Add security policy checks.

1 files changed, 26 insertions, 4 deletions

diff --git a/repoze/bfg/wsgiadapter.py b/repoze/bfg/wsgiadapter.py
index f76360c27..16effe1a5 100644
--- a/repoze/bfg/wsgiadapter.py
+++ b/repoze/bfg/wsgiadapter.py
@@ -1,19 +1,40 @@
-from zope.interface import implements
+from zope.component import queryMultiAdapter
 from zope.interface import classProvides
+from zope.interface import implements
+from zope.interface import Interface
 
 from repoze.bfg.interfaces import IWSGIApplicationFactory
 from repoze.bfg.interfaces import IWSGIApplication
 from repoze.bfg.mapply import mapply
 
+class IViewSecurityPolicy(Interface):
+    """ Marker interface for a view security policy; a view security
+    policy. """
+    def __call__():
+        """ Return None if the security check succeeded,
+        otherwise it should return a WSGI application representing an
+        unauthorized view"""
+
 class NaiveWSGIViewAdapter:
     classProvides(IWSGIApplicationFactory)
     implements(IWSGIApplication)
 
-    def __init__(self, view, request):
-        self.view = view
+    def __init__(self, context, request, view):
+        self.context = context
         self.request = request
+        self.view = view
 
     def __call__(self, environ, start_response):
+        context = self.context
+        request = self.request
+        view = self.view
+        security_policy = queryMultiAdapter((context, request),
+                                            IViewSecurityPolicy)
+        if security_policy:
+            failed_view = security_policy()
+            if failed_view:
+                view = failed_view
+
         catch_response = []
         def replace_start_response(status, headers):
             catch_response[:] = (status, headers)
@@ -22,7 +43,8 @@ class NaiveWSGIViewAdapter:
             'environ':environ,
             'start_response':start_response,
             }
-        response =  mapply(self.view, positional = (), keyword = kwdict)
+
+        response =  mapply(view, positional = (), keyword = kwdict)
         if not catch_response:
             catch_response = (response.status, response.headerlist)
         start_response(*catch_response)