python 实现 netcat

import sys
import socket
import getopt
import threading
import subprocess
listen = False
command = False
upload = False
execute = ""
target = ""
upload_destination = ""
port = 0

def usage():
    print "BHP Net Tool"
    print
    print "Usage: bhpnet.py -t target_host -p port"
    print "-l --listen -listen on [host]:[port] for incoming connections"
    print "-e --execute=file_to_run -execute the given file uponreceiving a connection"
    print "-c --command - initialize a command shell"
    print "-u --upload=destination - upon receiveing connection upload a file and write to [destination]"
    print
    print
    print "Examples:"
    print "bhpnet.py -t 192.168.0.1 -p 5555 -l -c"
    print "bhpnet.py -t 192.168.0.1 -p 5555 -l -u=c:\\target.exe"
    print "echo 'ABCDEFGHI' | ./bhpnet.py -t 192.168.11.12 -p 135"
    sys.exit(0)
def main():
    global listen
    global port
    global execute
    global command
    global upload_destination
    global target

    if not len(sys.argv[1:]):
        usage()
    try:
        opts,args = getopt.getopt(sys.argv[1:],"hle:t:p:cu:",["help","listen","execute","port","command","upload"])
    except getopt.GetoptError as err:
        print str(err)
        usage()
    for o,a in opts:
        if o in ("-h","--help"):
            usage()
        elif o in ("-l","--listen"):
            listen = True
        elif o in ("-e","--execute"):
            execute = a
        elif o in ("-c","--commandshell"):
            command = True
        elif o in ("-u","--upload"):
            upload_destination = a
        elif o in ("-t","--target"):
            target = a
        elif o in ("-p","--port"):
            port = int(a)
        else:
            assert False,"unhanded Option"
    if not listen and len(target) and port > 0:
        buffer = sys.stdin.read()
        client_sender(buffer)
    if listen:
        server_loop()
main()
def client_sender(buffer):
    client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    try:
        client.connect((target,port))
        if len(buffer):
            client.send(buffer)
        while True:
            recv_len = 1
            response = ""
            while recv_len:
                data = client.recv(4096)
                recv_len = len(data)
                response += data

                if recv_len < 4096:
                    break
            print response,
            buffer = raw_input("")
            buffer += "\n"
            client.send(buffer)
    except:
        print "[*] Exception! Exiting."
        client.close()
def server_loop():
    global target
    if not len(target):
        target = "0.0.0.0"
    server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    server.bind((target,port))
    server.listen(5)

    while True:
        client_socket,addr = server.accept()
        client_thread = threading.Thread(target=client_handler,args=(client_socket,))
        client_thread.start()
def run_command(command):
    command = command.rstrip()
    try:
        output = subprocess.check_output(command,stderr=subprocess.STDOUT,shell=True)
    except:
        output = "Failed to execute command.\r\n"
    return output
def client_handler(client_soket):
    global upload
    global execute
    global command

    if len(upload_destination):
        file_buffer = ""
        while True:
            data = client_soket.recv(4096)
            if not data:
                break
            else:
                file_buffer += data
        try:
            file_description = open(upload_destination,"wb")
            file_description.write(file_buffer)
            file_description.close()
            client_soket.send("Successfully saved file to %s\r\n" % upload_destination)
        except:
            client_soket.send("Failed to save file to %s\r\n" % upload_destination)
    if len(execute):
        output = run_command(execute)
        client_soket.send(output)
    if command:
        while True:
            client_soket("<BHP:#>")
            cmd_buffer = ""
            while "\n" not in cmd_buffer:
                cmd_buffer += client_soket.recv(1024)
            response = run_command(cmd_buffer)
            client_soket.send(response)