AES.php

<?php
/**
Aes encryption
*/
class AES {
  
  const M_CBC = 'cbc';
  const M_CFB = 'cfb';
  const M_ECB = 'ecb';
  const M_NOFB = 'nofb';
  const M_OFB = 'ofb';
  const M_STREAM = 'stream';
  
  protected $key;
  protected $cipher;
  protected $data;
  protected $mode;
  protected $IV;
/**
* 
* @param type $data
* @param type $key
* @param type $blockSize
* @param type $mode
*/
  function __construct($data = null, $key = null, $blockSize = null, $mode = null) {
    $this->setData($data);
    $this->setKey($key);
    $this->setBlockSize($blockSize);
    $this->setMode($mode);
    $this->setIV("");
  }
  
/**
* 
* @param type $data
*/
  public function setData($data) {
    $this->data = $data;
  }
  
/**
* 
* @param type $key
*/
  public function setKey($key) {
    $len = strlen($key);
    if($len < 24 && $len != 16){
       $key = str_pad($key, 24, "\0", STR_PAD_RIGHT); 
    }elseif ($len > 24 && $len < 32) {
        $key = str_pad($key, 32, "\0", STR_PAD_RIGHT);       
    }elseif ($len > 32){
        $key = substr($key, 0, 32);
    }
    $this->key = $key;
  }
  
/**
* 
* @param type $blockSize
*/
  public function setBlockSize($blockSize) {
    switch ($blockSize) {
      case 128:
      $this->cipher = MCRYPT_RIJNDAEL_128;
      break;
      
      case 192:
      $this->cipher = MCRYPT_RIJNDAEL_192;
      break;
      
      case 256:
      $this->cipher = MCRYPT_RIJNDAEL_256;
      break;
    }
  }
  
/**
* 
* @param type $mode
*/
  public function setMode($mode) {
    switch ($mode) {
      case AES::M_CBC:
      $this->mode = MCRYPT_MODE_CBC;
      break;
      case AES::M_CFB:
      $this->mode = MCRYPT_MODE_CFB;
      break;
      case AES::M_ECB:
      $this->mode = MCRYPT_MODE_ECB;
      break;
      case AES::M_NOFB:
      $this->mode = MCRYPT_MODE_NOFB;
      break;
      case AES::M_OFB:
      $this->mode = MCRYPT_MODE_OFB;
      break;
      case AES::M_STREAM:
      $this->mode = MCRYPT_MODE_STREAM;
      break;
      default:
      $this->mode = MCRYPT_MODE_ECB;
      break;
    }
  }
  
/**
* 
* @return boolean
*/
  public function validateParams() {
    if ($this->data != null &&
        $this->key != null &&
        $this->cipher != null) {
      return true;
    } else {
      return FALSE;
    }
  }
  
  public function setIV($IV) {
        $this->IV = $IV;
    }
  protected function getIV() {
      if ($this->IV == "") {
        $this->IV = mcrypt_create_iv(mcrypt_get_iv_size($this->cipher, $this->mode), MCRYPT_RAND);
      }
      return $this->IV;
  }
  
/**
* @return type
* @throws Exception
*/
  public function encrypt() {
    
    if ($this->validateParams()) {
      return trim(base64_encode(
        mcrypt_encrypt(
          $this->cipher, $this->key, $this->data, $this->mode, $this->getIV())));
    } else {
      throw new Exception('Invlid params!');
    }
  }
/**
* 
* @return type
* @throws Exception
*/
  public function decrypt() {
    if ($this->validateParams()) {
      return trim(mcrypt_decrypt(
        $this->cipher, $this->key, base64_decode($this->data), $this->mode, $this->getIV()));
    } else {
      throw new Exception('Invlid params!');
    }
  }
  
}
?>