decodeBase58.php

php

function decodeBase58($input) {
        $alphabet = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
 
        $out = array_fill(0, 25, 0);
        for($i=0;$i<strlen($input);$i++){
                if(($p=strpos($alphabet, $input[$i]))===false){
                        return false;
                }
                $c = $p;
                for ($j = 25; $j--; ) {
                        $c += (int)(58 * $out[$j]);
                        $out[$j] = (int)($c % 256);
                        $c /= 256;
                        $c = (int)$c;
                }
                if($c != 0){
                 return false;
                }
        }
 
        $result = "";
        foreach($out as $val){
                $result .= chr($val);
        }
 
        return $result;
}