Make the wallet backwards-compatible

wallet.py

@@ -2,6 +2,7 @@
 
 import base64, socket, sys, time
 from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey, Ed25519PublicKey
+from cryptography.hazmat.primitives.serialization import Encoding, PrivateFormat, PublicFormat, NoEncryption
 
 def format_address(raw_address):
     return base64.b64encode(raw_address).decode()
@@ -23,7 +24,7 @@ def write_transaction(timestamp, message, amount):
     print(f"{formatted_time}  {message:<44}  {format_amount(amount):>14}")
 
 def show_balance(public_key):
-    public_key_raw = public_key.public_bytes_raw()
+    public_key_raw = public_key.public_bytes(Encoding.Raw, PublicFormat.Raw)
     with open("blockchain", "rb") as f:
         total_amount = 0
         while True:
@@ -101,7 +102,7 @@ def send_payment(private_key, target, amount, fee):
     if amount == 0:
         raise Exception("Amount must not be zero")
     fee = parse_amount_checked(fee)
-    public_key_raw = private_key.public_key().public_bytes_raw()
+    public_key_raw = private_key.public_key().public_bytes(Encoding.Raw, PublicFormat.Raw)
     transaction_id = find_free_id(public_key_raw)
     transaction_prefix = transaction_id.to_bytes(4, "big") + \
         public_key_raw + \
@@ -141,12 +142,12 @@ def main():
         private_key = Ed25519PrivateKey.from_private_bytes(private_key_raw)
     except FileNotFoundError:
         private_key = Ed25519PrivateKey.generate()
-        private_key_raw = private_key.private_bytes_raw()
+        private_key_raw = private_key.private_bytes(Encoding.Raw, PrivateFormat.Raw, NoEncryption())
         with open("wallet-key", "wb") as f:
             f.write(private_key_raw)
 
     public_key = private_key.public_key()
-    wallet_addr = format_address(public_key.public_bytes_raw())
+    wallet_addr = format_address(public_key.public_bytes(Encoding.Raw, PublicFormat.Raw))
     print(f"Your wallet address: {wallet_addr}\n")
 
     if len(sys.argv) == 1: