#!/usr/bin/env python

# mailman-smime.py - demo on how to deal with smime messages in the Mailman
#                      framework.
#
# usage: this script should get installed in mailman/bin.  On Debian
#  GNU/Linux systems this is /usr/lib/mailman/bin/ .  It reads a raw S/MIME
#  message on stdin.

# Copyright (C) 2005 Tilburg University http://www.uvt.nl/
# Author: Joost van Baal
#
#    This program 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 2 of the License, or
#    (at your option) any later version.
#
#    This program 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 this program; if not, write to the Free Software
#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

import paths
from Mailman import mm_cfg
import sys
import email
import base64

sys.path.append('/usr/lib/mailman/Mailman/Handlers')
sys.path.append('/usr/lib/mailman/Mailman/')

import Utils
from Mailman import Message

# import pyme
from pyme import core, constants, errors
import pyme.constants.validity

# Initialize our context.
c = pyme.core.Context()

# We prefer ascii armored output
c.set_armor(1)

c.set_protocol(pyme.util.gpgme.GPGME_PROTOCOL_CMS)

# fp = file("/home/joostvb/tmp/mailtje.mail")
# msg = fp.read()

# msg = sys.stdin.read()
# msg = email.message_from_string(msg, Message.Message)

msg = email.message_from_string(sys.stdin.read(), Message.Message)

if msg.is_multipart():
    for submsg in msg.get_payload():
        if submsg.get_content_type()=="application/x-pkcs7-signature":
            cms = base64.decodestring(submsg.get_payload())
    print "cms contains CMS part of message"
else:
    if msg.get_content_type()=="application/x-pkcs7-mime":
        cms = base64.decodestring(msg.get_payload())
        print "cms contains crypted CMS stuff"

        # Prepare for decryption: Set up input and output buffers
        cipher = pyme.core.Data(cms)
        plain = pyme.core.Data()

        # Do the decryption.
        try:
            c.op_decrypt(cipher, plain)
            plain.seek(0,0)
            print plain.read()
        except pyme.errors.GPGMEError, ex:
            print ex.getstring()