Error “The Encrypt library requires the Mcrypt extension.” pada PHP 7.2

Cara menghilangkan error “The Encrypt library requires the Mcrypt extension.” pada saat kita menjalankan codeigniter di server APACHE PHP 7.2 keatas adalah dengan menambahkan  file dengan nama Encrypt.php yang terdapat di dalam folder Application/Libraries yaitu dengan penampakan script sebagai berikut

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
* CodeIgniter
*
* An open source application development framework for PHP 5.1.6 or newer
*
* @package CodeIgniter
* @author ExpressionEngine Dev Team
* @copyright Copyright (c) 2008 - 2011, EllisLab, Inc.
* @license http://codeigniter.com/user_guide/license.html
* @link http://codeigniter.com
* @since Version 1.0
* @filesource
*/
// ------------------------------------------------------------------------
/**
* CodeIgniter Encryption Class
*
* Provides two-way keyed encoding using XOR Hashing and Mcrypt
*
* @package CodeIgniter
* @subpackage Libraries
* @category Libraries
* @author ExpressionEngine Dev Team
* @link http://codeigniter.com/user_guide/libraries/encryption.html
*/
class CI_Encrypt {
var $CI;
var $encryption_key = '';
var $_hash_type = 'sha1';
var $_mcrypt_exists = FALSE;
var $_mcrypt_cipher;
var $_mcrypt_mode;
/**
* Constructor
*
* Simply determines whether the mcrypt library exists.
*
*/
public function __construct()
{
$this->CI =& get_instance();
$this->_mcrypt_exists = ( ! function_exists('mcrypt_encrypt')) ? FALSE : TRUE;
log_message('debug', "Encrypt Class Initialized");
}
// --------------------------------------------------------------------
/**
* Fetch the encryption key
*
* Returns it as MD5 in order to have an exact-length 128 bit key.
* Mcrypt is sensitive to keys that are not the correct length
*
* @access public
* @param string
* @return string
*/
function get_key($key = '')
{
if ($key == '')
{
if ($this->encryption_key != '')
{
return $this->encryption_key;
}
$CI =& get_instance();
$key = $CI->config->item('encryption_key');
if ($key == FALSE)
{
show_error('In order to use the encryption class requires that you set an encryption key in your config file.');
}
}
return md5($key);
}
// --------------------------------------------------------------------
/**
* Set the encryption key
*
* @access public
* @param string
* @return void
*/
function set_key($key = '')
{
$this->encryption_key = $key;
}
// --------------------------------------------------------------------
/**
* Encode
*
* Encodes the message string using bitwise XOR encoding.
* The key is combined with a random hash, and then it
* too gets converted using XOR. The whole thing is then run
* through mcrypt (if supported) using the randomized key.
* The end result is a double-encrypted message string
* that is randomized with each call to this function,
* even if the supplied message and key are the same.
*
* @access public
* @param string the string to encode
* @param string the key
* @return string
*/
function encode($string, $key = '')
{
$key = $this->get_key($key);
if ($this->_mcrypt_exists === TRUE)
{
$enc = $this->mcrypt_encode($string, $key);
}
else
{
$enc = $this->_xor_encode($string, $key);
}
return base64_encode($enc);
}
// --------------------------------------------------------------------
/**
* Decode
*
* Reverses the above process
*
* @access public
* @param string
* @param string
* @return string
*/
function decode($string, $key = '')
{
$key = $this->get_key($key);
if (preg_match('/[^a-zA-Z0-9\/\+=]/', $string))
{
return FALSE;
}
$dec = base64_decode($string);
if ($this->_mcrypt_exists === TRUE)
{
if (($dec = $this->mcrypt_decode($dec, $key)) === FALSE)
{
return FALSE;
}
}
else
{
$dec = $this->_xor_decode($dec, $key);
}
return $dec;
}
// --------------------------------------------------------------------
/**
* Encode from Legacy
*
* Takes an encoded string from the original Encryption class algorithms and
* returns a newly encoded string using the improved method added in 2.0.0
* This allows for backwards compatibility and a method to transition to the
* new encryption algorithms.
