sorrydave

Should be production-quality Python library for the DAVE (Discord Audio/Video End-to-End Encryption) protocol. Currently it passes the tests i made but i have problem using it. I mean the library it uses(rfc9420) passes official vectors. It implements the protocol as a pure data-transformation and state-management layer on top of rfc9420 (PyMLS), with no I/O or networking: you pass in bytes (Voice Gateway opcodes, encoded media frames) and get back bytes (opcode payloads, encrypted/decrypted frames).

Features

• MLS integration: Key packages, external sender handling, proposals, commit/welcome (opcodes 25–30), exporter-based sender keys
• Sender key ratchet: Per-sender, per-epoch keys via MLS-Exporter + HKDF; cache for out-of-order decryption
• Frame transform: Codec-aware encrypt/decrypt (OPUS, VP9, VP8, H264, H265, AV1), ULEB128, truncated AES128-GCM, DAVE footer (0xFAFA)
• Identity: Pairwise fingerprint (scrypt) and displayable codes (45-digit / 30-digit)
• Voice Gateway helpers: Parse-and-apply wrappers that return explicit applied / media_ready results without sending frames

Install

pip install -e .

Requires Python 3.9+, rfc9420, cryptography, and pycryptodome.

Minimal lifecycle

1. Create a session: DaveSession(local_user_id=123456789, channel_id=voice_channel_id). The MLS group ID is the channel snowflake as 8 big-endian bytes; Discord will silently drop commits that use any other group ID. For Go Live, pass channel_id=mls_channel_id_from_stream_server_id(rtc_server_id).
2. On select_protocol_ack (or prepare_epoch with epoch=1), call session.prepare_epoch(1) and send the returned bytes as opcode 26 (Key Package).
3. On opcode 11 / 13, call sync_clients_connect / sync_client_disconnect (or the session add_expected_members / remove_expected_member methods). If opcode 11 listed other users before this session existed, call configure_occupied_join(...) so you wait for opcode 30 instead of committing a local group.
4. On opcode 25, call handle_external_sender_wire(session, package_bytes).
5. On opcode 27, call apply_proposals_message(session, proposal_bytes). After a short quiet period, send session.take_commit_welcome() as opcode 28 if it returns bytes. Batching and the send itself stay in the caller.
6. On opcode 29 / 30, call handle_announce_commit_wire / handle_welcome_wire. If applied is True and media is ready, send opcode 23 with build_ready_for_transition_dict(transition_id). Do not execute the transition here.
7. On opcode 22, parse with parse_execute_transition (or handle_execute_transition_message) and then switch send ratchets. Senders must keep the previous epoch until this opcode, per protocol.md.
8. Media: session.encrypt_frame(frame, codec="OPUS") and session.decrypt_frame(protocol_frame, sender_id). Silence packets (SILENCE_PACKET) and frames that fail protocol_frame_check pass through.

Error recovery: On InvalidCommitError, call recover_invalid_commit(session, transition_id) and send the returned opcode 31 JSON, then the opcode 26 key package. Do not send opcode 23 or execute opcode 22 for the rejected transition.

Caller-owned: Voice Gateway WebSocket I/O, proposal coalescing timers, opcode 23 sends, opcode 22 execution policy (including the documented transition_id=0 init path), recovery retry caps, and join watchdogs.

API overview

• DaveSession: handle_external_sender_package, prepare_epoch, apply_proposals, take_commit_welcome, handle_commit, handle_welcome, execute_transition, configure_occupied_join, leave_group, encrypt_frame, decrypt_frame, receive_ratchet_user_ids
• sorrydave.voice_gateway: sync_clients_connect, handle_external_sender_wire, apply_proposals_message, handle_announce_commit_wire, handle_welcome_wire, recover_invalid_commit
• FrameEncryptor.encrypt(encoded_frame, codec) / FrameDecryptor.decrypt(protocol_frame)
• generate_fingerprint(local_id, local_pub, remote_id, remote_pub) → 45-digit string
• displayable_code(data, total_digits, group_size) for epoch authenticator (e.g. 30 digits, group 5)

Scope

• In scope: MLS state, ratchet, OPUS/VP9/VP8/H264/H265/AV1 codec handling, frame encrypt/decrypt, identity fingerprint, opcode parse/build, and transport-free Voice Gateway helpers.
• Out of scope: Voice Gateway WebSocket I/O, proposal debounce timers, SFU silence-packet generation, WebRTC depacketizer patches.

License

MIT.