Use EIP-191 Signatures on Geth and PyEVM backends

nucypher/blockchain/eth/clients.py

@@ -231,7 +231,9 @@ class GethClient(Web3Client):
     def unlock_account(self, address, password):
         return self.w3.geth.personal.unlockAccount(address, password)
 
-    def verify_signature(self, account, message, signature) -> bool:
+
+    @staticmethod
+    def verify_signature(account: str, message: bytes, signature: bytes) -> bool:
         """
         EIP-191 Compatible signature verification for usage with w3.eth.sign.
 

nucypher/crypto/powers.py

@@ -107,33 +107,26 @@ class BlockchainPower(CryptoPowerUp):
         if not self.is_unlocked:
             raise PowerUpError("Failed to unlock account {}".format(self.account))
 
-    def sign_message(self, message: bytes):
+    def sign_message(self, message: bytes) -> bytes:
         """
         Signs the message with the private key of the BlockchainPower.
         """
         if not self.is_unlocked:
             raise PowerUpError("Account is not unlocked.")
+        signature = self.blockchain.interface.client.sign_message(self.account, message)
+        return signature
 
-        signature = self.blockchain.interface.call_backend_sign(self.account, message)
-        return bytes(signature)
-
-    def verify_message(self, address: str, pubkey: bytes, message: bytes, signature_bytes: bytes):
+    def verify_message(self, address: str, message: bytes, signature: bytes) -> bool:
         """
-        Verifies that the message was signed by the keypair.
+        Verifies that the message was signed by the private key of the address provided.
         """
-        # Check that address and pubkey match
-        eth_pubkey = PublicKey(pubkey)
-        signature = EthSignature(signature_bytes=signature_bytes)
-        if not eth_pubkey.to_checksum_address() == address:
-            raise ValueError("Pubkey address ({}) doesn't match the provided address ({})".format(eth_pubkey.to_checksum_address, address))
-
-        hashed_message = keccak(message)
-
-        if not self.blockchain.interface.call_backend_verify(
-                eth_pubkey, signature, hashed_message):
-            raise PowerUpError("Signature is not valid for this message or pubkey.")
-        else:
+        signature_is_valid = self.blockchain.interface.client.verify_message(address=address,
+                                                                             message=message,
+                                                                             signature=signature)
+        if signature_is_valid:
             return True
+        else:
+            raise PowerUpError("Signature is not valid for this message or pubkey.")
 
     def __del__(self):
         """

nucypher/network/nodes.py

@@ -907,15 +907,14 @@ class Teacher:
     # Stamp
     #
 
-    def _stamp_has_valid_wallet_signature(self):
+    def _stamp_has_valid_wallet_signature(self) -> bool:
         signature_bytes = self._evidence_of_decentralized_identity
         if signature_bytes is NOT_SIGNED:
             return False
-
-        signature = EthSignature(signature_bytes)
-        proper_pubkey = signature.recover_public_key_from_msg(bytes(self.stamp))
-        proper_address = proper_pubkey.to_checksum_address()
-        return proper_address == self.checksum_public_address
+        signature_is_valid = Web3Client.verify_signature(message=bytes(self.stamp),
+                                                         signature=signature_bytes,
+                                                         account=self.checksum_public_address)
+        return signature_is_valid
 
     def stamp_is_valid(self):
         """

tests/blockchain/eth/interfaces/test_clients.py

@@ -95,7 +95,7 @@ def test_ganache_web3_client():
     assert interface.is_local
 
 
-def test_client_signature():
+def test_EIP_191_client_signatures():
 
     # Start a geth process
     geth = NuCypherGethDevProcess()