fix(api): hash session token with SHA-256 before DB lookup (#136)

fix(api): hash session token with SHA-256 before DB lookup

src/cartsnitch_api/auth/dependencies.py

@@ -4,6 +4,7 @@ Validates Better-Auth session tokens from cookies or Bearer header.
 Sessions are verified by querying the shared sessions table directly.
 """
 
+import hashlib
 from datetime import UTC, datetime
 from fastapi import Cookie, Depends, Header, HTTPException, Request, status
 from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
@@ -26,11 +27,14 @@ SECURE_SESSION_COOKIE_NAME = "__Secure-better-auth.session_token"
 async def _validate_session_token(token: str, db: AsyncSession) -> str:
     """Validate a Better-Auth session token against the sessions table.
 
-    Returns the user_id (as str) if the session is valid and not expired.
+    Better-Auth v1.2+ stores SHA-256(raw_token) in the DB.
+    The cookie/Bearer header carries the raw token, so we hash before lookup.
     """
+    token_hash = hashlib.sha256(token.encode()).hexdigest()
+
     result = await db.execute(
         text("SELECT user_id, expires_at FROM sessions WHERE token = :token"),
-        {"token": token},
+        {"token": token_hash},
     )
     row = result.first()
 

tests/conftest.py

@@ -4,6 +4,7 @@ Session-based auth: tests create users and sessions directly in the DB,
 matching the Better-Auth session validation flow.
 """
 
+import hashlib
 import secrets
 import uuid
 from datetime import UTC, datetime, timedelta
@@ -136,12 +137,14 @@ async def client(db_engine):
 async def _create_test_user_and_session(client: AsyncClient, db_engine, **user_overrides) -> tuple[dict, str]:
     """Create a test user and a valid session directly in the DB.
 
-    Returns (user_dict, session_token).
+    Returns (user_dict, session_token).  Better-Auth v1.2+ stores SHA-256
+    hashed tokens in the DB, so the token is hashed before insertion.
     """
     user_id = str(uuid.uuid4())
     email = user_overrides.get("email", "test@example.com")
     display_name = user_overrides.get("display_name", "Test User")
     session_token = secrets.token_urlsafe(32)
+    token_hash = hashlib.sha256(session_token.encode()).hexdigest()
     session_id = str(uuid.uuid4())
     now = datetime.now(UTC).isoformat()
     expires = (datetime.now(UTC) + timedelta(days=7)).isoformat()
@@ -169,7 +172,7 @@ async def _create_test_user_and_session(client: AsyncClient, db_engine, **user_o
             ),
             {
                 "id": session_id,
-                "token": session_token,
+                "token": token_hash,
                 "user_id": user_id,
                 "expires_at": expires,
                 "created_at": now,

tests/test_auth/test_auth_endpoints.py

@@ -74,6 +74,7 @@ async def test_delete_me(client, auth_headers):
 @pytest.mark.asyncio
 async def test_expired_session_rejected(client, db_engine):
     """Expired sessions must be rejected."""
+    import hashlib
     import secrets
     import uuid
     from datetime import UTC, datetime, timedelta
@@ -82,6 +83,7 @@ async def test_expired_session_rejected(client, db_engine):
 
     user_id = str(uuid.uuid4())
     session_token = secrets.token_urlsafe(32)
+    token_hash = hashlib.sha256(session_token.encode()).hexdigest()
     now = datetime.now(UTC).isoformat()
     expired = (datetime.now(UTC) - timedelta(hours=1)).isoformat()
 
@@ -108,7 +110,7 @@ async def test_expired_session_rejected(client, db_engine):
             ),
             {
                 "id": str(uuid.uuid4()),
-                "token": session_token,
+                "token": token_hash,
                 "uid": user_id,
                 "ea": expired,
                 "ca": now,