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gpgme/lang/python/src/core.py
NIIBE Yutaka f8d99bb9e4 python: Don't call __del__ from __exit__ method. 
* lang/python/src/core.py (Context, Data): Don't call __del__
from __exit__ method, as the object may be still in use.
* lang/python/tests/t-idiomatic.py: Fix the test.

--

GnuPG-bug-id: 6060
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2022-08-09 09:57:28 +09:00

1796 lines
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# -*- coding: utf-8 -*-
from __future__ import absolute_import, print_function, unicode_literals
import re
import os
import warnings
import weakref
from . import gpgme
from .errors import errorcheck, GPGMEError
from . import constants
from . import errors
from . import util
del absolute_import, print_function, unicode_literals
# Copyright (C) 2016-2018 g10 Code GmbH
# Copyright (C) 2004, 2008 Igor Belyi <belyi@users.sourceforge.net>
# Copyright (C) 2002 John Goerzen <jgoerzen@complete.org>
#
# This library 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 library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
"""Core functionality
Core functionality of GPGME wrapped in a object-oriented fashion.
Provides the 'Context' class for performing cryptographic operations,
and the 'Data' class describing buffers of data.
"""
class GpgmeWrapper(object):
"""Base wrapper class
Not to be instantiated directly.
"""
def __init__(self, wrapped):
self._callback_excinfo = None
self.wrapped = wrapped
def __repr__(self):
return '<{}/{!r}>'.format(
super(GpgmeWrapper, self).__repr__(), self.wrapped)
def __str__(self):
acc = ['{}.{}'.format(__name__, self.__class__.__name__)]
flags = [f for f in self._boolean_properties if getattr(self, f)]
if flags:
acc.append('({})'.format(' '.join(flags)))
return '<{}>'.format(' '.join(acc))
def __hash__(self):
return hash(repr(self.wrapped))
def __eq__(self, other):
if other is None:
return False
else:
return repr(self.wrapped) == repr(other.wrapped)
@property
def _ctype(self):
"""The name of the c type wrapped by this class
Must be set by child classes.
"""
raise NotImplementedError()
@property
def _cprefix(self):
"""The common prefix of c functions wrapped by this class
Must be set by child classes.
"""
raise NotImplementedError()
def _errorcheck(self, name):
"""Must be implemented by child classes.
This function must return a trueish value for all c functions
returning gpgme_error_t."""
raise NotImplementedError()
"""The set of all boolean properties"""
_boolean_properties = set()
def __wrap_boolean_property(self, key, do_set=False, value=None):
get_func = getattr(gpgme, "{}get_{}".format(self._cprefix, key))
set_func = getattr(gpgme, "{}set_{}".format(self._cprefix, key))
def get(slf):
if not slf.wrapped:
return False
return bool(get_func(slf.wrapped))
def set_(slf, value):
if not slf.wrapped:
return
set_func(slf.wrapped, bool(value))
p = property(get, set_, doc="{} flag".format(key))
setattr(self.__class__, key, p)
if do_set:
set_(self, bool(value))
else:
return get(self)
_munge_docstring = re.compile(r'gpgme_([^(]*)\(([^,]*), (.*\) -> .*)')
def __getattr__(self, key):
"""On-the-fly generation of wrapper methods and properties"""
if key[0] == '_' or self._cprefix is None:
return None
if key in self._boolean_properties:
return self.__wrap_boolean_property(key)
name = self._cprefix + key
func = getattr(gpgme, name)
if self._errorcheck(name):
def _funcwrap(slf, *args):
if not slf.wrapped:
return None
result = func(slf.wrapped, *args)
if slf._callback_excinfo:
gpgme.gpg_raise_callback_exception(slf)
return errorcheck(result, name)
else:
def _funcwrap(slf, *args):
if not slf.wrapped:
return None
result = func(slf.wrapped, *args)
if slf._callback_excinfo:
gpgme.gpg_raise_callback_exception(slf)
return result
doc_orig = getattr(func, "__doc__")
if doc_orig:
doc = self._munge_docstring.sub(r'\2.\1(\3', doc_orig)
else:
doc = None
_funcwrap.__doc__ = doc
# Monkey-patch the class.
setattr(self.__class__, key, _funcwrap)
# Bind the method to 'self'.
def wrapper(*args):
return _funcwrap(self, *args)
wrapper.__doc__ = doc
return wrapper
def __setattr__(self, key, value):
"""On-the-fly generation of properties"""
if key in self._boolean_properties:
self.__wrap_boolean_property(key, True, value)
else:
super(GpgmeWrapper, self).__setattr__(key, value)
class Context(GpgmeWrapper):
"""Context for cryptographic operations
All cryptographic operations in GPGME are performed within a
context, which contains the internal state of the operation as
well as configuration parameters. By using several contexts you
can run several cryptographic operations in parallel, with
different configuration.
Access to a context must be synchronized.
"""
def __init__(self,
armor=False,
textmode=False,
offline=False,
signers=[],
pinentry_mode=constants.PINENTRY_MODE_DEFAULT,
protocol=constants.PROTOCOL_OpenPGP,
wrapped=None,
home_dir=None):
"""Construct a context object
Keyword arguments:
armor -- enable ASCII armoring (default False)
textmode -- enable canonical text mode (default False)
offline -- do not contact external key sources (default False)
signers -- list of keys used for signing (default [])
pinentry_mode -- pinentry mode (default PINENTRY_MODE_DEFAULT)
protocol -- protocol to use (default PROTOCOL_OpenPGP)
home_dir -- state directory (default is the engine default)
"""
if wrapped:
self.own = False
else:
tmp = gpgme.new_gpgme_ctx_t_p()
errorcheck(gpgme.gpgme_new(tmp))
wrapped = gpgme.gpgme_ctx_t_p_value(tmp)
gpgme.delete_gpgme_ctx_t_p(tmp)
self.own = True
super(Context, self).__init__(wrapped)
self.armor = armor
self.textmode = textmode
self.offline = offline
self.signers = signers
self.pinentry_mode = pinentry_mode
self.protocol = protocol
self.home_dir = home_dir
def __read__(self, sink, data):
"""Read helper
Helper function to retrieve the results of an operation, or
None if SINK is given.
