port password encryption from Java to PHP!

src/phpseclib/Crypt/AES.php

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+<?php
+
+/**
+ * Pure-PHP implementation of AES.
+ *
+ * Uses mcrypt, if available/possible, and an internal implementation, otherwise.
+ *
+ * PHP versions 4 and 5
+ *
+ * NOTE: Since AES.php is (for compatibility and phpseclib-historical reasons) virtually 
+ * just a wrapper to Rijndael.php you may consider using Rijndael.php instead of
+ * to save one include_once().
+ *
+ * If {@link Crypt_AES::setKeyLength() setKeyLength()} isn't called, it'll be calculated from
+ * {@link Crypt_AES::setKey() setKey()}.  ie. if the key is 128-bits, the key length will be 128-bits.  If it's 136-bits
+ * it'll be null-padded to 192-bits and 192 bits will be the key length until {@link Crypt_AES::setKey() setKey()}
+ * is called, again, at which point, it'll be recalculated.
+ *
+ * Since Crypt_AES extends Crypt_Rijndael, some functions are available to be called that, in the context of AES, don't
+ * make a whole lot of sense.  {@link Crypt_AES::setBlockLength() setBlockLength()}, for instance.  Calling that function,
+ * however possible, won't do anything (AES has a fixed block length whereas Rijndael has a variable one).
+ *
+ * Here's a short example of how to use this library:
+ * <code>
+ * <?php
+ *    include 'Crypt/AES.php';
+ *
+ *    $aes = new Crypt_AES();
+ *
+ *    $aes->setKey('abcdefghijklmnop');
+ *
+ *    $size = 10 * 1024;
+ *    $plaintext = '';
+ *    for ($i = 0; $i < $size; $i++) {
+ *        $plaintext.= 'a';
+ *    }
+ *
+ *    echo $aes->decrypt($aes->encrypt($plaintext));
+ * ?>
+ * </code>
+ *
+ * LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @category  Crypt
+ * @package   Crypt_AES
+ * @author    Jim Wigginton <[email protected]>
+ * @copyright 2008 Jim Wigginton
+ * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @link      http://phpseclib.sourceforge.net
+ */
+
+/**
+ * Include Crypt_Rijndael
+ */
+if (!class_exists('Crypt_Rijndael')) {
+    include_once 'Rijndael.php';
+}
+
+/**#@+
+ * @access public
+ * @see Crypt_AES::encrypt()
+ * @see Crypt_AES::decrypt()
+ */
+/**
+ * Encrypt / decrypt using the Counter mode.
+ *
+ * Set to -1 since that's what Crypt/Random.php uses to index the CTR mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Counter_.28CTR.29
+ */
+define('CRYPT_AES_MODE_CTR', CRYPT_MODE_CTR);
+/**
+ * Encrypt / decrypt using the Electronic Code Book mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29
+ */
+define('CRYPT_AES_MODE_ECB', CRYPT_MODE_ECB);
+/**
+ * Encrypt / decrypt using the Code Book Chaining mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher-block_chaining_.28CBC.29
+ */
+define('CRYPT_AES_MODE_CBC', CRYPT_MODE_CBC);
+/**
+ * Encrypt / decrypt using the Cipher Feedback mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher_feedback_.28CFB.29
+ */
+define('CRYPT_AES_MODE_CFB', CRYPT_MODE_CFB);
+/**
+ * Encrypt / decrypt using the Cipher Feedback mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Output_feedback_.28OFB.29
+ */
+define('CRYPT_AES_MODE_OFB', CRYPT_MODE_OFB);
+/**#@-*/
+
+/**
+ * Pure-PHP implementation of AES.
+ *
+ * @package Crypt_AES
+ * @author  Jim Wigginton <[email protected]>
+ * @access  public
+ */
+class Crypt_AES extends Crypt_Rijndael
+{
+    /**
+     * The namespace used by the cipher for its constants.
+     *
+     * @see Crypt_Base::const_namespace
+     * @var String
+     * @access private
+     */
+    var $const_namespace = 'AES';
+
+    /**
+     * Dummy function
+     *
+     * Since Crypt_AES extends Crypt_Rijndael, this function is, technically, available, but it doesn't do anything.
+     *
+     * @see Crypt_Rijndael::setBlockLength()
+     * @access public
+     * @param Integer $length
+     */
+    function setBlockLength($length)
+    {
+        return;
+    }
+
+    /**
+     * Sets the key length
+     *
+     * Valid key lengths are 128, 192, and 256.  If the length is less than 128, it will be rounded up to
+     * 128.  If the length is greater than 128 and invalid, it will be rounded down to the closest valid amount.
+     *
+     * @see Crypt_Rijndael:setKeyLength()
+     * @access public
+     * @param Integer $length
+     */
+    function setKeyLength($length)
+    {
+        switch ($length) {
+            case 160:
+                $length = 192;
+                break;
+            case 224:
+                $length = 256;
+        }
+        parent::setKeyLength($length);
+    }
+
+    /**
+     * Sets the key.
+     *
+     * Rijndael supports five different key lengths, AES only supports three.
+     *
+     * @see Crypt_Rijndael:setKey()
+     * @see setKeyLength()
+     * @access public
+     * @param String $key
+     */
+    function setKey($key)
+    {
+        parent::setKey($key);
+
+        if (!$this->explicit_key_length) {
+            $length = strlen($key);
+            switch (true) {
+                case $length <= 16:
+                    $this->key_size = 16;
+                    break;
+                case $length <= 24:
+                    $this->key_size = 24;
+                    break;
+                default:
+                    $this->key_size = 32;
+            }
+            $this->_setEngine();
+        }
+    }
+}