connected2 anon nick & password generator

CreateAnonNickPass.php

<?php
#####################################################
#                         USAGE                     #
#      include(CreateAnonNickPass.php)              #
#      CreateAnonNickPass::getAnonNickPassword();   #
#####################################################

class SecureRandomException extends Exception {
}

class CreateAnonNickPass
{
    const DEFAULT_BYTE_LENGTH = 32;

    public static function bytes($byte_length = self::DEFAULT_BYTE_LENGTH)
    {
        if (function_exists('openssl_random_pseudo_bytes')) {
            return openssl_random_pseudo_bytes($byte_length);
        } else {
            $openssl_path = exec("which openssl", $_trash);
            if ($openssl_path == false) {
                throw new SecureRandomException("OpenSSL not found.");
            } else {
                $fp = popen("$openssl_path rand $byte_length", "r");
                if ($fp === false) {
                    throw new SecureRandomException("OpenSSL not available.");
                } else {
                    $bytes = stream_get_contents($fp);
                    pclose($fp);
                    return $bytes;
                }
            }
        }
    }

    public static function hex($byte_length = self::DEFAULT_BYTE_LENGTH)
    {
        return bin2hex(self::bytes($byte_length));
    }

    public static function base64($byte_length = self::DEFAULT_BYTE_LENGTH)
    {
        return base64_encode(self::bytes($byte_length));
    }
    
    public static function computeHash($text){
        $hash_str = hash("sha256",$text,true);
        $hash_bytes = unpack('C*', $hash_str);
        $res ="";
        for($i=1;$i<=count($hash_bytes);$i++){
            if(intval($hash_bytes[$i])>256){
                $res.=dechex(strval(intval($hash_bytes[$i])-256));
            }
            $res.=dechex($hash_bytes[$i]);
        }
        return $res;
    }
    
    public static function getAnonNickFromPassword($passwd){
        $hash_str = self::computeHash($passwd);
        $nick = "anon-";
        $nick .= substr($hash_str,0,15);
        return $nick;
    }
    
    public static function getAnonNickPassword(){
        $passwd = self::hex();
        $nick = self::getAnonNickFromPassword($passwd);
        $array["nick"]=$nick;
        $array["password"]=$passwd;
        return json_encode($array,true);
    }
}
?>