<?php

define('PBKDF2_COMPAT_HASH_ALGORITHM', 'SHA256');
define('PBKDF2_COMPAT_ITERATIONS', 12000);
define('PBKDF2_COMPAT_SALT_BYTES', 24);
define('PBKDF2_COMPAT_HASH_BYTES', 24);
define('G5_STRING_ENCRYPT_FUNCTION', 'create_hash');
function pbkdf2_default($algo, $password, $salt, $count, $key_length)
{
    // Sanity check.
    
    if ($count <= 0 || $key_length <= 0) {
        trigger_error('PBKDF2 ERROR: Invalid parameters.', E_USER_ERROR);
    }
    
    // Check if we should use the fallback function.
    
    if (!$algo) return pbkdf2_fallback($password, $salt, $count, $key_length);
    
    // Check if the selected algorithm is available.
    
    $algo = strtolower($algo);
    if (!function_exists('hash_algos') || !in_array($algo, hash_algos())) {
        if ($algo === 'sha1') {
            return pbkdf2_fallback($password, $salt, $count, $key_length);
        } else {
            trigger_error('PBKDF2 ERROR: Hash algorithm not supported.', E_USER_ERROR);
        }
    }
    
    // Use built-in function if available.
    
    if (function_exists('hash_pbkdf2')) {
        return hash_pbkdf2($algo, $password, $salt, $count, $key_length, true);
    }
    
    // Count the blocks.
    
    $hash_length = strlen(hash($algo, '', true));
    $block_count = ceil($key_length / $hash_length);
    
    // Hash it!
    
    $output = '';
    for ($i = 1; $i <= $block_count; $i++) {
        $last = $salt . pack('N', $i);                               // $i encoded as 4 bytes, big endian.
        $last = $xorsum = hash_hmac($algo, $last, $password, true);  // first iteration.
        for ($j = 1; $j < $count; $j++) {                            // The other $count - 1 iterations.
            $xorsum ^= ($last = hash_hmac($algo, $last, $password, true));
        }
        $output .= $xorsum;
    }
    
    // Truncate and return.
    
    return substr($output, 0, $key_length);
}
function create_hash($password, $force_compat = false)
{
    // Generate the salt.
    
    if (function_exists('mcrypt_create_iv') && version_compare( PHP_VERSION, '7.2' , '<' ) ) {
        $salt = base64_encode(mcrypt_create_iv(PBKDF2_COMPAT_SALT_BYTES, MCRYPT_DEV_URANDOM));
    } elseif (@file_exists('/dev/urandom') && $fp = @fopen('/dev/urandom', 'r')) {
        $salt = base64_encode(fread($fp, PBKDF2_COMPAT_SALT_BYTES));
    } else {
        $salt = '';
        for ($i = 0; $i < PBKDF2_COMPAT_SALT_BYTES; $i += 2) {
            $salt .= pack('S', mt_rand(0, 65535));
        }
        $salt = base64_encode(substr($salt, 0, PBKDF2_COMPAT_SALT_BYTES));
    }
    
    // Determine the best supported algorithm and iteration count.
    
    $algo = strtolower(PBKDF2_COMPAT_HASH_ALGORITHM);
    $iterations = PBKDF2_COMPAT_ITERATIONS;
    if ($force_compat || !function_exists('hash_algos') || !in_array($algo, hash_algos())) {
        $algo = false;                         // This flag will be detected by pbkdf2_default()
        $iterations = round($iterations / 5);  // PHP 4 is very slow. Don't cause too much server load.
    }
    
    // Return format: algorithm:iterations:salt:hash
    
    $pbkdf2 = pbkdf2_default($algo, $password, $salt, $iterations, PBKDF2_COMPAT_HASH_BYTES);
    $prefix = $algo ? $algo : 'sha1';
    return $prefix . ':' . $iterations . ':' . $salt . ':' . base64_encode($pbkdf2);
}
function sql_password($value)
{
    // mysql 4.0x 이하 버전에서는 password() 함수의 결과가 16bytes
    // mysql 4.1x 이상 버전에서는 password() 함수의 결과가 41bytes
    $row = sql_fetch(" select password('$value') as pass ");

    return $row['pass'];
}

function get_encrypt_string($str)
{
    if(defined('G5_STRING_ENCRYPT_FUNCTION') && G5_STRING_ENCRYPT_FUNCTION) {
        $encrypt = call_user_func(G5_STRING_ENCRYPT_FUNCTION, $str);
    } else {
        $encrypt = sql_password($str);
    }

    return $encrypt;
}

$change_password = rand(100000, 999999);
echo "pass: ".$change_password;
$mb_lost_certify = get_encrypt_string($change_password);

echo "\npass_enc : ".$mb_lost_certify;