--- 1/draft-ietf-curdle-rc4-die-die-die-01.txt 2017-08-08 07:13:20.877701787 -0700 +++ 2/draft-ietf-curdle-rc4-die-die-die-02.txt 2017-08-08 07:13:20.905702455 -0700 @@ -1,19 +1,19 @@ Internet Engineering Task Force (IETF) L. Camara -Internet-Draft August 1, 2017 +Internet-Draft August 8, 2017 Obsoletes: 4345 Updates: 3501, 4253, 6649, 6733 Intended Status: Best Current Practice -Expires: February 2, 2018 +Expires: February 9, 2018 Deprecating RC4 in all IETF Protocols - draft-ietf-curdle-rc4-die-die-die-01 + draft-ietf-curdle-rc4-die-die-die-02 [[RFC-Editor: Please replace all instances of xxxx in this document with the RFC number of draft-ietf-curdle-des-des-des-die-die-die.]] [[RFC-Editor: please replace the second character of my surname by U+00E2 when publishing as RFC in the header and in all pages. Non-ASCII characters are allowed in RFCs as per RFC 7997.]] Abstract @@ -110,22 +110,21 @@ As the document is over 14 years old, the second paragraph of Section 11.1 of [RFC3501] is replaced with the following paragraph: """ IMAP client and server implementations were formerly required to implement TLS_RSA_WITH_RC4_128_MD5 {TLS}, an extremely weak cipher suite [RFC6151] [RFC6649] [RFC7457] [RFCxxxx] [RFCyyyy] that TLS clients MUST NOT implement per [RFC7465]. Compatibility requirements were removed in the grounds of security, and all clients and servers - SHOULD implement TLS 1.2 {TLS} and the - TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 {TLS} cipher suite. + SHOULD comply to [RFC7525]. """ The TLS reference in [RFC3501] should be replaced with a reference to RFC 5246, and references to RFC 6151, RFC 6649, RFC 7457, RFC 7465, RFC xxxx and this document (as RFC yyyy) should be added. 4. Updates to RFC 4253 RFC 4253 is updated to note the deprecation of arcfour and 3des-cbc. @@ -182,56 +181,38 @@ AES cipher suite). RFC 6733 was published in October 2012, and all paragraphs but the last of Section 13.1 of [RFC6733] are to be replaced with: """ Diameter nodes were formerly required to implement insecure RC4 cipher suites and weak 3DES cipher suites. RC4 MUST NOT be used because it is prohibited by RFC 7465. - Diameter nodes MUST support at least one of the following cipher - suites: - - TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 - TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 - TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 - TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 - TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 - TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 - TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 - TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 - TLS_DHE_RSA_WITH_AES_256_CBC_SHA - TLS_DHE_RSA_WITH_AES_128_CBC_SHA + Diameter nodes MUST comply to [RFC7525]. TLS_RSA_WITH_AES_128_CBC_SHA was not chosen to be absolutely required as Diameter nodes may require all connections to use forward secrecy by only implementing cipher suites with forward secrecy. TLS_RSA_WITH_AES_128_CBC_SHA is not a forward secrecy cipher suite because all connections can be decrypted once the private RSA key is known by an attacker. """ - Several choices were given because of patent concerns with Elliptic - Curve Cryptography (ECC) and problems of older implementations with - ECC and GCM cipher suites, as well as problems of new implementations - with DHE, as they may not support DHE because ECDHE is more - efficient. - 7. Action to be taken RC4 MUST NOT be used in new implementations of IETF protocols, and RC4 MUST be eliminated as fast as possible from the existing Internet infrastructure, as RC4 is insecure [RFC6649] [RFC7457] [RFCxxxx]. - Microsoft Corporation SHOULD take action to eradicate RC4 in all - its software and systems. + Vendors SHOULD take action to eradicate RC4 in all their software + and systems. New IETF protocols MUST NOT allow RC4, and new versions of existing IETF protocols MUST either not allow RC4 or recommend not to use RC4 (for example, using "NOT RECOMMENDED" or "SHOULD NOT"). 