"""
if sink or data is None:
return None
data.seek(0, os.SEEK_SET)
return data.read()
def __repr__(self):
return ("Context(armor={0.armor}, "
"textmode={0.textmode}, offline={0.offline}, "
"signers={0.signers}, pinentry_mode={0.pinentry_mode}, "
"protocol={0.protocol}, home_dir={0.home_dir}"
")").format(self)
def encrypt(self,
plaintext,
recipients=[],
sign=True,
sink=None,
passphrase=None,
always_trust=False,
add_encrypt_to=False,
prepare=False,
expect_sign=False,
compress=True):
"""Encrypt data
Encrypt the given plaintext for the given recipients. If the
list of recipients is empty, the data is encrypted
symmetrically with a passphrase.
The passphrase can be given as parameter, using a callback
registered at the context, or out-of-band via pinentry.
Keyword arguments:
recipients -- list of keys to encrypt to
sign -- sign plaintext (default True)
sink -- write result to sink instead of returning it
passphrase -- for symmetric encryption
always_trust -- always trust the keys (default False)
add_encrypt_to -- encrypt to configured additional keys (default False)
prepare -- (ui) prepare for encryption (default False)
expect_sign -- (ui) prepare for signing (default False)
compress -- compress plaintext (default True)
Returns:
ciphertext -- the encrypted data (or None if sink is given)
result -- additional information about the encryption
sign_result -- additional information about the signature(s)
Raises:
InvalidRecipients -- if encryption using a particular key failed
InvalidSigners -- if signing using a particular key failed
GPGMEError -- as signaled by the underlying library
"""
ciphertext = sink if sink else Data()
flags = 0
flags |= always_trust * constants.ENCRYPT_ALWAYS_TRUST
flags |= (not add_encrypt_to) * constants.ENCRYPT_NO_ENCRYPT_TO
flags |= prepare * constants.ENCRYPT_PREPARE
flags |= expect_sign * constants.ENCRYPT_EXPECT_SIGN
flags |= (not compress) * constants.ENCRYPT_NO_COMPRESS
if passphrase is not None:
old_pinentry_mode = self.pinentry_mode
old_passphrase_cb = getattr(self, '_passphrase_cb', None)
self.pinentry_mode = constants.PINENTRY_MODE_LOOPBACK
def passphrase_cb(hint, desc, prev_bad, hook=None):
return passphrase
self.set_passphrase_cb(passphrase_cb)
try:
if sign:
self.op_encrypt_sign(recipients, flags, plaintext, ciphertext)
else:
self.op_encrypt(recipients, flags, plaintext, ciphertext)
except errors.GPGMEError as e:
result = self.op_encrypt_result()
sig_result = self.op_sign_result() if sign else None
results = (self.__read__(sink, ciphertext), result, sig_result)
if e.getcode() == errors.UNUSABLE_PUBKEY:
if result.invalid_recipients:
raise errors.InvalidRecipients(
result.invalid_recipients,
error=e.error,
results=results)
if e.getcode() == errors.UNUSABLE_SECKEY:
sig_result = self.op_sign_result()
if sig_result.invalid_signers:
raise errors.InvalidSigners(
sig_result.invalid_signers,
error=e.error,
results=results)
# Otherwise, just raise the error, but attach the results
# first.
e.results = results
raise e
finally:
if passphrase is not None:
self.pinentry_mode = old_pinentry_mode
gpgme.gpg_set_passphrase_cb(self, old_passphrase_cb)
result = self.op_encrypt_result()
assert not result.invalid_recipients
sig_result = self.op_sign_result() if sign else None
assert not sig_result or not sig_result.invalid_signers
return self.__read__(sink, ciphertext), result, sig_result
def decrypt(self, ciphertext, sink=None, passphrase=None, verify=True, filter_signatures=True):
"""Decrypt data
Decrypt the given ciphertext and verify any signatures. If
VERIFY is an iterable of keys, the ciphertext must be signed
by all those keys, otherwise a MissingSignatures error is
raised. Note: if VERIFY is an empty iterable, that is treated
the same as passing verify=True (that is, verify signatures
and return data about any valid signatures found, but no
signatures are required and no MissingSignatures error will be
raised).
The filter_signatures argument can be used to force this
function to return signatures that are not fully trusted - for
example because they were made by unknown keys.
If the ciphertext is symmetrically encrypted using a
passphrase, that passphrase can be given as parameter, using a
callback registered at the context, or out-of-band via
pinentry.
Keyword arguments:
sink -- write result to sink instead of returning it
passphrase -- for symmetric decryption
verify -- check signatures (boolean or iterable of keys,
see above) (default True)
filter_signatures -- if this function should filter out signatures
that are not completely OK (default True)
Returns:
plaintext -- the decrypted data (or None if sink is given)
result -- additional information about the decryption
verify_result -- additional information about the valid
signature(s) found
Raises:
UnsupportedAlgorithm -- if an unsupported algorithm was used
MissingSignatures -- if expected signatures are missing or bad
GPGMEError -- as signaled by the underlying library
"""
do_sig_verification = False
required_keys = None
plaintext = sink if sink else Data()
if passphrase is not None:
old_pinentry_mode = self.pinentry_mode
old_passphrase_cb = getattr(self, '_passphrase_cb', None)
self.pinentry_mode = constants.PINENTRY_MODE_LOOPBACK
def passphrase_cb(hint, desc, prev_bad, hook=None):
return passphrase
self.set_passphrase_cb(passphrase_cb)
try:
if isinstance(verify, bool):
do_sig_verification = verify
elif verify is None:
warnings.warn(
"ctx.decrypt called with verify=None, should be bool or iterable (treating as False).",
category=DeprecationWarning)
do_sig_verification = False
else:
# we hope this is an iterable:
required_keys = verify
do_sig_verification = True
if do_sig_verification:
self.op_decrypt_verify(ciphertext, plaintext)
else:
self.op_decrypt(ciphertext, plaintext)
except errors.GPGMEError as e:
result = self.op_decrypt_result()
if do_sig_verification:
verify_result = self.op_verify_result()
else:
