#!/usr/bin/env python

# This software is provided 'as-is', without any express or implied
# warranty.  In no event will the author be held liable for any damages
# arising from the use of this software.
#
# Permission is granted to anyone to use this software for any purpose,
# including commercial applications, and to alter it and redistribute it
# freely, subject to the following restrictions:
#
# 1. The origin of this software must not be misrepresented; you must not
#    claim that you wrote the original software. If you use this software
#    in a product, an acknowledgment in the product documentation would be
#    appreciated but is not required.
# 2. Altered source versions must be plainly marked as such, and must not be
#    misrepresented as being the original software.
# 3. This notice may not be removed or altered from any source distribution.
#
# Copyright (c) 2008 Greg Hewgill http://hewgill.com
#
# This has been modified from the original software.
# Copyright (c) 2011 William Grant <me@williamgrant.id.au>
#
# This has been modified from the original software.
# Copyright (c) 2016 Google, Inc.
# Contact: Brandon Long <blong@google.com>
# This has been modified from the original software.
# Copyright (c) 2017, 2018, 2019 Scott Kitterman <scott@kitterman.com>
#
# This has been modified from the original software.
# Copyright (c) 2017 Valimail Inc
# Contact: Gene Shuman <gene@valimail.com>


from __future__ import print_function

import logging
import re
import sys

import dkim

logging.basicConfig(level=10)


def main():
    if len(sys.argv) != 5:
        print("Usage: arcsign.py selector domain privatekeyfile srv_id", file=sys.stderr)
        sys.exit(1)

    if sys.version_info[0] >= 3:
        # Make sys.stdin and stdout binary streams.
        sys.stdin = sys.stdin.detach()
        sys.stdout = sys.stdout.detach()

    selector = sys.argv[1].encode('ascii')
    domain = sys.argv[2].encode('ascii')
    privatekeyfile = sys.argv[3]
    srv_id = sys.argv[4].encode('ascii')

    message = sys.stdin.read()

    # Pick a cv status
    cv = dkim.CV_None
    if re.search(b'arc-seal', message, re.IGNORECASE):
        cv = dkim.CV_Pass

    #try:
    sig = dkim.arc_sign(message, selector, domain, open(privatekeyfile, "rb").read(),
                   srv_id, cv, linesep=dkim.util.get_linesep(message))
    for line in sig:
        sys.stdout.write(line)
    sys.stdout.write(message)
    #except Exception as e:
    #    print(e, file=sys.stderr)
        #sys.stdout.write(message)


if __name__ == "__main__":
    main()