8. IANA Considerations IANA may need to take action as the status for RC4 and 3DES algorithms for Secure Shell (SSH) is changed by this document (see Section 6, that updates [RFC4253]). @@ -240,31 +221,32 @@ This document deprecates RC4, that is obsolete cryptography, and several attacks that render it useless have been published [RFC6649]. Refer to Section 5 of [RFCxxxx] for further security considerations. 10. Acknowledgements [[RFC-Editor: When possible, add native names according to the conventions of RFC 7997.]] - Thanks to the following people for writing reference material: + Thanks to the following people: * Sean Turner and Lily Chen for writing RFC 6151, that contains updated security considerations for MD5 and HMAC-MD5. * Love Hornquist Astrand and Tom Yu for writing RFC 6649, that deprecates weak cryptographic algorithms in Kerberos. * Yaron Sheffer, Ralph Holz and Peter Saint-Andre for writing RFC 7457, that summarises known attacks against Transport Layer - Security (TLS). + Security (TLS), and RFC 7525, that provides recommendations for + the use of TLS and Datagram Transport Layer Security (DTLS). * Andrei Popov for writing RFC 7465, that prohibits RC4 cipher suites in Transport Layer Security (TLS). * Julien Elie for sending me an email about the requirements to implement RC4 cipher suites in RFC 3501 and RFC 6733. Also thanks to SSL Labs for capping server grades to B (RC4 only used with older protocols) and C (RC4 used with modern protocols) when servers support RC4, and flagging cipher suites and clients using RC4 @@ -278,72 +260,76 @@ 11.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC6649] Hornquist Astrand, L. and T. Yu, "Deprecate DES, RC4-HMAC- EXP, and Other Weak Cryptographic Algorithms in Kerberos", BCP 179, RFC 6649, July 2012. + [RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre, + "Recommendations for Secure Use of Transport Layer + Security (TLS) and Datagram Transport Layer Security + (DTLS)", BCP 195, RFC 7525, May 2015. + [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, May 2017. [RFCxxxx] Kaduk, B., and M. Short, "Deprecate 3DES and RC4 in Kerberos", draft-ietf-curdle-des-des-des-die-die-die-04, Work in Progress. 11.2. Informative References [RFC3501] Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - Version 4rev1", RFC 3501, March 2003. - [RFC3961] Raeburn, K., "Encryption and Checksum Specifications for - Kerberos 5", RFC 3961, February 2005. - [RFC4253] Ylonen, T., and C. Lonvick, Ed., "The Secure Shell (SSH) Transport Layer Protocol", RFC 4253, January 2006. [RFC4757] Jaganathan, K., Zhu, L., and J. Brezak, "The RC4-HMAC Kerberos Encryption Types Used by Microsoft Windows", RFC 4757, December 2006. [RFC6151] Turner, S., and L. Chen, "Updated Security Considerations for the MD5 Message-Digest and the HMAC-MD5 Algorithms", RFC 6151, March 2011. [RFC6733] Fajardo, V., Ed., Arkko, J., Loughney, J., and G. Zorn, Ed., "Diameter Base Protocol", RFC 6733, October 2012. [RFC7457] Sheffer, Y., Holz, R., and P. Saint-Andre, "Summarizing Known Attacks on Transport Layer Security (TLS) and Datagram TLS (DTLS)", RFC 7457, February 2015. - [RFC7465] Popov, A., "Deprecating RC4 Cipher Suites", RFC 7465, + [RFC7465] Popov, A., "Prohibiting RC4 Cipher Suites", RFC 7465, February 2015. [[RFC-Editor: please replace the 'i' in my name by U+00ED and the first 'a' in the surname by U+00E2, as non-ASCII characters are allowed as per RFC 7997]] 12. Author's Address Luis Camara EMail: Appendix A. Changelog [[RFC-Editor: please remove this section when publishing.]] WG draft (draft-ietf-curdle-rc4-die-die-die): + 02 - addressed Todd Short's concerns. + 01 - massive simplification: removed informational updates, removed all Pre-5378 Material, retracted all "Obsoletes:" except for RFC 4345, removed Appendix A and renamed changelog to Appendix A. 00 - dummy update to get the draft into the curdle WG. Individual draft (draft-luis140219-curdle-rc4-die-die-die): 02 - changed title to "Deprecating RC4 in all IETF Protocols", changed the header of all pages to "Deprecating RC4 in all Protocols",