black hat python中tcp代理的python3實現

由於black hat python中的代碼是採用python2實現的，而python2已經太過久遠了，所以用python3實現了一遍，算是複習了一下socket編程的基礎部分。其中hexdump函數很有意思，由於寫的時候忘掉了bytes相關的東西，所以借鑑了某位大佬的代碼，當然實現的效果還不錯，很像一些16進制編輯器讀取的樣子。

#!/usr/local/bin/python3
import sys
import socket
import threading

def server_loop(local_host,local_port,remote_host,remote_port,receive_first):
    
    server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)

    try:
        server.bind((local_host,local_port))
    except:
        print("[!] Failed to listen on %s:%d." % (local_host,local_port))
        print("[!] Check for other listening sockets or correct permissions.")
        sys.exit(0)

    print("[*] Listening on %s:%d" % (local_host,local_port))

    server.listen(5)

    while True:
        client_socket, addr = server.accept()

        print("[==>] Received incoming connection from %s:%d" % (addr[0],addr[1]))
        proxy_thread = threading.Thread(target=proxy_handler,args=(client_socket,remote_host,remote_port,receive_first))

        proxy_thread.start()

def main():
    if len(sys.argv[1:]) != 5:
        print("Usage: ./proxy.py [local_host][local_port][remote_host][remote_port][receive_first]")
        print("Example: ./proxy.py 127.0.0.1 9000 10.12.132.1 9000 True")
        sys.exit(0)

    #設置本地監聽參數
    local_host = sys.argv[1]
    local_port = int(sys.argv[2])

    #設置遠程主機參數
    remote_host = sys.argv[3]
    remote_port = int(sys.argv[4])

    receive_first = sys.argv[5]

    if "True" in receive_first:
        receive_first = True
    else:
        receive_first = False
    
    server_loop(local_host,local_port,remote_host,remote_port,receive_first)

def proxy_handler(client_socket,remote_host,remote_port,receive_first):
    remote_socket = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    remote_socket.connect((remote_host,remote_port))

    if receive_first:
        remote_buffer = receive_from(remote_socket)
        hexdump(remote_buffer)

        remote_buffer = response_handler(remote_buffer)

        if len(remote_buffer):
            print("[<==] Sending %d bytes to localhost." % len(remote_buffer))
            client_socket.send(remote_buffer)
    
    while True:
        #從本地讀取數據        
        local_buffer = receive_from(client_socket)
        
        if len(local_buffer):
            print("[==>] Received %d bytes from localhost." % len(local_buffer))
            hexdump(local_buffer)

            local_buffer = request_handler(local_buffer)

            remote_socket.send(local_buffer)
            print("[==>] Sent to remote.")
        
        #從遠程主機讀取數據
        remote_buffer = receive_from(remote_socket)

        if len(remote_buffer):
            print("[<==] Received %d bytes from remote." % len(remote_buffer))
            hexdump(remote_buffer)

            remote_buffer = response_handler(remote_buffer)
            
            client_socket.send(remote_buffer)
            print("[==>] Sent to client.")

        if not len(local_buffer) and not len(remote_buffer):
            client_socket.close()
            remote_socket.close()
            print("No more data. Closing connections.")
            break

def hexdump(src,length = 16):
    result = []
    digits = 2 if isinstance(src,str) else 4

    for i in range(0, len(src),length):
        s = src[i:i+length]
        hexa = ' '.join([hex(x)[2:].upper().zfill(digits) for x in s])
        text = ''.join([chr(x) if 0x20 <= x < 0x7F else '.' for x in s])
        result.append("{0:04X}".format(i) + ' ' * 4 + hexa.ljust(length * (digits + 1)) + ' ' * 4 + "{0}".format(text))
    for i in result:
        print(i)

def receive_from(connection):
    buffer = ""
    connection.settimeout(2)

    try:
        while True:
            data = connection.recv(4096)
            print(type(data))
            if not data:
                break

            data = bytes.decode(data)
            buffer += data
            buffer = str.encode(buffer) 
    except:
        pass

    return buffer

def request_handler(buffer):
    return buffer

def response_handler(buffer):
    return buffer

main()

用curl測試比較好，瀏覽器代理會失敗，原因還未知。