[gnutls-devel] GnuTLS | gnutls server negotiates X25519 instead of X25519MLKEM768 unless FFDHE also configured (#1828)

[Read-only notification of GnuTLS library development activities]

Glenn Strauss commented: https://gitlab.com/gnutls/gnutls/-/work_items/1828#note_3193191731


The bug appears to be in `lib/ext/supported_groups.c:_gnutls_supported_groups_recv_params()` inside the `if (serv_hybrid_idx != -1) { ... }` block where unavailable types represented as -1 are always less than `serv_hybrid_idx` and result in `session->internals.cand_group` not being set using `serv_hybrid_idx`.  If EC *and* FFDHE types are both set, then the PQC hybrid is preferred.  If one of EC or FFDHE is set, but not both, then the PQC hybrid group is not set for `session->internals.cand_group`.

Note: AI-generated code for a fix was posted in https://github.com/mozilla/ssl-config-generator/issues/342#issuecomment-4129456184

-- 
Reply to this email directly or view it on GitLab: https://gitlab.com/gnutls/gnutls/-/work_items/1828#note_3193191731
You're receiving this email because of your account on gitlab.com. Unsubscribe from this thread: https://gitlab.com/-/sent_notifications/3-b7htg7ryv4r9gyynurns9kgve/unsubscribe | Manage all notifications: https://gitlab.com/-/profile/notifications | Help: https://gitlab.com/help


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.gnupg.org/pipermail/gnutls-devel/attachments/20260326/307d2eef/attachment.html>