Begin the coven evolution of cmd-chat (see docs/spec-collaborative-sandbox.md):
a Rust/ratatui client for the unchanged Python Sanic server, plus the
multi-user + zero-knowledge groundwork.
P0 — crypto parity (the spec's #1 risk), proven three ways:
- Hand-rolled SRP-6a (NG_2048, SHA-256, rfc5054 padding) matching pysrp
byte-for-byte, incl. the fixed b"chat" SRP identity and minimal-vs-256B
width quirks. Golden-vector unit test + offline selftest.
- Live handshake against the running server (H_AMK verified).
- Cross-language E2E: Python client decrypts a Rust-encrypted Fernet message.
P2 — multi-user coven (server):
- CMD_CHAT_MAX_USERS capacity cap (default 4, infra-for-more).
- Authoritative roster + user_joined broadcasts.
- Free the slot/username on ws disconnect (was held until 1h stale sweep).
Also: fix requirements.txt (was UTF-16, unparseable by pip).
coven/ : Rust crate (crypto.rs proven; main.rs spike CLI: selftest/handshake/srpm)
docs/ : full feature spec for the 6 requested features.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
CRITICAL fixes:
- Auto-generated self-signed TLS certs (HTTPS/WSS by default)
- Removed session_key from /srp/verify response (was sent in plaintext)
- Replaced with HMAC-SHA256 ws_token for WebSocket authentication
HIGH fixes:
- WebSocket auth now validates ws_token via hmac.compare_digest()
- /clear endpoint requires Bearer admin_token (printed at server start)
- Password no longer required as CLI arg — supports env var + getpass prompt
- Removed user_ip from Message model (no longer broadcast to clients)
MEDIUM fixes:
- Rate limiter on /srp/init and /srp/verify (10 req/min/IP)
- MessageStore capped at 1000 messages (prevents RAM DoS)
- access_log disabled (was leaking request metadata)
LOW fixes:
- Username sanitization against rich markup injection
- Dead code removed from helpers.py
All 79 tests passing.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
