/**
* Decrypt a string
*
* @param string $cipher Encrypted text
* @param string $key Encryption key to retrieve from the configuration, defaults to 'des_key'
* @param boolean $base64 Whether or not input is base64-encoded
*
* @return string Decrypted text
*/
public function decrypt($cipher, $key = 'des_key', $base64 = true)
{
if (!$cipher) {
return '';
}
$cipher = $base64 ? base64_decode($cipher) : $cipher;
$ckey = $this->config->get_crypto_key($key);
$method = $this->config->get_crypto_method();
$opts = defined('OPENSSL_RAW_DATA') ? OPENSSL_RAW_DATA : true;
$iv_size = openssl_cipher_iv_length($method);
$iv = substr($cipher, 0, $iv_size);
// session corruption? (#1485970)
if (strlen($iv) < $iv_size) {
return '';
}
$cipher = substr($cipher, $iv_size);
$clear = openssl_decrypt($cipher, $method, $ckey, $opts, $iv);
return $clear;
}
