# Copyright (C) 2016 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.
"""
import re
import weakref
from . import pygpgme
from .errors import errorcheck, GPGMEError
from . import constants
from . import errors
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().__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 == 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(pygpgme,
"{}get_{}".format(self._cprefix, key))
set_func = getattr(pygpgme,
"{}set_{}".format(self._cprefix, key))
def get(slf):
return bool(get_func(slf.wrapped))
def set_(slf, value):
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 == None:
return None
if key in self._boolean_properties:
return self.__wrap_boolean_property(key)
name = self._cprefix + key
func = getattr(pygpgme, name)
if self._errorcheck(name):
def _funcwrap(slf, *args):
result = func(slf.wrapped, *args)
if slf._callback_excinfo:
pygpgme.pygpgme_raise_callback_exception(slf)
return errorcheck(result, "Invocation of " + name)
else:
def _funcwrap(slf, *args):
result = func(slf.wrapped, *args)
if slf._callback_excinfo:
pygpgme.pygpgme_raise_callback_exception(slf)
return result
doc = self._munge_docstring.sub(r'\2.\1(\3', getattr(func, "__doc__"))
_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().__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.
"""
@property
def signers(self):
"""Keys used for signing"""
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)
_ctype = 'gpgme_ctx_t'
_cprefix = 'gpgme_'
def _errorcheck(self, name):
"""This function should list all functions returning gpgme_error_t"""
if (name.startswith('gpgme_op_') and \
not name.endswith('_result')) or \
name == 'gpgme_signers_add' or \
name == 'gpgme_set_locale' or \
name == 'gpgme_set_keylist_mode' or \
name == 'gpgme_set_protocol':
return 1
return 0
_boolean_properties = {'armor', 'textmode', 'offline'}
def __init__(self, armor=False, textmode=False, offline=False,
signers=[], pinentry_mode=constants.PINENTRY_MODE_DEFAULT,
wrapped=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)
"""
if wrapped:
self.own = False
else:
tmp = pygpgme.new_gpgme_ctx_t_p()
errorcheck(pygpgme.gpgme_new(tmp))
wrapped = pygpgme.gpgme_ctx_t_p_value(tmp)
pygpgme.delete_gpgme_ctx_t_p(tmp)
self.own = True
super().__init__(wrapped)
self.armor = armor
self.textmode = textmode
self.offline = offline
self.signers = signers
self.pinentry_mode = pinentry_mode
def __del__(self):
if not pygpgme:
# At interpreter shutdown, pygpgme is set to NONE.
return
self._free_passcb()
self._free_progresscb()
self._free_statuscb()
if self.own and self.wrapped and pygpgme.gpgme_release:
pygpgme.gpgme_release(self.wrapped)
self.wrapped = None
# Implement the context manager protocol.
def __enter__(self):
return self
def __exit__(self, type, value, tb):
self.__del__()
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()
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 = pygpgme.new_gpgme_key_t_p()
try:
errorcheck(pygpgme.gpgme_op_keylist_next(self.wrapped, ptr))
key = pygpgme.gpgme_key_t_p_value(ptr)
except errors.GPGMEError as excp:
key = None
if excp.getcode() != errors.EOF:
raise excp
pygpgme.delete_gpgme_key_t_p(ptr)
if key:
key.__del__ = lambda self: pygpgme.gpgme_key_unref(self)
return key
def get_key(self, fpr, secret):
"""Return the key corresponding to the fingerprint 'fpr'"""
ptr = pygpgme.new_gpgme_key_t_p()
errorcheck(pygpgme.gpgme_get_key(self.wrapped, fpr, ptr, secret))
key = pygpgme.gpgme_key_t_p_value(ptr)
pygpgme.delete_gpgme_key_t_p(ptr)
if key:
key.__del__ = lambda self: pygpgme.gpgme_key_unref(self)
return key
def op_trustlist_all(self, *args, **kwargs):
self.op_trustlist_start(*args, **kwargs)
trust = self.ctx.op_trustlist_next()
while trust:
yield trust
trust = self.ctx.op_trustlist_next()
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 = pygpgme.new_gpgme_trust_item_t_p()
try:
errorcheck(pygpgme.gpgme_op_trustlist_next(self.wrapped, ptr))
trust = pygpgme.gpgme_trust_item_t_p_value(ptr)
except errors.GPGMEError as excp:
trust = None
if excp.getcode() != errors.EOF:
raise
pygpgme.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 == None:
hookdata = None
else:
if hook == None:
hookdata = (weakref.ref(self), func)
else:
hookdata = (weakref.ref(self), func, hook)
pygpgme.pygpgme_set_passphrase_cb(self, hookdata)
def _free_passcb(self):
if pygpgme.pygpgme_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 == None:
hookdata = None
else:
if hook == None:
hookdata = (weakref.ref(self), func)
else:
hookdata = (weakref.ref(self), func, hook)
pygpgme.pygpgme_set_progress_cb(self, hookdata)
def _free_progresscb(self):
if pygpgme.pygpgme_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 == None:
hookdata = None
else:
if hook == None:
hookdata = (weakref.ref(self), func)
else:
hookdata = (weakref.ref(self), func, hook)
pygpgme.pygpgme_set_status_cb(self, hookdata)
def _free_statuscb(self):
if pygpgme.pygpgme_set_status_cb:
self.set_status_cb(None)
def get_engine_info(self):
"""Returns this context specific engine info"""
return pygpgme.gpgme_ctx_get_engine_info(self.wrapped)
def set_engine_info(self, proto, file_name, home_dir=None):
"""Changes the configuration of the crypto engine implementing the
protocol 'proto' for the context. '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(pygpgme.gpgme_ctx_set_engine_info(self.wrapped, 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 = pygpgme.new_gpgme_error_t_p()
pygpgme.gpgme_wait(self.wrapped, ptr, hang)
status = pygpgme.gpgme_error_t_p_value(ptr)
pygpgme.delete_gpgme_error_t_p(ptr)
errorcheck(status)
def op_edit(self, key, func, fnc_value, out):
"""Start key editing using supplied callback function"""
if key == None:
raise ValueError("op_edit: First argument cannot be None")
if fnc_value:
opaquedata = (weakref.ref(self), func, fnc_value)
else:
opaquedata = (weakref.ref(self), func)
result = pygpgme.gpgme_op_edit(self.wrapped, key, opaquedata, out)
if self._callback_excinfo:
pygpgme.pygpgme_raise_callback_exception(self)
errorcheck(result)
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"""
return name not in {
'gpgme_data_release_and_get_mem',
'gpgme_data_get_encoding',
'gpgme_data_seek',
'gpgme_data_get_file_name',
}
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().__init__(None)
self.data_cbs = None
if cbs != None:
self.new_from_cbs(*cbs)
elif string != None:
self.new_from_mem(string, copy)
elif file != None and offset != None and length != None:
self.new_from_filepart(file, offset, length)
elif file != None:
if type(file) == type("x"):
self.new_from_file(file, copy)
else:
self.new_from_fd(file)
else:
self.new()
def __del__(self):
if not pygpgme:
