merge: Phase 11.5 security remediation, invite redesign, per-node identity

Brings in the security remediation branch. Three bodies of work, and what they
changed about what this project may claim.

Phase 11.5 closed the gap between the documents and the code: the unauthenticated
node HTTP API and the TCP transport deleted, one handshake shared by the
remaining two transports, mutual authentication, structured admin transcripts,
upload confinement, group isolation, revocation that reaches nodes. Six critical
and seven high findings closed, bounded, or deferred by decision.

The invite redesign closed H3 and M3 — the last open High. The hub was the key
directory: an inviter fetched the invitee's key from it and wrapped the group key
for whatever came back, so a hub answering with its own key was handed the group
key by an honest member following the protocol exactly. That lookup is gone. The
node holds the group key and wraps it itself, for a key its recipient proves
possession of, bound to an account by a one-time code the hub never sees. M3 fell
out of the same work: node authority comes from a local roster, never from the
hub.

Per-node identity cut what remains of C4 down to one operator. A single keypair
used to be copied to every node its owner joined; each node now gets its own, so
cracking the bundle on one machine yields a key that is a stranger everywhere
else — and on that machine, one that unlocks nothing its holder did not already
serve. The bundle KDF moved to Argon2id 128 MB, and the hub stopped storing or
publishing user keys at all.

What this project may now say: the hub cannot read your content unless it ships
you malicious client code. T3 remains, accepted (D1), and is what the native
client removes. C4 is reduced, not closed, until 13.3. Chat is still plaintext at
rest until Phase 15. Draft-v5 §2 states each claim against the adversary it holds
against, which is the convention this branch exists to keep.

Four defects were found by deploying it and using a browser, none by the test
suite: a node going deaf on its hub socket, a token that predated group
membership, a client reading values before they were assigned, and identity keys
a browser held but never re-read. The lessons are recorded in CLAUDE.md.

Tests: 343 across the three packages, plus QE/deploy/e2e.py — register, pair,
invite, join, download, stream, second browser, revoke — run against the live
deployment on a wiped hub and node.

