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# -*- test-case-name: twisted.conch.test.test_userauth -*-
# Copyright (c) 2007-2010 Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Tests for the implementation of the ssh-userauth service.
Maintainer: Paul Swartz
"""
from zope.interface import implements
from twisted.cred.checkers import ICredentialsChecker
from twisted.cred.credentials import IUsernamePassword, ISSHPrivateKey
from twisted.cred.credentials import IPluggableAuthenticationModules
from twisted.cred.credentials import IAnonymous
from twisted.cred.error import UnauthorizedLogin
from twisted.cred.portal import IRealm, Portal
from twisted.conch.error import ConchError, ValidPublicKey
from twisted.internet import defer, task
from twisted.protocols import loopback
from twisted.trial import unittest
try:
import Crypto.Cipher.DES3, Crypto.Cipher.XOR
import pyasn1
except ImportError:
keys = None
class transport:
class SSHTransportBase:
"""
A stub class so that later class definitions won't die.
"""
class userauth:
class SSHUserAuthClient:
"""
A stub class so that leter class definitions won't die.
"""
else:
from twisted.conch.ssh.common import NS
from twisted.conch.checkers import SSHProtocolChecker
from twisted.conch.ssh import keys, userauth, transport
from twisted.conch.test import keydata
class ClientUserAuth(userauth.SSHUserAuthClient):
"""
A mock user auth client.
"""
def getPublicKey(self):
"""
If this is the first time we've been called, return a blob for
the DSA key. Otherwise, return a blob
for the RSA key.
"""
if self.lastPublicKey:
return keys.Key.fromString(keydata.publicRSA_openssh)
else:
return defer.succeed(keys.Key.fromString(keydata.publicDSA_openssh))
def getPrivateKey(self):
"""
Return the private key object for the RSA key.
"""
return defer.succeed(keys.Key.fromString(keydata.privateRSA_openssh))
def getPassword(self, prompt=None):
"""
Return 'foo' as the password.
"""
return defer.succeed('foo')
def getGenericAnswers(self, name, information, answers):
"""
Return 'foo' as the answer to two questions.
"""
return defer.succeed(('foo', 'foo'))
class OldClientAuth(userauth.SSHUserAuthClient):
"""
The old SSHUserAuthClient returned a PyCrypto key object from
getPrivateKey() and a string from getPublicKey
"""
def getPrivateKey(self):
return defer.succeed(keys.Key.fromString(
keydata.privateRSA_openssh).keyObject)
def getPublicKey(self):
return keys.Key.fromString(keydata.publicRSA_openssh).blob()
class ClientAuthWithoutPrivateKey(userauth.SSHUserAuthClient):
"""
This client doesn't have a private key, but it does have a public key.
"""
def getPrivateKey(self):
return
def getPublicKey(self):
return keys.Key.fromString(keydata.publicRSA_openssh)
class FakeTransport(transport.SSHTransportBase):
"""
L{userauth.SSHUserAuthServer} expects an SSH transport which has a factory
attribute which has a portal attribute. Because the portal is important for
testing authentication, we need to be able to provide an interesting portal
object to the L{SSHUserAuthServer}.
In addition, we want to be able to capture any packets sent over the
transport.
@ivar packets: a list of 2-tuples: (messageType, data). Each 2-tuple is
a sent packet.
@type packets: C{list}
@param lostConnecion: True if loseConnection has been called on us.
@type lostConnection: C{bool}
"""
class Service(object):
"""
A mock service, representing the other service offered by the server.
"""
name = 'nancy'
def serviceStarted(self):
pass
class Factory(object):
"""
A mock factory, representing the factory that spawned this user auth
service.
"""
def getService(self, transport, service):
"""
Return our fake service.
"""
if service == 'none':
return FakeTransport.Service
def __init__(self, portal):
self.factory = self.Factory()
self.factory.portal = portal
self.lostConnection = False
self.transport = self
self.packets = []
def sendPacket(self, messageType, message):
"""
Record the packet sent by the service.
"""
self.packets.append((messageType, message))
def isEncrypted(self, direction):
"""
Pretend that this transport encrypts traffic in both directions. The
SSHUserAuthServer disables password authentication if the transport
isn't encrypted.
"""
return True
def loseConnection(self):
self.lostConnection = True
class Realm(object):
"""
A mock realm for testing L{userauth.SSHUserAuthServer}.
