diff --git a/gluon/tools.py b/gluon/tools.py
index 664f2f56..053dc9ad 100644
--- a/gluon/tools.py
+++ b/gluon/tools.py
@@ -2005,6 +2005,12 @@ class Auth(object):
                 return self.cas_validate(version=2, proxy=False)
             elif args(1) == self.settings.cas_actions['proxyvalidate']:
                 return self.cas_validate(version=2, proxy=True)
+            elif (args(1) == 'p3'
+                  and args(2) == self.settings.cas_actions['servicevalidate']):
+                return self.cas_validate(version=3, proxy=False)
+            elif (args(1) == 'p3'
+                  and args(2) == self.settings.cas_actions['proxyvalidate']):
+                return self.cas_validate(version=3, proxy=True)
             elif args(1) == self.settings.cas_actions['logout']:
                 return self.logout(next=request.vars.service or DEFAULT)
         else:
@@ -2830,6 +2836,15 @@ class Auth(object):
         if success:
             if version == 1:
                 message = 'yes\n%s' % user[userfield]
+            elif version == 3:
+                username = user.get('username', user[userfield])
+                message = build_response(
+                    TAG['cas:authenticationSuccess'](
+                        TAG['cas:user'](username),
+                        TAG['cas:attributes'](
+                            *[TAG['cas:' + field.name](user[field.name])
+                              for field in self.table_user()
+                              if field.readable])))
             else:  # assume version 2
                 username = user.get('username', user[userfield])
                 message = build_response(
@@ -7072,4 +7087,4 @@ class Config(object):
 
 if __name__ == '__main__':
     import doctest
-    doctest.testmod()
\ No newline at end of file
+    doctest.testmod()