python socket模块,nmap模块实现端口扫描器以及编码问题

socket模块实现端口扫描器

# -*- coding: utf-8 -*-
# @Author  : Lan126

import optparse
from socket import *
from threading import *

screenLock = Semaphore(value=1)


def connScan(tgtHost, tgtPort):
    try:
        connSkt = socket(AF_INET, SOCK_STREAM)
        connSkt.connect((tgtHost, tgtPort))
        connSkt.send(b"Hello!Baby!!!\r\n")
        results = connSkt.recv(100)
        screenLock.acquire()
        print("[+]%d/tcp open" % tgtPort)
        print("[+] " + results.decode("utf-8"))
        //得到的result为bytes转成str要用utf-8解码
    except Exception as e:
        screenLock.acquire()
        print("[-]%d/tcp closed " % tgtPort)
        print("\n"+str(e))
    finally:
        screenLock.release()
        connSkt.close()


def portScan(tgtHost, tgtPorts):
    try:
        tgtIp = gethostbyname(tgtHost)
    except:
        print("[-] Cannot resolve '%s': Unknown host" % tgtHost)
        return
    try:
        tgtName = gethostbyaddr(tgtIp)
        print("\n[+] Scan Results for: " + tgtName[0])
    except:
        print("\n[+] Scan Results for: " + tgtIp)
    setdefaulttimeout(1)
    for tgtPort in tgtPorts:
        t = Thread(target=connScan, args=(tgtHost, int(tgtPort)))
        t.start()


def main():
    parser = optparse.OptionParser("usage%prog" + "-H <target host> -p <target port>")
    parser.add_option("-H", dest="tgtHost", type="string", help="specify target host")
    parser.add_option("-p", dest="tgtPort", type="string", help="specify target port[s] separated by comma")
    options, args = parser.parse_args()
    tgtHost = options.tgtHost
    tgtPorts = str(options.tgtPort).split(",")
    if (tgtHost is None) | (tgtPorts is None):
        print(parser.usage)
        exit(0)
    portScan(tgtHost, tgtPorts)


if __name__ == "__main__":
    main()

结果图

思路

__optargs__已经没有什么好说的了,这一次的脚本中主要是利用了socket模块
我们首先创建TCP/IP套接字,这是编写进行网络通信应用程序的基础

connSkt = socket(AF_INET, SOCK_STREAM)
connSkt.connect((tgtHost, tgtPort))

利用AF_INET族,SOCK_STREAM类型的socket来实例化一个socket对象
因为选定了AF_INET族,这里的connect函数连接远端时参数为一个tuple,第一个为主机名或ip地址,第二个是端口号为整型
然后利用revc函数接受一定大小的数据,在进行如上操作的过程中,如果产生异常,则判定为端口关闭

细节

gethostbyname函数返回一个Ipv4的字符串,如果本身传入ipv4地址,则直接返回
gethostbyaddr函数返回一个triple,(hostname, aliaslist, ipaddrlist),hostname就是绑定在传入参数的hostname
这里为了能够实现正常的打印操作,必须利用信号量机制,用screenLock.acquire()进行加锁操作,如果信号量被锁上该进程继续执行,其他进程等待.finally块中释放信号量
其中Semaphore(value=1)的value为内置计数器的大小

nmap端口扫描

由于windows平台无法使用nmap模块,这里换成centos操作系统

结果

思路

和上面的实现其实大同小异不过,这里是上面的一个更高级的封装,不过这里得传ip地址和端口号,传主机名会gg

python3编码和字符串

详细讲解
主要是得知道传输或接受到网络或磁盘的的都是bytes对象,转成str要用decode从str到bytes用encode