*
* For more details, see http://codeigniter.com/user_guide/installation/upgrade_200.html#encryption
*
* @access public
* @param string
* @param int (mcrypt mode constant)
* @param string
* @return string
*/
function encode_from_legacy($string, $legacy_mode = MCRYPT_MODE_ECB, $key = '')
{
if ($this->_mcrypt_exists === FALSE)
{
log_message('error', 'Encoding from legacy is available only when Mcrypt is in use.');
return FALSE;
}
// decode it first
// set mode temporarily to what it was when string was encoded with the legacy
// algorithm - typically MCRYPT_MODE_ECB
$current_mode = $this->_get_mode();
$this->set_mode($legacy_mode);
$key = $this->get_key($key);
if (preg_match('/[^a-zA-Z0-9\/\+=]/', $string))
{
return FALSE;
}
$dec = base64_decode($string);
if (($dec = $this->mcrypt_decode($dec, $key)) === FALSE)
{
return FALSE;
}
$dec = $this->_xor_decode($dec, $key);
// set the mcrypt mode back to what it should be, typically MCRYPT_MODE_CBC
$this->set_mode($current_mode);
// and re-encode
return base64_encode($this->mcrypt_encode($dec, $key));
}
// --------------------------------------------------------------------
/**
* XOR Encode
*
* Takes a plain-text string and key as input and generates an
* encoded bit-string using XOR
*
* @access private
* @param string
* @param string
* @return string
*/
function _xor_encode($string, $key)
{
$rand = '';
while (strlen($rand) < 32)
{
$rand .= mt_rand(0, mt_getrandmax());
}
$rand = $this->hash($rand);
$enc = '';
for ($i = 0; $i < strlen($string); $i++)
{
$enc .= substr($rand, ($i % strlen($rand)), 1).(substr($rand, ($i % strlen($rand)), 1) ^ substr($string, $i, 1));
}
return $this->_xor_merge($enc, $key);
}
// --------------------------------------------------------------------
/**
* XOR Decode
*
* Takes an encoded string and key as input and generates the
* plain-text original message
*
* @access private
* @param string
* @param string
* @return string
*/
function _xor_decode($string, $key)
{
$string = $this->_xor_merge($string, $key);
$dec = '';
for ($i = 0; $i < strlen($string); $i++)
{
$dec .= (substr($string, $i++, 1) ^ substr($string, $i, 1));
}
return $dec;
}
// --------------------------------------------------------------------
/**
* XOR key + string Combiner
*
* Takes a string and key as input and computes the difference using XOR
*
* @access private
* @param string
* @param string
* @return string
*/
function _xor_merge($string, $key)
{
$hash = $this->hash($key);
$str = '';
for ($i = 0; $i < strlen($string); $i++)
{
$str .= substr($string, $i, 1) ^ substr($hash, ($i % strlen($hash)), 1);
}
return $str;
}
// --------------------------------------------------------------------
/**
* Encrypt using Mcrypt
*
* @access public
* @param string
* @param string
* @return string
*/
function mcrypt_encode($data, $key)
{
$init_size = mcrypt_get_iv_size($this->_get_cipher(), $this->_get_mode());
$init_vect = mcrypt_create_iv($init_size, MCRYPT_RAND);
return $this->_add_cipher_noise($init_vect.mcrypt_encrypt($this->_get_cipher(), $key, $data, $this->_get_mode(), $init_vect), $key);
}
// --------------------------------------------------------------------
/**
* Decrypt using Mcrypt
*
* @access public
* @param string
* @param string
* @return string
*/
function mcrypt_decode($data, $key)
{
$data = $this->_remove_cipher_noise($data, $key);
$init_size = mcrypt_get_iv_size($this->_get_cipher(), $this->_get_mode());
if ($init_size > strlen($data))