This realm is not actually used in the course of testing, so it returns the
simplest thing that could possibly work.
"""
implements(IRealm)
def requestAvatar(self, avatarId, mind, *interfaces):
return defer.succeed((interfaces[0], None, lambda: None))
class PasswordChecker(object):
"""
A very simple username/password checker which authenticates anyone whose
password matches their username and rejects all others.
"""
credentialInterfaces = (IUsernamePassword,)
implements(ICredentialsChecker)
def requestAvatarId(self, creds):
if creds.username == creds.password:
return defer.succeed(creds.username)
return defer.fail(UnauthorizedLogin("Invalid username/password pair"))
class PrivateKeyChecker(object):
"""
A very simple public key checker which authenticates anyone whose
public/private keypair is the same keydata.public/privateRSA_openssh.
"""
credentialInterfaces = (ISSHPrivateKey,)
implements(ICredentialsChecker)
def requestAvatarId(self, creds):
if creds.blob == keys.Key.fromString(keydata.publicRSA_openssh).blob():
if creds.signature is not None:
obj = keys.Key.fromString(creds.blob)
if obj.verify(creds.signature, creds.sigData):
return creds.username
else:
raise ValidPublicKey()
raise UnauthorizedLogin()
class PAMChecker(object):
"""
A simple PAM checker which asks the user for a password, verifying them
if the password is the same as their username.
"""
credentialInterfaces = (IPluggableAuthenticationModules,)
implements(ICredentialsChecker)
def requestAvatarId(self, creds):
d = creds.pamConversion([('Name: ', 2), ("Password: ", 1)])
def check(values):
if values == [(creds.username, 0), (creds.username, 0)]:
return creds.username
raise UnauthorizedLogin()
return d.addCallback(check)
class AnonymousChecker(object):
"""
A simple checker which isn't supported by L{SSHUserAuthServer}.
"""
credentialInterfaces = (IAnonymous,)
implements(ICredentialsChecker)
class SSHUserAuthServerTestCase(unittest.TestCase):
"""
Tests for SSHUserAuthServer.
"""
if keys is None:
skip = "cannot run w/o PyCrypto"
def setUp(self):
self.realm = Realm()
self.portal = Portal(self.realm)
self.portal.registerChecker(PasswordChecker())
self.portal.registerChecker(PrivateKeyChecker())
self.portal.registerChecker(PAMChecker())
self.authServer = userauth.SSHUserAuthServer()
self.authServer.transport = FakeTransport(self.portal)
self.authServer.serviceStarted()
self.authServer.supportedAuthentications.sort() # give a consistent
# order
def tearDown(self):
self.authServer.serviceStopped()
self.authServer = None
def _checkFailed(self, ignored):
"""
Check that the authentication has failed.
"""
self.assertEquals(self.authServer.transport.packets[-1],
(userauth.MSG_USERAUTH_FAILURE,
NS('keyboard-interactive,password,publickey') + '\x00'))
def test_noneAuthentication(self):
"""
A client may request a list of authentication 'method name' values
that may continue by using the "none" authentication 'method name'.
See RFC 4252 Section 5.2.
"""
d = self.authServer.ssh_USERAUTH_REQUEST(NS('foo') + NS('service') +
NS('none'))
return d.addCallback(self._checkFailed)
def test_successfulPasswordAuthentication(self):
"""
When provided with correct password authentication information, the
server should respond by sending a MSG_USERAUTH_SUCCESS message with
no other data.
See RFC 4252, Section 5.1.
"""
packet = NS('foo') + NS('none') + NS('password') + chr(0) + NS('foo')
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
def check(ignored):
self.assertEqual(
self.authServer.transport.packets,
[(userauth.MSG_USERAUTH_SUCCESS, '')])
return d.addCallback(check)
def test_failedPasswordAuthentication(self):
"""
When provided with invalid authentication details, the server should
respond by sending a MSG_USERAUTH_FAILURE message which states whether
the authentication was partially successful, and provides other, open
options for authentication.
See RFC 4252, Section 5.1.
