= Messages encryption =
I'll document the effort to add support for optionally message encryption using GnuPG.

== Code structure ==
=== Where ===
Where to kick in and mangle the message body is of course an essential decision.
Reading the current code from trunk I found this in ./announcerplugin_trunk/announcer/distributors/mail.py
{{{
        parentMessage.attach(msgText)
        decorators = self._get_decorators()
        if len(decorators) > 0:
            decorator = decorators.pop()
            decorator.decorate_message(event, rootMessage, decorators)
-->
        recip_adds = [x[2] for x in recipients if x]
        # Append any to, cc or bccs added to the recipient list
        for field in ('To', 'Cc', 'Bcc'):
 
}}}
--> Here I'll add some code to make encryption just work (1st step). Encryption/signing key ID hard-coded, growing number of variables I'd like to see as options in [annoucer] section of trac.ini and other ugliness. This will evolve over time.

[FIXME: add more Q+A here to help with code design evaluation and code review]  
 ?: Why not implement encryption as another IAnnouncementEmailDecorator
  A: Decorators are called without guaranteed order. Encryption needs control, that it'll be the last message body mangling action.
 ?: Why not implement encryption as another IAnnouncementFormatter
  A: Encryption is not about encoding etc.

=== What ===
What to do. It greatly depends on decision about how much is read from configuration or qualified deduction/guessing. Less configuration is good for the Admin in charge.

Overview of expected behavior/features:
 * set gpg environment, preferable a dedicated place
 * read recipient list, optionally group recipients into require_encryption_group and allow_verbatim_msg_group
 * associate each recipient in require_encryption_group with key
 * handle behavior on missing key
 * embed DEBUG logging into all operations mentioned above

sources (ideas and code)
 * Intro to python-gnupg at http://groups.google.de/group/comp.lang.python/browse_thread/thread/f2b97a2c11e1df63
 * Python Wrapper for GnuPG v0.2.4 documentation: http://www.red-dove.com/python_gnupg/index.html
 * some real-world implementations of python-gnupg (not found by now, hints?)

-- hasienda