refactor: update message signing (#158)

Author: alexbarnsley

crypto/identity/private_key.py

@@ -7,11 +7,6 @@
 from crypto.configuration.network import get_network
 from crypto.enums.constants import Constants
 
-def keccak256(data: bytes) -> bytes:
-    """Keccak256 hash function"""
-
-    return bytes.fromhex(keccak.new(data=data, digest_bits=256).hexdigest())
-
 class PrivateKey(object):
     def __init__(self, private_key: str):
         self.private_key = PvtKey.from_hex(private_key)
@@ -26,20 +21,10 @@ def sign(self, message: bytes) -> bytes:
         Returns:
             bytes: signature of the signed message
         """
-        signature = self.private_key.sign(message)
-
-        return hexlify(signature)
-
-    def sign_compact(self, message: bytes) -> bytes:
-        """Sign a message with this private key object
 
-        Args:
-            message (bytes): bytes data you want to sign
+        message_hash = bytes.fromhex(keccak.new(data=message, digest_bits=256).hexdigest())
 
-        Returns:
-            bytes: signature of the signed message
-        """
-        der = self.private_key.sign_recoverable(message, hasher=keccak256)
+        der = self.private_key.sign_recoverable(message_hash, hasher=None)
 
         return bytes([der[64] + Constants.ETHEREUM_RECOVERY_ID_OFFSET.value]) + der[0:64]
 

crypto/transactions/signature.py

@@ -29,7 +29,7 @@ def sign(self, private_key: PrivateKey):
 
         message = bytes.fromhex(transaction_hash)
 
-        transaction_signature = private_key.sign_compact(message)
+        transaction_signature = private_key.sign(message)
 
         self.data['v'] = transaction_signature[0]
         self.data['r'] = transaction_signature[1:33].hex()

crypto/transactions/types/abstract_transaction.py

@@ -1,33 +1,35 @@
 import json
 from binascii import unhexlify
+from typing import Union
+
+from Cryptodome.Hash import keccak
+from coincurve import PublicKey
 
 from crypto.identity.private_key import PrivateKey
-from crypto.transactions.signature import Signature
-from typing import Union
 
 class Message(object):
     public_key: bytes
     message: bytes
     signature: bytes
 
-    def __init__(self, public_key: bytes, message: bytes, signature: bytes):
-        if type(public_key) is bytes:
-            self.public_key = public_key
-        else:
+    def __init__(self, public_key: Union[bytes, str], message: Union[bytes, str], signature: Union[bytes, str]):
+        if isinstance(public_key, str):
             self.public_key = public_key.encode()
-
-        if type(message) is bytes:
-            self.message = message
         else:
-            self.message = message.encode()
+            self.public_key = public_key
 
-        if type(signature) is bytes:
-            self.signature = signature
+        if isinstance(message, str):
+            self.message = message.encode()
         else:
+            self.message = message
+
+        if isinstance(signature, str):
             self.signature = signature.encode()
+        else:
+            self.signature = signature
 
     @classmethod
-    def sign(cls, message: Union[bytes, str], passphrase: bytes):
+    def sign(cls, message: Union[bytes, str], passphrase: Union[bytes, str]):
         """Signs a message
 
         Args:
@@ -38,13 +40,22 @@ def sign(cls, message: Union[bytes, str], passphrase: bytes):
             Message: returns a message object
         """
 
-        if type(message) is str:
+        if isinstance(message, str):
             message = message.encode()
 
+        if not isinstance(passphrase, str):
+            passphrase = passphrase.hex()
 
         private_key = PrivateKey.from_passphrase(passphrase)
         public_key = private_key.public_key
-        signature = Signature.sign(message, private_key)
+
+        transaction_signature = private_key.sign(message)
+
+        signature_v = bytes([transaction_signature[0]]).hex()
+        signature_r = transaction_signature[1:33].hex()
+        signature_s = transaction_signature[33:].hex()
+
+        signature = signature_r + signature_s + signature_v
 
         return cls(
             message=message,
@@ -59,10 +70,18 @@ def verify(self):
             bool: returns a boolean - true if verified, false if not
         """
 
-        public_key = unhexlify(self.public_key)
         signature = unhexlify(self.signature)
+        message_hash = keccak.new(data=self.message, digest_bits=256).digest()
+
+        signature_r = signature[0:32]
+        signature_s = signature[32:64]
+        signature_v = signature[64]
+
+        signature = signature_r + signature_s + bytes([signature_v - 27])
+
+        public_key = PublicKey.from_signature_and_message(signature, message_hash, hasher=None)
 
-        return Signature.verify(signature, self.message, public_key)
+        return public_key.format() == unhexlify(self.public_key)
 
     def to_dict(self):
         """Return a dictionary of the message

crypto/utils/message.py

@@ -236,14 +236,3 @@ def transaction_type_9():
         'serialized': 'ff011e0100000009000900000000000000023efc1da7f315f3c533a4080e491f32cd4219731cef008976c3876539e1f192d300f902950000000000728c2c5d5f090e8c5dfd433bb2b15b30442cbafb9b882117f7b6f284da4093c6a96e8456f764628ec809514ac4e8b06d5450978b9b763f7d01f696b8881f702a'
     }
     return data
-
-
-@pytest.fixture
-def message():
-    data = {
-        'publicKey': '034151a3ec46b5670a682b0a63394f863587d1bc97483b1b6c70eb58e7f0aed192',
-        'signature': '22ff2371becb58439efdb95d116215f75bc41a380e1491605cc4874dd0d2c7d7958e4072da22fd307fe419c8864ba313a28bdb6fecbc6407839b6ba472395fe9',  # noqa
-        'message': 'Hello World',
-        'passphrase': 'this is a top secret passphrase',
-    }
-    return data

tests/conftest.py

@@ -0,0 +1,5 @@
+{
+	"message": "Hello, world!",
+	"publicKey": "0243333347c8cbf4e3cbc7a96964181d02a2b0c854faa2fef86b4b8d92afcf473d",
+	"signature": "0e2e53409be748834cac44052817ecef569b429a0492aa6bbc0d934eb71a09547e77aeef33d45669bbcba0498149f0e2b637fe8905186e08a5410c6f2b013bb41b"
+}