From c1be7571973c3d0b671ed4db2da41266ae3099d8 Mon Sep 17 00:00:00 2001 From: Christophe Besson Date: Thu, 3 Sep 2026 15:20:40 +0200 Subject: refactor!: one file_chunk and index_sync encoder for every transport MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit `file_chunk` and `index_sync` were each built twice, once per transport, and the two copies did not agree. WebRTC sent binary, unsigned chunks carrying a `file_id`; QUIC sent base64 fields, two BLAKE3 hashes, a per-chunk Ed25519 signature and no `file_id`. `index_sync` was plain entries on one transport and a `GroupIndex.serialize()` envelope on the other. One message type, two shapes, one consumer each, and nothing that failed when they drifted — finding C6 one size down, in the two places the handshake unification did not reach. Phase 9.15 moved WebRTC to the binary format and dropped the per-chunk signature; the QUIC encoder was never brought along. It is dropped here rather than reintroduced: the AES-GCM tag authenticates the ciphertext under a GEK-derived key, and since C3 the node authenticates itself once in the handshake instead of once per megabyte. `meshbay_common.protocol` now owns the chunk codec (`chunk_ciphertext`, `file_chunk_wire`, `file_chunk_plaintext`) and `meshbay_node/transport/wire.py` the index builder, which also absorbs the delta the daemon used to hand-build. `test_transport_wire_parity.py` fails if either server grows its own copy back. `ChunkRequest`/`ChunkResponse` are deleted. `ChunkResponse` described the QUIC half while reading like the contract for both, which is what made the fork hard to see at all. BREAKING CHANGE: MNP 0.15 changes the encoding of `file_chunk` and `index_sync` on the QUIC transport. The WebRTC shapes are byte for byte unchanged and no QUIC client ships, which is why this is a MINOR bump; a deployed QUIC peer would have made it MAJOR. Also fixes a test fixture that put a `Path` where the daemon puts a `RootSet`. Nothing caught it: the old QUIC index handler never touched `roots`, and `entry_abs_path` fell through `Path.resolve(strict=...)`, reading the virtual path as a truthy flag and returning the right file by accident. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01AsoWC3GmhNdwVFomW3QjH3 --- packages/meshbay-common/src/meshbay_common/crypto.py | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'packages/meshbay-common/src/meshbay_common/crypto.py') diff --git a/packages/meshbay-common/src/meshbay_common/crypto.py b/packages/meshbay-common/src/meshbay_common/crypto.py index b2ff3c0..eadb42b 100644 --- a/packages/meshbay-common/src/meshbay_common/crypto.py +++ b/packages/meshbay-common/src/meshbay_common/crypto.py @@ -225,7 +225,14 @@ def decrypt_keystore(iv: bytes, ciphertext: bytes, tag: bytes, key: bytes) -> by def sign_chunk(sk_node: Ed25519PrivateKey, chunk_index: int, nonce: bytes, ct_hash: bytes) -> bytes: - """Sign chunk metadata. Payload: chunk_index || nonce || ct_hash.""" + """ + Sign chunk metadata. Payload: chunk_index || nonce || ct_hash. + + Despite the name, this no longer signs file chunks — Phase 9.15 dropped per-chunk + signatures on the WebRTC path and 2026-09-03 dropped the QUIC copy that had been + left behind. Its one caller is `GroupIndex.serialize()`, which signs a whole index + envelope under the pseudo-index `INDEX_CHUNK`. + """ payload = chunk_index.to_bytes(4, "big") + nonce + ct_hash return sk_node.sign(payload) -- cgit v1.2.3