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

Javascript Object Signing and Encryption                       N. Madden
Internet-Draft                                  Illuminated Security Ltd
Updates: 7518 (if approved)                                18 March 2024
Intended status: Standards Track                                        
Expires: 19 September 2024

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

Abstract

   This draft updates [RFC7518] to deprecate the JWS algorithm "none"
   and the JWE algorithm "RSA1_5".

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-madden-
   jose-deprecate-none-rsa15.html.  Status information for this document
   may be found at https://datatracker.ietf.org/doc/draft-madden-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.

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   This Internet-Draft will expire on 19 September 2024.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  The 'none' algorithm  . . . . . . . . . . . . . . . . . .   3
     1.2.  The 'RSA1_5' algorithm  . . . . . . . . . . . . . . . . .   3
     1.3.  Guidance on deprecation . . . . . . . . . . . . . . . . .   3
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   4
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     5.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     5.2.  Informative References  . . . . . . . . . . . . . . . . .   4
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   5
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   5

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:

   *  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.

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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.

   Although there are some legitimate use-cases for Unsecured JWS, these
   are relatively few in number and can easily be satisfied by simply
   base64url-encoding some JSON instead.  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.SP800-131r2] and a
   CFRG draft [I-D.kario-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.

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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

   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".

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

   [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>.

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   [I-D.kario-rsa-guidance]
              Kario, H., "Implementation Guidance for the PKCS #1 RSA
              Cryptography Specification", Work in Progress, Internet-
              Draft, draft-kario-rsa-guidance-02, 22 November 2023,
              <https://datatracker.ietf.org/doc/html/draft-kario-rsa-
              guidance-02>.

   [NIST.SP800-131r2]
              Barker, E. and A. Roginsky, "NIST SP 800-131A Rev. 2:
              Transitioning the Use of Cryptographic Algorithms and Key
              Lengths", 21 March 2019,
              <https://csrc.nist.gov/pubs/sp/800/131/a/r2/final>.

   [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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