用python模拟的ssh系统，只能验证登陆，别的功能暂时没有。版本定为0.1把，以后慢慢改进。

import socket
host=''
port=4444
addr=(host,port)
ss=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
ss.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
ss.bind(addr)
ss.listen(5)
while True:
    clientsock,clientaddr=ss.accept()
    while True:
        clientsock.send('user:')
        data=clientsock.recv(4096)
        print data
        while data.strip()!='root':
            clientsock.send('user:')
            data=clientsock.recv(4096)
            print data
        clientsock.send('pass:')
        data=clientsock.recv(4096)
        print data
        while data.strip()!='111111':
            clientsock.send('pass:')
            data=clientsock.recv(4096)
            print data
        clientsock.send('login success!!!\n')
        clientsock.close()
        break