fix: update second_sign method to use schnorr (#106)

* fix - update secondsign to use schnorr

* feat - add schnorr second verify

* feat - add second verify function to base.py

* Update base.py

* Update transaction.py

* Update serializer.py

* Update base.py

* Update test_transfer.py

* Update base.py

* Update test_transfer.py

Author: galperins4

crypto/transactions/builder/base.py

@@ -47,8 +47,9 @@ def second_sign(self, passphrase):
         Args:
             passphrase (str): 2nd passphrase associated with the account sending this transaction
         """
-        message = Message.sign(self.transaction.to_bytes(skip_signature=False), passphrase)
-        self.transaction.signSignature = message.signature
+        msg = hashlib.sha256(self.transaction.to_bytes(False, True, False)).digest()
+        secret = unhexlify(PrivateKey.from_passphrase(passphrase).to_hex())
+        self.transaction.signSignature = hexlify(schnorr.bcrypto410_sign(msg, secret))   
         self.transaction.id = self.transaction.get_id()
 
     def multi_sign(self, passphrase, index):
@@ -66,6 +67,9 @@ def multi_sign(self, passphrase, index):
 
     def schnorr_verify(self):
         return self.transaction.verify_schnorr()
+    
+    def schnorr_verify_second(self, secondPublicKey):
+        return self.transaction.verify_schnorr_secondsig(secondPublicKey)
 
     def schnorr_verify_multisig(self):
         return self.transaction.verify_schnorr_multisig()

crypto/transactions/serializer.py

@@ -94,9 +94,8 @@ def _handle_signature(self, bytes_data, skip_signature, skip_second_signature, s
 
         if not skip_second_signature and self.transaction.get('secondSignature'):
             bytes_data += unhexlify(self.transaction['secondSignature'])
-        elif self.transaction.get('signSignature'):
+        if not skip_second_signature and self.transaction.get('signSignature'):
             bytes_data += unhexlify(self.transaction['signSignature'])
-
         if not skip_multi_signature and self.transaction.get('signatures'):
             bytes_data += unhexlify(''.join(self.transaction['signatures']))
 

crypto/transactions/transaction.py

@@ -162,6 +162,15 @@ def verify_schnorr(self):
 
         return is_valid
 
+    def verify_schnorr_secondsig(self, secondPublicKey):
+        """Verify the transaction. Method will raise an exception if invalid, if it's valid it will
+        returns True
+        """
+        is_valid = schnorr.b410_schnorr_verify(self.to_bytes(False, True), secondPublicKey, self.signSignature)
+        
+        if not is_valid:
+            raise ArkInvalidTransaction('Transaction could not be verified')
+    
     def verify_schnorr_multisig(self):
         """Verify the multisignatures transaction. Method will raise an exception if invalid, it will
         returns True

tests/transactions/builder/test_transfer.py

@@ -1,5 +1,6 @@
 from crypto.configuration.network import set_network
 from crypto.constants import TRANSACTION_TRANSFER, TRANSACTION_TYPE_GROUP
+from crypto.identity.public_key import PublicKey
 from crypto.networks.devnet import Devnet
 from crypto.transactions.builder.transfer import Transfer
 
@@ -27,6 +28,30 @@ def test_transfer_transaction():
     transaction.schnorr_verify()  # if no exception is raised, it means the transaction is valid
 
 
+def test_transfer_secondsig_transaction():
+    """Test if a transfer transaction with second signature gets built
+    """
+    transaction = Transfer(
+        recipientId='AGeYmgbg2LgGxRW2vNNJvQ88PknEJsYizC',
+        amount=200000000,
+    )
+    transaction.set_type_group(TRANSACTION_TYPE_GROUP.CORE)
+    transaction.set_nonce(1)
+    transaction.schnorr_sign('this is a top secret passphrase')
+    transaction.second_sign('second top secret passphrase')
+    transaction_dict = transaction.to_dict()
+
+    assert transaction_dict['nonce'] == 1
+    assert transaction_dict['signature']
+    assert transaction_dict['signSignature']
+    assert transaction_dict['type'] is TRANSACTION_TRANSFER
+    assert transaction_dict['typeGroup'] == 1
+    assert transaction_dict['typeGroup'] == TRANSACTION_TYPE_GROUP.CORE.value
+
+    transaction.schnorr_verify()  # if no exception is raised, it means the transaction is valid
+    transaction.schnorr_verify_second(PublicKey.from_passphrase('second top secret passphrase')) # if no exception is raised, it means the transaction is valid
+    
+    
 def test_parse_signatures(transaction_type_0):
     """Test if parse signature works when parsing serialized data
     """