/usr/lib/python3/dist-packages/kdcproxy/codec.py is in python3-kdcproxy 0.3.2-1.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 | # Copyright (C) 2013, Red Hat, Inc.
# All rights reserved.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
import struct
from pyasn1 import error
from pyasn1.codec.der import decoder, encoder
import kdcproxy.asn1 as asn1
class ParsingError(Exception):
def __init__(self, message):
super(ParsingError, self).__init__(message)
self.message = message
class ProxyRequest(object):
TYPE = None
OFFSET = 4
@classmethod
def parse(cls, data):
(req, err) = decoder.decode(data, asn1Spec=asn1.ProxyMessage())
if err:
raise ParsingError("Invalid request.")
request = req.getComponentByName('message').asOctets()
realm = req.getComponentByName('realm').asOctets()
try: # Python 3.x
realm = str(realm, "UTF8")
except TypeError: # Python 2.x
realm = str(realm)
# Check the length of the whole request message.
(length, ) = struct.unpack("!I", request[0:4])
if length + 4 != len(request):
raise ParsingError("Invalid request length.")
for subcls in cls.__subclasses__():
try:
(req, err) = decoder.decode(request[subcls.OFFSET:],
asn1Spec=subcls.TYPE())
return subcls(realm, request, err)
except error.PyAsn1Error:
pass
raise ParsingError("Invalid request.")
def __init__(self, realm, request, err):
self.realm = realm
self.request = request
if len(err) > 0:
type = self.__class__.__name__[:0 - len(ProxyRequest.__name__)]
raise ParsingError("%s request has %d extra bytes." %
(type, len(err)))
def __str__(self):
type = self.__class__.__name__[:0 - len(ProxyRequest.__name__)]
return "%s %s-REQ (%d bytes)" % (self.realm, type,
len(self.request) - 4)
class TGSProxyRequest(ProxyRequest):
TYPE = asn1.TGSREQ
class ASProxyRequest(ProxyRequest):
TYPE = asn1.ASREQ
class KPASSWDProxyRequest(ProxyRequest):
TYPE = asn1.APREQ
OFFSET = 10
def __init__(self, realm, request, err):
# Check the length count in the password change request, assuming it
# actually is a password change request. It should be the length of
# the rest of the request, including itself.
(length, ) = struct.unpack("!H", request[4:6])
if length != len(request) - 4:
raise ParsingError("Parsing the KPASSWD request length failed.")
# Check the version number in the password change request, assuming it
# actually is a password change request. Officially we support version
# 1, but 0xff80 is used for set-password, so try to accept that, too.
(version, ) = struct.unpack("!H", request[6:8])
if version != 0x0001 and version != 0xff80:
raise ParsingError("The KPASSWD request is an incorrect version.")
# Read the length of the AP-REQ part of the change request. There
# should be at least that may bytes following this length, since the
# rest of the request is the KRB-PRIV message.
(length, ) = struct.unpack("!H", request[8:10])
if length > len(request) - 10:
raise ParsingError("The KPASSWD request appears to be truncated.")
# See if the tag looks like an AP request, which would look like the
# start of a password change request. The rest of it should be a
# KRB-PRIV message.
(apreq, err) = decoder.decode(request[10:length + 10],
asn1Spec=asn1.APREQ())
(krbpriv, err) = decoder.decode(request[length + 10:],
asn1Spec=asn1.KRBPriv())
super(KPASSWDProxyRequest, self).__init__(realm, request, err)
self.version = version
def __str__(self):
tmp = super(KPASSWDProxyRequest, self).__str__()
tmp += " (version 0x%04x)" % self.version
return tmp
def decode(data):
return ProxyRequest.parse(data)
def encode(data):
rep = asn1.ProxyMessage()
rep.setComponentByName('message', data)
return encoder.encode(rep)
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