Add syntax check of get_default_redirect_uri

Authorization Code was missing this check, whereas Implicit was checking it.

oauthlib/oauth2/rfc6749/grant_types/authorization_code.py

@@ -312,6 +312,8 @@ def validate_authorization_request(self, request):
             log.debug('Using default redirect_uri %s.', request.redirect_uri)
             if not request.redirect_uri:
                 raise errors.MissingRedirectURIError(request=request)
+            if not is_absolute_uri(request.redirect_uri):
+                raise errors.InvalidRedirectURIError(request=request)
 
         # Then check for normal errors.
 

tests/oauth2/rfc6749/endpoints/test_error_responses.py

@@ -44,6 +44,22 @@ def test_invalid_redirect_uri(self):
         self.assertRaises(errors.InvalidRedirectURIError,
                 self.mobile.create_authorization_response, uri.format('token'), scopes=['foo'])
 
+    def test_invalid_default_redirect_uri(self):
+        uri = 'https://example.com/authorize?response_type={0}&client_id=foo'
+        self.validator.get_default_redirect_uri.return_value = "wrong"
+
+        # Authorization code grant
+        self.assertRaises(errors.InvalidRedirectURIError,
+                self.web.validate_authorization_request, uri.format('code'))
+        self.assertRaises(errors.InvalidRedirectURIError,
+                self.web.create_authorization_response, uri.format('code'), scopes=['foo'])
+
+        # Implicit grant
+        self.assertRaises(errors.InvalidRedirectURIError,
+                self.mobile.validate_authorization_request, uri.format('token'))
+        self.assertRaises(errors.InvalidRedirectURIError,
+                self.mobile.create_authorization_response, uri.format('token'), scopes=['foo'])
+
     def test_missing_redirect_uri(self):
         uri = 'https://example.com/authorize?response_type={0}&client_id=foo'