inital commit

server/app/security/api_keys.py

@@ -0,0 +1,80 @@
+from __future__ import annotations
+
+import hashlib
+import hmac
+import secrets
+from dataclasses import dataclass
+from datetime import datetime, timezone
+
+from sqlalchemy.orm import Session
+
+from app.db.models import ApiKey, User
+
+API_KEY_PREFIX_LENGTH = 12
+API_KEY_RANDOM_BYTES = 32
+
+
+@dataclass(slots=True)
+class CreatedApiKey:
+    model: ApiKey
+    secret: str
+
+
+def hash_api_key(secret: str) -> str:
+    return hashlib.sha256(secret.encode("utf-8")).hexdigest()
+
+
+def verify_api_key(secret: str, expected_hash: str) -> bool:
+    return hmac.compare_digest(hash_api_key(secret), expected_hash)
+
+
+def generate_api_key_secret() -> str:
+    return "mm_" + secrets.token_urlsafe(API_KEY_RANDOM_BYTES)
+
+
+def api_key_prefix(secret: str) -> str:
+    # Prefix is only a lookup helper and must not be enough to authenticate.
+    return secret[:API_KEY_PREFIX_LENGTH]
+
+
+def create_api_key(
+    session: Session,
+    *,
+    user: User,
+    name: str,
+    scopes: list[str],
+    secret: str | None = None,
+    expires_at: datetime | None = None,
+) -> CreatedApiKey:
+    secret = secret or generate_api_key_secret()
+    model = ApiKey(
+        tenant_id=user.tenant_id,
+        user_id=user.id,
+        name=name,
+        prefix=api_key_prefix(secret),
+        key_hash=hash_api_key(secret),
+        scopes=scopes,
+        expires_at=expires_at,
+    )
+    session.add(model)
+    session.flush()
+    return CreatedApiKey(model=model, secret=secret)
+
+
+def authenticate_api_key(session: Session, secret: str) -> ApiKey | None:
+    prefix = api_key_prefix(secret)
+    candidates = session.query(ApiKey).filter(ApiKey.prefix == prefix, ApiKey.revoked_at.is_(None)).all()
+    now = datetime.now(timezone.utc)
+    for candidate in candidates:
+        if candidate.expires_at and candidate.expires_at < now:
+            continue
+        if verify_api_key(secret, candidate.key_hash):
+            candidate.last_used_at = now
+            session.add(candidate)
+            return candidate
+    return None
+
+
+def has_scope(api_key: ApiKey, required_scope: str) -> bool:
+    scopes = set(api_key.scopes or [])
+    return "*" in scopes or required_scope in scopes