"""
# packet = username, next_service, authentication type, FALSE, password
packet = NS('foo') + NS('none') + NS('password') + chr(0) + NS('bar')
self.authServer.clock = task.Clock()
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
self.assertEquals(self.authServer.transport.packets, [])
self.authServer.clock.advance(2)
return d.addCallback(self._checkFailed)
def test_successfulPrivateKeyAuthentication(self):
"""
Test that private key authentication completes sucessfully,
"""
blob = keys.Key.fromString(keydata.publicRSA_openssh).blob()
obj = keys.Key.fromString(keydata.privateRSA_openssh)
packet = (NS('foo') + NS('none') + NS('publickey') + '\xff'
+ NS(obj.sshType()) + NS(blob))
self.authServer.transport.sessionID = 'test'
signature = obj.sign(NS('test') + chr(userauth.MSG_USERAUTH_REQUEST)
+ packet)
packet += NS(signature)
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
def check(ignored):
self.assertEquals(self.authServer.transport.packets,
[(userauth.MSG_USERAUTH_SUCCESS, '')])
return d.addCallback(check)
def test_requestRaisesConchError(self):
"""
ssh_USERAUTH_REQUEST should raise a ConchError if tryAuth returns
None. Added to catch a bug noticed by pyflakes.
"""
d = defer.Deferred()
def mockCbFinishedAuth(self, ignored):
self.fail('request should have raised ConochError')
def mockTryAuth(kind, user, data):
return None
def mockEbBadAuth(reason):
d.errback(reason.value)
self.patch(self.authServer, 'tryAuth', mockTryAuth)
self.patch(self.authServer, '_cbFinishedAuth', mockCbFinishedAuth)
self.patch(self.authServer, '_ebBadAuth', mockEbBadAuth)
packet = NS('user') + NS('none') + NS('public-key') + NS('data')
# If an error other than ConchError is raised, this will trigger an
# exception.
self.authServer.ssh_USERAUTH_REQUEST(packet)
return self.assertFailure(d, ConchError)
def test_verifyValidPrivateKey(self):
"""
Test that verifying a valid private key works.
"""
blob = keys.Key.fromString(keydata.publicRSA_openssh).blob()
packet = (NS('foo') + NS('none') + NS('publickey') + '\x00'
+ NS('ssh-rsa') + NS(blob))
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
def check(ignored):
self.assertEquals(self.authServer.transport.packets,
[(userauth.MSG_USERAUTH_PK_OK, NS('ssh-rsa') + NS(blob))])
return d.addCallback(check)
def test_failedPrivateKeyAuthenticationWithoutSignature(self):
"""
Test that private key authentication fails when the public key
is invalid.
"""
blob = keys.Key.fromString(keydata.publicDSA_openssh).blob()
packet = (NS('foo') + NS('none') + NS('publickey') + '\x00'
+ NS('ssh-dsa') + NS(blob))
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
return d.addCallback(self._checkFailed)
def test_failedPrivateKeyAuthenticationWithSignature(self):
"""
Test that private key authentication fails when the public key
is invalid.
"""
blob = keys.Key.fromString(keydata.publicRSA_openssh).blob()
obj = keys.Key.fromString(keydata.privateRSA_openssh)
packet = (NS('foo') + NS('none') + NS('publickey') + '\xff'
+ NS('ssh-rsa') + NS(blob) + NS(obj.sign(blob)))
self.authServer.transport.sessionID = 'test'
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
return d.addCallback(self._checkFailed)
def test_successfulPAMAuthentication(self):
"""
Test that keyboard-interactive authentication succeeds.
"""
packet = (NS('foo') + NS('none') + NS('keyboard-interactive')
+ NS('') + NS(''))
response = '\x00\x00\x00\x02' + NS('foo') + NS('foo')
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
self.authServer.ssh_USERAUTH_INFO_RESPONSE(response)
def check(ignored):
self.assertEquals(self.authServer.transport.packets,
[(userauth.MSG_USERAUTH_INFO_REQUEST, (NS('') + NS('')
+ NS('') + '\x00\x00\x00\x02' + NS('Name: ') + '\x01'
+ NS('Password: ') + '\x00')),
(userauth.MSG_USERAUTH_SUCCESS, '')])
return d.addCallback(check)
def test_failedPAMAuthentication(self):
"""
Test that keyboard-interactive authentication fails.
