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# "AvahiService" class, and some lines in "main".
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# Everything else is
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# Copyright © 2008-2017 Teddy Hogeborn
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# Copyright © 2008-2017 Björn Påhlsson
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# Copyright © 2008-2019 Teddy Hogeborn
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# Copyright © 2008-2019 Björn Påhlsson
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# This file is part of Mandos.
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# Mandos is free software: you can redistribute it and/or modify it
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# under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# Mandos is distributed in the hope that it will be useful, but
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# WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see
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# <http://www.gnu.org/licenses/>.
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# along with Mandos. If not, see <http://www.gnu.org/licenses/>.
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# Contact the authors at <mandos@recompile.se>.
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# Pretend that we have a GnuTLS module
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class GnuTLS(object):
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"""This isn't so much a class as it is a module-like namespace.
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It is instantiated once, and simulates having a GnuTLS module."""
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class gnutls(object):
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"""This isn't so much a class as it is a module-like namespace."""
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library = ctypes.util.find_library("gnutls")
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if library is None:
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library = ctypes.util.find_library("gnutls-deb0")
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_library = ctypes.cdll.LoadLibrary(library)
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_need_version = b"3.3.0"
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# Need to use "self" here, since this method is called before
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# the assignment to the "gnutls" global variable happens.
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if self.check_version(self._need_version) is None:
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raise self.Error("Needs GnuTLS {} or later"
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.format(self._need_version))
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# Unless otherwise indicated, the constants and types below are
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# all from the gnutls/gnutls.h C header file.
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class Error(Exception):
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# We need to use the class name "GnuTLS" here, since this
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# exception might be raised from within GnuTLS.__init__,
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# which is called before the assignment to the "gnutls"
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# global variable has happened.
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def __init__(self, message=None, code=None, args=()):
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# Default usage is by a message string, but if a return
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# code is passed, convert it to a string with
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# gnutls.strerror()
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if message is None and code is not None:
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message = GnuTLS.strerror(code)
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return super(GnuTLS.Error, self).__init__(
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message = gnutls.strerror(code)
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return super(gnutls.Error, self).__init__(
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class CertificateSecurityError(Error):
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class ClientSession(object):
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def __init__(self, socket, credentials=None):
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self._c_object = gnutls.session_t()
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gnutls.init(ctypes.byref(self._c_object), gnutls.CLIENT)
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gnutls_flags = gnutls.CLIENT
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if gnutls.check_version(b"3.5.6"):
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gnutls_flags |= gnutls.NO_TICKETS
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gnutls_flags |= gnutls.ENABLE_RAWPK
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gnutls.init(ctypes.byref(self._c_object), gnutls_flags)
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gnutls.set_default_priority(self._c_object)
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gnutls.transport_set_ptr(self._c_object, socket.fileno())
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gnutls.handshake_set_private_extensions(self._c_object,
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check_version.argtypes = [ctypes.c_char_p]
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check_version.restype = ctypes.c_char_p
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# All the function declarations below are from gnutls/openpgp.h
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openpgp_crt_init = _library.gnutls_openpgp_crt_init
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openpgp_crt_init.argtypes = [ctypes.POINTER(openpgp_crt_t)]
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openpgp_crt_init.restype = _error_code
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openpgp_crt_import = _library.gnutls_openpgp_crt_import
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openpgp_crt_import.argtypes = [openpgp_crt_t,
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ctypes.POINTER(datum_t),
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openpgp_crt_import.restype = _error_code
