[Checkins] SVN: grokui.admin/branches/ulif-securitynotifications/src/grokui/admin/security.py SecurityNotfier implementation (draft).

[Uli Fouquet]

Log message for revision 94221:
  SecurityNotfier implementation (draft).

Changed:
  A   grokui.admin/branches/ulif-securitynotifications/src/grokui/admin/security.py

-=-
Added: grokui.admin/branches/ulif-securitynotifications/src/grokui/admin/security.py
===================================================================
--- grokui.admin/branches/ulif-securitynotifications/src/grokui/admin/security.py	                        (rev 0)
+++ grokui.admin/branches/ulif-securitynotifications/src/grokui/admin/security.py	2008-12-21 17:54:37 UTC (rev 94221)
@@ -0,0 +1,155 @@
+##############################################################################
+#
+# Copyright (c) 2008 Zope Corporation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+"""Security notifications for `grokui.admin`.
+
+The machinery to do home-calling security notifications.
+"""
+import grok
+import pkg_resources
+import time
+import urllib2
+import urlparse
+from zope.app.appsetup.interfaces import IDatabaseOpenedWithRootEvent
+from zope.component import adapter, provideHandler
+from persistent import Persistent
+from grokui.admin.interfaces import ISecurityNotifier
+
+class SecurityNotifier(Persistent):
+    """A security notifier.
+
+    It can be placed in a site to store notification dates and other
+    data persistently.
+    """
+
+    grok.implements(ISecurityNotifier)
+
+    VERSION = 1 # for possibly updates/downgrades
+    MSG_DISABLED = u'Security notifications are disabled.'
+    
+    lookup_url = 'http://grok.zope.org/releaseinfo/'
+    last_lookup = None   # When did we do the last lookup?
+    lookup_timeout = 2   # Number of seconds to wait
+    last_display = None  # When did we display the last time?
+    enabled = False      # By default we disable the notfier.
+
+    lookup_frequency = 3600 * 3 # Lookup every three hours.
+    display_frequency = 3600 * 3 # Display warnings every three hours.
+
+    _message = u''
+    _warningstate = False
+    
+    def enable(self):
+        """Enable security notifications.
+        """
+        self.enabled = True
+        return
+
+    def disable(self):
+        """Disable security notifications.
+        """
+        self.enabled = False
+        return
+
+    def getNotification(self):
+        """Get the current security notification.
+        """
+        if self.enabled is False:
+            return self.MSG_DISABLED
+        self.updateMessage()
+        return self._message
+
+    def isWarning(self):
+        self.updateMessage()
+        return self._warningstate
+    
+    def updateMessage(self):
+        """Update the security message.
+        """
+        if self.enabled is False:
+            return
+        if self.last_lookup is not None:
+            if time.time() - self.lookup_frequency < self.last_lookup:
+                return
+        self.fetchMessage()
+        return
+    
+    def fetchMessage(self):
+        """Possibly fetch security notfications from grok.zope.org.
+        """
+        if self.enabled is False:
+            # Safety belt.
+            return
+        version = self.getGrokVersion()
+        filename = 'grok-%s.security.txt' % version
+        url = urlparse.urljoin(self.lookup_url, filename)
+        try:
+            self._message = urllib2.urlopen(url).read()
+        except:
+            # Currently we tolerate any error, while only certain
+            # ones, like HTTPError 404 or OSError 'File not found'
+            # should be accepted.
+            #
+            # In case of an error we assume, that there is no security
+            # notification available.
+            self._message = u''
+        self.last_lookup = time.time()
+        return
+
+    def display(self):
+        """Display the message.
+
+        In fact we only keep track of timestamps of display actions.
+        """
+        self.last_display = time.time()
+        return
+
+    def getGrokVersion(self):
+        """Determine the version of grok used in background.
+        """
+        info = pkg_resources.get_distribution('grok')
+        if info.has_version and info.version:
+            return info.version
+        return None
+
+def setupSecurityNotification(site):
+    """Setup a SecurityNotifier as persistent utility.
+
+    The utility is installed as a local and persistent utility. It is
+    local to `site` and installed under the name
+    ``grokadmin_security`` in the site manager of `site`.
+
+    It can be retrieved with a call like::
+
+      site.getSiteManager().getUtiliy(ISecurityNotifier)
+
+    See also ``security.py`` in ``tests``.
+    """
+    site_manager = site.getSiteManager()
+    if 'grokadmin_security' not in site_manager:
+        site_manager['grokadmin_security'] = SecurityNotifier()
+    utility = site_manager['grokadmin_security']
+    site_manager.registerUtility(utility, ISecurityNotifier, name=u'')
+    return
+    
+ at adapter(IDatabaseOpenedWithRootEvent)
+def securitySetupHandler(event):
+    """Call security notification setup as soon as DB is ready.
+    """
+    from zope.app.appsetup.bootstrap import getInformationFromEvent
+    
+    db, connection, root, root_folder = getInformationFromEvent(event)
+    setupSecurityNotification(root_folder)
+    
+# ...then install the event handler:
+provideHandler(securitySetupHandler)