{
return FALSE;
}
$init_vect = substr($data, 0, $init_size);
$data = substr($data, $init_size);
return rtrim(mcrypt_decrypt($this->_get_cipher(), $key, $data, $this->_get_mode(), $init_vect), "\0");
}
// --------------------------------------------------------------------
/**
* Adds permuted noise to the IV + encrypted data to protect
* against Man-in-the-middle attacks on CBC mode ciphers
* http://www.ciphersbyritter.com/GLOSSARY.HTM#IV
*
* Function description
*
* @access private
* @param string
* @param string
* @return string
*/
function _add_cipher_noise($data, $key)
{
$keyhash = $this->hash($key);
$keylen = strlen($keyhash);
$str = '';
for ($i = 0, $j = 0, $len = strlen($data); $i < $len; ++$i, ++$j)
{
if ($j >= $keylen)
{
$j = 0;
}
$str .= chr((ord($data[$i]) + ord($keyhash[$j])) % 256);
}
return $str;
}
// --------------------------------------------------------------------
/**
* Removes permuted noise from the IV + encrypted data, reversing
* _add_cipher_noise()
*
* Function description
*
* @access public
* @param type
* @return type
*/
function _remove_cipher_noise($data, $key)
{
$keyhash = $this->hash($key);
$keylen = strlen($keyhash);
$str = '';
for ($i = 0, $j = 0, $len = strlen($data); $i < $len; ++$i, ++$j)
{
if ($j >= $keylen)
{
$j = 0;
}
$temp = ord($data[$i]) - ord($keyhash[$j]);
if ($temp < 0)
{
$temp = $temp + 256;
}
$str .= chr($temp);
}
return $str;
}
// --------------------------------------------------------------------
/**
* Set the Mcrypt Cipher
*
* @access public
* @param constant
* @return string
*/
function set_cipher($cipher)
{
$this->_mcrypt_cipher = $cipher;
}
// --------------------------------------------------------------------
/**
* Set the Mcrypt Mode
*
* @access public
* @param constant
* @return string
*/
function set_mode($mode)
{
$this->_mcrypt_mode = $mode;
}
// --------------------------------------------------------------------
/**
* Get Mcrypt cipher Value
*
* @access private
* @return string
*/
function _get_cipher()
{
if ($this->_mcrypt_cipher == '')
{
$this->_mcrypt_cipher = MCRYPT_RIJNDAEL_256;
}
return $this->_mcrypt_cipher;
}
// --------------------------------------------------------------------
/**
* Get Mcrypt Mode Value
*
* @access private
* @return string
*/
function _get_mode()
{
if ($this->_mcrypt_mode == '')
{
$this->_mcrypt_mode = MCRYPT_MODE_CBC;
}
return $this->_mcrypt_mode;
}
// --------------------------------------------------------------------
/**
* Set the Hash type
*
* @access public
* @param string
* @return string
*/
function set_hash($type = 'sha1')
{
$this->_hash_type = ($type != 'sha1' AND $type != 'md5') ? 'sha1' : $type;
}
// --------------------------------------------------------------------
/**
* Hash encode a string
*
* @access public
* @param string
* @return string
*/
function hash($str)
{
return ($this->_hash_type == 'sha1') ? $this->sha1($str) : md5($str);
}
// --------------------------------------------------------------------
/**
* Generate an SHA1 Hash
*
* @access public
* @param string
* @return string
*/
function sha1($str)
{
if ( ! function_exists('sha1'))
{
if ( ! function_exists('mhash'))
{
require_once(BASEPATH.'libraries/Sha1.php');
$SH = new CI_SHA;
return $SH->generate($str);
}
else
{
return bin2hex(mhash(MHASH_SHA1, $str));
}
}
else
{
return sha1($str);
}
}
}
// END CI_Encrypt class
/* End of file Encrypt.php */

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