Current Path : C:/xampp/htdocs/moodle/lib/horde/framework/Horde/ |
Current File : C:/xampp/htdocs/moodle/lib/horde/framework/Horde/Secret.php |
<?php /** * Provides an API for encrypting and decrypting small pieces of data with the * use of a shared key stored in a cookie. * * Copyright 1999-2017 Horde LLC (http://www.horde.org/) * * See the enclosed file LICENSE for license information (LGPL). If you * did not receive this file, see http://www.horde.org/licenses/lgpl21. * * @author Chuck Hagenbuch <chuck@horde.org> * @author Michael Slusarz <slusarz@horde.org> * @category Horde * @license http://www.horde.org/licenses/lgpl21 LGPL * @package Secret */ class Horde_Secret { /** Generic, default keyname. */ const DEFAULT_KEY = 'generic'; /** * Configuration parameters. * * @var array */ protected $_params = array( 'cookie_domain' => '', 'cookie_path' => '', 'cookie_ssl' => false, 'session_name' => 'horde_secret' ); /** * Cipher cache. * * @var array */ protected $_cipherCache = array(); /** * Key cache. * * @var array */ protected $_keyCache = array(); /** * Constructor. * * @param array $params Configuration parameters: * - cookie_domain: (string) The cookie domain. * - cookie_path: (string) The cookie path. * - cookie_ssl: (boolean) Only transmit cookie securely? * - session_name: (string) The cookie session name. */ public function __construct($params = array()) { $this->_params = array_merge($this->_params, $params); } /** * Take a small piece of data and encrypt it with a key. * * @param string $key The key to use for encryption. * @param string $message The plaintext message. * * @return string The ciphertext message. * @throws Horde_Secret_Exception */ public function write($key, $message) { $message = strval($message); return (strlen($key) && strlen($message)) ? $this->_getCipherOb($key)->encrypt($message) : ''; } /** * Decrypt a message encrypted with write(). * * @param string $key The key to use for decryption. * @param string $message The ciphertext message. * * @return string The plaintext message. * @throws Horde_Secret_Exception */ public function read($key, $ciphertext) { $ciphertext = strval($ciphertext); return (strlen($key) && strlen($ciphertext)) ? $this->_getCipherOb($key)->decrypt($ciphertext) : ''; } /** * Returns the cached crypt object. * * @param string $key The key to use for [de|en]cryption. Only the first * 56 bytes of this string is used. * * @return Horde_Crypt_Blowfish The crypt object. * @throws Horde_Secret_Exception */ protected function _getCipherOb($key) { if (!is_string($key)) { throw new Horde_Secret_Exception('Key must be a string', Horde_Secret_Exception::KEY_NOT_STRING); } if (!strlen($key)) { throw new Horde_Secret_Exception('Key must be non-zero.', Horde_Secret_Exception::KEY_ZERO_LENGTH); } $key = substr($key, 0, 56); $idx = hash('md5', $key); if (!isset($this->_cipherCache[$idx])) { $this->_cipherCache[$idx] = new Horde_Crypt_Blowfish($key); } return $this->_cipherCache[$idx]; } /** * Generate a secret key (for encryption), either using a random * string and storing it in a cookie if the user has cookies * enabled, or munging some known values if they don't. * * @param string $keyname The name of the key to set. * * @return string The secret key that has been generated. */ public function setKey($keyname = self::DEFAULT_KEY) { $set = true; if (isset($_COOKIE[$this->_params['session_name']])) { if (isset($_COOKIE[$keyname . '_key'])) { $key = $_COOKIE[$keyname . '_key']; $set = false; } else { $key = $_COOKIE[$keyname . '_key'] = strval(new Horde_Support_Randomid()); } } else { $key = session_id(); } if ($set) { $this->_setCookie($keyname, $key); } return $key; } /** * Return a secret key, either from a cookie, or if the cookie * isn't there, assume we are using a munged version of a known * base value. * * @param string $keyname The name of the key to get. * * @return string The secret key. */ public function getKey($keyname = self::DEFAULT_KEY) { if (!isset($this->_keyCache[$keyname])) { if (isset($_COOKIE[$keyname . '_key'])) { $key = $_COOKIE[$keyname . '_key']; } else { $key = session_id(); $this->_setCookie($keyname, $key); } $this->_keyCache[$keyname] = $key; } return $this->_keyCache[$keyname]; } /** * Clears a secret key entry from the current cookie. * * @param string $keyname The name of the key to clear. * * @return boolean True if key existed, false if not. */ public function clearKey($keyname = self::DEFAULT_KEY) { if (isset($_COOKIE[$this->_params['session_name']]) && isset($_COOKIE[$keyname . '_key'])) { $this->_setCookie($keyname, false); return true; } return false; } /** * Sets the cookie with the given keyname/key. * * @param string $keyname The name of the key to set. * @param string $key The key to use for encryption. */ protected function _setCookie($keyname, $key) { @setcookie( $keyname . '_key', $key, 0, $this->_params['cookie_path'], $this->_params['cookie_domain'], $this->_params['cookie_ssl'], true ); if ($key === false) { unset($_COOKIE[$keyname . '_key'], $this->_keyCache[$keyname]); } else { $_COOKIE[$keyname . '_key'] = $this->_keyCache[$keyname] = $key; } } }