1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
# -*- coding: utf-8 -*-
# wrapper.py
# Copyright (C) 2016 LEAP
#
# 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 3 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, see <http://www.gnu.org/licenses/>.
"""
GPG wrapper for temporary keyrings
"""
import os
import platform
import shutil
import tempfile
from gnupg import GPG
from twisted.logger import Logger
from leap.common.check import leap_assert
try:
from gnupg.gnupg import GPGUtilities
GNUPG_NG = True
except ImportError:
GNUPG_NG = False
logger = Logger()
class TempGPGWrapper(object):
"""
A context manager that wraps a temporary GPG keyring which only contains
the keys given at object creation.
"""
def __init__(self, keys=None, gpgbinary=None):
"""
Create an empty temporary keyring and import any given C{keys} into
it.
:param keys: OpenPGP key, or list of.
:type keys: OpenPGPKey or list of OpenPGPKeys
:param gpgbinary: Name for GnuPG binary executable.
:type gpgbinary: C{str}
"""
self._gpg = None
self._gpgbinary = gpgbinary
if not keys:
keys = list()
if not isinstance(keys, list):
keys = [keys]
self._keys = keys
def __enter__(self):
"""
Build and return a GPG keyring containing the keys given on
object creation.
:return: A GPG instance containing the keys given on object creation.
:rtype: gnupg.GPG
"""
self._build_keyring()
return self._gpg
def __exit__(self, exc_type, exc_value, traceback):
"""
Ensure the gpg is properly destroyed.
"""
# TODO handle exceptions and log here
self._destroy_keyring()
def _build_keyring(self):
"""
Create a GPG keyring containing the keys given on object creation.
:return: A GPG instance containing the keys given on object creation.
:rtype: gnupg.GPG
"""
privkeys = [key for key in self._keys if key and key.private is True]
publkeys = [key for key in self._keys if key and key.private is False]
# here we filter out public keys that have a correspondent
# private key in the list because the private key_data by
# itself is enough to also have the public key in the keyring,
# and we want to count the keys afterwards.
privfps = map(lambda privkey: privkey.fingerprint, privkeys)
publkeys = filter(
lambda pubkey: pubkey.fingerprint not in privfps, publkeys)
listkeys = lambda: self._gpg.list_keys()
listsecretkeys = lambda: self._gpg.list_keys(secret=True)
try:
self._gpg = GPG(binary=self._gpgbinary,
homedir=tempfile.mkdtemp())
except TypeError:
# compat-mode with python-gnupg until windows
# support is fixed in gnupg-ng
self._gpg = GPG(gpgbinary=self._gpgbinary,
gnupghome=tempfile.mkdtemp(),
options=[])
leap_assert(len(listkeys()) is 0, 'Keyring not empty.')
# import keys into the keyring:
# concatenating ascii-armored keys, which is correctly
# understood by GPG.
self._gpg.import_keys("".join(
[x.key_data for x in publkeys + privkeys]))
# assert the number of keys in the keyring
leap_assert(
len(listkeys()) == len(publkeys) + len(privkeys),
'Wrong number of public keys in keyring: %d, should be %d)' %
(len(listkeys()), len(publkeys) + len(privkeys)))
leap_assert(
len(listsecretkeys()) == len(privkeys),
'Wrong number of private keys in keyring: %d, should be %d)' %
(len(listsecretkeys()), len(privkeys)))
def _destroy_keyring(self):
"""
Securely erase the keyring.
"""
# TODO: implement some kind of wiping of data or a more
# secure way that
# does not write to disk.
try:
for secret in [True, False]:
for key in self._gpg.list_keys(secret=secret):
self._gpg.delete_keys(
key['fingerprint'],
secret=secret)
leap_assert(len(self._gpg.list_keys()) is 0, 'Keyring not empty!')
except:
raise
finally:
try:
homedir = self._gpg.homedir
except AttributeError:
homedir = self._gpg.gnupghome
leap_assert(homedir != os.path.expanduser('~/.gnupg'),
"watch out! Tried to remove default gnupg home!")
# TODO some windows debug ....
homedir = os.path.normpath(homedir).replace("\\", "/")
homedir = str(homedir.replace("c:/", "c://"))
if platform.system() == "Windows":
logger.error("BUG! Not erasing folder in Windows")
return
shutil.rmtree(homedir)
|
