python3: use smart bytes for signatures

combo/utils/signature.py

@@ -21,6 +21,7 @@ import hashlib
 import random
 
 from django.conf import settings
+from django.utils.encoding import smart_bytes
 from django.utils.http import quote, urlencode
 from django.utils.six.moves.urllib.parse import urlparse, urlunparse, parse_qs
 
@@ -51,7 +52,7 @@ def sign_query(query, key, algo='sha256', timestamp=None, nonce=None):
 
 def sign_string(s, key, algo='sha256', timedelta=30):
     digestmod = getattr(hashlib, algo)
-    hash = hmac.HMAC(str(key), digestmod=digestmod, msg=s)
+    hash = hmac.HMAC(smart_bytes(key), digestmod=digestmod, msg=smart_bytes(s))
     return hash.digest()
 
 def check_request_signature(django_request, keys=[]):