proxy_https.py

import sys
import socket
import threading

#這是直接從下列網址註解中取得的16進位美觀傾印函式:
#http://code.activestate.com/recipes/142812-hex-dumper/

def hexdump(src,length=16):
    result =[]
    digths = 4 if isinstance(src,unicode) else 2
    for i in xrange(0,len(src),length):
        s=src[i:i+length]
        hexa = b''.join(["%0*X"%(digits,ord(x))for x in s])
        text = b''.join([x if 0x20 <= ord(x) < 0x7F else b'.'for x in s])
        result.append(b"%04X %-*s %s"%(i,length*(digits+1),hexa,text))
        print(b'\n'.join(result))

def receive_from(connection):

    buffer = ""

    #我們設定2秒timeout
    #這可能須要根據您的測試對象調整
    connection.settimeout(2)

    try:
            #持續讀取 buffer 直到沒有資料
            #或是timeout
        while True:
            data =connection.recv(4096)

            if not data:

                    break
            buffer += data
    except:
            pass
    return buffer

#修改要傳到遠端的要求
def request_handler(buffer):
    #進行修改動作
    return buffer

#修改傳回本機的資料
def response_handler(buffer):
   #進行修改動作
    return buffer

def proxy_handle(client_socket,remote_host,remote_port,receive_first):

    #連接遠端主機
    remote_socket=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    remote_socket.connect((remote_host,remote_port))

    #如果有需要，先從遠端主機接收資料
    if receive_first:

        remote_buffer = receive_from(remote_socket)
        hexdump(remote_buffer)

        #送到處理回應的函式
        remote_buffer = response_handler(remote_buffer)

        #如果有資料要回傳，就回傳
        if len(remote_buffer):
            print("[<==]Sending %d bytes to localhost."% len(remote_buffer))
            client_socket.send(remote_buffer)

    #然後進入迴圈並從本機讀取
        #送到遠端，送回本機
    #反覆不斷
    while True:

        #從本機讀取
        local_buffer = receive_from(client_socket)

        if len(local_buffer):

            print ("[==> Receivd %d bytes from localhost.]" % len(local_buffer))
            hexdump(local_buffer)

            #送到處理請求的函式
            local_buffer = request_handler(local_buffer)

            #把資料傳送到遠端
            remote_socket.send(local_buffer)
            print("[==>]Sent to remote.")

        #接收回應
        remote_buffer = receive_from(remote_socket)

        if len(remote_buffer):

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

            #送到處理回應的函式
            remote_buffer = response_handler(remote_buffer)

            #把回應送回本機socket
            client_socket.send(remote_buffer)

            print("[<==] Sent to localhost.")
            
        #如果兩邊都沒有後續資料，就關掉連線

        if not len(local_buffer) or not len(remote_buffer):

            client_socket.close()
            remote_socket.close()
            print("[*] No more data. Closing connections.")

            break

    
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 corrent permissions.")
        sys.exit(0)

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

    server.listen(5)

    while True:

        client_socket,addr = server.accept()  #客戶端連線addr=server.accept()

        #顯示本機連線資訊
        print("[==>] Received incoming connection from %s:%d" % (addr[0],addr[1]))

        #啟動一個thread 與遠端溝通

        proxy_thread = threading.Thread(target=proxy_handler,args=(client_socket,remote_host,remote_port,receive_first))

        proxy_thread.start()

def main():
    #沒有華麗的命令列解釋
    if len(sys.argv[1:])!= 5:
        print("Usage: ./proxy.py [localhost] [localport] [remotehost] [remoteport] [receive_first]")
        print("Example: ./proxy.py 127.0.0.1 9000 10.12.132.1 9000 True ")
        sys.exit(0)
    #設定本機監聽資訊
    local_host = sys.argv[1]
    local_port = int(sys.argv[2])

    #設定遠端資訊
    remote_host = sys.argv[3]
    remote_port = int(sys.argv[4])

    #這告訴我們的proxy 先連上遠端主機、接收資料
    #傳回來
    receive_first = sys.argv[5]

    if "True" in receive_first:
        receive_first = True
    else:
        receive_first = False

    #然後建立我們監聽用socket

    server_loop(local_host,local_port,remote_host,remote_port,receive_first)

main()