/**
* Setup the \Topxia\Service\Util\Phpsec\Crypt\Base::ENGINE_MCRYPT $engine
*
* @access private
* @see \Topxia\Service\Util\Phpsec\Crypt\Base::_setupMcrypt()
*/
public function _setupMcrypt()
{
$this->key = str_pad(substr($this->key, 0, $this->key_size), $this->key_size, "");
parent::_setupMcrypt();
}
/**
* Test for engine validity
*
* This is mainly just a wrapper to set things up for Crypt_Base::isValidEngine()
*
* @access public
* @see \Topxia\Service\Util\Phpsec\Crypt\Base::isValidEngine()
*
* @param Integer $engine
* @return Boolean
*/
public function isValidEngine($engine)
{
if ($engine == self::ENGINE_OPENSSL) {
if (strlen($this->key) != 16) {
return false;
}
$this->cipher_name_openssl_ecb = 'bf-ecb';
$this->cipher_name_openssl = 'bf-' . $this->_openssl_translate_mode();
}
return parent::isValidEngine($engine);
}
/**
* Sets the key.
*
* Keys can be of any length. Twofish, itself, requires the use of a key that's 128, 192 or 256-bits long.
* If the key is less than 256-bits we round the length up to the closest valid key length,
* padding $key with null bytes. If the key is more than 256-bits, we trim the excess bits.
*
* If the key is not explicitly set, it'll be assumed a 128 bits key to be all null bytes.
*
* @access public
* @see \Topxia\Service\Util\Phpsec\Crypt\Base::setKey()
*
* @param String $key
*/
public function setKey($key)
{
$keylength = strlen($key);
switch (true) {
case $keylength <= 16:
$key = str_pad($key, 16, "");
break;
case $keylength <= 24:
$key = str_pad($key, 24, "");
break;
case $keylength < 32:
$key = str_pad($key, 32, "");
break;
case $keylength > 32:
$key = substr($key, 0, 32);
}
parent::setKey($key);
}
/**
* Decrypts a message.
*
* $this->decrypt($this->encrypt($plaintext)) == $this->encrypt($this->encrypt($plaintext)).
* At least if the continuous buffer is disabled.
*
* @access public
* @see \Topxia\Service\Util\Phpsec\Crypt\Base::encrypt()
* @see \Topxia\Service\Util\Phpsec\Crypt\RC4::_crypt()
*
* @param String $ciphertext
* @return String $plaintext
*/
public function decrypt($ciphertext)
{
if ($this->engine != Base::ENGINE_INTERNAL) {
return parent::decrypt($ciphertext);
}
return $this->_crypt($ciphertext, self::DECRYPT);
}
/**
* Setup the \Topxia\Service\Util\Phpsec\Crypt\Base::ENGINE_MCRYPT $engine
*
* @access private
* @see \Topxia\Service\Util\Phpsec\Crypt\Base::_setupMcrypt()
*/
public function _setupMcrypt()
{
if (!isset($this->key)) {
$this->setKey('');
}
parent::_setupMcrypt();
}
