twisted/plugins/cred_sshkeys.py

   1 # -*- test-case-name: twisted.test.test_strcred -*-
   2 #
   3 # Copyright (c) Twisted Matrix Laboratories.
   4 # See LICENSE for details.
   5
   6 """
   7 Cred plugin for ssh key login
   8 """
   9
  10 from zope.interface import implements
  11
  12 from twisted import plugin
  13 from twisted.cred.strcred import ICheckerFactory
  14 from twisted.cred.credentials import ISSHPrivateKey
  15
  16
  17 sshKeyCheckerFactoryHelp = """
  18 This allows SSH public key authentication, based on public keys listed in
  19 authorized_keys and authorized_keys2 files in user .ssh/ directories.
  20 """
  21
  22
  23 try:
  24     from twisted.conch.checkers import SSHPublicKeyDatabase
  25
  26     class SSHKeyCheckerFactory(object):
  27         """
  28         Generates checkers that will authenticate a SSH public key
  29         """
  30         implements(ICheckerFactory, plugin.IPlugin)
  31         authType = 'sshkey'
  32         authHelp = sshKeyCheckerFactoryHelp
  33         argStringFormat = 'No argstring required.'
  34         credentialInterfaces = SSHPublicKeyDatabase.credentialInterfaces
  35
  36
  37         def generateChecker(self, argstring=''):
  38             """
  39             This checker factory ignores the argument string. Everything
  40             needed to authenticate users is pulled out of the public keys
  41             listed in user .ssh/ directories.
  42             """
  43             return SSHPublicKeyDatabase()
  44
  45
  46
  47     theSSHKeyCheckerFactory = SSHKeyCheckerFactory()
  48
  49 except ImportError:
  50     # if checkers can't be imported, then there should be no SSH cred plugin
  51     pass