Use to_hex instead of hex

Author: rakanalh

raiden/api/rest.py

@@ -8,7 +8,7 @@
 import gevent
 import gevent.pool
 import structlog
-from eth_utils import encode_hex, to_checksum_address
+from eth_utils import encode_hex, to_checksum_address, to_hex
 from flask import Flask, make_response, request, send_from_directory, url_for
 from flask.json import jsonify
 from flask_cors import CORS
@@ -1052,8 +1052,8 @@ def initiate_payment(
             'target_address': target_address,
             'amount': amount,
             'identifier': identifier,
-            'secret': payment_status.secret.hex(),
-            'secret_hash': payment_status.secret_hash.hex(),
+            'secret': to_hex(payment_status.secret),
+            'secret_hash': to_hex(payment_status.secret_hash),
         }
         result = self.payment_schema.dump(payment)
         return api_response(result=result.data)

raiden/tests/integration/api/test_restapi.py

@@ -3,7 +3,13 @@
 import gevent
 import grequests
 import pytest
-from eth_utils import is_checksum_address, to_canonical_address, to_checksum_address
+from eth_utils import (
+    is_checksum_address,
+    to_bytes,
+    to_canonical_address,
+    to_checksum_address,
+    to_hex,
+)
 from flask import url_for
 
 from raiden.api.v1.encoding import AddressField, HexAddressConverter
@@ -931,9 +937,11 @@ def test_api_payments(api_server_test_instance, raiden_network, token_addresses)
     assert response.items() >= payment.items()
     assert 'secret' in response
     assert 'secret_hash' in response
-    assert len(response['secret']) == 64
-    assert len(response['secret_hash']) == 64
-    assert sha3(bytes.fromhex(response['secret'])).hex() == response['secret_hash']
+    assert len(response['secret']) == 66
+    assert len(response['secret_hash']) == 66
+
+    generated_secret_hash = to_hex(sha3(to_bytes(hexstr=response['secret'])))
+    assert generated_secret_hash == response['secret_hash']
 
 
 def assert_payment_conflict(responses):