CSecurityManager

protected function computeHMAC($data,$key=null)
{
    if($key===null)
        $key=$this->getValidationKey();

    if(function_exists('hash_hmac'))
        return hash_hmac($this->hashAlgorithm, $data, $key);

    if(!strcasecmp($this->hashAlgorithm,'sha1'))
    {
        $pack='H40';
        $func='sha1';
    }
    else
    {
        $pack='H32';
        $func='md5';
    }
    if($this->strlen($key) > 64)
        $key=pack($pack, $func($key));
    if($this->strlen($key) < 64)
        $key=str_pad($key, 64, chr(0));
    $key=$this->substr($key,0,64);
    return $func((str_repeat(chr(0x5C), 64) ^ $key) . pack($pack, $func((str_repeat(chr(0x36), 64) ^ $key) . $data)));
}

public function decrypt($data,$key=null)
{
    $module=$this->openCryptModule();
    $key=$this->substr($key===null ? md5($this->getEncryptionKey()) : $key,0,mcrypt_enc_get_key_size($module));
    $ivSize=mcrypt_enc_get_iv_size($module);
    $iv=$this->substr($data,0,$ivSize);
    mcrypt_generic_init($module,$key,$iv);
    $decrypted=mdecrypt_generic($module,$this->substr($data,$ivSize,$this->strlen($data)));
    mcrypt_generic_deinit($module);
    mcrypt_module_close($module);
    return rtrim($decrypted,"\0");
}

public function encrypt($data,$key=null)
{
    $module=$this->openCryptModule();
    $key=$this->substr($key===null ? md5($this->getEncryptionKey()) : $key,0,mcrypt_enc_get_key_size($module));
    srand();
    $iv=mcrypt_create_iv(mcrypt_enc_get_iv_size($module), MCRYPT_RAND);
    mcrypt_generic_init($module,$key,$iv);
    $encrypted=$iv.mcrypt_generic($module,$data);
    mcrypt_generic_deinit($module);
    mcrypt_module_close($module);
    return $encrypted;
}

protected function generateRandomKey()
{
    return sprintf('%08x%08x%08x%08x',mt_rand(),mt_rand(),mt_rand(),mt_rand());
}

public function getEncryptionKey()
{
    if($this->_encryptionKey!==null)
        return $this->_encryptionKey;
    else
    {
        if(($key=Yii::app()->getGlobalState(self::STATE_ENCRYPTION_KEY))!==null)
            $this->setEncryptionKey($key);
        else
        {
            $key=$this->generateRandomKey();
            $this->setEncryptionKey($key);
            Yii::app()->setGlobalState(self::STATE_ENCRYPTION_KEY,$key);
        }
        return $this->_encryptionKey;
    }
}

public function getValidation()
{
    return $this->hashAlgorithm;
}

public function getValidationKey()
{
    if($this->_validationKey!==null)
        return $this->_validationKey;
    else
    {
        if(($key=Yii::app()->getGlobalState(self::STATE_VALIDATION_KEY))!==null)
            $this->setValidationKey($key);
        else
        {
            $key=$this->generateRandomKey();
            $this->setValidationKey($key);
            Yii::app()->setGlobalState(self::STATE_VALIDATION_KEY,$key);
        }
        return $this->_validationKey;
    }
}

public function hashData($data,$key=null)
{
    return $this->computeHMAC($data,$key).$data;
}

public function init()
{
    parent::init();
    $this->_mbstring=extension_loaded('mbstring');
}

protected function openCryptModule()
{
    if(extension_loaded('mcrypt'))
    {
        if(is_array($this->cryptAlgorithm))
            $module=@call_user_func_array('mcrypt_module_open',$this->cryptAlgorithm);
        else
            $module=@mcrypt_module_open($this->cryptAlgorithm,'', MCRYPT_MODE_CBC,'');

        if($module===false)
            throw new CException(Yii::t('yii','Failed to initialize the mcrypt module.'));

        return $module;
    }
    else
        throw new CException(Yii::t('yii','CSecurityManager requires PHP mcrypt extension to be loaded in order to use data encryption feature.'));
}

public function setEncryptionKey($value)
{
    if(!empty($value))
        $this->_encryptionKey=$value;
    else
        throw new CException(Yii::t('yii','CSecurityManager.encryptionKey cannot be empty.'));
}

public function setValidation($value)
{
    $this->hashAlgorithm=$value;
}

public function setValidationKey($value)
{
    if(!empty($value))
        $this->_validationKey=$value;
    else
        throw new CException(Yii::t('yii','CSecurityManager.validationKey cannot be empty.'));
}

public function validateData($data,$key=null)
{
    $len=$this->strlen($this->computeHMAC('test'));
    if($this->strlen($data)>=$len)
    {
        $hmac=$this->substr($data,0,$len);
        $data2=$this->substr($data,$len,$this->strlen($data));
        return $hmac===$this->computeHMAC($data2,$key)?$data2:false;
    }
    else
        return false;
}