verify_result = None
# Just raise the error, but attach the results first.
e.results = (self.__read__(sink, plaintext), result, verify_result)
raise e
finally:
if passphrase is not None:
self.pinentry_mode = old_pinentry_mode
gpgme.gpg_set_passphrase_cb(self, old_passphrase_cb)
result = self.op_decrypt_result()
if do_sig_verification:
verify_result = self.op_verify_result()
else:
verify_result = None
results = (self.__read__(sink, plaintext), result, verify_result)
if result.unsupported_algorithm:
raise errors.UnsupportedAlgorithm(result.unsupported_algorithm,
results=results)
if do_sig_verification:
if filter_signatures:
verify_result.signatures = list(filter(lambda s: s.status == errors.NO_ERROR, verify_result.signatures))
if required_keys is not None:
missing = []
for key in required_keys:
ok = False
for subkey in key.subkeys:
for sig in verify_result.signatures:
if sig.summary & constants.SIGSUM_VALID == 0:
continue
if subkey.can_sign and subkey.fpr == sig.fpr:
ok = True
break
if ok:
break
if not ok:
missing.append(key)
if missing:
raise errors.MissingSignatures(verify_result, missing,
results=results)
return results
def sign(self, data, sink=None, mode=constants.SIG_MODE_NORMAL):
"""Sign data
Sign the given data with either the configured default local
key, or the 'signers' keys of this context.
Keyword arguments:
mode -- signature mode (default: normal, see below)
sink -- write result to sink instead of returning it
Returns:
either
signed_data -- encoded data and signature (normal mode)
signature -- only the signature data (detached mode)
cleartext -- data and signature as text (cleartext mode)
(or None if sink is given)
result -- additional information about the signature(s)
Raises:
InvalidSigners -- if signing using a particular key failed
GPGMEError -- as signaled by the underlying library
"""
signeddata = sink if sink else Data()
try:
self.op_sign(data, signeddata, mode)
except errors.GPGMEError as e:
results = (self.__read__(sink, signeddata), self.op_sign_result())
if e.getcode() == errors.UNUSABLE_SECKEY:
if results[1].invalid_signers:
raise errors.InvalidSigners(
results[1].invalid_signers,
error=e.error,
results=results)
e.results = results
raise e
result = self.op_sign_result()
assert not result.invalid_signers
return self.__read__(sink, signeddata), result
def verify(self, signed_data, signature=None, sink=None, verify=[]):
"""Verify signatures
Verify signatures over data. If VERIFY is an iterable of
keys, the ciphertext must be signed by all those keys,
otherwise an error is raised.
Keyword arguments:
signature -- detached signature data
sink -- write result to sink instead of returning it
Returns:
data -- the plain data
(or None if sink is given, or we verified a detached signature)
result -- additional information about the signature(s)
Raises:
BadSignatures -- if a bad signature is encountered
MissingSignatures -- if expected signatures are missing or bad
GPGMEError -- as signaled by the underlying library
"""
if signature:
# Detached signature, we don't return the plain text.
data = None
else:
data = sink if sink else Data()
try:
if signature:
self.op_verify(signature, signed_data, None)
else:
self.op_verify(signed_data, None, data)
except errors.GPGMEError as e:
# Just raise the error, but attach the results first.
e.results = (self.__read__(sink, data), self.op_verify_result())
raise e
results = (self.__read__(sink, data), self.op_verify_result())
if any(s.status != errors.NO_ERROR for s in results[1].signatures):
raise errors.BadSignatures(results[1], results=results)
missing = list()
for key in verify:
ok = False
for subkey in key.subkeys:
for sig in results[1].signatures:
if sig.summary & constants.SIGSUM_VALID == 0:
continue
if subkey.can_sign and subkey.fpr == sig.fpr:
ok = True
break
if ok:
break
if not ok:
missing.append(key)
if missing:
raise errors.MissingSignatures(
results[1], missing, results=results)
return results
def key_import(self, data):
"""Import data
Imports the given data into the Context.
Returns:
-- an object describing the results of imported or updated
keys
Raises:
TypeError -- Very rarely.
GPGMEError -- as signaled by the underlying library:
Import status errors, when they occur, will usually
be of NODATA. NO_PUBKEY indicates something
managed to run the function without any
arguments, while an argument of None triggers
the first NODATA of errors.GPGME in the
exception.
"""
try:
self.op_import(data)
result = self.op_import_result()
if result.considered == 0:
status = constants.STATUS_IMPORT_PROBLEM
else:
status = constants.STATUS_KEY_CONSIDERED
except Exception as e:
if e == errors.GPGMEError:
if e.code_str == "No data":
status = constants.STATUS_NODATA
else:
status = constants.STATUS_FILE_ERROR
elif e == TypeError and hasattr(data, "decode") is True:
status = constants.STATUS_NO_PUBKEY
elif e == TypeError and hasattr(data, "encode") is True:
status = constants.STATUS_FILE_ERROR
else:
status = constants.STATUS_ERROR
if status == constants.STATUS_KEY_CONSIDERED:
import_result = result
else:
import_result = status
return import_result
def key_export(self, pattern=None):
"""Export keys.
Exports public keys matching the pattern specified. If no
pattern is specified then exports all available keys.
Keyword arguments:
pattern -- return keys matching pattern (default: all keys)
Returns:
-- A key block containing one or more OpenPGP keys in
either ASCII armoured or binary format as determined
by the Context(). If there are no matching keys it
returns None.
Raises:
GPGMEError -- as signaled by the underlying library.
"""
data = Data()
mode = 0
try:
self.op_export(pattern, mode, data)
data.seek(0, os.SEEK_SET)
pk_result = data.read()
except GPGMEError as e:
raise e
if len(pk_result) > 0:
result = pk_result
else:
result = None
return result
def key_export_minimal(self, pattern=None):
"""Export keys.
Exports public keys matching the pattern specified in a
minimised format. If no pattern is specified then exports all
available keys.
Keyword arguments:
pattern -- return keys matching pattern (default: all keys)
Returns:
-- A key block containing one or more minimised OpenPGP
keys in either ASCII armoured or binary format as
determined by the Context(). If there are no matching
keys it returns None.
Raises:
GPGMEError -- as signaled by the underlying library.
"""
data = Data()
mode = gpgme.GPGME_EXPORT_MODE_MINIMAL
try:
self.op_export(pattern, mode, data)
data.seek(0, os.SEEK_SET)
pk_result = data.read()
except GPGMEError as e:
raise e
if len(pk_result) > 0:
result = pk_result
else:
result = None
return result
def key_export_secret(self, pattern=None):
"""Export secret keys.
