need PHP Help for Base64 decode

[gorance]

I have implemented the base64_encode() function with some custom  mapping table so I could encode some binary data more securely without anyone knowing how to decode it

here is the class

<?php 

class Base64 {
    
    /**
     * I have changed letter placement (P <=> x, S <=> 9) and the cases
     * You can completely redo the mapping table
     */

    private static $BinaryMap = array(
        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', //  7
        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'x', // 15
        'q', 'r', '9', 't', 'u', 'v', 'w', 'x', // 23
        'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', // 31
        'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', // 39
        'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', // 47
        'W', 'P', 'Y', 'Z', '0', '1', '2', '3', // 55
        '4', '5', '6', '7', '8', 'S', '+', '/', // 63 
        '=',  // padding char
    );
    
    public function __construct() {}
    
    public function base64_encode($input) {
        
        $output = "";
        $chr1 = $chr2 = $chr3 = $enc1 = $enc2 = $enc3 = $enc4 = null;
        $i = 0;
        
//        $input = self::utf8_encode($input);
        
        while($i < strlen($input)) {
            $chr1 = ord($input[$i++]);
            $chr2 = ord($input[$i++]);
            $chr3 = ord($input[$i++]);
            
            $enc1 = $chr1 >> 2;
            $enc2 = (($chr1 & 3) << 4) | ($chr2 >> 4);
            $enc3 = (($chr2 & 15) << 2) | ($chr3 >> 6);
            $enc4 = $chr3 & 63;
            
            if (is_nan($chr2)) {
                $enc3 = $enc4 = 64;
            } else if (is_nan($chr3)) {
                $enc4 = 64;
            }
            
            $output .=  self::$BinaryMap[$enc1]
                      . self::$BinaryMap[$enc2]
                      . self::$BinaryMap[$enc3]
                      . self::$BinaryMap[$enc4]; 
        }
        
        return $output;
    }
    
    public function utf8_encode($input) {
        $utftext = null;
        
        for ($n = 0; $n < strlen($input); $n++) {

            $c = ord($input[$n]);
            
            if ($c < 128) {
                $utftext .= chr($c);
            } else if (($c > 128) && ($c < 2048)) {
                $utftext .= chr(($c >> 6) | 192);
                $utftext .= chr(($c & 63) | 128);
            } else {
                $utftext .= chr(($c >> 12) | 224);
                $utftext .= chr((($c & 6) & 63) | 128);
                $utftext .= chr(($c & 63) | 128);
            }
        }
        
        return $utftext;
    }
}

?>

and the usage as follows:

<?php
$string = pack('H*', "31c85c5aaa56c1f0102301ea497d0ab010e4e131af261787"); //HEX

echo Base64::base64_encode($string);
echo "<br />";
echo base64_encode($string);
?>

and the output will be:

mCHCwQPwWFaqiWhQ9x0kSbdK4tgVjHEh   //  with custom mapping
MchcWqpWwfAQIwHqSX0KsBDk4TGvJheH   //  the base64_encode() 

 

I need help how to decode the this key

[gorance]

i use this to decode base64 code its work only for base64

bat dont work to decode this

mCHCwQPwWFaqiWhQ9x0kSbdK4tgVjHEh  //  with custom mapping

 

<?
$id = base64_decode($_GET["channel"]);
$fp = FOpen ("bolt.txt", "r");
$blem = FRead ($fp, FileSize ("bolt.txt"));
$id = str_replace ("\n", " ", $id);
$id = str_replace ("SELECT", " ", $id);
$id = str_replace ("FROM", " ", $id);
$id = str_replace ("select", " ", $id);
$id = str_replace ("from", " ", $id);
$id = str_replace (">", ">", $id);
$id = str_replace ("<", "<", $id);
$stream = base64_decode("proxy list URL");
$kontrola_funkcnosti_odkazu = file_get_contents("$stream");
$adresa = StrChr($id, "|");
$adresa = str_replace ("|", "", $adresa);
$heslo = current(explode("|", $id, 2));
if (($heslo==$blem) AND ($kontrola_funkcnosti_odkazu=="OK")){
header('Content-type: application/octet-stream');
$q = "$adresa";
readfile ($q);
}
else{
header('Content-type: application/octet-stream');
$q = "http://stramlink/Intro.mp4";
readfile ($q);
}
?>