"""
packet = (NS('foo') + NS('none') + NS('keyboard-interactive')
+ NS('') + NS(''))
response = '\x00\x00\x00\x02' + NS('bar') + NS('bar')
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
self.authServer.ssh_USERAUTH_INFO_RESPONSE(response)
def check(ignored):
self.assertEquals(self.authServer.transport.packets[0],
(userauth.MSG_USERAUTH_INFO_REQUEST, (NS('') + NS('')
+ NS('') + '\x00\x00\x00\x02' + NS('Name: ') + '\x01'
+ NS('Password: ') + '\x00')))
return d.addCallback(check).addCallback(self._checkFailed)
def test_invalid_USERAUTH_INFO_RESPONSE_not_enough_data(self):
"""
If ssh_USERAUTH_INFO_RESPONSE gets an invalid packet,
the user authentication should fail.
"""
packet = (NS('foo') + NS('none') + NS('keyboard-interactive')
+ NS('') + NS(''))
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
self.authServer.ssh_USERAUTH_INFO_RESPONSE(NS('\x00\x00\x00\x00' +
NS('hi')))
return d.addCallback(self._checkFailed)
def test_invalid_USERAUTH_INFO_RESPONSE_too_much_data(self):
"""
If ssh_USERAUTH_INFO_RESPONSE gets too much data, the user
authentication should fail.
"""
packet = (NS('foo') + NS('none') + NS('keyboard-interactive')
+ NS('') + NS(''))
response = '\x00\x00\x00\x02' + NS('foo') + NS('foo') + NS('foo')
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
self.authServer.ssh_USERAUTH_INFO_RESPONSE(response)
return d.addCallback(self._checkFailed)
def test_onlyOnePAMAuthentication(self):
"""
Because it requires an intermediate message, one can't send a second
keyboard-interactive request while the first is still pending.
"""
packet = (NS('foo') + NS('none') + NS('keyboard-interactive')
+ NS('') + NS(''))
self.authServer.ssh_USERAUTH_REQUEST(packet)
self.authServer.ssh_USERAUTH_REQUEST(packet)
self.assertEquals(self.authServer.transport.packets[-1][0],
transport.MSG_DISCONNECT)
self.assertEquals(self.authServer.transport.packets[-1][1][3],
chr(transport.DISCONNECT_PROTOCOL_ERROR))
def test_ignoreUnknownCredInterfaces(self):
"""
L{SSHUserAuthServer} sets up
C{SSHUserAuthServer.supportedAuthentications} by checking the portal's
credentials interfaces and mapping them to SSH authentication method
strings. If the Portal advertises an interface that
L{SSHUserAuthServer} can't map, it should be ignored. This is a white
box test.
"""
server = userauth.SSHUserAuthServer()
server.transport = FakeTransport(self.portal)
self.portal.registerChecker(AnonymousChecker())
server.serviceStarted()
server.serviceStopped()
server.supportedAuthentications.sort() # give a consistent order
self.assertEquals(server.supportedAuthentications,
['keyboard-interactive', 'password', 'publickey'])
def test_removePasswordIfUnencrypted(self):
"""
Test that the userauth service does not advertise password
authentication if the password would be send in cleartext.
"""
self.assertIn('password', self.authServer.supportedAuthentications)
# no encryption
clearAuthServer = userauth.SSHUserAuthServer()
clearAuthServer.transport = FakeTransport(self.portal)
clearAuthServer.transport.isEncrypted = lambda x: False
clearAuthServer.serviceStarted()
clearAuthServer.serviceStopped()
self.failIfIn('password', clearAuthServer.supportedAuthentications)
# only encrypt incoming (the direction the password is sent)
halfAuthServer = userauth.SSHUserAuthServer()
halfAuthServer.transport = FakeTransport(self.portal)
halfAuthServer.transport.isEncrypted = lambda x: x == 'in'
halfAuthServer.serviceStarted()
halfAuthServer.serviceStopped()
self.assertIn('password', halfAuthServer.supportedAuthentications)
def test_removeKeyboardInteractiveIfUnencrypted(self):
"""
Test that the userauth service does not advertise keyboard-interactive
authentication if the password would be send in cleartext.