Exports secret keys matching the pattern specified. If no
pattern is specified then exports or attempts to export all
available secret keys.
IMPORTANT: Each secret key to be exported will prompt for its
passphrase via an invocation of pinentry and gpg-agent. If the
passphrase is not entered or does not match then no data will be
exported. This is the same result as when specifying a pattern
that is not matched by the available keys.
Keyword arguments:
pattern -- return keys matching pattern (default: all keys)
Returns:
-- On success a key block containing one or more OpenPGP
secret keys in either ASCII armoured or binary format
as determined by the Context().
-- On failure while not raising an exception, returns None.
Raises:
GPGMEError -- as signaled by the underlying library.
"""
data = Data()
mode = gpgme.GPGME_EXPORT_MODE_SECRET
try:
self.op_export(pattern, mode, data)
data.seek(0, os.SEEK_SET)
sk_result = data.read()
except GPGMEError as e:
raise e
if len(sk_result) > 0:
result = sk_result
else:
result = None
return result
def keylist(self,
pattern=None,
secret=False,
mode=constants.keylist.mode.LOCAL,
source=None):
"""List keys
Keyword arguments:
pattern -- return keys matching pattern (default: all keys)
secret -- return only secret keys (default: False)
mode -- keylist mode (default: list local keys)
source -- read keys from source instead from the keyring
(all other options are ignored in this case)
Returns:
-- an iterator returning key objects
Raises:
GPGMEError -- as signaled by the underlying library
"""
if not source:
self.set_keylist_mode(mode)
self.op_keylist_start(pattern, secret)
else:
# Automatic wrapping of SOURCE is not possible here,
# because the object must not be deallocated until the
# iteration over the results ends.
if not isinstance(source, Data):
source = Data(file=source)
self.op_keylist_from_data_start(source, 0)
key = self.op_keylist_next()
while key:
yield key
key = self.op_keylist_next()
self.op_keylist_end()
def create_key(self,
userid,
algorithm=None,
expires_in=0,
expires=True,
sign=False,
encrypt=False,
certify=False,
authenticate=False,
passphrase=None,
force=False):
"""Create a primary key
Create a primary key for the user id USERID.
ALGORITHM may be used to specify the public key encryption
algorithm for the new key. By default, a reasonable default
is chosen. You may use "future-default" to select an
algorithm that will be the default in a future implementation
of the engine. ALGORITHM may be a string like "rsa", or
"rsa2048" to explicitly request an algorithm and a key size.
EXPIRES_IN specifies the expiration time of the key in number
of seconds since the keys creation. By default, a reasonable
expiration time is chosen. If you want to create a key that
does not expire, use the keyword argument EXPIRES.
SIGN, ENCRYPT, CERTIFY, and AUTHENTICATE can be used to
request the capabilities of the new key. If you don't request
any, a reasonable set of capabilities is selected, and in case
of OpenPGP, a subkey with a reasonable set of capabilities is
created.
If PASSPHRASE is None (the default), then the key will not be
protected with a passphrase. If PASSPHRASE is a string, it
will be used to protect the key. If PASSPHRASE is True, the
passphrase must be supplied using a passphrase callback or
out-of-band with a pinentry.
Keyword arguments:
algorithm -- public key algorithm, see above (default: reasonable)
expires_in -- expiration time in seconds (default: reasonable)
expires -- whether or not the key should expire (default: True)
sign -- request the signing capability (see above)
encrypt -- request the encryption capability (see above)
certify -- request the certification capability (see above)
authenticate -- request the authentication capability (see above)
passphrase -- protect the key with a passphrase (default: no
passphrase)
force -- force key creation even if a key with the same userid
exists (default: False)
Returns:
-- an object describing the result of the key creation
Raises:
GPGMEError -- as signaled by the underlying library
"""
if util.is_a_string(passphrase):
old_pinentry_mode = self.pinentry_mode
old_passphrase_cb = getattr(self, '_passphrase_cb', None)
self.pinentry_mode = constants.PINENTRY_MODE_LOOPBACK
def passphrase_cb(hint, desc, prev_bad, hook=None):
return passphrase
self.set_passphrase_cb(passphrase_cb)
try:
self.op_createkey(
userid,
algorithm,
0, # reserved
expires_in,
None, # extrakey
((constants.create.SIGN if sign else 0) |
(constants.create.ENCR if encrypt else 0) |
(constants.create.CERT if certify else 0) |
(constants.create.AUTH if authenticate else 0) |
(constants.create.NOPASSWD if passphrase is None else 0) |
(0 if expires else constants.create.NOEXPIRE) |
(constants.create.FORCE if force else 0)))
finally:
if util.is_a_string(passphrase):
self.pinentry_mode = old_pinentry_mode
gpgme.gpg_set_passphrase_cb(self, old_passphrase_cb)
return self.op_genkey_result()
def create_subkey(self,
key,
algorithm=None,
expires_in=0,
expires=True,
sign=False,
encrypt=False,
authenticate=False,
passphrase=None):
"""Create a subkey
Create a subkey for the given KEY. As subkeys are a concept
of OpenPGP, calling this is only valid for the OpenPGP
protocol.
ALGORITHM may be used to specify the public key encryption
algorithm for the new subkey. By default, a reasonable
default is chosen. You may use "future-default" to select an
algorithm that will be the default in a future implementation
of the engine. ALGORITHM may be a string like "rsa", or
"rsa2048" to explicitly request an algorithm and a key size.
EXPIRES_IN specifies the expiration time of the subkey in
number of seconds since the subkeys creation. By default, a
reasonable expiration time is chosen. If you want to create a
subkey that does not expire, use the keyword argument EXPIRES.
SIGN, ENCRYPT, and AUTHENTICATE can be used to request the
capabilities of the new subkey. If you don't request any, an
encryption subkey is generated.
If PASSPHRASE is None (the default), then the subkey will not
be protected with a passphrase. If PASSPHRASE is a string, it
will be used to protect the subkey. If PASSPHRASE is True,
the passphrase must be supplied using a passphrase callback or
out-of-band with a pinentry.
