#!/usr/bin/env python3

# -*- coding: utf-8 -*-

from __future__ import absolute_import, division, unicode_literals

# Copyright (C) 2018 Ben McGinnes <ben@gnupg.org>

#

# 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 free software; you can redistribute it and/or modify it under

# the terms of the GNU Lesser General Public License as published by the Free

# Software Foundation; either version 2.1 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 and the GNU

# Lesser General Public License for more details.

#

# You should have received a copy of the GNU General Public License and the GNU

# Lesser General Public along with this program; if not, see

# <https://www.gnu.org/licenses/>.

import gpg

import sys

import time

"""

Verifies a signed file which has been signed with a detached signature.

"""

if len(sys.argv) > 2:

    filename = sys.argv[1]

    sig_file = sys.argv[2]

elif len(sys.argv) == 2:

    filename = sys.argv[1]

    sig_file = input("Enter the path and filename of the detached signature: ")

else:

    filename = input("Enter the path and filename to verify: ")

    sig_file = input("Enter the path and filename of the detached signature: ")

c = gpg.Context()

try:

    data, result = c.verify(open(filename), open(sig_file))

    verified = True

except gpg.errors.BadSignatures as e:

    verified = False

    print(e)

if verified is True:

    for i in range(len(result.signatures)):

        sign = result.signatures[i]

        print("""Good signature from:

{0}

with key {1}

made at {2}

""".format(c.get_key(sign.fpr).uids[0].uid, sign.fpr,

           time.ctime(sign.timestamp)))

else:

    pass