/usr/lib/python2.7/dist-packages/twisted/conch/ssh/factory.py is in python-twisted-conch 1:14.0.2-3.
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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 | # Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
A Factory for SSH servers, along with an OpenSSHFactory to use the same
data sources as OpenSSH.
Maintainer: Paul Swartz
"""
from twisted.internet import protocol
from twisted.python import log
from twisted.conch import error
import transport, userauth, connection
import random
class SSHFactory(protocol.Factory):
"""
A Factory for SSH servers.
"""
protocol = transport.SSHServerTransport
services = {
'ssh-userauth':userauth.SSHUserAuthServer,
'ssh-connection':connection.SSHConnection
}
def startFactory(self):
"""
Check for public and private keys.
"""
if not hasattr(self,'publicKeys'):
self.publicKeys = self.getPublicKeys()
if not hasattr(self,'privateKeys'):
self.privateKeys = self.getPrivateKeys()
if not self.publicKeys or not self.privateKeys:
raise error.ConchError('no host keys, failing')
if not hasattr(self,'primes'):
self.primes = self.getPrimes()
def buildProtocol(self, addr):
"""
Create an instance of the server side of the SSH protocol.
@type addr: L{twisted.internet.interfaces.IAddress} provider
@param addr: The address at which the server will listen.
@rtype: L{twisted.conch.ssh.SSHServerTransport}
@return: The built transport.
"""
t = protocol.Factory.buildProtocol(self, addr)
t.supportedPublicKeys = self.privateKeys.keys()
if not self.primes:
log.msg('disabling diffie-hellman-group-exchange because we '
'cannot find moduli file')
ske = t.supportedKeyExchanges[:]
ske.remove('diffie-hellman-group-exchange-sha1')
t.supportedKeyExchanges = ske
return t
def getPublicKeys(self):
"""
Called when the factory is started to get the public portions of the
servers host keys. Returns a dictionary mapping SSH key types to
public key strings.
@rtype: C{dict}
"""
raise NotImplementedError('getPublicKeys unimplemented')
def getPrivateKeys(self):
"""
Called when the factory is started to get the private portions of the
servers host keys. Returns a dictionary mapping SSH key types to
C{Crypto.PublicKey.pubkey.pubkey} objects.
@rtype: C{dict}
"""
raise NotImplementedError('getPrivateKeys unimplemented')
def getPrimes(self):
"""
Called when the factory is started to get Diffie-Hellman generators and
primes to use. Returns a dictionary mapping number of bits to lists
of tuple of (generator, prime).
@rtype: C{dict}
"""
def getDHPrime(self, bits):
"""
Return a tuple of (g, p) for a Diffe-Hellman process, with p being as
close to bits bits as possible.
@type bits: C{int}
@rtype: C{tuple}
"""
primesKeys = self.primes.keys()
primesKeys.sort(lambda x, y: cmp(abs(x - bits), abs(y - bits)))
realBits = primesKeys[0]
return random.choice(self.primes[realBits])
def getService(self, transport, service):
"""
Return a class to use as a service for the given transport.
@type transport: L{transport.SSHServerTransport}
@type service: C{str}
@rtype: subclass of L{service.SSHService}
"""
if service == 'ssh-userauth' or hasattr(transport, 'avatar'):
return self.services[service]
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