Christian Gick d586ddfa6d fix(e2ee): pre-derive HKDF keys in Python instead of Rust FFI (MAT-144) ...

Switch from Rust-side HKDF (KDF_HKDF=1) to Python-side HKDF derivation
with raw key mode (KDF_RAW=0). This eliminates potential HKDF implementation
mismatches between Rust FFI and Element Call JS that caused video frame
decryption failures (audio worked, video showed 8x8 garbage frames).

Changes:
- Add _derive_and_set_key() helper that pre-derives HKDF then calls set_key()
- Set key_derivation_function=KDF_RAW (proto 0 = no Rust-side derivation)
- Replace all direct set_key() calls with _derive_and_set_key()
- Add per-track diagnostic logging (audio vs video)
- Add frame size check in look_at_screen (detect E2EE failure early)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

2026-03-09 17:05:59 +02:00

68 KiB

Raw Blame History

View Raw