X-Git-Url: https://projects.mako.cc/source/twitter-api-cdsw/blobdiff_plain/b5d973d7a0a14eca21b2981ffacf4fb9ea77ba41..HEAD:/oauthlib/oauth2/rfc6749/grant_types/implicit.py

diff --git a/oauthlib/oauth2/rfc6749/grant_types/implicit.py b/oauthlib/oauth2/rfc6749/grant_types/implicit.py
index 27bcb24..2a92a02 100644
--- a/oauthlib/oauth2/rfc6749/grant_types/implicit.py
+++ b/oauthlib/oauth2/rfc6749/grant_types/implicit.py
@@ -260,6 +260,15 @@ class ImplicitGrant(GrantTypeBase):
         # error and MUST NOT automatically redirect the user-agent to the
         # invalid redirection URI.
 
+        # First check duplicate parameters
+        for param in ('client_id', 'response_type', 'redirect_uri', 'scope', 'state'):
+            try:
+                duplicate_params = request.duplicate_params
+            except ValueError:
+                raise errors.InvalidRequestFatalError(description='Unable to parse query string', request=request)
+            if param in duplicate_params:
+                raise errors.InvalidRequestFatalError(description='Duplicate %s parameter.' % param, request=request)
+
         # REQUIRED. The client identifier as described in Section 2.2.
         # http://tools.ietf.org/html/rfc6749#section-2.2
         if not request.client_id:
@@ -304,23 +313,21 @@ class ImplicitGrant(GrantTypeBase):
         # http://tools.ietf.org/html/rfc6749#appendix-B
 
         # Note that the correct parameters to be added are automatically
-        # populated through the use of specific exceptions.
-        if request.response_type is None:
-            raise errors.InvalidRequestError(description='Missing response_type parameter.',
-                                             request=request)
+        # populated through the use of specific exceptions
 
-        for param in ('client_id', 'response_type', 'redirect_uri', 'scope', 'state'):
-            if param in request.duplicate_params:
-                raise errors.InvalidRequestError(description='Duplicate %s parameter.' % param, request=request)
-
-        # REQUIRED. Value MUST be set to "token".
-        if request.response_type != 'token':
+        # REQUIRED.
+        if request.response_type is None:
+            raise errors.MissingResponseTypeError(request=request)
+        # Value MUST be set to "token".
+        elif request.response_type != 'token':
             raise errors.UnsupportedResponseTypeError(request=request)
 
         log.debug('Validating use of response_type token for client %r (%r).',
                   request.client_id, request.client)
         if not self.request_validator.validate_response_type(request.client_id,
-                                                             request.response_type, request.client, request):
+                                                             request.response_type,
+                                                             request.client, request):
+
             log.debug('Client %s is not authorized to use response_type %s.',
                       request.client_id, request.response_type)
             raise errors.UnauthorizedClientError(request=request)