Restrict DTLS 1.2 key exchange to P-256/P-384 (for now)#70
Merged
Conversation
algesten
changed the title
xnorpx
approved these changes
Mar 1, 2026
Adding X25519 support for DTLS 1.3 inadvertently exposed it to DTLS 1.2 via the shared kx_groups field. Add supported_dtls12_kx_groups() filter and use it in all DTLS 1.2 code paths.
algesten
force-pushed
the
fix/dtls12-kx-groups
branch
from
edd4dc2 to
18e11f9
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
kx_groupsfield onCryptoProvidersupported_dtls12_kx_groups()filter that restricts to P-256/P-384 (the pre-3222754 set)SupportedGroupsExtension::from_provider(),init_ecdh_server(), andprocess_ecdh_params()Discussed here: comment