issue #62 Create binary signed message from credentials and verify binary...

issue #62 Create binary signed message from credentials and verify binary signed message with public key

duniterpy/key/verifying_key.py

@@ -4,10 +4,12 @@ duniter public and private keys
 @author: inso
 """
 
-import base58
 import base64
 import libnacl.sign
-from pylibscrypt import scrypt
+import libnacl.encode
+
+from duniterpy.documents import Document
+from duniterpy.documents.ws2p.heads import HeadV2
 from .base58 import Base58Encoder
 
 
@@ -15,7 +17,7 @@ class VerifyingKey(libnacl.sign.Verifier):
     """
     Class to verify documents
     """
-    def __init__(self, pubkey):
+    def __init__(self, pubkey: str) -> None:
         """
         Creates a Verify class from base58 pubkey
         :param pubkey:
@@ -23,7 +25,7 @@ class VerifyingKey(libnacl.sign.Verifier):
         key = libnacl.encode.hex_encode(Base58Encoder.decode(pubkey))
         super().__init__(key)
 
-    def verify_document(self, document, **kwargs):
+    def verify_document(self, document: Document, **kwargs) -> bool:
         """
         Check specified document
         :param duniterpy.documents.Document document:
@@ -38,10 +40,10 @@ class VerifyingKey(libnacl.sign.Verifier):
         except ValueError:
             return False
 
-    def verify_ws2p_head(self, head):
+    def verify_ws2p_head(self, head: HeadV2) -> bool:
         """
         Check specified document
-        :param duniterpy.documents.Document document:
+        :param HeadV2 head:
         :return:
         """
         signature = base64.b64decode(head.signature)
@@ -53,3 +55,15 @@ class VerifyingKey(libnacl.sign.Verifier):
             return True
         except ValueError:
             return False
+
+    def verify_message(self, message: bytes) -> str:
+        """
+        Check specified signed message signature and return message
+
+        Return error message if signature is invalid
+
+        :param bytes message: Message + signature
+        :return str:
+        """
+        return self.verify(message).decode('utf-8')
+

examples/save_binary_signed_message.py

+import getpass
+from duniterpy.key import SigningKey
+import libnacl.sign
+
+################################################
+
+SIGNED_MESSAGE_FILENAME = 'duniter_signed_message.bin'
+
+if __name__ == '__main__':
+
+    # prompt hidden user entry
+    salt = getpass.getpass("Enter your passphrase (salt): ")
+
+    # prompt hidden user entry
+    password = getpass.getpass("Enter your password: ")
+
+    # Create key object
+    key = SigningKey(salt, password)
+
+    # Display your public key
+    print("Public key for your credentials: %s" % key.pubkey)
+
+    message = input("Enter your message: ")
+
+    # Sign the message, the signed string is the message itself plus the
+    # signature
+    signed_message = key.sign(bytes(message, 'utf-8'))  # type: bytes
+
+    # To create a verifier pass in the verify key:
+    veri = libnacl.sign.Verifier(key.hex_vk())
+    # Verify the message!
+    verified = veri.verify(signed_message)
+
+    # save signed message in a file
+    with open(SIGNED_MESSAGE_FILENAME, 'wb') as file_handler:
+        file_handler.write(signed_message)
+
+    print("Signed message saved in file ./{0}".format(SIGNED_MESSAGE_FILENAME))

examples/verify_binary_signed_message.py

+import sys
+
+from duniterpy.key import VerifyingKey
+
+if __name__ == '__main__':
+
+    if len(sys.argv) < 2:
+        print("""
+        Usage:
+            python verify_signed_message.py SIGNED_MESSAGE_FILEPATH
+        """)
+
+    # capture signed message filepath argument
+    signed_message_path = sys.argv[1]
+
+    # ask public key of the signer
+    pubkeyBase58 = input("Enter public key of the message issuer: ")
+
+    # open signed message file
+    with open(signed_message_path, 'rb') as file_handler:
+        signed_message = file_handler.read()
+
+    # Verify the message!
+    verifier = VerifyingKey(pubkeyBase58)
+    try:
+        message = verifier.verify_message(signed_message)
+        print("Signature valid for this message:")
+    except ValueError as error:
+        message = str(error)
+
+    print(message)