diff --git a/laravel/security/crypter.php b/laravel/security/crypter.php
index 314a8cb0..3d4abdda 100644
--- a/laravel/security/crypter.php
+++ b/laravel/security/crypter.php
@@ -26,6 +26,9 @@ class Crypter {
/**
* Create a new Crypter instance.
*
+ * A valid cipher and mode supported by the Mcrypt extension must be given to the constructor.
+ * Also, an encryption key (typically from the application configuration) must be specified.
+ *
* @param string $cipher
* @param string $mode
* @param string $key
@@ -33,9 +36,9 @@ class Crypter {
*/
public function __construct($cipher, $mode, $key)
{
- $this->cipher = $cipher;
- $this->mode = $mode;
$this->key = $key;
+ $this->mode = $mode;
+ $this->cipher = $cipher;
if (trim((string) $this->key) === '')
{
@@ -46,48 +49,62 @@ class Crypter {
/**
* Encrypt a string using Mcrypt.
*
+ * The string will be encrypted using the cipher and mode specified when the crypter
+ * instance was created, and the final result will be base64 encoded.
+ *
+ *
+ * // Encrypt a string using the Mcrypt PHP extension
+ * $encrypted = Crypter::encrpt('secret');
+ *
+ *
* @param string $value
* @return string
*/
public function encrypt($value)
{
- $iv = mcrypt_create_iv($this->iv_size(), $this->randomizer());
+ // Determine the most appropriate random number generator for the operating
+ // system and environment the application is running on.
+ if (defined('MCRYPT_DEV_URANDOM'))
+ {
+ $randomizer = MCRYPT_DEV_URANDOM;
+ }
+ elseif (defined('MCRYPT_DEV_RANDOM'))
+ {
+ $randomizer = MCRYPT_DEV_RANDOM;
+ }
+ else
+ {
+ $randomizer = MCRYPT_RAND;
+ }
+
+ $iv = mcrypt_create_iv($this->iv_size(), $randomizer);
return base64_encode($iv.mcrypt_encrypt($this->cipher, $this->key, $value, $this->mode, $iv));
}
- /**
- * Get the random number source available to the OS.
- *
- * @return int
- */
- protected function randomizer()
- {
- if (defined('MCRYPT_DEV_URANDOM'))
- {
- return MCRYPT_DEV_URANDOM;
- }
- elseif (defined('MCRYPT_DEV_RANDOM'))
- {
- return MCRYPT_DEV_RANDOM;
- }
-
- return MCRYPT_RAND;
- }
-
/**
* Decrypt a string using Mcrypt.
*
+ * The string will be decrypted using the cipher and mode specified when the crypter was created.
+ *
+ *
+ * // Decrypt a string using the Mcrypt PHP extension
+ * $decrypted = Crypter::decrypt($secret);
+ *
+ *
* @param string $value
* @return string
*/
public function decrypt($value)
{
+ // Since all encrypted strings generated by this class are base64 encoded, we will
+ // first attempt to base64 decode the string. If we can't do it, we'll bail out.
if ( ! is_string($value = base64_decode($value, true)))
{
throw new \Exception('Decryption error. Input value is not valid base64 data.');
}
+ // Extract the input vector and the encrypted string from the value
list($iv, $value) = array(substr($value, 0, $this->iv_size()), substr($value, $this->iv_size()));
return rtrim(mcrypt_decrypt($this->cipher, $this->key, $value, $this->mode, $iv), "\0");