Python Port Forwarding Proxy Server to redirect HTTP-Requests to different host and/or port, with embedded authentication

port-forwarding-proxy.py

#!/usr/bin/python
#
# PFP 1.0 =-
# Port Forwarding Proxy
#
# This is a port-forwarding proxy.
# It connects to another server:port and returns the received data.
# Useful for server-side redirects to local services or resources.
# So you can hide services from public access, but enable controlled
# access through the proxy.
#
# The embedded authentication module protects the proxy itself against
# unauthorized access. This is only an example implementation, which works
# with 2 plain text URL-Parameters. You can us it, how it is (you shouldn't!),
# you can replace it with your own authentication module or you can disable
# the authentication.
#
# Inspired by: https://gist.github.com/darkwave/52842722c0c451807df4
#
# Jann Westphal 02/2020
#

import sys
import time
import socket
import select

# Socket options
delay = 0.0001
buffer_size = 4096

# Proxy options
proxyPort = 9800
proxyBinding = '0.0.0.0'
proxyForwardTo = ('127.0.0.1', 8081)
proxyAuthentication = False # Re-implement authenticate() and verifyUserAccount(), if used!


class Authenticate:
    #
    # This Authenticate implementation works with 2 parameters:
    # - 2 URL-arguments (uname = User name, upass = User Password)
    # Sample-URL: http://192.168.1.17:9800/?uname=admin&upass=test1234
    #

    def __init__(self):
        self.authenticated = False

    def authenticate(self, clientsock, clientaddr):
        path = self.getHTTPPath(clientsock)
        uname = self.getUNameFromHTTPPath(path)
        upass = self.getUPassFromHTTPPath(path)

        if self.verifyUserAccount(uname, upass, clientaddr[0]):
            self.authenticated = True
            print("Client", clientaddr, "authenticated")

        return self.authenticated
    #
    # TODO Re-implement this method, if you use authentication!
    def verifyUserAccount(self, uname, upass, clientIp):
        return uname == 'admin' and upass == 'test1234'

    # Returns the called URI from http-request
    def getHTTPPath(self, client):
        try:
            req = client.recv(4096)
            path = req.split()[1]
            return path
        except Exception as e:
            print(e)
            return ''

    # Extract argument uname from the called URI
    def getUNameFromHTTPPath(self, path):
        try:
            uname = path[path.rfind('uname=')+6:path.rfind('&upass=')]
            return uname
        except Exception as e:
            print(e)
            return ''

    # Extract argument upass from the called URI
    def getUPassFromHTTPPath(self, path):
        try:
            uid = path[path.rfind('upass=')+6:]
            return uid
        except Exception as e:
            print(e)
            return ''


class Forward:

    def __init__(self):
        self.forward = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    def start(self, host, port):
        try:
            self.forward.connect((host, port))
            print("Forward", [host, port], "connected")
            return self.forward
        except Exception as e:
            print(e)
            return False


class Proxy:

    input_list = []
    channel = {}

    def __init__(self, host, port):
        self.server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.server.bind((host, port))
        self.server.listen(200)

    def main_loop(self):
        self.input_list.append(self.server)
        while 1:
            time.sleep(delay)
            ss = select.select
            inputready, outputready, exceptready = ss(self.input_list, [], [])
            for self.s in inputready:
                if self.s == self.server:
                    self.on_accept()
                    break

                try:
                    self.data = self.s.recv(buffer_size)
                    if len(self.data) == 0:
                        self.on_close()
                        break
                    else:
                        self.on_recv()

                except Exception as e:
                    print(e)
                    self.on_close()
                    break

    def on_accept(self):
        clientsock, clientaddr = self.server.accept()

        authenticated = not proxyAuthentication
        if not authenticated:
            authenticated = Authenticate().authenticate(clientsock, clientaddr)
        else:
            print("Connecting client", clientaddr, "without authentication")

        if authenticated:
            forward = Forward().start(proxyForwardTo[0], proxyForwardTo[1])
            if forward:
                print("Client", clientaddr, "connected")
                self.input_list.append(clientsock)
                self.input_list.append(forward)
                self.channel[clientsock] = forward
                self.channel[forward] = clientsock
            else:
                print("Can't establish connection with remote server")
                print("Closing connection with client", clientaddr)
                clientsock.close()
        else:
            print("Client", clientaddr, "not authenticated")
            print("Rejecting connection from", clientaddr)
            clientsock.close()

    def on_close(self):
        try:
            print(self.s.getpeername(), "disconnected")
        except Exception as e:
            print(e)
            print("Client closed")

        self.input_list.remove(self.s)
        self.input_list.remove(self.channel[self.s])
        out = self.channel[self.s]
        self.channel[out].close()  # equivalent to do self.s.close()
        self.channel[self.s].close()
        del self.channel[out]
        del self.channel[self.s]

    def on_recv(self):
        data = self.data
        # print data
        self.channel[self.s].send(data)


if __name__ == '__main__':

    print(' * PFP 1.0 =-')
    print(' * Port Forwarding Proxy')
    proxy = Proxy(proxyBinding, proxyPort)
    print(' * Listening on: ' + str(proxyBinding) + ' : ' + str(proxyPort))
    print(' * Forwarding to: ' + str(proxyForwardTo[0]) + ' : ' + str(proxyForwardTo[1]))
    if proxyAuthentication:
        print(' * Authentication: enabled')
    else:
        print(' * Authentication: disabled')
    try:
        proxy.main_loop()
    except KeyboardInterrupt:
        print("Ctrl C - Stopping server")
        sys.exit(1)

I am making the request like this curl -x "http://username:password@localhost:9800" -k "http://httpbin.org/ip". But this is not working. Can you help?