使用Python的TCP代理
我正在学习并试图理解TCP代理代码 我现在几乎明白了,但是当我试着用使用Python的TCP代理,python,sockets,tcp,Python,Sockets,Tcp,我正在学习并试图理解TCP代理代码 我现在几乎明白了,但是当我试着用 python proxy.py localhost 21 ftp.target.ca 21 True 在一个终端和 ftp ftp.target.ca 21 另一方面 在第一个终端中,我只在端口21上的本地主机上侦听,其他什么都没有;在第二个终端,是我和服务器之间的连接,我写了用户名和密码 在我和服务器之间传输的包应该出现在第一个终端中 我做错了什么 代码如下: import sys import socket impor
python proxy.py localhost 21 ftp.target.ca 21 True
在一个终端和
ftp ftp.target.ca 21
另一方面
在第一个终端中,我只在端口21上的本地主机上侦听,其他什么都没有;在第二个终端,是我和服务器之间的连接,我写了用户名和密码
在我和服务器之间传输的包应该出现在第一个终端中
我做错了什么
代码如下:
import sys
import socket
import threading
# this is a pretty hex dumping function directly taken from
# http://code.activestate.com/recipes/142812-hex-dumper/
def hexdump(src, length=16):
result = []
digits = 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 = ""
# We set a 2 second time out depending on your
# target this may need to be adjusted
connection.settimeout(2)
try:
# keep reading into the buffer until there's no more data
# or we time out
while True:
data = connection.recv(4096)
if not data:
break
buffer += data
except:
pass
return buffer
# modify any requests destined for the remote host
def request_handler(buffer):
# perform packet modifications
return buffer
# modify any responses destined for the local host
def response_handler(buffer):
# perform packet modifications
return buffer
def proxy_handler(client_socket, remote_host, remote_port, receive_first):
# connect to the remote host
remote_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
remote_socket.connect((remote_host,remote_port))
# receive data from the remote end if necessary
if receive_first:
remote_buffer = receive_from(remote_socket)
hexdump(remote_buffer)
# send it to our response handler
remote_buffer = response_handler(remote_buffer)
# if we have data to send to our local client send it
if len(remote_buffer):
print "[<==] Sending %d bytes to localhost." % len(remote_buffer)
client_socket.send(remote_buffer)
# now let's loop and reading from local, send to remote, send to local
# rinse wash repeat
while True:
# read from local host
local_buffer = receive_from(client_socket)
if len(local_buffer):
print "[==>] Received %d bytes from localhost." % len(local_buffer)
hexdump(local_buffer)
# send it to our request handler
local_buffer = request_handler(local_buffer)
# send off the data to the remote host
remote_socket.send(local_buffer)
print "[==>] Sent to remote."
# receive back the response
remote_buffer = receive_from(remote_socket)
if len(remote_buffer):
print "[<==] Received %d bytes from remote." % len(remote_buffer)
hexdump(remote_buffer)
# send to our response handler
remote_buffer = response_handler(remote_buffer)
# send the response to the local socket
client_socket.send(remote_buffer)
print "[<==] Sent to localhost."
# if no more data on either side close the connections
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 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 out the local connection information
print "[==>] Received incoming connection from %s:%d" % (addr[0],addr[1])
# start a thread to talk to the remote host
proxy_thread = threading.Thread(target=proxy_handler,args=(client_socket,remote_host,remote_port,receive_first))
proxy_thread.start()
def main():
# no fancy command line parsing here
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)
# setup local listening parameters
local_host = sys.argv[1]
local_port = int(sys.argv[2])
# setup remote target
remote_host = sys.argv[3]
remote_port = int(sys.argv[4])
# this tells our proxy to connect and receive data
# before sending to the remote host
receive_first = sys.argv[5]
if "True" in receive_first:
receive_first = True
else:
receive_first = False
# now spin up our listening socket
server_loop(local_host,local_port,remote_host,remote_port,receive_first)
main()
导入系统
导入套接字
导入线程
#这是一个非常漂亮的十六进制转储函数,直接取自
# http://code.activestate.com/recipes/142812-hex-dumper/
def hexdump(src,长度=16):
结果=[]
如果isinstance(src,unicode)为2,则数字=4
对于X范围内的i(0,长度(src),长度):
s=src[i:i+长度]
hexa=b“”。为s中的X连接([%0*X”%(数字,ord(X)))
text=b“”。加入([x如果0x20仅在端口21上运行代理服务器不会使ftp客户端使用它-因此您不应该尝试连接到远程主机。如果命令行在例如9000上运行代理,则ftp将发送到该端口,即本地主机9000,代理将转发到该远程主机的通信。我将ftp端口更改为1234在proftpd.conf中,这就是您的意思,什么也不发生我编写了python proxy.py localhost 1234 ftp.target.ca 21 True和相同的结果,而不是ftp ftp.target.ca 21执行ftp localhost 21(假设您在同一主机上运行代理)因为proxy.py命令行告诉它将端口21转发到ftp.target.calike this python proxy.py localhost 1234 localhost 1234 True并在另一个终端ftp localhost 1234中?它或我是如何理解错误的no.python proxy.py localhost 1234 ftp.target.ca 21 True并在同一主机ftp localhost 1234上的另一个终端中如何侦听同一端口两次,同时本地主机1234将在1234上侦听,本地主机(服务器)将在同一端口上侦听,并对我说端口为busyHi@AN HA。此代码的许可证是什么?