Merge pull request #35 from pattern-tech/feat/siwe-verify

`/auth/verify` API

Author: mkermani144

api/src/auth/routers/auth_router.py

@@ -3,6 +3,7 @@
     AuthService,
     LoginInput,
     RegisterInput,
+    VerifyInput
 )
 from src.db.sql_alchemy import Database
 from src.util.response import global_response
@@ -19,6 +20,7 @@
     "/register",
     summary="User Registration",
     description="Register a new user with email and password.",
+    deprecated=True
 )
 def register(input: RegisterInput, db: Session = Depends(database.get_db)):
     """
@@ -42,6 +44,7 @@ def register(input: RegisterInput, db: Session = Depends(database.get_db)):
     "/login",
     summary="User Login",
     description="Authenticate a user with email and password.",
+    deprecated=True,
 )
 def login(input: LoginInput, db: Session = Depends(database.get_db)):
     """
@@ -59,3 +62,29 @@ def login(input: LoginInput, db: Session = Depends(database.get_db)):
             "access_token": token,
         }
     )
+
+
+@router.post(
+    "/verify",
+    summary="Verify a Signature",
+    description="Verify a signature according to SIWE spec",
+)
+def verify(input: VerifyInput):
+    """
+    Verify a signature according to SIWE spec and return an access token
+
+    - **message**: A SIWE message
+    - **signature**: User's signature for the message
+    """
+    verification_result = auth.verify_signature(
+        input.message, input.signature)
+
+    payload = {"id": "{}:{}".format(
+        verification_result.chain_id, verification_result.address)}
+
+    token = generate_access_token(data=payload)
+    return global_response(
+        {
+            "access_token": token,
+        }
+    )

api/src/auth/services/auth_service.py

@@ -5,6 +5,7 @@
 from src.auth.utils.bcrypt_helper import hash_password, verify_password
 from src.db.models import UserModel
 from src.db.sql_alchemy import Database
+from siwe import SiweMessage
 
 database = Database()
 
@@ -31,6 +32,15 @@ class LoginInput(BaseModel):
     )
 
 
+class VerifyInput(BaseModel):
+    message: str = Field(
+        ..., example="0x0...", description="The SIWE message"
+    )
+    signature: str = Field(
+        ..., example="0x0...", description="User's signature for a message"
+    )
+
+
 class AuthService:
     """
     Service class for handling user authentication and registration logic.
@@ -91,3 +101,34 @@ def authenticate_user(self, email: str, password: str, db: Session):
             raise HTTPException(status_code=401, detail="Incorrect email or password")
 
         return user
+
+    def verify_signature(self, message: str, signature: str):
+        """
+        Verify a signature according to SIWE spec
+
+        Args:
+            message (str): A SIWE message
+            signature (str): User's signature for the message
+
+        Returns:
+            VerificationResult: The result of the verification, containing the address and chain id of the signing wallet
+
+        Raises:
+            HTTPException: If message cannot be parsed or verified
+        """
+
+        try:
+            siwe_message = SiweMessage.from_message(message)
+            siwe_message.verify(signature)
+        except ValueError:
+            # ValueError is raised if message is invalid according to SIWE
+            raise HTTPException(
+                status_code=400, detail="The provided message is not a valid SIWE message")
+        except:
+            raise HTTPException(
+                status_code=401, detail="Signature is not valid")
+
+        return {
+            "chain_id": siwe_message.chain_id,
+            "address": siwe_message.address,
+        }