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openpgp_crt_verify_self = _library.gnutls_openpgp_crt_verify_self
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openpgp_crt_verify_self.argtypes = [openpgp_crt_t, ctypes.c_uint,
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ctypes.POINTER(ctypes.c_uint)]
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openpgp_crt_verify_self.restype = _error_code
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openpgp_crt_deinit = _library.gnutls_openpgp_crt_deinit
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openpgp_crt_deinit.argtypes = [openpgp_crt_t]
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openpgp_crt_deinit.restype = None
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openpgp_crt_get_fingerprint = (
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_library.gnutls_openpgp_crt_get_fingerprint)
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openpgp_crt_get_fingerprint.argtypes = [openpgp_crt_t,
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openpgp_crt_get_fingerprint.restype = _error_code
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_need_version = b"3.3.0"
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if check_version(_need_version) is None:
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raise self.Error("Needs GnuTLS {} or later"
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.format(_need_version))
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_tls_rawpk_version = b"3.6.6"
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has_rawpk = bool(check_version(_tls_rawpk_version))
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class pubkey_st(ctypes.Structure):
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pubkey_t = ctypes.POINTER(pubkey_st)
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x509_crt_fmt_t = ctypes.c_int
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# All the function declarations below are from gnutls/abstract.h
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pubkey_init = _library.gnutls_pubkey_init
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pubkey_init.argtypes = [ctypes.POINTER(pubkey_t)]
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pubkey_init.restype = _error_code
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pubkey_import = _library.gnutls_pubkey_import
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pubkey_import.argtypes = [pubkey_t, ctypes.POINTER(datum_t),
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pubkey_import.restype = _error_code
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pubkey_get_key_id = _library.gnutls_pubkey_get_key_id
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pubkey_get_key_id.argtypes = [pubkey_t, ctypes.c_int,
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ctypes.POINTER(ctypes.c_ubyte),
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ctypes.POINTER(ctypes.c_size_t)]
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pubkey_get_key_id.restype = _error_code
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pubkey_deinit = _library.gnutls_pubkey_deinit
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pubkey_deinit.argtypes = [pubkey_t]
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pubkey_deinit.restype = None
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# All the function declarations below are from gnutls/openpgp.h
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openpgp_crt_init = _library.gnutls_openpgp_crt_init
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openpgp_crt_init.argtypes = [ctypes.POINTER(openpgp_crt_t)]
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openpgp_crt_init.restype = _error_code
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openpgp_crt_import = _library.gnutls_openpgp_crt_import
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openpgp_crt_import.argtypes = [openpgp_crt_t,
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ctypes.POINTER(datum_t),
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openpgp_crt_import.restype = _error_code
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openpgp_crt_verify_self = _library.gnutls_openpgp_crt_verify_self
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openpgp_crt_verify_self.argtypes = [openpgp_crt_t, ctypes.c_uint,
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ctypes.POINTER(ctypes.c_uint)]
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openpgp_crt_verify_self.restype = _error_code
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openpgp_crt_deinit = _library.gnutls_openpgp_crt_deinit
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openpgp_crt_deinit.argtypes = [openpgp_crt_t]
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openpgp_crt_deinit.restype = None
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openpgp_crt_get_fingerprint = (
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_library.gnutls_openpgp_crt_get_fingerprint)
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openpgp_crt_get_fingerprint.argtypes = [openpgp_crt_t,
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openpgp_crt_get_fingerprint.restype = _error_code
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if check_version(b"3.6.4"):
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certificate_type_get2 = _library.gnutls_certificate_type_get2
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certificate_type_get2.argtypes = [session_t, ctypes.c_int]
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certificate_type_get2.restype = _error_code
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# Remove non-public functions
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del _error_code, _retry_on_error
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# Create the global "gnutls" object, simulating a module
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def call_pipe(connection, # : multiprocessing.Connection
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approved: bool(); 'None' if not yet approved/disapproved
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approval_delay: datetime.timedelta(); Time to wait for approval
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approval_duration: datetime.timedelta(); Duration of one approval
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checker: subprocess.Popen(); a running checker process used
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to see if the client lives.
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'None' if no process is running.
