/usr/lib/python2.7/dist-packages/txwinrm/krb5.py is in python-txwinrm 1.1.28-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 | ##############################################################################
#
# Copyright (C) Zenoss, Inc. 2013, all rights reserved.
#
# This content is made available according to terms specified in
# License.zenoss under the directory where your Zenoss product is installed.
#
##############################################################################
import logging
LOG = logging.getLogger('txwinrm.krb5')
import collections
import os
import re
from twisted.internet import defer, reactor
from twisted.internet.protocol import ProcessProtocol
__all__ = [
'kinit',
'ccname',
]
KRB5_CONF_TEMPLATE = (
"# DO NOT EDIT THIS FILE!!\n"
"#\n"
"# This file is managed by the txwinrm python module.\n"
"# NOTE: Any changes to this file will be overwritten.\n"
"#\n"
"\n"
"includedir {includedir}\n"
"[logging]\n"
" default = FILE:/var/log/krb5libs.log\n"
" kdc = FILE:/var/log/krb5kdc.log\n"
" admin_server = FILE:/var/log/kadmind.log\n"
"\n"
"[libdefaults]\n"
" default_realm = EXAMPLE.COM\n"
" dns_lookup_realm = false\n"
" dns_lookup_kdc = false\n"
" ticket_lifetime = 24h\n"
" renew_lifetime = 7d\n"
" forwardable = true\n"
"\n"
"[realms]\n"
"{realms_text}"
"\n"
"[domain_realm]\n"
"{domain_realm_text}"
)
REALM_TEMPLATE = (
" {realm} = {{\n"
" kdc = {kdc}\n"
" admin_server = {kdc}\n"
" }}\n"
)
DOMAIN_REALM_TEMPLATE = (
" .{domain} = {realm}\n"
" {domain} = {realm}\n"
)
class Config(object):
'''
Manages KRB5_CONFIG.
'''
def __init__(self):
'''
Initialize instance with data from KRB5_CONFIG.
'''
self.path = self.get_path()
self.realms = self.load()
# For further usage by kerberos python module.
os.environ['KRB5_CONFIG'] = self.path
def add_kdc(self, realm, kdc):
'''
Add realm and KDC to KRB5_CONFIG.
'''
if kdc in self.realms[realm]:
return
'''
Remove any old kdcs ZEN-13244
'''
try:
self.realms[realm].pop()
except KeyError:
pass
self.realms[realm].add(kdc)
self.save()
def get_path(self):
'''
Return the path to krb5.conf.
Order of preference:
1. $KRB5_CONFIG
2. $ZENHOME/var/krb5.conf
3. $HOME/.txwinrm/krb5.conf
4. /etc/krb5.conf
'''
if 'KRB5_CONFIG' in os.environ:
return os.environ['KRB5_CONFIG']
if 'ZENHOME' in os.environ:
return os.path.join(os.environ['ZENHOME'], 'var', 'krb5.conf')
if 'HOME' in os.environ:
return os.path.join(os.environ['HOME'], '.txwinrm', 'krb5.conf')
return os.path.join('/etc', 'krb5.conf')
def get_ccname(self, username):
'''
Return KRB5CCNAME environment for username.
We use a separate credential cache for each username because
kinit causes all previous credentials to be destroyed when a new
one is initialized.
https://groups.google.com/forum/#!topic/comp.protocols.kerberos/IjtK9Mo39qc
'''
if 'ZENHOME' in os.environ:
return os.path.join(
os.environ['ZENHOME'], 'var', 'krb5cc', username)
if 'HOME' in os.environ:
return os.path.join(
os.environ['HOME'], '.txwinrm', 'krb5cc', username)
return ''
def load(self):
'''
Load current realms from KRB5_CONFIG file.
'''
realm_kdcs = collections.defaultdict(set)
if not os.path.isfile(self.path):
return realm_kdcs
with open(self.path, 'r') as krb5_conf:
in_realms_section = False
in_realm = None
for line in krb5_conf:
if line.strip().startswith('[realms]'):
in_realms_section = True
elif line.strip().startswith('['):
in_realms_section = False
elif in_realms_section:
line = line.strip()
if not line:
continue
match = re.search(r'(\S+)\s+=\s+{', line)
if match:
in_realm = match.group(1)
continue
if in_realm:
match = re.search(r'kdc\s+=\s+(\S+)', line)
if match:
realm_kdcs[in_realm].add(match.group(1))
return realm_kdcs
def save(self):
'''
Save current realm KDCs to KRB5_CONFIG.
'''
realms_list = []
domain_realm_list = []
for realm, kdcs in self.realms.iteritems():
if not kdcs:
continue
realms_list.append(
REALM_TEMPLATE.format(
realm=realm.upper(), kdc=tuple(kdcs)[0]))
domain_realm_list.append(
DOMAIN_REALM_TEMPLATE.format(
domain=realm.lower(), realm=realm.upper()))
dirname = os.path.dirname(self.path)
if not os.path.isdir(dirname):
os.makedirs(dirname)
# create config dir for user supplied options
includedir = os.path.join(dirname, 'config')
if not os.path.isdir(includedir):
os.makedirs(includedir)
with open(self.path, 'w') as krb5_conf:
krb5_conf.write(
KRB5_CONF_TEMPLATE.format(
includedir=includedir,
realms_text=''.join(realms_list),
domain_realm_text=''.join(domain_realm_list)))
# Singleton. Loads from KRB5_CONFIG on import.
config = Config()
class KinitProcessProtocol(ProcessProtocol):
'''
Communicates with kinit command.
The only thing we do is answer the password prompt. We don't even
care about the output.
'''
def __init__(self, password):
self._password = password
self.d = defer.Deferred()
self._data = ''
self._error = ''
def errReceived(self, data):
self._error += data
def outReceived(self, data):
self._data += data
if 'Password for' in self._data and ':' in self._data:
self.transport.write('{0}\n'.format(self._password))
self._data = ''
elif 'Password expired' in data:
# strip off '\nEnter new password:'
self._error = data.split('\n')[0]
self.transport.signalProcess('KILL')
def processEnded(self, reason):
self.d.callback(self._error if self._error else None)
@defer.inlineCallbacks
def kinit(username, password, kdc):
'''
Perform kerberos initialization.
'''
kinit = None
for path in ('/usr/bin/kinit', '/usr/kerberos/bin/kinit'):
if os.path.isfile(path):
kinit = path
break
if not kinit:
raise Exception("krb5-workstation is not installed")
try:
user, realm = username.split('@')
except ValueError:
raise Exception("kerberos username must be in user@domain format")
realm = realm.upper()
global config
config.add_kdc(realm, kdc)
ccname = config.get_ccname(username)
dirname = os.path.dirname(ccname)
if not os.path.isdir(dirname):
os.makedirs(dirname)
kinit_args = [kinit, '{}@{}'.format(user, realm)]
kinit_env = {
'KRB5_CONFIG': config.path,
'KRB5CCNAME': ccname,
}
protocol = KinitProcessProtocol(password)
reactor.spawnProcess(protocol, kinit, kinit_args, kinit_env)
results = yield protocol.d
defer.returnValue(results)
def ccname(username):
'''
Return KRB5CCNAME value for username.
'''
return config.get_ccname(username)
def add_trusted_realm(realm, kdc):
'''
Add a trusted realm for cross realm authentication
'''
trusted_realm = realm.upper()
global config
config.add_kdc(trusted_realm, kdc)
|