fix 3262: protobuf SerializeToString() returns bytes..

lib/paymentrequest.py

@@ -411,7 +411,7 @@ def sign_request_with_x509(pr, key_path, cert_path):
         s = f.read()
         bList = pem.dePemList(s, "CERTIFICATE")
     certificates = pb2.X509Certificates()
-    certificates.certificate.extend(map(str, bList))
+    certificates.certificate.extend(map(bytes, bList))
     pr.pki_type = 'x509+sha256'
     pr.pki_data = certificates.SerializeToString()
     msgBytes = bytearray(pr.SerializeToString())

lib/wallet.py

@@ -1292,7 +1292,7 @@ class Abstract_Wallet(PrintError):
                 except OSError as exc:
                     if exc.errno != errno.EEXIST:
                         raise
-            with open(os.path.join(path, key), 'w') as f:
+            with open(os.path.join(path, key), 'wb') as f:
                 f.write(pr.SerializeToString())
             # reload
             req = self.get_payment_request(addr, config)