feat(hub): add production hub — config, auth, API routers, tests

config.py: TOML + env var priority. auth.py: Argon2id passwords,
JWT EdDSA with jti, refresh token hashed (blake3). Routers:
hub (info/pubkey), users (register/login/refresh/pubkeys),
nodes (announce/get), groups (create/gek-bundle/gek-retrieve).
Rate limiting via slowapi. app.py factory with lifespan.

All 40 tests pass (SQLite in-memory, no PostgreSQL required).
Fix: remove tests/__init__.py to resolve namespace conflicts.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

1 files changed, 145 insertions, 0 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/auth.py b/packages/meshbay-hub/src/meshbay_hub/auth.py
new file mode 100644
index 0000000..a4c3bfb
--- /dev/null
+++ b/packages/meshbay-hub/src/meshbay_hub/auth.py
@@ -0,0 +1,145 @@
+"""
+MeshBay Hub — authentication helpers.
+
+  - Password hashing/verification: Argon2id
+  - JWT issuance/verification: Ed25519 (EdDSA), includes jti
+  - Refresh token: random 32-byte, stored as blake3 hex hash
+  - Hub keypair: loaded from PEM file on startup
+"""
+
+import base64
+import hashlib
+import os
+import time
+import uuid
+from pathlib import Path
+
+import blake3
+import jwt
+from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.kdf.argon2 import Argon2id
+
+# Argon2id parameters — see CLAUDE.md for production calibration guidance
+_ARGON2_ITERATIONS  = 3
+_ARGON2_MEMORY_COST = 65536   # 64 MB — increase to 262144 in production
+_ARGON2_LANES       = 4
+_ARGON2_KEY_LEN     = 32
+
+# Module-level hub keypair (loaded once at startup)
+_hub_sk_pem: bytes | None = None
+_hub_pk_pem: bytes | None = None
+_hub_id:     str          = "meshbay.org"
+
+
+# ── Hub keypair ───────────────────────────────────────────────────────────────
+
+def load_hub_keypair(private_key_path: Path, hub_id: str) -> None:
+    """Load hub Ed25519 keypair from PEM file. Call once at startup."""
+    global _hub_sk_pem, _hub_pk_pem, _hub_id
+    _hub_sk_pem = private_key_path.read_bytes()
+    sk = serialization.load_pem_private_key(_hub_sk_pem, password=None)
+    _hub_pk_pem = sk.public_key().public_bytes(
+        serialization.Encoding.PEM,
+        serialization.PublicFormat.SubjectPublicKeyInfo,
+    )
+    _hub_id = hub_id
+
+
+def generate_hub_keypair(private_key_path: Path) -> None:
+    """Generate a new hub Ed25519 keypair and save PEM files. Run once."""
+    private_key_path.parent.mkdir(parents=True, exist_ok=True)
+    sk = Ed25519PrivateKey.generate()
+    private_key_path.write_bytes(sk.private_bytes(
+        serialization.Encoding.PEM,
+        serialization.PrivateFormat.PKCS8,
+        serialization.NoEncryption(),
+    ))
+    private_key_path.chmod(0o600)
+
+    pk_path = private_key_path.with_suffix(".pub.pem")
+    pk_path.write_bytes(sk.public_key().public_bytes(
+        serialization.Encoding.PEM,
+        serialization.PublicFormat.SubjectPublicKeyInfo,
+    ))
+
+
+def hub_public_key_pem() -> bytes:
+    if _hub_pk_pem is None:
+        raise RuntimeError("Hub keypair not loaded — call load_hub_keypair() first")
+    return _hub_pk_pem
+
+
+# ── Password ──────────────────────────────────────────────────────────────────
+
+def hash_password(password: str) -> tuple[bytes, bytes]:
+    """Hash a password with Argon2id. Returns (hash, salt)."""
+    salt = os.urandom(16)
+    pw_hash = Argon2id(
+        salt=salt,
+        length=_ARGON2_KEY_LEN,
+        iterations=_ARGON2_ITERATIONS,
+        lanes=_ARGON2_LANES,
+        memory_cost=_ARGON2_MEMORY_COST,
+    ).derive(password.encode())
+    return pw_hash, salt
+
+
+def verify_password(password: str, pw_hash: bytes, salt: bytes) -> bool:
+    try:
+        Argon2id(
+            salt=salt,
+            length=_ARGON2_KEY_LEN,
+            iterations=_ARGON2_ITERATIONS,
+            lanes=_ARGON2_LANES,
+            memory_cost=_ARGON2_MEMORY_COST,
+        ).verify(password.encode(), pw_hash)
+        return True
+    except Exception:
+        return False
+
+
+# ── JWT ───────────────────────────────────────────────────────────────────────
+
+def issue_access_token(
+    user_id: str,
+    pk_user: str,
+    ttl: int = 3600,
+) -> str:
+    """
+    Issue a signed JWT access token.
+    Includes jti (UUID4) — required to prevent replay and enable revocation.
+    """
+    if _hub_sk_pem is None:
+        raise RuntimeError("Hub keypair not loaded")
+    now = int(time.time())
+    payload = {
+        "iss":     _hub_id,
+        "sub":     user_id,
+        "pk_user": pk_user,
+        "hub_id":  _hub_id,
+        "jti":     str(uuid.uuid4()),
+        "iat":     now,
+        "exp":     now + ttl,
+    }
+    return jwt.encode(payload, _hub_sk_pem, algorithm="EdDSA")
+
+
+def decode_access_token(token: str) -> dict:
+    """Verify and decode an access token. Raises on failure."""
+    if _hub_pk_pem is None:
+        raise RuntimeError("Hub keypair not loaded")
+    return jwt.decode(token, _hub_pk_pem, algorithms=["EdDSA"])
+
+
+# ── Refresh tokens ────────────────────────────────────────────────────────────
+
+def generate_refresh_token() -> tuple[str, str]:
+    """Return (raw_token, token_hash). Store hash; give raw to client."""
+    raw   = base64.urlsafe_b64encode(os.urandom(32)).decode()
+    hashed = blake3.blake3(raw.encode()).hexdigest()
+    return raw, hashed
+
+
+def hash_refresh_token(raw: str) -> str:
+    return blake3.blake3(raw.encode()).hexdigest()