Reorganize base modules

fastapi_users/db/base.py

@@ -0,0 +1,59 @@
+from typing import List, Optional
+
+from fastapi.security import OAuth2PasswordRequestForm
+
+from fastapi_users.models import BaseUserDB
+from fastapi_users.password import get_password_hash, verify_and_update_password
+
+
+class BaseUserDatabase:
+    """Base adapter for retrieving, creating and updating users from a database."""
+
+    async def list(self) -> List[BaseUserDB]:
+        """List all users."""
+        raise NotImplementedError()
+
+    async def get(self, id: str) -> Optional[BaseUserDB]:
+        """Get a single user by id."""
+        raise NotImplementedError()
+
+    async def get_by_email(self, email: str) -> Optional[BaseUserDB]:
+        """Get a single user by email."""
+        raise NotImplementedError()
+
+    async def create(self, user: BaseUserDB) -> BaseUserDB:
+        """Create a user."""
+        raise NotImplementedError()
+
+    async def update(self, user: BaseUserDB) -> BaseUserDB:
+        """Update a user."""
+        raise NotImplementedError()
+
+    async def authenticate(
+        self, credentials: OAuth2PasswordRequestForm
+    ) -> Optional[BaseUserDB]:
+        """
+        Authenticate and return a user following an email and a password.
+
+        Will automatically upgrade password hash if necessary.
+        """
+        user = await self.get_by_email(credentials.username)
+
+        # Always run the hasher to mitigate timing attack
+        # Inspired from Django: https://code.djangoproject.com/ticket/20760
+        get_password_hash(credentials.password)
+
+        if user is None:
+            return None
+        else:
+            verified, updated_password_hash = verify_and_update_password(
+                credentials.password, user.hashed_password
+            )
+            if not verified:
+                return None
+            # Update password hash to a more robust one if needed
+            if updated_password_hash is not None:
+                user.hashed_password = updated_password_hash
+                await self.update(user)
+
+        return user