"""
self.assertIn('keyboard-interactive',
self.authServer.supportedAuthentications)
# no encryption
clearAuthServer = userauth.SSHUserAuthServer()
clearAuthServer.transport = FakeTransport(self.portal)
clearAuthServer.transport.isEncrypted = lambda x: False
clearAuthServer.serviceStarted()
clearAuthServer.serviceStopped()
self.failIfIn('keyboard-interactive',
clearAuthServer.supportedAuthentications)
# only encrypt incoming (the direction the password is sent)
halfAuthServer = userauth.SSHUserAuthServer()
halfAuthServer.transport = FakeTransport(self.portal)
halfAuthServer.transport.isEncrypted = lambda x: x == 'in'
halfAuthServer.serviceStarted()
halfAuthServer.serviceStopped()
self.assertIn('keyboard-interactive',
halfAuthServer.supportedAuthentications)
def test_unencryptedConnectionWithoutPasswords(self):
"""
If the L{SSHUserAuthServer} is not advertising passwords, then an
unencrypted connection should not cause any warnings or exceptions.
This is a white box test.
"""
# create a Portal without password authentication
portal = Portal(self.realm)
portal.registerChecker(PrivateKeyChecker())
# no encryption
clearAuthServer = userauth.SSHUserAuthServer()
clearAuthServer.transport = FakeTransport(portal)
clearAuthServer.transport.isEncrypted = lambda x: False
clearAuthServer.serviceStarted()
clearAuthServer.serviceStopped()
self.assertEquals(clearAuthServer.supportedAuthentications,
['publickey'])
# only encrypt incoming (the direction the password is sent)
halfAuthServer = userauth.SSHUserAuthServer()
halfAuthServer.transport = FakeTransport(portal)
halfAuthServer.transport.isEncrypted = lambda x: x == 'in'
halfAuthServer.serviceStarted()
halfAuthServer.serviceStopped()
self.assertEquals(clearAuthServer.supportedAuthentications,
['publickey'])
def test_loginTimeout(self):
"""
Test that the login times out.
"""
timeoutAuthServer = userauth.SSHUserAuthServer()
timeoutAuthServer.clock = task.Clock()
timeoutAuthServer.transport = FakeTransport(self.portal)
timeoutAuthServer.serviceStarted()
timeoutAuthServer.clock.advance(11 * 60 * 60)
timeoutAuthServer.serviceStopped()
self.assertEquals(timeoutAuthServer.transport.packets,
[(transport.MSG_DISCONNECT,
'\x00' * 3 +
chr(transport.DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE) +
NS("you took too long") + NS(''))])
self.assertTrue(timeoutAuthServer.transport.lostConnection)
def test_cancelLoginTimeout(self):
"""
Test that stopping the service also stops the login timeout.
"""
timeoutAuthServer = userauth.SSHUserAuthServer()
timeoutAuthServer.clock = task.Clock()
timeoutAuthServer.transport = FakeTransport(self.portal)
timeoutAuthServer.serviceStarted()
timeoutAuthServer.serviceStopped()
timeoutAuthServer.clock.advance(11 * 60 * 60)
self.assertEquals(timeoutAuthServer.transport.packets, [])
self.assertFalse(timeoutAuthServer.transport.lostConnection)
def test_tooManyAttempts(self):
"""
Test that the server disconnects if the client fails authentication
too many times.
"""
packet = NS('foo') + NS('none') + NS('password') + chr(0) + NS('bar')
self.authServer.clock = task.Clock()
for i in range(21):
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
self.authServer.clock.advance(2)
def check(ignored):
self.assertEquals(self.authServer.transport.packets[-1],
(transport.MSG_DISCONNECT,
'\x00' * 3 +
chr(transport.DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE) +
NS("too many bad auths") + NS('')))
return d.addCallback(check)
def test_failIfUnknownService(self):
"""
If the user requests a service that we don't support, the
authentication should fail.
"""
packet = NS('foo') + NS('') + NS('password') + chr(0) + NS('foo')
self.authServer.clock = task.Clock()
d = self.authServer.ssh_USERAUTH_REQUEST(packet)
return d.addCallback(self._checkFailed)
def test__pamConvErrors(self):
"""
_pamConv should fail if it gets a message that's not 1 or 2.
"""
def secondTest(ignored):
d2 = self.authServer._pamConv([('', 90)])
return self.assertFailure(d2, ConchError)
d = self.authServer._pamConv([('', 3)])
return self.assertFailure(d, ConchError).addCallback(secondTest)
def test_tryAuthEdgeCases(self):
"""
tryAuth() has two edge cases that are difficult to reach.
1) an authentication method auth_* returns None instead of a Deferred.
2) an authentication type that is defined does not have a matching
auth_* method.
Both these cases should return a Deferred which fails with a
ConchError.
