library/Msd/Crypt.php

@@ -0,0 +1,248 @@
+<?php
+/**
+ * This file is part of MySQLDumper released under the GNU/GPL 2 license
+ * http://www.mysqldumper.net
+ *
+ * @package         MySQLDumper
+ * @subpackage      Encryption
+ * @version         SVN: $Rev$
+ * @author          $Author$
+ */
+/**
+ * Class for text en- and decryption.
+ *
+ * @package         MySQLDumper
+ * @subpackage      Encryption
+ */
+class Msd_Crypt
+{
+    /**
+     * Holds the encryption descriptor
+     *
+     * @var resource
+     */
+    private $_encDescriptor = null;
+
+    /**
+     * Holds the initialization vector
+     *
+     * @var resource
+     */
+    private $_initVector = null;
+
+    /**
+     * Holds the algorithm wichc is currently used.
+     *
+     * @var string
+     */
+    private $_algorithm = MCRYPT_TWOFISH;
+
+    /**
+     * Holds the current encryption key.
+     *
+     * @var string
+     */
+    private $_encryptionKey = null;
+
+    /**
+     * Instance of this class.
+     *
+     * @var Msd_Crypt
+     */
+    private static $_instance = null;
+
+    /**
+     * Identificator for encrypted text
+     *
+     * @var string
+     */
+    private $_cryptIdent = 'Z';
+
+    /**
+     * Class constructor
+     *
+     * @param string $cryptKey  Encryption key
+     * @param string $algorithm Algorithm for encryption
+     *
+     * @return void
+     */
+    private function __construct($cryptKey = null, $algorithm = null)
+    {
+        if ($cryptKey === null) {
+            $cryptKey = md5(time());
+        }
+        if ($algorithm === null) {
+            $algorithm = $this->_algorithm;
+        }
+        $this->init($cryptKey, $algorithm);
+    }
+
+    /**
+     * Get the instance of this class.
+     *
+     * @param string $cryptKey  Encryption key
+     * @param string $algorithm Algorithm for encryption
+     *
+     * @return Msd_Crypt
+     */
+    public static function getInstance($cryptKey = null, $algorithm = null)
+    {
+        if (self::$_instance === null) {
+            self::$_instance = new self($cryptKey, $algorithm);
+        }
+
+        return self::$_instance;
+    }
+
+    /**
+     * Initializes the encryption descriptor.
+     *
+     * @param string $encryptionKey Key for encryption
+     * @param string $algorithm     Algorithm for encryption
+     *
+     * @return void
+     */
+    public function init($encryptionKey = null, $algorithm = null)
+    {
+        if ($encryptionKey === null) {
+            $encryptionKey = $this->_encryptionKey;
+        }
+        if ($algorithm === null) {
+            $algorithm = $this->_algorithm;
+        }
+        if (!is_resource($this->_encDescriptor)) {
+            $this->_encDescriptor = mcrypt_module_open(
+                $algorithm,
+                '',
+                MCRYPT_MODE_ECB,
+                ''
+            );
+            $vectorSize = mcrypt_enc_get_iv_size($this->_encDescriptor);
+            $this->_initVector = mcrypt_create_iv($vectorSize, MCRYPT_RAND);
+            $keySize = mcrypt_enc_get_key_size($this->_encDescriptor);
+            $key = substr(md5($encryptionKey), 0, $keySize);
+
+            mcrypt_generic_init(
+                $this->_encDescriptor,
+                $key,
+                $this->_initVector
+            );
+            $this->_encryptionKey = $encryptionKey;
+        }
+    }
+
+    /**
+     * Uninitialize the encryption descriptor.
+     *
+     * @return void
+     */
+    public function deinit()
+    {
+        if (is_resource($this->_encDescriptor)) {
+            mcrypt_generic_deinit($this->_encDescriptor);
+        }
+    }
+
+    /**
+     * Close the encryption descriptor
+     *
+     * @return void
+     */
+    public function close()
+    {
+        $this->deinit();
+        if (is_resource($this->_encDescriptor)) {
+            mcrypt_module_close($this->_encDescriptor);
+        }
+        $this->_encDescriptor = null;
+    }
+
+    /**
+     * Decodes an base64 encoded string.
+     *
+     * @param string $encodedString base64 encoded string
+     *
+     * @return sting
+     */
+    private function _base64Decode($encodedString)
+    {
+        if (substr($encodedString, 0, 1) !== $this->_cryptIdent) {
+            return $encodedString;
+        }
+        $encodedString = str_replace(
+            array('.', '_', '-'),
+            array('+', '/', '='),
+            substr($encodedString, 1)
+        );
+        $decodedString = base64_decode($encodedString);
+        return $decodedString;
+    }
+
+    /**
+     * Encode a string into base64 notation.
+     *
+     * @param string $plainString Plaintext
+     *
+     * @return string
+     */
+    private function _base64Encode($plainString)
+    {
+        $encodedString = base64_encode($plainString);
+        $encodedString = str_replace(
+            array('+', '/', '='),
+            array('.', '_', '-'),
+            $encodedString
+        );
+        return $this->_cryptIdent . $encodedString;
+    }
+
+    /**
+     * Decrypts a text.
+     *
+     * @param string $encryptedText Text to decrypt
+     *
+     * @return string
+     */
+    public function decrypt($encryptedText)
+    {
+        $encryptedText = $this->_base64Decode($encryptedText);
+        if (!is_resource($this->_encDescriptor)) {
+            $this->init($this->_encryptionKey);
+        }
+        $clearText = mdecrypt_generic(
+            $this->_encDescriptor,
+            $encryptedText
+        );
+        return trim($clearText);
+    }
+
+    /**
+     * Encrypts a text
+     *
+     * @param string $clearText Text to encrypt
+     *
+     * @return string
+     */
+    public function encrypt($clearText)
+    {
+        if (!is_resource($this->_encDescriptor)) {
+            $this->init();
+        }
+        $encryptedText = mcrypt_generic(
+            $this->_encDescriptor,
+            $clearText
+        );
+        return $this->_base64Encode($encryptedText);
+    }
+
+    /**
+     * Class destructor
+     *
+     * @return void
+     */
+    public function __destruct()
+    {
+        $this->close();
+    }
+}
+