Keyword arguments:
algorithm -- public key algorithm, see above (default: reasonable)
expires_in -- expiration time in seconds (default: reasonable)
expires -- whether or not the subkey should expire (default: True)
sign -- request the signing capability (see above)
encrypt -- request the encryption capability (see above)
authenticate -- request the authentication capability (see above)
passphrase -- protect the subkey with a passphrase (default: no
passphrase)
Returns:
-- an object describing the result of the subkey creation
Raises:
GPGMEError -- as signaled by the underlying library
"""
if util.is_a_string(passphrase):
old_pinentry_mode = self.pinentry_mode
old_passphrase_cb = getattr(self, '_passphrase_cb', None)
self.pinentry_mode = constants.PINENTRY_MODE_LOOPBACK
def passphrase_cb(hint, desc, prev_bad, hook=None):
return passphrase
self.set_passphrase_cb(passphrase_cb)
try:
self.op_createsubkey(
key,
algorithm,
0, # reserved
expires_in,
((constants.create.SIGN if sign else 0) |
(constants.create.ENCR if encrypt else 0) |
(constants.create.AUTH if authenticate else 0) |
(constants.create.NOPASSWD if passphrase is None else 0) |
(0 if expires else constants.create.NOEXPIRE)))
finally:
if util.is_a_string(passphrase):
self.pinentry_mode = old_pinentry_mode
gpgme.gpg_set_passphrase_cb(self, old_passphrase_cb)
return self.op_genkey_result()
def key_add_uid(self, key, uid):
"""Add a UID
Add the uid UID to the given KEY. Calling this function is
only valid for the OpenPGP protocol.
Raises:
GPGMEError -- as signaled by the underlying library
"""
self.op_adduid(key, uid, 0)
def key_revoke_uid(self, key, uid):
"""Revoke a UID
Revoke the uid UID from the given KEY. Calling this function
is only valid for the OpenPGP protocol.
Raises:
GPGMEError -- as signaled by the underlying library
"""
self.op_revuid(key, uid, 0)
def key_sign(self, key, uids=None, expires_in=False, local=False):
"""Sign a key
Sign a key with the current set of signing keys. Calling this
function is only valid for the OpenPGP protocol.
If UIDS is None (the default), then all UIDs are signed. If
it is a string, then only the matching UID is signed. If it
is a list of strings, then all matching UIDs are signed. Note
that a case-sensitive exact string comparison is done.
EXPIRES_IN specifies the expiration time of the signature in
seconds. If EXPIRES_IN is False, the signature does not
expire.
Keyword arguments:
uids -- user ids to sign, see above (default: sign all)
expires_in -- validity period of the signature in seconds
(default: do not expire)
local -- create a local, non-exportable signature
(default: False)
Raises:
GPGMEError -- as signaled by the underlying library
"""
flags = 0
if uids is None or util.is_a_string(uids):
pass # through unchanged
else:
flags |= constants.keysign.LFSEP
uids = "\n".join(uids)
if not expires_in:
flags |= constants.keysign.NOEXPIRE
if local:
flags |= constants.keysign.LOCAL
self.op_keysign(key, uids, expires_in, flags)
def key_tofu_policy(self, key, policy):
"""Set a keys' TOFU policy
Set the TOFU policy associated with KEY to POLICY. Calling
this function is only valid for the OpenPGP protocol.
Raises:
GPGMEError -- as signaled by the underlying library
"""
self.op_tofu_policy(key, policy)
def assuan_transact(self,
command,
data_cb=None,
inquire_cb=None,
status_cb=None):
"""Issue a raw assuan command
This function can be used to issue a raw assuan command to the
engine.
If command is a string or bytes, it will be used as-is. If it
is an iterable of strings, it will be properly escaped and
joined into an well-formed assuan command.
Keyword arguments:
data_cb -- a callback receiving data lines
inquire_cb -- a callback providing more information
status_cb -- a callback receiving status lines
Returns:
result -- the result of command as GPGMEError
Raises:
GPGMEError -- as signaled by the underlying library
"""
if util.is_a_string(command) or isinstance(command, bytes):
cmd = command
else:
cmd = " ".join(util.percent_escape(f) for f in command)
errptr = gpgme.new_gpgme_error_t_p()
err = gpgme.gpgme_op_assuan_transact_ext(
self.wrapped, cmd, (weakref.ref(self), data_cb)
if data_cb else None, (weakref.ref(self), inquire_cb)
if inquire_cb else None, (weakref.ref(self), status_cb)
if status_cb else None, errptr)
if self._callback_excinfo:
gpgme.gpg_raise_callback_exception(self)
errorcheck(err)
status = gpgme.gpgme_error_t_p_value(errptr)
gpgme.delete_gpgme_error_t_p(errptr)
return GPGMEError(status) if status != 0 else None
def interact(self, key, func, sink=None, flags=0, fnc_value=None):
"""Interact with the engine
This method can be used to edit keys and cards interactively.
KEY is the key to edit, FUNC is called repeatedly with two
unicode arguments, 'keyword' and 'args'. See the GPGME manual
for details.
