Plans for a PQC-only TLS group list alias?

[Gianluigi Ianniello]

Hello,

We use OpenSSL in our communication framework and are preparing to enforce (in the future) quantum-resistant TLS 1.3 key establishment, with no fallback to classical-only groups.

We can currently do this by passing an explicit list of group names to SSL_CTX_set1_groups_list(). However, we would prefer not to maintain that list ourselves: it could become outdated as new groups are introduced or recommendations change.

File ssl/t1_lib.c defines DEFAULT_GROUP_NAME and TLS_DEFAULT_GROUP_LIST, as well as a DEFAULT_SUITE_B pseudo-group:
https://github.com/openssl/openssl/blob/2fa266a4430da52654f612381bdb44e094841113/ssl/t1_lib.c#L211

Is there an existing mechanism for selecting an OpenSSL-recommended list containing only hybrid and purely post-quantum groups?

An alias usable with SSL_CTX_set1_groups_list(), such as DEFAULT_PQC, would suit our needs, but we could also adapt our code to use a different configuration mechanism. The goal is to enforce "no classical-only key exchange" and keep the group list up to date simply by upgrading OpenSSL.

We would also like to be able to exclude a specific group (for example, if an issue is discovered with it, pending an OpenSSL update that addresses the issue or removes the group from the defaults). I understand that syntax "DEFAULT:-GroupName" already supports this. If an alias such as DEFAULT_PQC were introduced, it would be useful to retain that exclusion capability.

Cheers,
Gianluigi