Playing with CodeIgniters Encryptation Library and Encrypt Class

Encrypt.php

<?php
/**
 * Encrypt Controller
 * 
 * You can set the key to encode/decode.
 * 
 * @uses	CodeIgniter's Encrypt Class
 * @see		http://www.codeigniter.com/user_guide/libraries/encrypt.html
 * @author	John Dias <joaodias@noctus.org>
 */
class Encrypt extends CI_Controller
{
	public function __construct()
	{
		parent::__construct();

		$this->load->library('encrypt');
	}

	public function index()
	{
		$this->load->helper('form');

		$post = $this->input->post();
		$hash = $this->input->get('hash');

		if ( ! empty($post['what']) AND ! empty($post['encrypt']) AND ! empty($post['chave'])) {
			$hash = self::encrypt($post['what'], $post['chave']);
			$what = '';
		}

		if ( ! empty($post['result']) AND ! empty($post['decrypt']) AND ! empty($post['chave'])) {
			$what = self::decrypt($post['result'], $post['chave']);
			$hash = '';
		}

		@$key = (isset($new_key)) ? $new_key : $post['chave'];
		@$result = (isset($hash)) ? $hash : $post['result'];
		@$what = (isset($what)) ? $what : $post['what'];

		echo form_open('encrypt')
			.form_textarea('what', $what, 'placeholder="Texto descriptografado"')
			.form_textarea('result', $result, 'placeholder="Texto criptografado"')
			.'<br/>'
			.form_input('chave', $key, 'placeholder="Senha" size="24"')
			.form_submit('encrypt', 'Criptografar')
			.form_submit('decrypt', 'Descriptografar')
			.form_close();
	}

	private function encrypt($what, $key)
	{
		return $this->encrypt->encode($what, $key);
	}

	private function decrypt($result, $key)
	{
		return $this->encrypt->decode($result, $key);
	}
}

Encryptation.php

<?php
/**
 * Encryptation Controller
 * 
 * The key to encode/decode must be a hexadecimal string.
 * 
 * @uses	CodeIgniter's Encrypt Class
 * @see		http://www.codeigniter.com/user_guide/libraries/encrypt.html
 * @author	John Dias <joaodias@noctus.org>
 */
class Encryptation extends CI_Controller
{
	public $params = array(
				'cipher' => 'aes-128',
				'mode' => 'cbc',
				'hmac_digest' => 'sha512',
				'hmac_key' => TRUE
			);

	public function __construct()
	{
		parent::__construct();

		$this->load->library('encryption');
	}

	public function index()
	{
		$this->load->helper('form');

		$post = $this->input->post();
		$hash = $this->input->get('hash');

		if ( ! empty($post['new_key'])) {
			$new_key = self::new_key();
		}

		if ( ! empty($post['what']) AND ! empty($post['encrypt']) AND ! empty($post['chave']) AND ctype_xdigit($post['chave'])) {
			$hash = self::encrypt($post['what'], $post['chave']);
			$what = '';
		}

		if ( ! empty($post['result']) AND ! empty($post['decrypt']) AND ! empty($post['chave']) AND ctype_xdigit($post['chave'])) {
			$what = self::decrypt($post['result'], $post['chave']);
			$hash = '';
		}

		@$key = (isset($new_key)) ? $new_key : $post['chave'];
		//@$result = (isset($result)) ? $result : $post['result'];
		@$result = (isset($hash)) ? $hash : $post['result'];
		@$what = (isset($what)) ? $what : $post['what'];

		echo form_open('encryptation')
			.form_textarea('what', $what, 'placeholder="Texto descriptografado"')
			.form_textarea('result', $result, 'placeholder="Texto criptografado"')
			.'<br/>'
			.form_input('chave', $key, 'placeholder="Chave" size="24"')
			.form_submit('new_key', 'Gerar chave')
			.form_submit('encrypt', 'Criptografar')
			.form_submit('decrypt', 'Descriptografar')
			.form_close();
	}

	private function new_key()
	{
		return bin2hex($this->encryption->create_key(16));
	}

	private function encrypt($what, $key)
	{
		$this->params['key'] = hex2bin($key);
		return bin2hex($this->encryption->encrypt($what, $this->params));
	}

	private function decrypt($result, $key)
	{
		$this->params['key'] = hex2bin($key);
		return $this->encryption->decrypt(hex2bin($result), $this->params);
	}
}