/usr/share/pyshared/paramiko/auth_handler.py is in python-paramiko 1.7.7.1-3.1.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 | # Copyright (C) 2003-2007 Robey Pointer <robeypointer@gmail.com>
#
# This file is part of paramiko.
#
# Paramiko 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.
#
# Paramiko is distrubuted 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 Paramiko; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
"""
L{AuthHandler}
"""
import threading
import weakref
# this helps freezing utils
import encodings.utf_8
from paramiko.common import *
from paramiko import util
from paramiko.message import Message
from paramiko.ssh_exception import SSHException, AuthenticationException, \
BadAuthenticationType, PartialAuthentication
from paramiko.server import InteractiveQuery
class AuthHandler (object):
"""
Internal class to handle the mechanics of authentication.
"""
def __init__(self, transport):
self.transport = weakref.proxy(transport)
self.username = None
self.authenticated = False
self.auth_event = None
self.auth_method = ''
self.password = None
self.private_key = None
self.interactive_handler = None
self.submethods = None
# for server mode:
self.auth_username = None
self.auth_fail_count = 0
def is_authenticated(self):
return self.authenticated
def get_username(self):
if self.transport.server_mode:
return self.auth_username
else:
return self.username
def auth_none(self, username, event):
self.transport.lock.acquire()
try:
self.auth_event = event
self.auth_method = 'none'
self.username = username
self._request_auth()
finally:
self.transport.lock.release()
def auth_publickey(self, username, key, event):
self.transport.lock.acquire()
try:
self.auth_event = event
self.auth_method = 'publickey'
self.username = username
self.private_key = key
self._request_auth()
finally:
self.transport.lock.release()
def auth_password(self, username, password, event):
self.transport.lock.acquire()
try:
self.auth_event = event
self.auth_method = 'password'
self.username = username
self.password = password
self._request_auth()
finally:
self.transport.lock.release()
def auth_interactive(self, username, handler, event, submethods=''):
"""
response_list = handler(title, instructions, prompt_list)
"""
self.transport.lock.acquire()
try:
self.auth_event = event
self.auth_method = 'keyboard-interactive'
self.username = username
self.interactive_handler = handler
self.submethods = submethods
self._request_auth()
finally:
self.transport.lock.release()
def abort(self):
if self.auth_event is not None:
self.auth_event.set()
### internals...
def _request_auth(self):
m = Message()
m.add_byte(chr(MSG_SERVICE_REQUEST))
m.add_string('ssh-userauth')
self.transport._send_message(m)
def _disconnect_service_not_available(self):
m = Message()
m.add_byte(chr(MSG_DISCONNECT))
m.add_int(DISCONNECT_SERVICE_NOT_AVAILABLE)
m.add_string('Service not available')
m.add_string('en')
self.transport._send_message(m)
self.transport.close()
def _disconnect_no_more_auth(self):
m = Message()
m.add_byte(chr(MSG_DISCONNECT))
m.add_int(DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE)
m.add_string('No more auth methods available')
m.add_string('en')
self.transport._send_message(m)
self.transport.close()
def _get_session_blob(self, key, service, username):
m = Message()
m.add_string(self.transport.session_id)
m.add_byte(chr(MSG_USERAUTH_REQUEST))
m.add_string(username)
m.add_string(service)
m.add_string('publickey')
m.add_boolean(1)
m.add_string(key.get_name())
m.add_string(str(key))
return str(m)
def wait_for_response(self, event):
while True:
event.wait(0.1)
if not self.transport.is_active():
e = self.transport.get_exception()
if (e is None) or issubclass(e.__class__, EOFError):
e = AuthenticationException('Authentication failed.')
raise e
if event.isSet():
break
if not self.is_authenticated():
e = self.transport.get_exception()
if e is None:
e = AuthenticationException('Authentication failed.')
