diff options
Diffstat (limited to 'library/phpsec/Crypt/AES.php')
| -rw-r--r-- | library/phpsec/Crypt/AES.php | 479 |
1 files changed, 479 insertions, 0 deletions
diff --git a/library/phpsec/Crypt/AES.php b/library/phpsec/Crypt/AES.php new file mode 100644 index 000000000..681800a81 --- /dev/null +++ b/library/phpsec/Crypt/AES.php @@ -0,0 +1,479 @@ +<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Pure-PHP implementation of AES.
+ *
+ * Uses mcrypt, if available, and an internal implementation, otherwise.
+ *
+ * PHP versions 4 and 5
+ *
+ * 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 160-bits and 160 bits will be the key length until {@link Crypt_Rijndael::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: This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ * @category Crypt
+ * @package Crypt_AES
+ * @author Jim Wigginton <terrafrost@php.net>
+ * @copyright MMVIII Jim Wigginton
+ * @license http://www.gnu.org/licenses/lgpl.txt
+ * @version $Id: AES.php,v 1.7 2010/02/09 06:10:25 terrafrost Exp $
+ * @link http://phpseclib.sourceforge.net
+ */
+
+/**
+ * Include Crypt_Rijndael
+ */
+require_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', -1);
+/**
+ * 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', 1);
+/**
+ * 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', 2);
+/**#@-*/
+
+/**#@+
+ * @access private
+ * @see Crypt_AES::Crypt_AES()
+ */
+/**
+ * Toggles the internal implementation
+ */
+define('CRYPT_AES_MODE_INTERNAL', 1);
+/**
+ * Toggles the mcrypt implementation
+ */
+define('CRYPT_AES_MODE_MCRYPT', 2);
+/**#@-*/
+
+/**
+ * Pure-PHP implementation of AES.
+ *
+ * @author Jim Wigginton <terrafrost@php.net>
+ * @version 0.1.0
+ * @access public
+ * @package Crypt_AES
+ */
+class Crypt_AES extends Crypt_Rijndael {
+ /**
+ * mcrypt resource for encryption
+ *
+ * The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
+ * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
+ *
+ * @see Crypt_AES::encrypt()
+ * @var String
+ * @access private
+ */
+ var $enmcrypt;
+
+ /**
+ * mcrypt resource for decryption
+ *
+ * The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
+ * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
+ *
+ * @see Crypt_AES::decrypt()
+ * @var String
+ * @access private
+ */
+ var $demcrypt;
+
+ /**
+ * Default Constructor.
+ *
+ * Determines whether or not the mcrypt extension should be used. $mode should only, at present, be
+ * CRYPT_AES_MODE_ECB or CRYPT_AES_MODE_CBC. If not explictly set, CRYPT_AES_MODE_CBC will be used.
+ *
+ * @param optional Integer $mode
+ * @return Crypt_AES
+ * @access public
+ */
+ function Crypt_AES($mode = CRYPT_AES_MODE_CBC)
+ {
+ if ( !defined('CRYPT_AES_MODE') ) {
+ switch (true) {
+ case extension_loaded('mcrypt'):
+ // i'd check to see if aes was supported, by doing in_array('des', mcrypt_list_algorithms('')),
+ // but since that can be changed after the object has been created, there doesn't seem to be
+ // a lot of point...
+ define('CRYPT_AES_MODE', CRYPT_AES_MODE_MCRYPT);
+ break;
+ default:
+ define('CRYPT_AES_MODE', CRYPT_AES_MODE_INTERNAL);
+ }
+ }
+
+ switch ( CRYPT_AES_MODE ) {
+ case CRYPT_AES_MODE_MCRYPT:
+ switch ($mode) {
+ case CRYPT_AES_MODE_ECB:
+ $this->mode = MCRYPT_MODE_ECB;
+ break;
+ case CRYPT_AES_MODE_CTR:
+ // ctr doesn't have a constant associated with it even though it appears to be fairly widely
+ // supported. in lieu of knowing just how widely supported it is, i've, for now, opted not to
+ // include a compatibility layer. the layer has been implemented but, for now, is commented out.
+ $this->mode = 'ctr';
+ //$this->mode = in_array('ctr', mcrypt_list_modes()) ? 'ctr' : CRYPT_AES_MODE_CTR;
+ break;
+ case CRYPT_AES_MODE_CBC:
+ default:
+ $this->mode = MCRYPT_MODE_CBC;
+ }
+
+ break;
+ default:
+ switch ($mode) {
+ case CRYPT_AES_MODE_ECB:
+ $this->mode = CRYPT_RIJNDAEL_MODE_ECB;
+ break;
+ case CRYPT_AES_MODE_CTR:
+ $this->mode = CRYPT_RIJNDAEL_MODE_CTR;
+ break;
+ case CRYPT_AES_MODE_CBC:
+ default:
+ $this->mode = CRYPT_RIJNDAEL_MODE_CBC;
+ }
+ }
+
+ if (CRYPT_AES_MODE == CRYPT_AES_MODE_INTERNAL) {
+ parent::Crypt_Rijndael($this->mode);
+ }
+ }
+
+ /**
+ * Dummy function
+ *
+ * Since Crypt_AES extends Crypt_Rijndael, this function is, technically, available, but it doesn't do anything.
+ *
+ * @access public
+ * @param Integer $length
+ */
+ function setBlockLength($length)
+ {
+ return;
+ }
+
+ /**
+ * Encrypts a message.
