Documentation

ProxyCheck

The Python script implements a basic SOCKS (Socket Secure) proxy client, specifically SOCKS4 and SOCKS5. It connects to a specified SOCKS proxy server, measures the time taken for connections, and handles error responses from the SOCKS server. Below is a detailed explanation of the code sections:

Imports and Setup

from socket import socket, AF_INET, SOCK_STREAM, inet_aton, getaddrinfo, inet_pton, SOL_TCP
from string import ascii_letters
from random import choice
from time import perf_counter
import sys

• The code imports necessary modules for socket programming, string manipulation, random selections, time measurements, and system-level operations.

Socket Reading Function

def sock_read(sock, n):
    b = "" 
    i = 0  
    while (i < n): 
        c = sock.recv(n - i) 
        if (len(c) < 1): 
            raise Exception("Closed socket") 
        b += c      
        i += len(c) 
    return b 

• sock_read(sock, n): Reads n bytes from a socket. It keeps reading until it has received the full amount or the socket is closed.

Address Conversion

def str2host(addr, ipv=4):
    for i in ascii_letters: 
        if i in addr[0]: 
            d = getaddrinfo(addr[0], addr[1], 0, 0, SOL_TCP)
            for j in d:
                if (len(j[-1]) == 2) and (ipv == 4): 
                    return inet_aton(j[-1][0])
                elif (len(j[-1]) == 4) and (ipv == 6): 
                    return inet_pton(AF_INET6, j[-1][0])
            raise Exception("Host not found")
    return inet_aton(addr[0])

• str2host(addr, ipv=4): Converts a hostname to an IP address. Uses getaddrinfo to resolve the hostname and handles both IPv4 and IPv6.

Conversion Helper

def uint16str(n):
    data = [] 
    data.append(chr(n & 255)) 
    n >>= 8 
    data.append(chr(n & 255)) 
    data.reverse() 
    return ''.join(data)

• uint16str(n): Converts a 16-bit integer to a two-character string representation.

SOCKS4 and SOCKS5 Error Handling

def SOCKS4_ex(ans):
    s4_ex = { ... }
    try:
        raise Exception(s4_ex[ord(ans)]) 
    except KeyError:
        raise Exception("Unknown error code #" + str(ord(ans)))

def SOCKS5_ex(ans):
    s5_ex = { ... }
    try:
        raise Exception(s5_ex[ord(ans)]) 
    except KeyError:
        raise Exception("Unknown error code #" + str(ord(ans)))

• SOCKS4_ex(ans) and SOCKS5_ex(ans): Functions to handle specific errors returned by the SOCKS server for SOCKS4 and SOCKS5, respectively. They raise exceptions with descriptive error messages.

SOCKS Proxy Connection

def SOCKS_hop(sock, addr, proto=4, ipv=4):
    if (proto == 4): 
        ...
    elif (proto == 5): 
        ...
    else: 
        raise Exception("Unknown SOCKS version")

• SOCKS_hop(sock, addr, proto=4, ipv=4): This function handles the connection to the SOCKS server based on the specified protocol (SOCKS4 or SOCKS5). It sends the appropriate request and checks for errors.

Main Execution Block

if __name__ == "__main__":
    pass

• The script checks if it's being run as the main module.

Reading from Input Files

check_host = "74.125.230.84" # IP www.google.com
check_port = 80

timings = {}
plist = []
i = 1
while (i < len(sys.argv)):
    f = open(sys.argv[i], "rt")
    ...
    s.close()
    f.close()
    i += 1

timed = sorted(timings, key=lambda key: timings[key])
for i in timed:
    print(i)

• The script takes input files as command line arguments. Each file is expected to contain addresses (IP:port) for SOCKS servers. It connects to each server, measures the time taken to connect, and performs a SOCKS hop to a specified check host (Google's IP). It then sorts the timings and prints the results.

Summary

• This Python script connects to specified SOCKS proxies, measures how long it takes to establish a connection, and handles any errors that arise during the process. It is useful for testing the availability and performance of SOCKS proxies.