/**
* Decrypt a value
*
* ## Usage
*
* $driver->decrypt($string);
*
* @param string The encrypted value
* @return string The decrypted value
*/
public function decrypt($string)
{
if (!Str::is($string = \base64_decode($string, true))) {
throw new \Exception('Decryption error. Input value is not valid base64 data.');
}
list($iv, $string) = array(Str::sub($string, 0, $this->iv_size()), Str::sub($string, $this->iv_size()));
return \rtrim(\mcrypt_decrypt(static::$cipher, Crypt::key(), $string, static::$mode, $iv), "");
}
/**
* Read all data from a datastore key
*
* @param string The datastore key
* @return string Returns the contents of the datastore, otherwise null
*/
public function read($key)
{
if (!F::exists(self::$path . $key)) {
return null;
}
// File based caches store have the expiration timestamp stored in
// UNIX format prepended to their contents. This timestamp is then
// extracted and removed when the cache is read to determine if the file
// is still valid
if (time() >= Str::sub($cache = F::get(self::$path . $key), 0, 10)) {
$this->delete($key);
return null;
}
return unserialize(substr($cache, 10));
}
