import socketimport paramikoimport threadingimport syshost_key = paramiko.RSAKey(filename='test_rsa.key')class Server(paramiko.ServerInterface):    def __init__(self):        self.event = threading.Event()    def check_channel_request(self,kind,chanid):        if kind == 'session':            return paramiko.OPEN_SUCCEEDED        return paramiko.OPEN_FATLED_ADMINISTRATIVELY_PROHIBITED    def check_auth_password(self,username,password):        if(username == 'justin') and (password == 'lovesthepython'):            return paramiko.AUTH_SUCCESSFUL        return paramiko.AUTH_FAILEDserver = sys.argv[1]ssh_port = int(sys.argv[2])try:    sock = socket.socket(socket.AF_INET,socket.SOCK_STREAM)    sock.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)    sock.bind((server,ssh_port))    sock.listen(100)    print '[+] Listening for connection ...'    client,addr = sock.accept()except Exception,e:    print '[-] Listen failed: '+ str(e)    sys.exit(1)print '[+] Got a connection!'try:    bhSession = paramiko.Transport(client)    bhSession.add_server_key(host_key)    server = Server()    try:        bhSession.start_server(server=server)    except paramiko.SSHExecption,x:        print '[-] SSH negotiation failed.'    chan = bhSession.accept(20)    print '[+] Authenticated!'    print chan.recv(1024)    chan.send('Welcome to bh_ssh')    while True:        try:            command = raw_input("Enter command:").strip('\n')            if command != 'exit':                chan.send(command)                print chan.recv(1024)+'\n'            else:                chan.send('exit')                print 'exiting'                bhSession.close()                raise Exception ('exit')        except KeyboardInterrupt:            bhSession.close()except Exception,e:    print '[-] Caught exception:'+str(e)    try:        bhSession.close()    except:        pass    sys.exit(1)