diff --git a/wiki/auth/cas.py b/wiki/auth/cas.py
index 12f50580..6a57db06 100644
--- a/wiki/auth/cas.py
+++ b/wiki/auth/cas.py
@@ -9,9 +9,12 @@
 """
 
 import sys
+import os
 import time, re
 import urlparse
 import urllib, urllib2
+from lxml import etree
+from lxml.etree import XMLSyntaxError
 
 from MoinMoin import log
 logging = log.getLogger(__name__)
@@ -19,7 +22,6 @@ logging = log.getLogger(__name__)
 from MoinMoin.auth import BaseAuth
 from MoinMoin import user, wikiutil
 
-
 class PyCAS(object):
     """A class for working with a CAS server."""
 
@@ -53,6 +55,14 @@ class PyCAS(object):
             url += "&renew=true"
         return url
 
+    def singlesignout(self, callback, body):
+        try:
+            nodes = etree.fromstring(body).xpath("/samlp:LogoutRequest/samlp:SessionIndex", namespaces={'samlp' : 'urn:oasis:names:tc:SAML:2.0:protocol'})
+            for node in nodes:
+                callback(node.text)
+        except XMLSyntaxError:
+            pass
+
     def validate_ticket(self, service, ticket):
         """Validate the given ticket against the given service."""
         f = urllib2.urlopen(self.validate_url(service, ticket))
@@ -68,13 +78,14 @@ class CASAuth(BaseAuth):
     login_inputs = ['username', 'password']
     logout_possible = True
 
-    def __init__(self, auth_server, login_path="/login", logout_path="/logout", validate_path="/validate", action="login_cas", create_user=False, fallback_url=None):
+    def __init__(self, auth_server, login_path="/login", logout_path="/logout", validate_path="/validate", action="login_cas", create_user=False, fallback_url=None, ticket_path=None):
         BaseAuth.__init__(self)
         self.cas = PyCAS(auth_server, login_path=login_path,
                          validate_path=validate_path, logout_path=logout_path)
         self.action = action
         self.create_user = create_user
         self.fallback_url = fallback_url
+        self.ticket_path = ticket_path
 
     def request(self, request, user_obj, **kw):
         ticket = request.args.get("ticket", "")
@@ -84,10 +95,46 @@ class CASAuth(BaseAuth):
         p = urlparse.urlparse(request.url)
         url = urlparse.urlunparse(('https', p.netloc, p.path, "", "", ""))
 
+        def store_ticket(ticket, username):
+            with open(self.ticket_path + ticket, 'w') as f:
+                 f.write(username)
+
+        def username_of_ticket(ticket):
+            try:
+                with open(self.ticket_path + ticket) as f:
+                    username = f.read()
+                os.remove(self.ticket_path + ticket)
+                return username
+            except IOError:
+                return None
+
+        def logout_user(ticket):
+            username = username_of_ticket(ticket)
+            if username:
+                u = user.User(request, None, username)
+                checks = []
+                if u.exists():
+                    def user_matches(session):
+                        try:
+                            return session['user.id'] == u.id
+                        except KeyError:
+                            return False
+                    session_service = request.cfg.session_service
+                    for sid in session_service.get_all_session_ids(request):
+                        session = session_service.get_session(request, sid)
+
+                        if user_matches(session):
+                            session_service.destroy_session(request, session)
+
         # authenticated user
         if not force and user_obj and user_obj.valid:
             return user_obj, True
 
+        if self.ticket_path and request.method == 'POST':
+            logoutRequest=request.form.get('logoutRequest', None)
+            if logoutRequest is not None:
+                self.cas.singlesignout(logout_user, logoutRequest)
+
         # anonymous
         if not ticket and not self.action == action:
             return user_obj, True
@@ -105,6 +152,8 @@ class CASAuth(BaseAuth):
                     u.valid = u.exists()
                 if self.fallback_url and not u.valid:
                     request.http_redirect("%s?action=%s&wiki_url=%s" % (self.fallback_url, self.action, url))
+                if u.valid:
+                    store_ticket(ticket, username)
                 return u, True
 
         # login