diff --git a/draft-ietf-tls-deprecate-obsolete-kex.md b/draft-ietf-tls-deprecate-obsolete-kex.md index b080024..1bc2d21 100644 --- a/draft-ietf-tls-deprecate-obsolete-kex.md +++ b/draft-ietf-tls-deprecate-obsolete-kex.md @@ -263,6 +263,8 @@ Note that TLS 1.0 and 1.1 are deprecated by {{!RFC8996}} and TLS 1.3 does not support ECDH {{!I-D.ietf-tls-rfc8446bis}}.) This includes all cipher suites listed in the table in {{appendix-ecdh}}. +In addition, to avoid the use of non-ephemeral Diffie Hellman, clients SHOULD NOT use use and server SHOULD NOT accept certificates with fixed DH parameters. These certificate types are rsa_fixed_dh, dss_fixed_dh, rsa_fixed_ecdh and ecdsa_fixed_ecdh. These values only apply to TLS versions of 1.2 and below. + # Ephemeral Finite Field Diffie Hellman {#dhe} Clients MUST NOT offer and servers MUST NOT select FFDHE cipher suites in TLS 1.2 connections. @@ -281,6 +283,13 @@ already marked as not recommended in the "TLS Cipher Suites" registry. This document requests IANA to mark the cipher suites listed in {{appendix-dh}}, {{appendix-ecdh}}, {{appendix-dhe}} and in {{appendix-rsa}} as "D" in the "Recommended" column, see {{I-D.ietf-tls-rfc8447bis}}, in the "TLS Cipher Suites" registry. +This document also requests IANA to populate a "D" in the recommended column of the TLS ClientCertificateType Identifiers for the following certificate types: + +- rsa_fixed_dh (3) +- dss_fixed_dh (4) +- rsa_fixed_ecdh (65) +- ecdsa_fixed_ecdh (66) + # Security Considerations {#sec-considerations} Non-ephemeral finite field DH cipher suites (TLS_DH_\*), as well as ephemeral key reuse