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|
#
# Copyright (C) 2017 FreeIPA Contributors see COPYING for license
#
import ctypes
import os
import sys
import six
class KRB5Error(Exception):
pass
PY3 = sys.version_info[0] == 3
try:
LIBKRB5 = ctypes.CDLL('libkrb5.so.3')
except OSError as e: # pragma: no cover
LIBKRB5 = e
else:
class c_text_p(ctypes.c_char_p): # noqa
"""A c_char_p variant that can handle UTF-8 text"""
@classmethod
def from_param(cls, value):
if value is None:
return None
if PY3 and isinstance(value, str):
return value.encode('utf-8')
elif not PY3 and isinstance(value, unicode): # noqa
return value.encode('utf-8')
elif not isinstance(value, bytes):
raise TypeError(value)
else:
return value
@property
def text(self):
value = self.value
if value is None:
return None
elif not isinstance(value, str):
return value.decode('utf-8')
return value
class _krb5_context(ctypes.Structure): # noqa
"""krb5/krb5.h struct _krb5_context"""
__slots__ = ()
_fields_ = []
class _krb5_ccache(ctypes.Structure): # noqa
"""krb5/krb5.h struct _krb5_ccache"""
__slots__ = ()
_fields_ = []
class _krb5_data(ctypes.Structure): # noqa
"""krb5/krb5.h struct _krb5_data"""
__slots__ = ()
_fields_ = [
("magic", ctypes.c_int32),
("length", ctypes.c_uint),
("data", ctypes.c_char_p),
]
class krb5_principal_data(ctypes.Structure): # noqa
"""krb5/krb5.h struct krb5_principal_data"""
__slots__ = ()
_fields_ = []
def krb5_errcheck(result, func, arguments):
"""Error checker for krb5_error return value"""
if result != 0:
raise KRB5Error(result, func.__name__, arguments)
krb5_principal = ctypes.POINTER(krb5_principal_data)
krb5_context = ctypes.POINTER(_krb5_context)
krb5_ccache = ctypes.POINTER(_krb5_ccache)
krb5_data_p = ctypes.POINTER(_krb5_data)
krb5_error = ctypes.c_int32
krb5_init_context = LIBKRB5.krb5_init_context
krb5_init_context.argtypes = (ctypes.POINTER(krb5_context), )
krb5_init_context.restype = krb5_error
krb5_init_context.errcheck = krb5_errcheck
krb5_free_context = LIBKRB5.krb5_free_context
krb5_free_context.argtypes = (krb5_context, )
krb5_free_context.retval = None
krb5_free_principal = LIBKRB5.krb5_free_principal
krb5_free_principal.argtypes = (krb5_context, krb5_principal)
krb5_free_principal.retval = None
krb5_free_data_contents = LIBKRB5.krb5_free_data_contents
krb5_free_data_contents.argtypes = (krb5_context, krb5_data_p)
krb5_free_data_contents.retval = None
krb5_cc_default = LIBKRB5.krb5_cc_default
krb5_cc_default.argtypes = (krb5_context, ctypes.POINTER(krb5_ccache), )
krb5_cc_default.restype = krb5_error
krb5_cc_default.errcheck = krb5_errcheck
krb5_cc_close = LIBKRB5.krb5_cc_close
krb5_cc_close.argtypes = (krb5_context, krb5_ccache, )
krb5_cc_close.retval = krb5_error
krb5_cc_close.errcheck = krb5_errcheck
krb5_parse_name = LIBKRB5.krb5_parse_name
krb5_parse_name.argtypes = (krb5_context, ctypes.c_char_p,
ctypes.POINTER(krb5_principal), )
krb5_parse_name.retval = krb5_error
krb5_parse_name.errcheck = krb5_errcheck
krb5_cc_set_config = LIBKRB5.krb5_cc_set_config
krb5_cc_set_config.argtypes = (krb5_context, krb5_ccache, krb5_principal,
ctypes.c_char_p, krb5_data_p, )
krb5_cc_set_config.retval = krb5_error
krb5_cc_set_config.errcheck = krb5_errcheck
krb5_cc_get_config = LIBKRB5.krb5_cc_get_config
krb5_cc_get_config.argtypes = (krb5_context, krb5_ccache, krb5_principal,
ctypes.c_char_p, krb5_data_p, )
krb5_cc_get_config.retval = krb5_error
krb5_cc_get_config.errcheck = krb5_errcheck
class session_store:
def __init__(self, name='X-IPA-Session-Cookie'):
self.__context = None
if isinstance(LIBKRB5, Exception): # pragma: no cover
raise LIBKRB5
context = krb5_context()
krb5_init_context(ctypes.byref(context))
self.__context = context
self._hidden_cred_name = name
def __enter__(self):
return self
def __exit__(self, type, value, traceback):
if self.__context:
krb5_free_context(self.__context)
self.__context = None
def __del__(self):
self.__exit__(None, None, None)
def store_cookie(self, client, value):
"""
Stores the session cookie in a hidden ccache entry.
"""
assert isinstance(client, six.string_types)
assert isinstance(value, bytes)
principal = ccache = None
try:
principal = krb5_principal()
krb5_parse_name(self.__context, ctypes.c_char_p(client),
ctypes.byref(principal))
ccache = krb5_ccache()
krb5_cc_default(self.__context, ctypes.byref(ccache))
buf = ctypes.create_string_buffer(value)
data = _krb5_data()
data.data = buf.value
data.length = len(buf)
krb5_cc_set_config(self.__context, ccache, principal,
self._hidden_cred_name, ctypes.byref(data))
finally:
if principal:
krb5_free_principal(self.__context, principal)
if ccache:
krb5_cc_close(self.__context, ccache)
def get_cookie(self, client):
"""
Gets the session cookie in a hidden ccache entry.
"""
assert isinstance(client, six.string_types)
principal = ccache = data = None
try:
principal = krb5_principal()
krb5_parse_name(self.__context, ctypes.c_char_p(client),
ctypes.byref(principal))
ccache = krb5_ccache()
krb5_cc_default(self.__context, ctypes.byref(ccache))
data = _krb5_data()
krb5_cc_get_config(self.__context, ccache, principal,
self._hidden_cred_name, ctypes.byref(data))
return str(data.data)
finally:
if principal:
krb5_free_principal(self.__context, principal)
if ccache:
krb5_cc_close(self.__context, ccache)
if data:
krb5_free_data_contents(self.__context, data)
def remove_cookie(self, client):
"""
Stores the session cookie in a hidden ccache entry.
"""
assert isinstance(client, six.string_types)
principal = ccache = None
try:
principal = krb5_principal()
krb5_parse_name(self.__context, ctypes.c_char_p(client),
ctypes.byref(principal))
ccache = krb5_ccache()
krb5_cc_default(self.__context, ctypes.byref(ccache))
krb5_cc_set_config(self.__context, ccache, principal,
self._hidden_cred_name, None)
finally:
if principal:
krb5_free_principal(self.__context, principal)
if ccache:
krb5_cc_close(self.__context, ccache)
|
