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authorBharat Mediratta <bharat@menalto.com>2009-05-27 15:11:53 -0700
committerBharat Mediratta <bharat@menalto.com>2009-05-27 15:11:53 -0700
commit12fe58d997d2066dc362fd393a18b4e5da190513 (patch)
tree3ad8e5afb77829e1541ec96d86785760d65c04ac /system/libraries/Encrypt.php
parent00f47d4ddddcd1902db817018dd79ac01bcc8e82 (diff)
Rename 'kohana' to 'system' to conform to the Kohana filesystem layout. I'm comfortable with us not clearly drawing the distinction about the fact that it's Kohana.
Diffstat (limited to 'system/libraries/Encrypt.php')
-rw-r--r--system/libraries/Encrypt.php164
1 files changed, 164 insertions, 0 deletions
diff --git a/system/libraries/Encrypt.php b/system/libraries/Encrypt.php
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+<?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * The Encrypt library provides two-way encryption of text and binary strings
+ * using the MCrypt extension.
+ * @see http://php.net/mcrypt
+ *
+ * $Id: Encrypt.php 4072 2009-03-13 17:20:38Z jheathco $
+ *
+ * @package Core
+ * @author Kohana Team
+ * @copyright (c) 2007-2008 Kohana Team
+ * @license http://kohanaphp.com/license.html
+ */
+class Encrypt_Core {
+
+ // OS-dependant RAND type to use
+ protected static $rand;
+
+ // Configuration
+ protected $config;
+
+ /**
+ * Returns a singleton instance of Encrypt.
+ *
+ * @param array configuration options
+ * @return Encrypt_Core
+ */
+ public static function instance($config = NULL)
+ {
+ static $instance;
+
+ // Create the singleton
+ empty($instance) and $instance = new Encrypt((array) $config);
+
+ return $instance;
+ }
+
+ /**
+ * Loads encryption configuration and validates the data.
+ *
+ * @param array|string custom configuration or config group name
+ * @throws Kohana_Exception
+ */
+ public function __construct($config = FALSE)
+ {
+ if ( ! defined('MCRYPT_ENCRYPT'))
+ throw new Kohana_Exception('encrypt.requires_mcrypt');
+
+ if (is_string($config))
+ {
+ $name = $config;
+
+ // Test the config group name
+ if (($config = Kohana::config('encryption.'.$config)) === NULL)
+ throw new Kohana_Exception('encrypt.undefined_group', $name);
+ }
+
+ if (is_array($config))
+ {
+ // Append the default configuration options
+ $config += Kohana::config('encryption.default');
+ }
+ else
+ {
+ // Load the default group
+ $config = Kohana::config('encryption.default');
+ }
+
+ if (empty($config['key']))
+ throw new Kohana_Exception('encrypt.no_encryption_key');
+
+ // Find the max length of the key, based on cipher and mode
+ $size = mcrypt_get_key_size($config['cipher'], $config['mode']);
+
+ if (strlen($config['key']) > $size)
+ {
+ // Shorten the key to the maximum size
+ $config['key'] = substr($config['key'], 0, $size);
+ }
+
+ // Find the initialization vector size
+ $config['iv_size'] = mcrypt_get_iv_size($config['cipher'], $config['mode']);
+
+ // Cache the config in the object
+ $this->config = $config;
+
+ Kohana::log('debug', 'Encrypt Library initialized');
+ }
+
+ /**
+ * Encrypts a string and returns an encrypted string that can be decoded.
+ *
+ * @param string data to be encrypted
+ * @return string encrypted data
+ */
+ public function encode($data)
+ {
+ // Set the rand type if it has not already been set
+ if (Encrypt::$rand === NULL)
+ {
+ if (KOHANA_IS_WIN)
+ {
+ // Windows only supports the system random number generator
+ Encrypt::$rand = MCRYPT_RAND;
+ }
+ else
+ {
+ if (defined('MCRYPT_DEV_URANDOM'))
+ {
+ // Use /dev/urandom
+ Encrypt::$rand = MCRYPT_DEV_URANDOM;
+ }
+ elseif (defined('MCRYPT_DEV_RANDOM'))
+ {
+ // Use /dev/random
+ Encrypt::$rand = MCRYPT_DEV_RANDOM;
+ }
+ else
+ {
+ // Use the system random number generator
+ Encrypt::$rand = MCRYPT_RAND;
+ }
+ }
+ }
+
+ if (Encrypt::$rand === MCRYPT_RAND)
+ {
+ // The system random number generator must always be seeded each
+ // time it is used, or it will not produce true random results
+ mt_srand();
+ }
+
+ // Create a random initialization vector of the proper size for the current cipher
+ $iv = mcrypt_create_iv($this->config['iv_size'], Encrypt::$rand);
+
+ // Encrypt the data using the configured options and generated iv
+ $data = mcrypt_encrypt($this->config['cipher'], $this->config['key'], $data, $this->config['mode'], $iv);
+
+ // Use base64 encoding to convert to a string
+ return base64_encode($iv.$data);
+ }
+
+ /**
+ * Decrypts an encoded string back to its original value.
+ *
+ * @param string encoded string to be decrypted
+ * @return string decrypted data
+ */
+ public function decode($data)
+ {
+ // Convert the data back to binary
+ $data = base64_decode($data);
+
+ // Extract the initialization vector from the data
+ $iv = substr($data, 0, $this->config['iv_size']);
+
+ // Remove the iv from the data
+ $data = substr($data, $this->config['iv_size']);
+
+ // Return the decrypted data, trimming the \0 padding bytes from the end of the data
+ return rtrim(mcrypt_decrypt($this->config['cipher'], $this->config['key'], $data, $this->config['mode'], $iv), "\0");
+ }
+
+} // End Encrypt