"""
def mockAuth(packet):
return None
self.patch(self.authServer, 'auth_publickey', mockAuth) # first case
self.patch(self.authServer, 'auth_password', None) # second case
def secondTest(ignored):
d2 = self.authServer.tryAuth('password', None, None)
return self.assertFailure(d2, ConchError)
d1 = self.authServer.tryAuth('publickey', None, None)
return self.assertFailure(d1, ConchError).addCallback(secondTest)
class SSHUserAuthClientTestCase(unittest.TestCase):
"""
Tests for SSHUserAuthClient.
"""
if keys is None:
skip = "cannot run w/o PyCrypto"
def setUp(self):
self.authClient = ClientUserAuth('foo', FakeTransport.Service())
self.authClient.transport = FakeTransport(None)
self.authClient.transport.sessionID = 'test'
self.authClient.serviceStarted()
def tearDown(self):
self.authClient.serviceStopped()
self.authClient = None
def test_init(self):
"""
Test that client is initialized properly.
"""
self.assertEquals(self.authClient.user, 'foo')
self.assertEquals(self.authClient.instance.name, 'nancy')
self.assertEquals(self.authClient.transport.packets,
[(userauth.MSG_USERAUTH_REQUEST, NS('foo') + NS('nancy')
+ NS('none'))])
def test_USERAUTH_SUCCESS(self):
"""
Test that the client succeeds properly.
"""
instance = [None]
def stubSetService(service):
instance[0] = service
self.authClient.transport.setService = stubSetService
self.authClient.ssh_USERAUTH_SUCCESS('')
self.assertEquals(instance[0], self.authClient.instance)
def test_publickey(self):
"""
Test that the client can authenticate with a public key.
"""
self.authClient.ssh_USERAUTH_FAILURE(NS('publickey') + '\x00')
self.assertEquals(self.authClient.transport.packets[-1],
(userauth.MSG_USERAUTH_REQUEST, NS('foo') + NS('nancy')
+ NS('publickey') + '\x00' + NS('ssh-dss')
+ NS(keys.Key.fromString(
keydata.publicDSA_openssh).blob())))
# that key isn't good
self.authClient.ssh_USERAUTH_FAILURE(NS('publickey') + '\x00')
blob = NS(keys.Key.fromString(keydata.publicRSA_openssh).blob())
self.assertEquals(self.authClient.transport.packets[-1],
(userauth.MSG_USERAUTH_REQUEST, (NS('foo') + NS('nancy')
+ NS('publickey') + '\x00'+ NS('ssh-rsa') + blob)))
self.authClient.ssh_USERAUTH_PK_OK(NS('ssh-rsa')
+ NS(keys.Key.fromString(keydata.publicRSA_openssh).blob()))
sigData = (NS(self.authClient.transport.sessionID)
+ chr(userauth.MSG_USERAUTH_REQUEST) + NS('foo')
+ NS('nancy') + NS('publickey') + '\xff' + NS('ssh-rsa')
+ blob)
obj = keys.Key.fromString(keydata.privateRSA_openssh)
self.assertEquals(self.authClient.transport.packets[-1],
(userauth.MSG_USERAUTH_REQUEST, NS('foo') + NS('nancy')
+ NS('publickey') + '\xff' + NS('ssh-rsa') + blob
+ NS(obj.sign(sigData))))
def test_publickey_without_privatekey(self):
"""
If the SSHUserAuthClient doesn't return anything from signData,
the client should start the authentication over again by requesting
'none' authentication.
"""
authClient = ClientAuthWithoutPrivateKey('foo',
FakeTransport.Service())
authClient.transport = FakeTransport(None)
authClient.transport.sessionID = 'test'
authClient.serviceStarted()
authClient.tryAuth('publickey')
authClient.transport.packets = []
self.assertIdentical(authClient.ssh_USERAUTH_PK_OK(''), None)
self.assertEquals(authClient.transport.packets, [
(userauth.MSG_USERAUTH_REQUEST, NS('foo') + NS('nancy') +
NS('none'))])
def test_old_publickey_getPublicKey(self):
"""
Old SSHUserAuthClients returned strings of public key blobs from
getPublicKey(). Test that a Deprecation warning is raised but the key is
verified correctly.