1 files changed, 0 insertions, 222 deletions

diff --git a/packages/meshbay-node/tests/test_transport.py b/packages/meshbay-node/tests/test_transport.py
deleted file mode 100644
index 0e70d72..0000000
--- a/packages/meshbay-node/tests/test_transport.py
+++ /dev/null
@@ -1,222 +0,0 @@
-"""
-Integration test: ChunkServer ↔ ChunkClient over TLS.
-
-Starts a real TLS server on localhost, connects a client,
-fetches index and a chunk, verifies signature+hash+decryption.
-"""
-
-import asyncio
-import base64
-import os
-import time
-import jwt
-import pytest
-from pathlib import Path
-from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey
-from cryptography.hazmat.primitives import serialization
-
-from meshbay_common.crypto import generate_gek, pk_to_b64
-from meshbay_node.indexer import DirectoryIndexer, GroupIndex
-from meshbay_node.transport.server import ChunkServer
-from meshbay_node.transport.client import ChunkClient
-
-
-@pytest.fixture
-def sk_node():
-    return Ed25519PrivateKey.generate()
-
-@pytest.fixture
-def sk_hub():
-    return Ed25519PrivateKey.generate()
-
-@pytest.fixture
-def gek():
-    return generate_gek()
-
-@pytest.fixture
-def shared_dir(tmp_path):
-    d = tmp_path / "shared"
-    d.mkdir()
-    (d / "test.mp4").write_bytes(os.urandom(2 * 1024 * 1024))   # 2 MB
-    (d / "small.txt").write_bytes(b"hello meshbay " * 100)
-    return d
-
-def make_jwt(sk_hub, pk_node_b64, user_id="user-001", ttl=3600, groups=None):
-    sk_pem = sk_hub.private_bytes(
-        serialization.Encoding.PEM,
-        serialization.PrivateFormat.PKCS8,
-        serialization.NoEncryption(),
-    )
-    now = int(time.time())
-    return jwt.encode({
-        "iss": "test-hub", "sub": user_id,
-        "pk_user": pk_node_b64, "hub_id": "test-hub",
-        "jti": "test-jti",
-        "iat": now, "exp": now + ttl,
-        "groups": groups or [],
-    }, sk_pem, algorithm="EdDSA")
-
-
-@pytest.mark.asyncio
-async def test_chunk_server_client_roundtrip(
-        sk_node, sk_hub, gek, shared_dir, tmp_path):
-    """Full integration: server serves a chunk, client verifies and decrypts."""
-
-    # Build index
-    indexer = DirectoryIndexer(
-        root=shared_dir, group_id="g", sk_node=sk_node, gek=gek)
-    await indexer.initial_scan()
-    assert indexer.index.count == 2
-
-    # Hub PK for JWT verification
-    hub_pk_pem = sk_hub.public_key().public_bytes(
-        serialization.Encoding.PEM,
-        serialization.PublicFormat.SubjectPublicKeyInfo)
-
-    # TLS cert in tmp dir
-    cert_path = tmp_path / "node.crt"
-    key_path  = tmp_path / "node.key"
-
-    server = ChunkServer(
-        sk_node=sk_node,
-        hub_pk_pem=hub_pk_pem,
-        gek=gek,
-        shared_root=shared_dir,
-        index=indexer.index,
-        host="127.0.0.1",
-        port=0,   # OS picks a free port
-        cert_path=cert_path,
-        key_path=key_path,
-    )
-    await server.start()
-    port = server._server.sockets[0].getsockname()[1]
-
-    token = make_jwt(sk_hub, pk_to_b64(sk_node.public_key()))
-
-    # Find the large test file in the index
-    entry = next(e for e in indexer.index.entries if e.name == "test.mp4")
-
-    async with ChunkClient(
-        host="127.0.0.1",
-        port=port,
-        jwt_token=token,
-        gek=gek,
-        pk_node_b64=pk_to_b64(sk_node.public_key()),
-    ) as client:
-        # Fetch first chunk
-        chunk0 = await client.fetch_chunk(entry.id, chunk_index=0)
-        assert len(chunk0) == 1024 * 1024   # first 1MB of 2MB file
-
-        # Fetch second chunk
-        chunk1 = await client.fetch_chunk(entry.id, chunk_index=1)
-        assert len(chunk1) == 1024 * 1024   # second 1MB
-
-        # Reassembled file matches original
-        original = (shared_dir / "test.mp4").read_bytes()
-        assert chunk0 + chunk1 == original
-
-    await server.stop()
-
-
-@pytest.mark.asyncio
-async def test_invalid_jwt_rejected(sk_node, sk_hub, gek, shared_dir, tmp_path):
-    hub_pk_pem = sk_hub.public_key().public_bytes(
-        serialization.Encoding.PEM, serialization.PublicFormat.SubjectPublicKeyInfo)
-
-    indexer = DirectoryIndexer(root=shared_dir, group_id="g",
-                               sk_node=sk_node, gek=gek)
-    await indexer.initial_scan()
-
-    cert_path = tmp_path / "node.crt"
-    key_path  = tmp_path / "node.key"
-
-    server = ChunkServer(
-        sk_node=sk_node, hub_pk_pem=hub_pk_pem, gek=gek,
-        shared_root=shared_dir, index=indexer.index,
-        host="127.0.0.1", port=0,
-        cert_path=cert_path, key_path=key_path,
-    )
-    await server.start()
-    port = server._server.sockets[0].getsockname()[1]
-
-    # Use a different hub key to sign the token
-    sk_other_hub = Ed25519PrivateKey.generate()
-    bad_token = make_jwt(sk_other_hub, pk_to_b64(sk_node.public_key()))
-
-    with pytest.raises(Exception):
-        async with ChunkClient(
-            host="127.0.0.1", port=port,
-            jwt_token=bad_token, gek=gek,
-            pk_node_b64=pk_to_b64(sk_node.public_key()),
-        ) as client:
-            pass
-
-    await server.stop()
-
-
-@pytest.mark.asyncio
-async def test_wrong_group_rejected(sk_node, sk_hub, gek, shared_dir, tmp_path):
-    """TCP+TLS server rejects a client whose JWT groups don't include the requested group_id."""
-    hub_pk_pem = sk_hub.public_key().public_bytes(
-        serialization.Encoding.PEM, serialization.PublicFormat.SubjectPublicKeyInfo)
-
-    indexer = DirectoryIndexer(root=shared_dir, group_id="g",
-                               sk_node=sk_node, gek=gek)
-    await indexer.initial_scan()
-
-    cert_path = tmp_path / "node.crt"
-    key_path  = tmp_path / "node.key"
-
-    server = ChunkServer(
-        sk_node=sk_node, hub_pk_pem=hub_pk_pem, gek=gek,
-        shared_root=shared_dir, index=indexer.index,
-        host="127.0.0.1", port=0,
-        cert_path=cert_path, key_path=key_path,
-    )
-    await server.start()
-    port = server._server.sockets[0].getsockname()[1]
-
-    token = make_jwt(sk_hub, pk_to_b64(sk_node.public_key()), groups=["group-a"])
-
-    with pytest.raises(ConnectionError, match="rejected"):
-        async with ChunkClient(
-            host="127.0.0.1", port=port,
-            jwt_token=token, gek=gek,
-            pk_node_b64=pk_to_b64(sk_node.public_key()),
-            group_id="group-b",
-        ) as client:
-            pass
-
-    await server.stop()
-
-
-@pytest.mark.asyncio
-async def test_fetch_index(sk_node, sk_hub, gek, shared_dir, tmp_path):
-    hub_pk_pem = sk_hub.public_key().public_bytes(
-        serialization.Encoding.PEM, serialization.PublicFormat.SubjectPublicKeyInfo)
-    indexer = DirectoryIndexer(root=shared_dir, group_id="g",
-                               sk_node=sk_node, gek=gek)
-    await indexer.initial_scan()
-
-    cert_path = tmp_path / "node.crt"
-    key_path  = tmp_path / "node.key"
-
-    server = ChunkServer(
-        sk_node=sk_node, hub_pk_pem=hub_pk_pem, gek=gek,
-        shared_root=shared_dir, index=indexer.index,
-        host="127.0.0.1", port=0,
-        cert_path=cert_path, key_path=key_path,
-    )
-    await server.start()
-    port = server._server.sockets[0].getsockname()[1]
-    token = make_jwt(sk_hub, pk_to_b64(sk_node.public_key()))
-
-    async with ChunkClient(
-        host="127.0.0.1", port=port, jwt_token=token,
-        gek=gek, pk_node_b64=pk_to_b64(sk_node.public_key()),
-    ) as client:
-        wire = await client.fetch_index()
-        recovered = GroupIndex.deserialize(wire, sk_node=sk_node, gek=gek)
-        assert recovered.count == 2
-
-    await server.stop()