1 files changed, 58 insertions, 0 deletions

diff --git a/src/mailman/pipeline/cleanse_dkim.py b/src/mailman/pipeline/cleanse_dkim.py
new file mode 100644
index 000000000..38623079c
--- /dev/null
+++ b/src/mailman/pipeline/cleanse_dkim.py
@@ -0,0 +1,58 @@
+# Copyright (C) 2006-2009 by the Free Software Foundation, Inc.
+#
+# This file is part of GNU Mailman.
+#
+# GNU Mailman is free software: you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option)
+# any later version.
+#
+# GNU Mailman is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+# more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Remove any 'DomainKeys' (or similar) headers.
+
+The values contained in these header lines are intended to be used by the
+recipient to detect forgery or tampering in transit, and the modifications
+made by Mailman to the headers and body of the message will cause these keys
+to appear invalid.  Removing them will at least avoid this misleading result,
+and it will also give the MTA the opportunity to regenerate valid keys
+originating at the Mailman server for the outgoing message.
+"""
+
+from __future__ import absolute_import, unicode_literals
+
+__metaclass__ = type
+__all__ = [
+    'CleanseDKIM',
+    ]
+
+
+from lazr.config import as_boolean
+from zope.interface import implements
+
+from mailman.config import config
+from mailman.i18n import _
+from mailman.interfaces.handler import IHandler
+
+
+
+class CleanseDKIM:
+    """Remove DomainKeys headers."""
+
+    implements(IHandler)
+
+    name = 'cleanse-dkim'
+    description = _('Remove DomainKeys headers.')
+
+    def process(self, mlist, msg, msgdata):
+        """See `IHandler`."""
+        if as_boolean(config.mta.remove_dkim_headers):
+            del msg['domainkey-signature']
+            del msg['dkim-signature']
+            del msg['authentication-results']