# this is horrible. python Exception isn't yet descended from
# object, so type(e) won't work. :(
if issubclass(e.__class__, PartialAuthentication):
return e.allowed_types
raise e
return []
def _parse_service_request(self, m):
service = m.get_string()
if self.transport.server_mode and (service == 'ssh-userauth'):
# accepted
m = Message()
m.add_byte(chr(MSG_SERVICE_ACCEPT))
m.add_string(service)
self.transport._send_message(m)
return
# dunno this one
self._disconnect_service_not_available()
def _parse_service_accept(self, m):
service = m.get_string()
if service == 'ssh-userauth':
self.transport._log(DEBUG, 'userauth is OK')
m = Message()
m.add_byte(chr(MSG_USERAUTH_REQUEST))
m.add_string(self.username)
m.add_string('ssh-connection')
m.add_string(self.auth_method)
if self.auth_method == 'password':
m.add_boolean(False)
password = self.password
if isinstance(password, unicode):
password = password.encode('UTF-8')
m.add_string(password)
elif self.auth_method == 'publickey':
m.add_boolean(True)
m.add_string(self.private_key.get_name())
m.add_string(str(self.private_key))
blob = self._get_session_blob(self.private_key, 'ssh-connection', self.username)
sig = self.private_key.sign_ssh_data(self.transport.rng, blob)
m.add_string(str(sig))
elif self.auth_method == 'keyboard-interactive':
m.add_string('')
m.add_string(self.submethods)
elif self.auth_method == 'none':
pass
else:
raise SSHException('Unknown auth method "%s"' % self.auth_method)
self.transport._send_message(m)
else:
self.transport._log(DEBUG, 'Service request "%s" accepted (?)' % service)
def _send_auth_result(self, username, method, result):
# okay, send result
m = Message()
if result == AUTH_SUCCESSFUL:
self.transport._log(INFO, 'Auth granted (%s).' % method)
m.add_byte(chr(MSG_USERAUTH_SUCCESS))
self.authenticated = True
else:
self.transport._log(INFO, 'Auth rejected (%s).' % method)
m.add_byte(chr(MSG_USERAUTH_FAILURE))
m.add_string(self.transport.server_object.get_allowed_auths(username))
if result == AUTH_PARTIALLY_SUCCESSFUL:
m.add_boolean(1)
else:
m.add_boolean(0)
self.auth_fail_count += 1
self.transport._send_message(m)
if self.auth_fail_count >= 10:
self._disconnect_no_more_auth()
if result == AUTH_SUCCESSFUL:
self.transport._auth_trigger()
def _interactive_query(self, q):
# make interactive query instead of response
m = Message()
m.add_byte(chr(MSG_USERAUTH_INFO_REQUEST))
m.add_string(q.name)
m.add_string(q.instructions)
m.add_string('')
m.add_int(len(q.prompts))
for p in q.prompts:
m.add_string(p[0])
m.add_boolean(p[1])
self.transport._send_message(m)
def _parse_userauth_request(self, m):
if not self.transport.server_mode:
# er, uh... what?
m = Message()
m.add_byte(chr(MSG_USERAUTH_FAILURE))
m.add_string('none')
m.add_boolean(0)
self.transport._send_message(m)
return
if self.authenticated:
# ignore
return
username = m.get_string()
service = m.get_string()
method = m.get_string()
self.transport._log(DEBUG, 'Auth request (type=%s) service=%s, username=%s' % (method, service, username))
if service != 'ssh-connection':
self._disconnect_service_not_available()
return
if (self.auth_username is not None) and (self.auth_username != username):
self.transport._log(WARNING, 'Auth rejected because the client attempted to change username in mid-flight')
self._disconnect_no_more_auth()
return
self.auth_username = username
if method == 'none':
result = self.transport.server_object.check_auth_none(username)
elif method == 'password':
changereq = m.get_boolean()
password = m.get_string()
try:
password = password.decode('UTF-8')
except UnicodeError:
