from twisted.conch import error
from twisted.conch.ssh import transport, connection, keys, userauth, channel, common
from twisted.internet import defer, protocol, reactor

class ClientCommandTransport(transport.SSHClientTransport):
    def __init__(self, username, password, command):
        self.username = username
        self.password = password
        self.command = command

    def verifyHostKey(self, pubKey, fingerprint):
        # in a real app, you should verify that the fingerprint matches
        # the one you expected to get from this server
        return defer.succeed(True)

    def connectionSecure(self):
        self.requestService(
            PasswordAuth(self.username, self.password,
                         ClientConnection(self.command)))

class PasswordAuth(userauth.SSHUserAuthClient):
    def __init__(self, user, password, connection):
        userauth.SSHUserAuthClient.__init__(self, user, connection)
        self.password = password

    def getPassword(self, prompt=None):
        return defer.succeed(self.password)

class ClientConnection(connection.SSHConnection):
    def __init__(self, cmd, *args, **kwargs):
        connection.SSHConnection.__init__(self)
        self.command = cmd

    def serviceStarted(self):
        self.openChannel(CommandChannel(self.command, conn=self))

class CommandChannel(channel.SSHChannel):
    name = 'session'

    def __init__(self, command, *args, **kwargs):
        channel.SSHChannel.__init__(self, *args, **kwargs)
        self.command = command

    def channelOpen(self, data):
        self.conn.sendRequest(
            self, 'exec', common.NS(self.command), wantReply=True).addCallback(
            self._gotResponse)

    def _gotResponse(self, _):
        self.conn.sendEOF(self)

    def dataReceived(self, data):
        print data

    def closed(self):
        reactor.stop()

class ClientCommandFactory(protocol.ClientFactory):
    def __init__(self, username, password, command):
        self.username = username
        self.password = password
        self.command = command

    def buildProtocol(self, addr):
        protocol = ClientCommandTransport(
            self.username, self.password, self.command)
        return protocol

if __name__ == "__main__":
    import sys, getpass
    server = sys.argv[1]
    command = sys.argv[2]
    username = raw_input("Username: ")
    password = getpass.getpass("Password: ")
    factory = ClientCommandFactory(username, password, command)
    reactor.connectTCP(server, 22, factory)
    reactor.run()