Method TranscriptTestVector

mlspp/lib/mls_vectors/src/mls_vectors.cpp:952–996

TranscriptTestVector

/// TranscriptTestVector
///
TranscriptTestVector::TranscriptTestVector(CipherSuite suite)
  : PseudoRandom(suite, "transcript")
  , cipher_suite(suite)
  , interim_transcript_hash_before(prg.secret("interim_transcript_hash_before"))
{
  auto transcript = TranscriptHash(suite);
  transcript.interim = interim_transcript_hash_before;

  auto group_id = prg.secret("group_id");
  auto epoch = prg.uint64("epoch");
  auto group_context_obj =
    GroupContext{ suite,
                  group_id,
                  epoch,
                  prg.secret("tree_hash_before"),
                  prg.secret("confirmed_transcript_hash_before"),
                  {} };
  auto group_context = tls::marshal(group_context_obj);

  auto init_secret = prg.secret("init_secret");
  auto ks_epoch = KeyScheduleEpoch(suite, init_secret, group_context);

  auto sig_priv = prg.signature_key("sig_priv");
  auto leaf_index = LeafIndex{ 0 };

  authenticated_content = AuthenticatedContent::sign(
    WireFormat::mls_public_message,
    GroupContent{
      group_id, epoch, { MemberSender{ leaf_index } }, {}, Commit{} },
    suite,
    sig_priv,
    group_context_obj);

  transcript.update_confirmed(authenticated_content);

  const auto confirmation_tag = ks_epoch.confirmation_tag(transcript.confirmed);
  authenticated_content.set_confirmation_tag(confirmation_tag);

  transcript.update_interim(authenticated_content);

  // Store the required data
  confirmation_key = ks_epoch.confirmation_key;
  confirmed_transcript_hash_after = transcript.confirmed;
  interim_transcript_hash_after = transcript.interim;
}

std::optional<std::string>
TranscriptTestVector::verify() const