# some clients/servers expect non-utf-8 passwords!
# in this case, just return the raw byte string.
pass
if changereq:
# always treated as failure, since we don't support changing passwords, but collect
# the list of valid auth types from the callback anyway
self.transport._log(DEBUG, 'Auth request to change passwords (rejected)')
newpassword = m.get_string()
try:
newpassword = newpassword.decode('UTF-8', 'replace')
except UnicodeError:
pass
result = AUTH_FAILED
else:
result = self.transport.server_object.check_auth_password(username, password)
elif method == 'publickey':
sig_attached = m.get_boolean()
keytype = m.get_string()
keyblob = m.get_string()
try:
key = self.transport._key_info[keytype](Message(keyblob))
except SSHException, e:
self.transport._log(INFO, 'Auth rejected: public key: %s' % str(e))
key = None
except:
self.transport._log(INFO, 'Auth rejected: unsupported or mangled public key')
key = None
if key is None:
self._disconnect_no_more_auth()
return
# first check if this key is okay... if not, we can skip the verify
result = self.transport.server_object.check_auth_publickey(username, key)
if result != AUTH_FAILED:
# key is okay, verify it
if not sig_attached:
# client wants to know if this key is acceptable, before it
# signs anything... send special "ok" message
m = Message()
m.add_byte(chr(MSG_USERAUTH_PK_OK))
m.add_string(keytype)
m.add_string(keyblob)
self.transport._send_message(m)
return
sig = Message(m.get_string())
blob = self._get_session_blob(key, service, username)
if not key.verify_ssh_sig(blob, sig):
self.transport._log(INFO, 'Auth rejected: invalid signature')
result = AUTH_FAILED
elif method == 'keyboard-interactive':
lang = m.get_string()
submethods = m.get_string()
result = self.transport.server_object.check_auth_interactive(username, submethods)
if isinstance(result, InteractiveQuery):
# make interactive query instead of response
self._interactive_query(result)
return
else:
result = self.transport.server_object.check_auth_none(username)
# okay, send result
self._send_auth_result(username, method, result)
def _parse_userauth_success(self, m):
self.transport._log(INFO, 'Authentication (%s) successful!' % self.auth_method)
self.authenticated = True
self.transport._auth_trigger()
if self.auth_event != None:
self.auth_event.set()
def _parse_userauth_failure(self, m):
authlist = m.get_list()
partial = m.get_boolean()
if partial:
self.transport._log(INFO, 'Authentication continues...')
self.transport._log(DEBUG, 'Methods: ' + str(authlist))
self.transport.saved_exception = PartialAuthentication(authlist)
elif self.auth_method not in authlist:
self.transport._log(DEBUG, 'Authentication type (%s) not permitted.' % self.auth_method)
self.transport._log(DEBUG, 'Allowed methods: ' + str(authlist))
self.transport.saved_exception = BadAuthenticationType('Bad authentication type', authlist)
else:
self.transport._log(INFO, 'Authentication (%s) failed.' % self.auth_method)
self.authenticated = False
self.username = None
if self.auth_event != None:
self.auth_event.set()
def _parse_userauth_banner(self, m):
banner = m.get_string()
lang = m.get_string()
self.transport._log(INFO, 'Auth banner: ' + banner)
# who cares.
def _parse_userauth_info_request(self, m):
if self.auth_method != 'keyboard-interactive':
raise SSHException('Illegal info request from server')
title = m.get_string()
instructions = m.get_string()
m.get_string() # lang
prompts = m.get_int()
prompt_list = []
for i in range(prompts):
prompt_list.append((m.get_string(), m.get_boolean()))
response_list = self.interactive_handler(title, instructions, prompt_list)
m = Message()
m.add_byte(chr(MSG_USERAUTH_INFO_RESPONSE))
m.add_int(len(response_list))
for r in response_list:
m.add_string(r)
self.transport._send_message(m)
def _parse_userauth_info_response(self, m):
if not self.transport.server_mode:
raise SSHException('Illegal info response from server')
n = m.get_int()
responses = []
for i in range(n):
responses.append(m.get_string())
result = self.transport.server_object.check_auth_interactive_response(responses)
if isinstance(type(result), InteractiveQuery):
# make interactive query instead of response
self._interactive_query(result)
return
self._send_auth_result(self.auth_username, 'keyboard-interactive', result)
_handler_table = {
MSG_SERVICE_REQUEST: _parse_service_request,
MSG_SERVICE_ACCEPT: _parse_service_accept,
MSG_USERAUTH_REQUEST: _parse_userauth_request,
MSG_USERAUTH_SUCCESS: _parse_userauth_success,
MSG_USERAUTH_FAILURE: _parse_userauth_failure,
MSG_USERAUTH_BANNER: _parse_userauth_banner,
MSG_USERAUTH_INFO_REQUEST: _parse_userauth_info_request,
MSG_USERAUTH_INFO_RESPONSE: _parse_userauth_info_response,
}
|