1. Confirmation tag verification (RFC 9420 Section 6.1):
processCommit now accepts optional confirmationTag parameter and
verifies it against HMAC(confirmation_key, confirmed_transcript_hash).
Rejects commits with invalid confirmation tags.
2. Proper ConfirmedTranscriptHashInput (RFC 9420 Section 8.2):
buildConfirmedTranscriptHashInput() constructs the RFC-compliant
structure: wire_format || FramedContent (group_id, epoch, sender,
content_type, commit) || signature. Used in both commit() and
processCommit() for consistent transcript hashing.
3. Proposal reference resolution (RFC 9420 Section 12.2):
processCommit now resolves ProposalOrRef.Reference entries by
computing RefHash("MLS 1.0 Proposal Reference", proposal_bytes)
and matching against pending proposals. Previously skipped.
4. PSK semantic support (RFC 9420 Section 8.4):
- Added pskStore (Map<String, ByteArray>) for PSK registration
- registerPsk(pskId, psk) to store pre-shared keys
- proposePsk() to create PSK proposals
- computePskSecret() chains Extract over all PSK values
- PSK secret integrated into KeySchedule.deriveEpochSecrets()
5. ReInit proposal flow (RFC 9420 Section 12.1.5):
- proposeReInit() creates ReInit proposals with new group parameters
- applyProposal sets reInitPending field
- Application can check reInitPending to know when to create new group
- Full TLS encoding/decoding already in place from earlier commit
All 120 MLS tests pass (41 interop + 79 unit), 0 failures.
https://claude.ai/code/session_01NocQDWj2Y92FugjfgazzL3
Claude
1bd5aa95e5