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checker: multiprocessing.Process(); a running checker process used
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to see if the client lives. 'None' if no process is
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checker_callback_tag: a GLib event source tag, or None
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checker_command: string; External command which is run to check
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if client lives. %() expansions are done at
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runtime_expansions = ("approval_delay", "approval_duration",
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"created", "enabled", "expires",
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"created", "enabled", "expires", "key_id",
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"fingerprint", "host", "interval",
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"last_approval_request", "last_checked_ok",
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"last_enabled", "name", "timeout")
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class ProxyClient(object):
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def __init__(self, child_pipe, fpr, address):
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def __init__(self, child_pipe, key_id, fpr, address):
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self._pipe = child_pipe
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self._pipe.send(('init', fpr, address))
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self._pipe.send(('init', key_id, fpr, address))
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if not self._pipe.recv():
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raise KeyError(key_id or fpr)
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def __getattribute__(self, name):
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if name == '_pipe':
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approval_required = False
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fpr = self.fingerprint(
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self.peer_certificate(session))
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except (TypeError, gnutls.Error) as error:
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logger.warning("Bad certificate: %s", error)
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logger.debug("Fingerprint: %s", fpr)
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client = ProxyClient(child_pipe, fpr,
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if gnutls.has_rawpk:
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key_id = self.key_id(
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self.peer_certificate(session))
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except (TypeError, gnutls.Error) as error:
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logger.warning("Bad certificate: %s", error)
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logger.debug("Key ID: %s", key_id)
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fpr = self.fingerprint(
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self.peer_certificate(session))
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except (TypeError, gnutls.Error) as error:
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logger.warning("Bad certificate: %s", error)
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logger.debug("Fingerprint: %s", fpr)
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client = ProxyClient(child_pipe, key_id, fpr,
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self.client_address)
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except KeyError:
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def peer_certificate(session):
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"Return the peer's OpenPGP certificate as a bytestring"
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# If not an OpenPGP certificate...
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if (gnutls.certificate_type_get(session._c_object)
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!= gnutls.CRT_OPENPGP):
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"Return the peer's certificate as a bytestring"
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cert_type = gnutls.certificate_type_get2(session._c_object,
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except AttributeError:
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cert_type = gnutls.certificate_type_get(session._c_object)
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if gnutls.has_rawpk:
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valid_cert_types = frozenset((gnutls.CRT_RAWPK,))
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valid_cert_types = frozenset((gnutls.CRT_OPENPGP,))
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# If not a valid certificate type...
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if cert_type not in valid_cert_types:
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logger.info("Cert type %r not in %r", cert_type,
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# ...return invalid data
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list_size = ctypes.c_uint(1)
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return ctypes.string_at(cert.data, cert.size)
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def key_id(certificate):
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"Convert a certificate bytestring to a hexdigit key ID"
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# New GnuTLS "datum" with the public key
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datum = gnutls.datum_t(
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ctypes.cast(ctypes.c_char_p(certificate),
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ctypes.POINTER(ctypes.c_ubyte)),
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ctypes.c_uint(len(certificate)))
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# XXX all these need to be created in the gnutls "module"
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# New empty GnuTLS certificate
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pubkey = gnutls.pubkey_t()
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gnutls.pubkey_init(ctypes.byref(pubkey))
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# Import the raw public key into the certificate
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gnutls.pubkey_import(pubkey,
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ctypes.byref(datum),
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gnutls.X509_FMT_DER)
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# New buffer for the key ID
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buf = ctypes.create_string_buffer(32)
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buf_len = ctypes.c_size_t(len(buf))
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# Get the key ID from the raw public key into the buffer
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gnutls.pubkey_get_key_id(pubkey,
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gnutls.KEYID_USE_SHA256,
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ctypes.cast(ctypes.byref(buf),
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ctypes.POINTER(ctypes.c_ubyte)),
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ctypes.byref(buf_len))
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# Deinit the certificate
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gnutls.pubkey_deinit(pubkey)
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# Convert the buffer to a Python bytestring
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key_id = ctypes.string_at(buf, buf_len.value)
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# Convert the bytestring to hexadecimal notation
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hex_key_id = binascii.hexlify(key_id).upper()
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def fingerprint(openpgp):
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"Convert an OpenPGP bytestring to a hexdigit fingerprint"
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# New GnuTLS "datum" with the OpenPGP public key
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command = request[0]
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if command == 'init':
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address = request[2]
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key_id = request[1].decode("ascii")
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fpr = request[2].decode("ascii")
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address = request[3]
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for c in self.clients.values():
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if c.fingerprint == fpr:
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if key_id == "E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855":
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if key_id and c.key_id == key_id:
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if fpr and c.fingerprint == fpr:
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logger.info("Client not found for fingerprint: %s, ad"
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"dress: %s", fpr, address)
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logger.info("Client not found for key ID: %s, address"
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": %s", key_id or fpr, address)
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if self.use_dbus:
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# Emit D-Bus signal
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mandos_dbus_service.ClientNotFound(fpr,
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mandos_dbus_service.ClientNotFound(key_id or fpr,
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parent_pipe.send(False)