#!/usr/bin/python

# vim:set et sw=4:

#

# certdata2pem.py - splits certdata.txt into multiple files

#

# Copyright (C) 2009 Philipp Kern <pkern@debian.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 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301,

# USA.

import base64

import os.path

import re

import sys

import textwrap

import io

objects = []

# Dirty file parser.

in_data, in_multiline, in_obj = False, False, False

field, type, value, obj = None, None, None, dict()

# Python 3 will not let us decode non-ascii characters if we

# have not specified an encoding, but Python 2's open does not

# have an option to set the encoding. Python 3's open is io.open

# and io.open has been backported to Python 2.6 and 2.7, so use io.open.

for line in io.open('certdata.txt', 'rt', encoding='utf8'):

    # Ignore the file header.

    if not in_data:

        if line.startswith('BEGINDATA'):

            in_data = True

        continue

    # Ignore comment lines.

    if line.startswith('#'):

        continue

    # Empty lines are significant if we are inside an object.

    if in_obj and len(line.strip()) == 0:

        objects.append(obj)

        obj = dict()

        in_obj = False

        continue

    if len(line.strip()) == 0:

        continue

    if in_multiline:

        if not line.startswith('END'):

            if type == 'MULTILINE_OCTAL':

                line = line.strip()

                for i in re.finditer(r'\\([0-3][0-7][0-7])', line):

                    value.append(int(i.group(1), 8))

            else:

                value += line

            continue

        obj[field] = value

        in_multiline = False

        continue

    if line.startswith('CKA_CLASS'):

        in_obj = True

    line_parts = line.strip().split(' ', 2)

    if len(line_parts) > 2:

        field, type = line_parts[0:2]

        value = ' '.join(line_parts[2:])

    elif len(line_parts) == 2:

        field, type = line_parts

        value = None

    else:

        raise NotImplementedError('line_parts < 2 not supported.')

    if type == 'MULTILINE_OCTAL':

        in_multiline = True

        value = bytearray()

        continue

    obj[field] = value

if len(obj) > 0:

    objects.append(obj)

# Read blacklist.

blacklist = []

if os.path.exists('blacklist.txt'):

    for line in open('blacklist.txt', 'r'):

        line = line.strip()

        if line.startswith('#') or len(line) == 0:

            continue

        item = line.split('#', 1)[0].strip()

        blacklist.append(item)

# Build up trust database.

trust = dict()

for obj in objects:

    if obj['CKA_CLASS'] != 'CKO_NSS_TRUST':

        continue

    if obj['CKA_LABEL'] in blacklist:

        print("Certificate %s blacklisted, ignoring." % obj['CKA_LABEL'])

    elif obj['CKA_TRUST_SERVER_AUTH'] == 'CKT_NSS_TRUSTED_DELEGATOR':

        trust[obj['CKA_LABEL']] = True

    elif obj['CKA_TRUST_EMAIL_PROTECTION'] == 'CKT_NSS_TRUSTED_DELEGATOR':

        trust[obj['CKA_LABEL']] = True

    elif obj['CKA_TRUST_SERVER_AUTH'] == 'CKT_NSS_NOT_TRUSTED':

        print('!'*74)

        print("UNTRUSTED BUT NOT BLACKLISTED CERTIFICATE FOUND: %s" % obj['CKA_LABEL'])

        print('!'*74)

    else:

        print("Ignoring certificate %s.  SAUTH=%s, EPROT=%s" % \

              (obj['CKA_LABEL'], obj['CKA_TRUST_SERVER_AUTH'],

               obj['CKA_TRUST_EMAIL_PROTECTION']))

for obj in objects:

    if obj['CKA_CLASS'] == 'CKO_CERTIFICATE':

        if not obj['CKA_LABEL'] in trust or not trust[obj['CKA_LABEL']]:

            continue

        bname = obj['CKA_LABEL'][1:-1].replace('/', '_')\

                                      .replace(' ', '_')\

                                      .replace('(', '=')\

                                      .replace(')', '=')\

                                      .replace(',', '_')

        # this is the only way to decode the way NSS stores multi-byte UTF-8

        # and we need an escaped string for checking existence of things

        # otherwise we're dependant on the user's current locale.

        if bytes != str:

            # We're in python 3, convert the utf-8 string to a

            # sequence of bytes that represents this utf-8 string

            # then encode the byte-sequence as an escaped string that

            # can be passed to open() and os.path.exists()

            bname = bname.encode('utf-8').decode('unicode_escape').encode('latin-1')

        else:

            # Python 2

            # Convert the unicode string back to its original byte form

            # (contents of files returned by io.open are returned as

            #  unicode strings)

            # then to an escaped string that can be passed to open()

            # and os.path.exists()

            bname = bname.encode('utf-8').decode('string_escape')

        fname = bname + b'.crt'

        if os.path.exists(fname):

            print("Found duplicate certificate name %s, renaming." % bname)

            fname = bname + b'_2.crt'

        f = open(fname, 'w')

        f.write("-----BEGIN CERTIFICATE-----\n")

        encoded = base64.b64encode(obj['CKA_VALUE']).decode('utf-8')

        f.write("\n".join(textwrap.wrap(encoded, 64)))

        f.write("\n-----END CERTIFICATE-----\n")