"""
oldAuth = OldClientAuth('foo', FakeTransport.Service())
oldAuth.transport = FakeTransport(None)
oldAuth.transport.sessionID = 'test'
oldAuth.serviceStarted()
oldAuth.transport.packets = []
self.assertWarns(DeprecationWarning, "Returning a string from "
"SSHUserAuthClient.getPublicKey() is deprecated since "
"Twisted 9.0. Return a keys.Key() instead.",
userauth.__file__, oldAuth.tryAuth, 'publickey')
self.assertEquals(oldAuth.transport.packets, [
(userauth.MSG_USERAUTH_REQUEST, NS('foo') + NS('nancy') +
NS('publickey') + '\x00' + NS('ssh-rsa') +
NS(keys.Key.fromString(keydata.publicRSA_openssh).blob()))])
def test_old_publickey_getPrivateKey(self):
"""
Old SSHUserAuthClients returned a PyCrypto key object from
getPrivateKey(). Test that _cbSignData signs the data warns the
user about the deprecation, but signs the data correctly.
"""
oldAuth = OldClientAuth('foo', FakeTransport.Service())
d = self.assertWarns(DeprecationWarning, "Returning a PyCrypto key "
"object from SSHUserAuthClient.getPrivateKey() is "
"deprecated since Twisted 9.0. "
"Return a keys.Key() instead.", userauth.__file__,
oldAuth.signData, None, 'data')
def _checkSignedData(sig):
self.assertEquals(sig,
keys.Key.fromString(keydata.privateRSA_openssh).sign(
'data'))
d.addCallback(_checkSignedData)
return d
def test_no_publickey(self):
"""
If there's no public key, auth_publickey should return a Deferred
called back with a False value.
"""
self.authClient.getPublicKey = lambda x: None
d = self.authClient.tryAuth('publickey')
def check(result):
self.assertFalse(result)
return d.addCallback(check)
def test_password(self):
"""
Test that the client can authentication with a password. This
includes changing the password.
"""
self.authClient.ssh_USERAUTH_FAILURE(NS('password') + '\x00')
self.assertEquals(self.authClient.transport.packets[-1],
(userauth.MSG_USERAUTH_REQUEST, NS('foo') + NS('nancy')
+ NS('password') + '\x00' + NS('foo')))
self.authClient.ssh_USERAUTH_PK_OK(NS('') + NS(''))
self.assertEquals(self.authClient.transport.packets[-1],
(userauth.MSG_USERAUTH_REQUEST, NS('foo') + NS('nancy')
+ NS('password') + '\xff' + NS('foo') * 2))
def test_no_password(self):
"""
If getPassword returns None, tryAuth should return False.
"""
self.authClient.getPassword = lambda: None
self.assertFalse(self.authClient.tryAuth('password'))
def test_keyboardInteractive(self):
"""
Test that the client can authenticate using keyboard-interactive
authentication.
"""
self.authClient.ssh_USERAUTH_FAILURE(NS('keyboard-interactive')
+ '\x00')
self.assertEquals(self.authClient.transport.packets[-1],
(userauth.MSG_USERAUTH_REQUEST, NS('foo') + NS('nancy')
+ NS('keyboard-interactive') + NS('')*2))
self.authClient.ssh_USERAUTH_PK_OK(NS('')*3 + '\x00\x00\x00\x02'
+ NS('Name: ') + '\xff' + NS('Password: ') + '\x00')
self.assertEquals(self.authClient.transport.packets[-1],
(userauth.MSG_USERAUTH_INFO_RESPONSE, '\x00\x00\x00\x02'
+ NS('foo')*2))
def test_USERAUTH_PK_OK_unknown_method(self):
"""
If C{SSHUserAuthClient} gets a MSG_USERAUTH_PK_OK packet when it's not
expecting it, it should fail the current authentication and move on to
the next type.
"""
self.authClient.lastAuth = 'unknown'
self.authClient.transport.packets = []
self.authClient.ssh_USERAUTH_PK_OK('')
self.assertEquals(self.authClient.transport.packets,
[(userauth.MSG_USERAUTH_REQUEST, NS('foo') +
NS('nancy') + NS('none'))])
def test_USERAUTH_FAILURE_sorting(self):
"""
ssh_USERAUTH_FAILURE should sort the methods by their position
in SSHUserAuthClient.preferredOrder. Methods that are not in
preferredOrder should be sorted at the end of that list.
