Fix some errors with Python2.6 and Python3

For Python2.6: fix non-existing total_seconds by converting datetime
delta to seconds.

For Python3: fix "datetime is not JSON serializable" issue by converting
the delta datetime to unix timestamp first.

Author: liamlin

rest_framework_jwt/serializers.py

@@ -1,5 +1,5 @@
 from calendar import timegm
-from datetime import datetime
+from datetime import datetime, timedelta
 import jwt
 
 from django.contrib.auth import authenticate, get_user_model
@@ -101,9 +101,12 @@ def validate(self, attrs):
         orig_iat = payload.get('orig_iat')
         if orig_iat:
             # Verify expiration
+            renewal_limit = api_settings.JWT_TOKEN_RENEWAL_LIMIT
+            if isinstance(renewal_limit, timedelta):
+                renewal_limit = renewal_limit.days * 24 * 3600 + renewal_limit.seconds
             expiration_timestamp = (
                 orig_iat +
-                int(api_settings.JWT_TOKEN_RENEWAL_LIMIT.total_seconds())
+                int(renewal_limit)
             )
             now_timestamp = timegm(datetime.utcnow().utctimetuple())
             if now_timestamp > expiration_timestamp:

rest_framework_jwt/utils.py

@@ -5,11 +5,15 @@
 
 
 def jwt_payload_handler(user):
+    delta_timestamp = (datetime.utcnow() + api_settings.JWT_EXPIRATION_DELTA) - datetime(1970,1,1)
+    # total seconds
+    exp = delta_timestamp.seconds + delta_timestamp.days * 24 * 3600
+
     return {
         'user_id': user.pk,
         'email': user.email,
         'username': user.get_username(),
-        'exp': datetime.utcnow() + api_settings.JWT_EXPIRATION_DELTA
+        'exp': exp
     }