Adopt BCP 195 for TLS ciphers about standards-maintenance HOT 2 OPEN

Participants are advised to verify their implementation against the recent Standards change:

The following cipher suites SHOULD NOT be supported:
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
TLS_DHE_RSA_WITH_AES_256_GCM_SHA384

and the additional proposal in this issue, to ensure any concerns can be considered during Maintenance Iteration 20.

from standards-maintenance.

The FAPI WG now has proposed wording for both FAPI 2.0 and FAPI-CIBA, but not yet FAPI 1.0 Advanced.

Note BCP195 link: https://www.rfc-editor.org/info/bcp195

FAPI 2.0 wording:

shall follow the recommendations for Secure Use of Transport Layer Security in [@!BCP195];

This change is accompanied by additional requirements the FAPI 2.0 Security Profile introduces for TLS which are not present in FAPI 1.0 Advanced.

FAPI-CIBA wording:

Only the cipher suites recommended in [@!BCP195] shall be permitted.

This change is closely aligned to the original wording in FAPI 1.0 Advanced and alters the constrained list of TLS 1.2 ciphers to instead adopt BCP195. As a result, it is proposed that this wording be adopted. Once FAPI 2.0 is adopted by the Consumer Data Standards, the Security Profile can simply defer to the FAPI 2.0 Security Profile for TLS.

Therefore, there is a small change to the original proposal altering "by" to be "in":

Proposed solution

In addition to section 8.5 of [FAPI-1.0-Advanced] only cipher suites recommended in BCP 195 SHALL be permitted.

from standards-maintenance.