# At interpreter shutdown, pygpgme is set to NONE.
return
if self.wrapped != None and pygpgme.gpgme_data_release:
pygpgme.gpgme_data_release(self.wrapped)
if self._callback_excinfo:
pygpgme.pygpgme_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):
self.__del__()
def _free_datacbs(self):
self._data_cbs = None
def new(self):
tmp = pygpgme.new_gpgme_data_t_p()
errorcheck(pygpgme.gpgme_data_new(tmp))
self.wrapped = pygpgme.gpgme_data_t_p_value(tmp)
pygpgme.delete_gpgme_data_t_p(tmp)
def new_from_mem(self, string, copy=True):
tmp = pygpgme.new_gpgme_data_t_p()
errorcheck(pygpgme.gpgme_data_new_from_mem(tmp,string,len(string),copy))
self.wrapped = pygpgme.gpgme_data_t_p_value(tmp)
pygpgme.delete_gpgme_data_t_p(tmp)
def new_from_file(self, filename, copy=True):
tmp = pygpgme.new_gpgme_data_t_p()
try:
errorcheck(pygpgme.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 = pygpgme.gpgme_data_t_p_value(tmp)
pygpgme.delete_gpgme_data_t_p(tmp)
def new_from_cbs(self, read_cb, write_cb, seek_cb, release_cb, hook=None):
tmp = pygpgme.new_gpgme_data_t_p()
if hook != 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)
pygpgme.pygpgme_data_new_from_cbs(self, hookdata, tmp)
self.wrapped = pygpgme.gpgme_data_t_p_value(tmp)
pygpgme.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 = pygpgme.new_gpgme_data_t_p()
filename = None
fp = None
if type(file) == type("x"):
filename = file
else:
fp = pygpgme.fdopen(file.fileno(), file.mode)
if fp == None:
raise ValueError("Failed to open file from %s arg %s" % \
(str(type(file)), str(file)))
errorcheck(pygpgme.gpgme_data_new_from_filepart(tmp, filename, fp,
offset, length))
self.wrapped = pygpgme.gpgme_data_t_p_value(tmp)
pygpgme.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 = pygpgme.new_gpgme_data_t_p()
errorcheck(pygpgme.gpgme_data_new_from_fd(tmp, file.fileno()))
self.wrapped = pygpgme.gpgme_data_t_p_value(tmp)
pygpgme.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 not difference
between file stream and file descriptor"""
self.new_from_fd(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 = pygpgme.gpgme_data_write(self.wrapped, buffer)
if written < 0:
if self._callback_excinfo:
pygpgme.pygpgme_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 = pygpgme.gpgme_data_read(self.wrapped, size)
except:
if self._callback_excinfo:
pygpgme.pygpgme_raise_callback_exception(self)
else:
raise
return result
else:
chunks = []
while True:
try:
result = pygpgme.gpgme_data_read(self.wrapped, 4096)
except:
if self._callback_excinfo:
pygpgme.pygpgme_raise_callback_exception(self)
else:
raise
if len(result) == 0:
break
chunks.append(result)
return b''.join(chunks)
def pubkey_algo_name(algo):
return pygpgme.gpgme_pubkey_algo_name(algo)
def hash_algo_name(algo):
return pygpgme.gpgme_hash_algo_name(algo)
def get_protocol_name(proto):
return pygpgme.gpgme_get_protocol_name(proto)
def check_version(version=None):
return pygpgme.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(pygpgme.gpgme_engine_check_version(proto))
return True
except errors.GPGMEError:
return False
def get_engine_info():
ptr = pygpgme.new_gpgme_engine_info_t_p()
try:
errorcheck(pygpgme.gpgme_get_engine_info(ptr))
info = pygpgme.gpgme_engine_info_t_p_value(ptr)
except errors.GPGMEError:
info = None
pygpgme.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(pygpgme.gpgme_set_engine_info(proto, file_name, home_dir))
def set_locale(category, value):
"""Sets the default locale used by contexts"""
errorcheck(pygpgme.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 = pygpgme.new_gpgme_error_t_p()
context = pygpgme.gpgme_wait(None, ptr, hang)
status = pygpgme.gpgme_error_t_p_value(ptr)
pygpgme.delete_gpgme_error_t_p(ptr)
if context == None:
errorcheck(status)
else:
context = Context(context)
return (status, context)