Keyword arguments:
sink -- if given, additional output is written here
flags -- use constants.INTERACT_CARD to edit a card
Raises:
GPGMEError -- as signaled by the underlying library
"""
if key is None:
raise ValueError("First argument cannot be None")
if sink is None:
sink = Data()
if fnc_value:
opaquedata = (weakref.ref(self), func, fnc_value)
else:
opaquedata = (weakref.ref(self), func)
result = gpgme.gpgme_op_interact(self.wrapped, key, flags, opaquedata,
sink)
if self._callback_excinfo:
gpgme.gpg_raise_callback_exception(self)
errorcheck(result)
@property
def signers(self):
"""Keys used for signing"""
if not self.wrapped:
return None
return [self.signers_enum(i) for i in range(self.signers_count())]
@signers.setter
def signers(self, signers):
old = self.signers
self.signers_clear()
try:
for key in signers:
self.signers_add(key)
except:
self.signers = old
raise
@property
def pinentry_mode(self):
"""Pinentry mode"""
return self.get_pinentry_mode()
@pinentry_mode.setter
def pinentry_mode(self, value):
self.set_pinentry_mode(value)
@property
def protocol(self):
"""Protocol to use"""
return self.get_protocol()
@protocol.setter
def protocol(self, value):
errorcheck(gpgme.gpgme_engine_check_version(value))
self.set_protocol(value)
@property
def home_dir(self):
"""Engine's home directory"""
if not self.wrapped:
return None
return self.engine_info.home_dir
@home_dir.setter
def home_dir(self, value):
self.set_engine_info(self.protocol, home_dir=value)
_ctype = 'gpgme_ctx_t'
_cprefix = 'gpgme_'
def _errorcheck(self, name):
"""This function should list all functions returning gpgme_error_t"""
# The list of functions is created using:
#
# $ grep '^gpgme_error_t ' obj/lang/python/python3.5-gpg/gpgme.h \
# | grep -v _op_ | awk "/\(gpgme_ctx/ { printf (\"'%s',\\n\", \$2) } "
return ((name.startswith('gpgme_op_') and not
name.endswith('_result')) or name in {
'gpgme_new', 'gpgme_set_ctx_flag', 'gpgme_set_protocol',
'gpgme_set_sub_protocol', 'gpgme_set_keylist_mode',
'gpgme_set_pinentry_mode', 'gpgme_set_locale',
'gpgme_ctx_set_engine_info', 'gpgme_signers_add',
'gpgme_sig_notation_add', 'gpgme_set_sender',
'gpgme_cancel', 'gpgme_cancel_async', 'gpgme_get_key',
'gpgme_get_sig_key',
})
_boolean_properties = {'armor', 'textmode', 'offline'}
def __del__(self):
if not gpgme:
# At interpreter shutdown, gpgme is set to NONE.
return
self._free_passcb()
self._free_progresscb()
self._free_statuscb()
if self.own and self.wrapped and gpgme.gpgme_release:
gpgme.gpgme_release(self.wrapped)
self.wrapped = None
# Implement the context manager protocol.
def __enter__(self):
return self
def __exit__(self, type, value, tb):
return False
def op_keylist_all(self, *args, **kwargs):
self.op_keylist_start(*args, **kwargs)
key = self.op_keylist_next()
while key:
yield key
key = self.op_keylist_next()
self.op_keylist_end()
def op_keylist_next(self):
"""Returns the next key in the list created
by a call to op_keylist_start(). The object returned
is of type Key."""
ptr = gpgme.new_gpgme_key_t_p()
try:
errorcheck(gpgme.gpgme_op_keylist_next(self.wrapped, ptr))
key = gpgme.gpgme_key_t_p_value(ptr)
except errors.GPGMEError as excp:
key = None
if excp.getcode() != errors.EOF:
raise excp
gpgme.delete_gpgme_key_t_p(ptr)
if key:
key.__del__ = lambda self: gpgme.gpgme_key_unref(self)
return key
def get_key(self, fpr, secret=False):
"""Get a key given a fingerprint
Keyword arguments:
secret -- to request a secret key
Returns:
-- the matching key
Raises:
KeyError -- if the key was not found
GPGMEError -- as signaled by the underlying library
"""
ptr = gpgme.new_gpgme_key_t_p()
try:
errorcheck(gpgme.gpgme_get_key(self.wrapped, fpr, ptr, secret))
except errors.GPGMEError as e:
if e.getcode() == errors.EOF:
raise errors.KeyNotFound(fpr)
raise e
key = gpgme.gpgme_key_t_p_value(ptr)
gpgme.delete_gpgme_key_t_p(ptr)
assert key
key.__del__ = lambda self: gpgme.gpgme_key_unref(self)
return key
def op_trustlist_all(self, *args, **kwargs):
self.op_trustlist_start(*args, **kwargs)
trust = self.op_trustlist_next()
while trust:
yield trust
trust = self.op_trustlist_next()
self.op_trustlist_end()
def op_trustlist_next(self):
"""Returns the next trust item in the list created
by a call to op_trustlist_start(). The object returned
is of type TrustItem."""
ptr = gpgme.new_gpgme_trust_item_t_p()
try:
errorcheck(gpgme.gpgme_op_trustlist_next(self.wrapped, ptr))
trust = gpgme.gpgme_trust_item_t_p_value(ptr)
except errors.GPGMEError as excp:
trust = None
if excp.getcode() != errors.EOF:
raise
gpgme.delete_gpgme_trust_item_t_p(ptr)
return trust
def set_passphrase_cb(self, func, hook=None):
"""Sets the passphrase callback to the function specified by func.
When the system needs a passphrase, it will call func with three args:
hint, a string describing the key it needs the passphrase for;
desc, a string describing the passphrase it needs;
prev_bad, a boolean equal True if this is a call made after
unsuccessful previous attempt.
If hook has a value other than None it will be passed into the func
as a forth argument.
Please see the GPGME manual for more information.
"""
if func is None:
hookdata = None
else:
if hook is None:
hookdata = (weakref.ref(self), func)
else:
hookdata = (weakref.ref(self), func, hook)
gpgme.gpg_set_passphrase_cb(self, hookdata)
def _free_passcb(self):
if gpgme.gpg_set_passphrase_cb:
self.set_passphrase_cb(None)
def set_progress_cb(self, func, hook=None):
"""Sets the progress meter callback to the function specified by FUNC.
If FUNC is None, the callback will be cleared.
This function will be called to provide an interactive update
of the system's progress. The function will be called with
three arguments, type, total, and current. If HOOK is not
None, it will be supplied as fourth argument.
Please see the GPGME manual for more information.
"""
if func is None:
hookdata = None
else:
if hook is None:
hookdata = (weakref.ref(self), func)
else:
hookdata = (weakref.ref(self), func, hook)
gpgme.gpg_set_progress_cb(self, hookdata)
def _free_progresscb(self):
if gpgme.gpg_set_progress_cb:
self.set_progress_cb(None)
def set_status_cb(self, func, hook=None):
"""Sets the status callback to the function specified by FUNC. If
FUNC is None, the callback will be cleared.
The function will be called with two arguments, keyword and
args. If HOOK is not None, it will be supplied as third
argument.
Please see the GPGME manual for more information.
"""
if func is None:
hookdata = None
else:
if hook is None:
hookdata = (weakref.ref(self), func)
else:
hookdata = (weakref.ref(self), func, hook)
gpgme.gpg_set_status_cb(self, hookdata)
def _free_statuscb(self):
if gpgme.gpg_set_status_cb:
self.set_status_cb(None)
@property
def engine_info(self):
"""Configuration of the engine currently in use"""
p = self.protocol
infos = [i for i in self.get_engine_info() if i.protocol == p]
assert len(infos) == 1
return infos[0]
def get_engine_info(self):
"""Get engine configuration
Returns information about all configured and installed
engines.
