones, M., "JSON Web Algorithms (JWA)", RFC 7518,
              DOI 10.17487/RFC7518, May 2015,
              <https://www.rfc-editor.org/rfc/rfc7518>.

   [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/rfc/rfc8174>.

5.2.  Informative References

   [CVE]      MITRE, "Common Vulnerability Enumeration Database", n.d.,
              <https://cve.mitre.org>.

   [CVSS]     FIRST, "Common Vulnerability Scoring System", n.d.,
              <https://www.first.org/cvss/>.

   [howmanydays]
              Sanderson, J., "How Many Days Has It Been Since a JWT
              alg:none Vulnerability?", 25 September 2023, <https://gith
              ub.com/zofrex/howmanydayssinceajwtalgnonevuln/blob/deploy/
              data/vulns.yml>.

   [I-D.irtf-cfrg-rsa-guidance]
              Kario, A., "Implementation Guidance for the PKCS #1 RSA
              Cryptography Specification", Work in Progress, Internet-
              Draft, draft-irtf-cfrg-rsa-guidance-01, 3 September 2024,
              <https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-
              rsa-guidance-01>.

   [IANA.jose]
              IANA, "JSON Object Signing and Encryption (JOSE)",
              <https://www.iana.org/assignments/jose>.

   [NIST.SP800-131Ar2]
              Barker, E. and A. Roginsky, "Transitioning the use of
              cryptographic algorithms and key lengths", National
              Institute of Standards and Technology,
              DOI 10.6028/nist.sp.800-131ar2, March 2019,
              <https://doi.org/10.6028/nist.sp.800-131ar2>.

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   [RFC8017]  Moriarty, K., Ed., Kaliski, B., Jonsson, J., and A. Rusch,
              "PKCS #1: RSA Cryptography Specifications Version 2.2",
              RFC 8017, DOI 10.17487/RFC8017, November 2016,
              <https://www.rfc-editor.org/rfc/rfc8017>.

Acknowledgments

Author's Address

   Neil Madden
   Illuminated Security Ltd
   Email: neil@illuminated-security.com

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