"""
def auth_firstmethod():
self.authClient.transport.sendPacket(255, 'here is data')
def auth_anothermethod():
self.authClient.transport.sendPacket(254, 'other data')
return True
self.authClient.auth_firstmethod = auth_firstmethod
self.authClient.auth_anothermethod = auth_anothermethod
# although they shouldn't get called, method callbacks auth_* MUST
# exist in order for the test to work properly.
self.authClient.ssh_USERAUTH_FAILURE(NS('anothermethod,password') +
'\x00')
# should send password packet
self.assertEquals(self.authClient.transport.packets[-1],
(userauth.MSG_USERAUTH_REQUEST, NS('foo') + NS('nancy')
+ NS('password') + '\x00' + NS('foo')))
self.authClient.ssh_USERAUTH_FAILURE(
NS('firstmethod,anothermethod,password') + '\xff')
self.assertEquals(self.authClient.transport.packets[-2:],
[(255, 'here is data'), (254, 'other data')])
def test_disconnectIfNoMoreAuthentication(self):
"""
If there are no more available user authentication messages,
the SSHUserAuthClient should disconnect with code
DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE.
"""
self.authClient.ssh_USERAUTH_FAILURE(NS('password') + '\x00')
self.authClient.ssh_USERAUTH_FAILURE(NS('password') + '\xff')
self.assertEquals(self.authClient.transport.packets[-1],
(transport.MSG_DISCONNECT, '\x00\x00\x00\x0e' +
NS('no more authentication methods available') +
'\x00\x00\x00\x00'))
def test_ebAuth(self):
"""
_ebAuth (the generic authentication error handler) should send
a request for the 'none' authentication method.
"""
self.authClient.transport.packets = []
self.authClient._ebAuth(None)
self.assertEquals(self.authClient.transport.packets,
[(userauth.MSG_USERAUTH_REQUEST, NS('foo') + NS('nancy')
+ NS('none'))])
def test_defaults(self):
"""
getPublicKey() should return None. getPrivateKey() should return a
failed Deferred. getPassword() should return a failed Deferred.
getGenericAnswers() should return a failed Deferred.
"""
authClient = userauth.SSHUserAuthClient('foo', FakeTransport.Service())
self.assertIdentical(authClient.getPublicKey(), None)
def check(result):
result.trap(NotImplementedError)
d = authClient.getPassword()
return d.addCallback(self.fail).addErrback(check2)
def check2(result):
result.trap(NotImplementedError)
d = authClient.getGenericAnswers(None, None, None)
return d.addCallback(self.fail).addErrback(check3)
def check3(result):
result.trap(NotImplementedError)
d = authClient.getPrivateKey()
return d.addCallback(self.fail).addErrback(check)
class LoopbackTestCase(unittest.TestCase):
if keys is None:
skip = "cannot run w/o PyCrypto or PyASN1"
class Factory:
class Service:
name = 'TestService'
def serviceStarted(self):
self.transport.loseConnection()
def serviceStopped(self):
pass
def getService(self, avatar, name):
return self.Service
def test_loopback(self):
"""
Test that the userauth server and client play nicely with each other.
"""
server = userauth.SSHUserAuthServer()
client = ClientUserAuth('foo', self.Factory.Service())
# set up transports
server.transport = transport.SSHTransportBase()
server.transport.service = server
server.transport.isEncrypted = lambda x: True
client.transport = transport.SSHTransportBase()
client.transport.service = client
server.transport.sessionID = client.transport.sessionID = ''
# don't send key exchange packet
server.transport.sendKexInit = client.transport.sendKexInit = \
lambda: None
# set up server authentication
server.transport.factory = self.Factory()
server.passwordDelay = 0 # remove bad password delay
realm = Realm()
portal = Portal(realm)
checker = SSHProtocolChecker()
checker.registerChecker(PasswordChecker())
checker.registerChecker(PrivateKeyChecker())
checker.registerChecker(PAMChecker())
checker.areDone = lambda aId: (
len(checker.successfulCredentials[aId]) == 3)
portal.registerChecker(checker)
server.transport.factory.portal = portal
d = loopback.loopbackAsync(server.transport, client.transport)
server.transport.transport.logPrefix = lambda: '_ServerLoopback'
client.transport.transport.logPrefix = lambda: '_ClientLoopback'
server.serviceStarted()
client.serviceStarted()
def check(ignored):
self.assertEquals(server.transport.service.name, 'TestService')
return d.addCallback(check)
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