paymentrequest: be explicit about only allowing "addresses"

electrum/paymentrequest.py

@@ -132,8 +132,12 @@ class PaymentRequest:
         self.details.ParseFromString(self.data.serialized_payment_details)
         self.outputs = []
         for o in self.details.outputs:
-            addr = transaction.get_address_from_output_script(o.script)[1]
-            self.outputs.append(TxOutput(TYPE_ADDRESS, addr, o.amount))
+            type_, addr = transaction.get_address_from_output_script(o.script)
+            if type_ != TYPE_ADDRESS:
+                # TODO maybe rm restriction but then get_requestor and get_id need changes
+                self.error = "only addresses are allowed as outputs"
+                return
+            self.outputs.append(TxOutput(type_, addr, o.amount))
         self.memo = self.details.memo
         self.payment_url = self.details.payment_url
 
@@ -195,6 +199,9 @@ class PaymentRequest:
             verify = pubkey0.verify(sigBytes, x509.PREFIX_RSA_SHA256 + hashBytes)
         elif paymntreq.pki_type == "x509+sha1":
             verify = pubkey0.hashAndVerify(sigBytes, msgBytes)
+        else:
+            self.error = f"ERROR: unknown pki_type {paymntreq.pki_type} in Payment Request"
+            return False
         if not verify:
             self.error = "ERROR: Invalid Signature for Payment Request Data"
             return False

electrum/transaction.py

@@ -1030,9 +1030,10 @@ class Transaction:
         if outputs:
             self._outputs.sort(key = lambda o: (o.value, self.pay_script(o.type, o.address)))
 
-    def serialize_output(self, output: TxOutput) -> str:
+    @classmethod
+    def serialize_output(cls, output: TxOutput) -> str:
         s = int_to_hex(output.value, 8)
-        script = self.pay_script(output.type, output.address)
+        script = cls.pay_script(output.type, output.address)
         s += var_int(len(script)//2)
         s += script
         return s

electrum/util.py

@@ -444,8 +444,7 @@ def assert_str(*args):
         assert isinstance(x, str)
 
 
-
-def to_string(x, enc):
+def to_string(x, enc) -> str:
     if isinstance(x, (bytes, bytearray)):
         return x.decode(enc)
     if isinstance(x, str):
@@ -453,7 +452,8 @@ def to_string(x, enc):
     else:
         raise TypeError("Not a string or bytes like object")
 
-def to_bytes(something, encoding='utf8'):
+
+def to_bytes(something, encoding='utf8') -> bytes:
     """
     cast string to bytes() like object, but for python2 support it's bytearray copy
     """
@@ -471,16 +471,13 @@ bfh = bytes.fromhex
 hfu = binascii.hexlify
 
 
-def bh2u(x):
+def bh2u(x: bytes) -> str:
     """
     str with hex representation of a bytes-like object
 
     >>> x = bytes((1, 2, 10))
     >>> bh2u(x)
     '01020A'
-
-    :param x: bytes
-    :rtype: str
     """
     return hfu(x).decode('ascii')