Returns:
infos -- a list of engine infos
"""
return gpgme.gpgme_ctx_get_engine_info(self.wrapped)
def set_engine_info(self, proto, file_name=None, home_dir=None):
"""Change engine configuration
Changes the configuration of the crypto engine implementing
the protocol 'proto' for the context.
Keyword arguments:
file_name -- engine program file name (unchanged if None)
home_dir -- configuration directory (unchanged if None)
"""
self.ctx_set_engine_info(proto, file_name, home_dir)
def wait(self, hang):
"""Wait for asynchronous call to finish. Wait forever if hang is True.
Raises an exception on errors.
Please read the GPGME manual for more information.
"""
ptr = gpgme.new_gpgme_error_t_p()
gpgme.gpgme_wait(self.wrapped, ptr, hang)
status = gpgme.gpgme_error_t_p_value(ptr)
gpgme.delete_gpgme_error_t_p(ptr)
errorcheck(status)
def op_edit(self, key, func, fnc_value, out):
"""Start key editing using supplied callback function
Note: This interface is deprecated and will be removed with
GPGME 1.8. Please use .interact instead. Furthermore, we
implement this using gpgme_op_interact, so callbacks will get
called with string keywords instead of numeric status
messages. Code that is using constants.STATUS_X or
constants.status.X will continue to work, whereas code using
magic numbers will break as a result.
"""
warnings.warn(
"Call to deprecated method op_edit.", category=DeprecationWarning)
return self.interact(key, func, sink=out, fnc_value=fnc_value)
class Data(GpgmeWrapper):
"""Data buffer
A lot of data has to be exchanged between the user and the crypto
engine, like plaintext messages, ciphertext, signatures and
information about the keys. The technical details about
exchanging the data information are completely abstracted by
GPGME. The user provides and receives the data via `gpgme_data_t'
objects, regardless of the communication protocol between GPGME
and the crypto engine in use.
This Data class is the implementation of the GpgmeData objects.
Please see the information about __init__ for instantiation.
"""
_ctype = 'gpgme_data_t'
_cprefix = 'gpgme_data_'
def _errorcheck(self, name):
"""This function should list all functions returning gpgme_error_t"""
# This list is compiled using
#
# $ grep -v '^gpgme_error_t ' obj/lang/python/python3.5-gpg/gpgme.h \
# | awk "/\(gpgme_data_t/ { printf (\"'%s',\\n\", \$2) } " \
# | sed "s/'\\*/'/"
return name not in {
'gpgme_data_read',
'gpgme_data_write',
'gpgme_data_seek',
'gpgme_data_release',
'gpgme_data_release_and_get_mem',
'gpgme_data_get_encoding',
'gpgme_data_get_file_name',
'gpgme_data_set_flag',
'gpgme_data_identify',
}
def __init__(self,
string=None,
file=None,
offset=None,
length=None,
cbs=None,
copy=True):
"""Initialize a new gpgme_data_t object.
If no args are specified, make it an empty object.
If string alone is specified, initialize it with the data
contained there.
If file, offset, and length are all specified, file must
be either a filename or a file-like object, and the object
will be initialized by reading the specified chunk from the file.
If cbs is specified, it MUST be a tuple of the form:
(read_cb, write_cb, seek_cb, release_cb[, hook])
where the first four items are functions implementing reading,
writing, seeking the data, and releasing any resources once
the data object is deallocated. The functions must match the
following prototypes:
def read(amount, hook=None):
return <a b"bytes" object>
def write(data, hook=None):
return <the number of bytes written>
def seek(offset, whence, hook=None):
return <the new file position>
def release(hook=None):
<return value and exceptions are ignored>
The functions may be bound methods. In that case, you can
simply use the 'self' reference instead of using a hook.
If file is specified without any other arguments, then
it must be a filename, and the object will be initialized from
that file.
"""
super(Data, self).__init__(None)
self.data_cbs = None
if cbs is not None:
self.new_from_cbs(*cbs)
elif string is not None:
self.new_from_mem(string, copy)
elif file is not None and offset is not None and length is not None:
self.new_from_filepart(file, offset, length)
elif file is not None:
if util.is_a_string(file):
self.new_from_file(file, copy)
else:
self.new_from_fd(file)
else:
self.new()
def __del__(self):
if not gpgme:
# At interpreter shutdown, gpgme is set to NONE.
return
if self.wrapped is not None and gpgme.gpgme_data_release:
gpgme.gpgme_data_release(self.wrapped)
if self._callback_excinfo:
gpgme.gpg_raise_callback_exception(self)
self.wrapped = None
self._free_datacbs()
# Implement the context manager protocol.
def __enter__(self):
return self
def __exit__(self, type, value, tb):
return False
def _free_datacbs(self):
self._data_cbs = None
def new(self):
tmp = gpgme.new_gpgme_data_t_p()
errorcheck(gpgme.gpgme_data_new(tmp))
self.wrapped = gpgme.gpgme_data_t_p_value(tmp)
gpgme.delete_gpgme_data_t_p(tmp)
def new_from_mem(self, string, copy=True):
tmp = gpgme.new_gpgme_data_t_p()
errorcheck(
gpgme.gpgme_data_new_from_mem(tmp, string, len(string), copy))
self.wrapped = gpgme.gpgme_data_t_p_value(tmp)
gpgme.delete_gpgme_data_t_p(tmp)
def new_from_file(self, filename, copy=True):
tmp = gpgme.new_gpgme_data_t_p()
try:
errorcheck(gpgme.gpgme_data_new_from_file(tmp, filename, copy))
except errors.GPGMEError as e:
if e.getcode() == errors.INV_VALUE and not copy:
raise ValueError("delayed reads are not yet supported")
else:
raise e
self.wrapped = gpgme.gpgme_data_t_p_value(tmp)
gpgme.delete_gpgme_data_t_p(tmp)
def new_from_cbs(self, read_cb, write_cb, seek_cb, release_cb, hook=None):
tmp = gpgme.new_gpgme_data_t_p()
if hook is not None:
hookdata = (weakref.ref(self), read_cb, write_cb, seek_cb,
release_cb, hook)
else:
hookdata = (weakref.ref(self), read_cb, write_cb, seek_cb,
release_cb)
gpgme.gpg_data_new_from_cbs(self, hookdata, tmp)
self.wrapped = gpgme.gpgme_data_t_p_value(tmp)
gpgme.delete_gpgme_data_t_p(tmp)
def new_from_filepart(self, file, offset, length):
"""This wraps the GPGME gpgme_data_new_from_filepart() function.
