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from common.configpaths import gajimpaths
from common import crypto
from common import exceptions
import dialogs
import os
import pickle
import gtk
import Crypto.Cipher.AES
import Crypto.Hash.SHA256
import Crypto.PublicKey.RSA
secrets_filename = gajimpaths['SECRETS_FILE']
secrets_cache = None
secrets_cipher = None
secrets_counter = None
# strength of the encryption used on SECRETS_FILE
n = 256
class Counter:
def __init__(self, n, iv):
self.n = n
self.c = crypto.decode_mpi(iv)
def __call__(self):
self.c = (self.c + 1) % (2 ** self.n)
return crypto.encode_mpi_with_padding(self.c)
# return en/decrypter if it's cached, otherwise create it from the user's
# passphrase
def get_key(counter, passph=None):
global secrets_cipher, secrets_counter
if secrets_cipher:
return secrets_cipher
if not passph:
passph, checked = dialogs.PassphraseDialog(_('Passphrase Required'),
_('To continue, Gajim needs to access your stored secrets. Enter your passphrase')
).run()
if passph == -1:
raise exceptions.Cancelled
sh = Crypto.Hash.SHA256.new()
sh.update(passph)
key = sh.digest()
secrets_counter = counter
secrets_cipher = Crypto.Cipher.AES.new(key, Crypto.Cipher.AES.MODE_CTR,
counter=secrets_counter)
return secrets_cipher
class Secrets:
def __init__(self, filename):
self.filename = filename
self.srs = {}
self.pubkeys = {}
self.privkeys = {}
def _save(self):
global secrets_cipher, secrets_counter
old_counter = secrets_counter.c
# pickle doesn't appear to have problems with trailing whitespace
padded = crypto.pad_to_multiple(pickle.dumps(self), n / 8, ' ', False)
encrypted = secrets_cipher.encrypt(padded)
f = open(secrets_filename, 'w')
f.write(crypto.encode_mpi_with_padding(old_counter) + encrypted)
f.close()
def cancel(self):
raise exceptions.Cancelled
def save(self):
passph1 = None
def _cont1(passph, checked):
dialogs.PassphraseDialog(_('Confirm Passphrase'),
_('Enter your new passphrase again for confirmation'),
is_modal=False, ok_handler=(_cont2, passph), cancel_handler=self.cancel)
def _cont2(passph, checked, passph1):
if passph != passph1:
dialogs.PassphraseDialog(_('Create Passphrase'),
_('Passphrases did not match.\n') +
_('Gajim needs you to create a passphrase to encrypt stored secrets'),
is_modal=False, ok_handler=_cont1, cancel_handler=self.cancel)
return
counter = Counter(16, crypto.random_bytes(16))
get_key(counter, passph1)
self._save()
if not os.path.exists(self.filename):
dialogs.PassphraseDialog(_('Create Passphrase'),
_('Gajim needs you to create a passphrase to encrypt stored secrets'),
is_modal=False, ok_handler=_cont1, cancel_handler=self.cancel)
else:
self._save()
def retained_secrets(self, account, bare_jid):
try:
return self.srs[account][bare_jid]
except KeyError:
return []
# retained secrets are stored as a tuple of the secret and whether the user
# has verified it
def save_new_srs(self, account, jid, secret, verified):
if not account in self.srs:
self.srs[account] = {}
if not jid in self.srs[account]:
self.srs[account][jid] = []
self.srs[account][jid].append((secret, verified))
self.save()
def find_srs(self, account, jid, srs):
our_secrets = self.srs[account][jid]
return filter(lambda (x,y): x == srs, our_secrets)[0]
# has the user verified this retained secret?
def srs_verified(self, account, jid, srs):
return self.find_srs(account, jid, srs)[1]
def replace_srs(self, account, jid, old_secret, new_secret, verified):
our_secrets = self.srs[account][jid]
idx = our_secrets.index(self.find_srs(account, jid, old_secret))
our_secrets[idx] = (new_secret, verified)
self.save()
# the public key associated with 'account'
def my_pubkey(self, account):
try:
pk = self.privkeys[account]
except KeyError:
pk = Crypto.PublicKey.RSA.generate(384, crypto.random_bytes)
self.privkeys[account] = pk
self.save()
return pk
def load_secrets(filename):
f = open(filename, 'r')
counter = Counter(16, f.read(16))
decrypted = get_key(counter).decrypt(f.read())
try:
secrets = pickle.loads(decrypted)
except:
f.close()
global secrets_cipher
secrets_cipher = None
return load_secrets(filename)
else:
f.close()
return secrets
def secrets():
global secrets_cache
if secrets_cache:
return secrets_cache
if os.path.exists(secrets_filename):
secrets_cache = load_secrets(secrets_filename)
else:
secrets_cache = Secrets(secrets_filename)
return secrets_cache
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