The argument "file" may be:
* a string specifying a file name, or
* a file-like object supporting the fileno() and the mode attribute.
"""
tmp = gpgme.new_gpgme_data_t_p()
filename = None
fp = None
if util.is_a_string(file):
filename = file
else:
fp = gpgme.fdopen(file.fileno(), file.mode)
if fp is None:
raise ValueError("Failed to open file from %s arg %s" % (str(
type(file)), str(file)))
errorcheck(
gpgme.gpgme_data_new_from_filepart(tmp, filename, fp, offset,
length))
self.wrapped = gpgme.gpgme_data_t_p_value(tmp)
gpgme.delete_gpgme_data_t_p(tmp)
def new_from_fd(self, file):
"""This wraps the GPGME gpgme_data_new_from_fd() function. The
argument "file" must be a file-like object, supporting the
fileno() method.
"""
tmp = gpgme.new_gpgme_data_t_p()
errorcheck(gpgme.gpgme_data_new_from_fd(tmp, file.fileno()))
self.wrapped = gpgme.gpgme_data_t_p_value(tmp)
gpgme.delete_gpgme_data_t_p(tmp)
def new_from_stream(self, file):
"""This wrap around gpgme_data_new_from_stream is an alias for
new_from_fd() method since in python there's no difference
between file stream and file descriptor."""
self.new_from_fd(file)
def new_from_estream(self, file):
"""This wrap around gpgme_data_new_from_estream is an alias for
new_from_fd() method since in python there's no difference
between file stream and file descriptor, but using fd broke."""
self.new_from_stream(file)
def write(self, buffer):
"""Write buffer given as string or bytes.
If a string is given, it is implicitly encoded using UTF-8."""
written = gpgme.gpgme_data_write(self.wrapped, buffer)
if written < 0:
if self._callback_excinfo:
gpgme.gpg_raise_callback_exception(self)
else:
raise GPGMEError.fromSyserror()
return written
def read(self, size=-1):
"""Read at most size bytes, returned as bytes.
If the size argument is negative or omitted, read until EOF is reached.
Returns the data read, or the empty string if there was no data
to read before EOF was reached."""
if size == 0:
return ''
if size > 0:
try:
result = gpgme.gpgme_data_read(self.wrapped, size)
except:
if self._callback_excinfo:
gpgme.gpg_raise_callback_exception(self)
else:
raise
return result
else:
chunks = []
while True:
try:
result = gpgme.gpgme_data_read(self.wrapped, 4096)
except:
if self._callback_excinfo:
gpgme.gpg_raise_callback_exception(self)
else:
raise
if len(result) == 0:
break
chunks.append(result)
return b''.join(chunks)
def pubkey_algo_string(subkey):
"""Return short algorithm string
Return a public key algorithm string (e.g. "rsa2048") for a given
SUBKEY.
Returns:
algo - a string
"""
return gpgme.gpgme_pubkey_algo_string(subkey)
def pubkey_algo_name(algo):
"""Return name of public key algorithm
Return the name of the public key algorithm for a given numeric
algorithm id ALGO (cf. RFC4880).
Returns:
algo - a string
"""
return gpgme.gpgme_pubkey_algo_name(algo)
def hash_algo_name(algo):
"""Return name of hash algorithm
Return the name of the hash algorithm for a given numeric
algorithm id ALGO (cf. RFC4880).
Returns:
algo - a string
"""
return gpgme.gpgme_hash_algo_name(algo)
def get_protocol_name(proto):
"""Get protocol description
Get the string describing protocol PROTO.
Returns:
proto - a string
"""
return gpgme.gpgme_get_protocol_name(proto)
def addrspec_from_uid(uid):
"""Return the address spec
Return the addr-spec (cf. RFC2822 section 4.3) from a user id UID.
Returns:
addr_spec - a string
"""
return gpgme.gpgme_addrspec_from_uid(uid)
def check_version(version=None):
return gpgme.gpgme_check_version(version)
# check_version also makes sure that several subsystems are properly
# initialized, and it must be run at least once before invoking any
# other function. We do it here so that the user does not have to do
# it unless she really wants to check for a certain version.
check_version()
def engine_check_version(proto):
try:
errorcheck(gpgme.gpgme_engine_check_version(proto))
return True
except errors.GPGMEError:
return False
def get_engine_info():
ptr = gpgme.new_gpgme_engine_info_t_p()
try:
errorcheck(gpgme.gpgme_get_engine_info(ptr))
info = gpgme.gpgme_engine_info_t_p_value(ptr)
except errors.GPGMEError:
info = None
gpgme.delete_gpgme_engine_info_t_p(ptr)
return info
def set_engine_info(proto, file_name, home_dir=None):
"""Changes the default configuration of the crypto engine implementing
the protocol 'proto'. 'file_name' is the file name of
the executable program implementing this protocol. 'home_dir' is the
directory name of the configuration directory (engine's default is
used if omitted)."""
errorcheck(gpgme.gpgme_set_engine_info(proto, file_name, home_dir))
def set_locale(category, value):
"""Sets the default locale used by contexts"""
errorcheck(gpgme.gpgme_set_locale(None, category, value))
def wait(hang):
"""Wait for asynchronous call on any Context to finish.
Wait forever if hang is True.
For finished anynch calls it returns a tuple (status, context):
status - status return by asnynchronous call.
context - context which caused this call to return.
Please read the GPGME manual of more information."""
ptr = gpgme.new_gpgme_error_t_p()
context = gpgme.gpgme_wait(None, ptr, hang)
status = gpgme.gpgme_error_t_p_value(ptr)
gpgme.delete_gpgme_error_t_p(ptr)
if context is None:
errorcheck(status)
else:
context = Context(context)
return (status, context)
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