+ *
+ * $plaintext will be padded with up to 16 additional bytes. Other AES implementations may or may not pad in the
+ * same manner. Other common approaches to padding and the reasons why it's necessary are discussed in the following
+ * URL:
+ *
+ * {@link http://www.di-mgt.com.au/cryptopad.html http://www.di-mgt.com.au/cryptopad.html}
+ *
+ * An alternative to padding is to, separately, send the length of the file. This is what SSH, in fact, does.
+ * strlen($plaintext) will still need to be a multiple of 16, however, arbitrary values can be added to make it that
+ * length.
+ *
+ * @see Crypt_AES::decrypt()
+ * @access public
+ * @param String $plaintext
+ */
+ function encrypt($plaintext)
+ {
+ if ( CRYPT_AES_MODE == CRYPT_AES_MODE_MCRYPT ) {
+ $this->_mcryptSetup();
+ /*
+ if ($this->mode == CRYPT_AES_MODE_CTR) {
+ $iv = $this->encryptIV;
+ $xor = mcrypt_generic($this->enmcrypt, $this->_generate_xor(strlen($plaintext), $iv));
+ $ciphertext = $plaintext ^ $xor;
+ if ($this->continuousBuffer) {
+ $this->encryptIV = $iv;
+ }
+ return $ciphertext;
+ }
+ */
+
+ if ($this->mode != 'ctr') {
+ $plaintext = $this->_pad($plaintext);
+ }
+
+ $ciphertext = mcrypt_generic($this->enmcrypt, $plaintext);
+
+ if (!$this->continuousBuffer) {
+ mcrypt_generic_init($this->enmcrypt, $this->key, $this->iv);
+ }
+
+ return $ciphertext;
+ }
+
+ return parent::encrypt($plaintext);
+ }
+
+ /**
+ * Decrypts a message.
+ *
+ * If strlen($ciphertext) is not a multiple of 16, null bytes will be added to the end of the string until it is.
+ *
+ * @see Crypt_AES::encrypt()
+ * @access public
+ * @param String $ciphertext
+ */
+ function decrypt($ciphertext)
+ {
+ if ( CRYPT_AES_MODE == CRYPT_AES_MODE_MCRYPT ) {
+ $this->_mcryptSetup();
+ /*
+ if ($this->mode == CRYPT_AES_MODE_CTR) {
+ $iv = $this->decryptIV;
+ $xor = mcrypt_generic($this->enmcrypt, $this->_generate_xor(strlen($ciphertext), $iv));
+ $plaintext = $ciphertext ^ $xor;
+ if ($this->continuousBuffer) {
+ $this->decryptIV = $iv;
+ }
+ return $plaintext;
+ }
+ */
+
+ if ($this->mode != 'ctr') {
+ // we pad with chr(0) since that's what mcrypt_generic does. to quote from http://php.net/function.mcrypt-generic :
+ // "The data is padded with "\0" to make sure the length of the data is n * blocksize."
+ $ciphertext = str_pad($ciphertext, (strlen($ciphertext) + 15) & 0xFFFFFFF0, chr(0));
+ }
+
+ $plaintext = mdecrypt_generic($this->demcrypt, $ciphertext);
+
+ if (!$this->continuousBuffer) {
+ mcrypt_generic_init($this->demcrypt, $this->key, $this->iv);
+ }
+
+ return $this->mode != 'ctr' ? $this->_unpad($plaintext) : $plaintext;
+ }
+
+ return parent::decrypt($ciphertext);
+ }
+
+ /**
+ * Setup mcrypt
+ *
+ * Validates all the variables.
+ *
+ * @access private
+ */
+ function _mcryptSetup()
+ {
+ if (!$this->changed) {
+ return;
+ }
+
+ if (!$this->explicit_key_length) {
+ // this just copied from Crypt_Rijndael::_setup()
+ $length = strlen($this->key) >> 2;
+ if ($length > 8) {
+ $length = 8;
+ } else if ($length < 4) {
+ $length = 4;
+ }
+ $this->Nk = $length;
+ $this->key_size = $length << 2;
+ }
+
+ switch ($this->Nk) {
+ case 4: // 128
+ $this->key_size = 16;
+ break;
+ case 5: // 160
+ case 6: // 192
+ $this->key_size = 24;
+ break;
+ case 7: // 224
+ case 8: // 256
+ $this->key_size = 32;
+ }
+
+ $this->key = substr($this->key, 0, $this->key_size);
+ $this->encryptIV = $this->decryptIV = $this->iv = str_pad(substr($this->iv, 0, 16), 16, chr(0));
+
+ if (!isset($this->enmcrypt)) {
+ $mode = $this->mode;
+ //$mode = $this->mode == CRYPT_AES_MODE_CTR ? MCRYPT_MODE_ECB : $this->mode;
+
+ $this->demcrypt = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', $mode, '');
+ $this->enmcrypt = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', $mode, '');
+ } // else should mcrypt_generic_deinit be called?
+
+ mcrypt_generic_init($this->demcrypt, $this->key, $this->iv);
+ mcrypt_generic_init($this->enmcrypt, $this->key, $this->iv);
+
+ $this->changed = false;
+ }
+
+ /**
+ * Encrypts a block
+ *
+ * Optimized over Crypt_Rijndael's implementation by means of loop unrolling.
+ *
+ * @see Crypt_Rijndael::_encryptBlock()
+ * @access private
+ * @param String $in
+ * @return String
+ */
+ function _encryptBlock($in)
+ {
+ $state = unpack('N*word', $in);
+
+ $Nr = $this->Nr;
+ $w = $this->w;
+ $t0 = $this->t0;
+ $t1 = $this->t1;
+ $t2 = $this->t2;
+ $t3 = $this->t3;
+
+ // addRoundKey and reindex $state
+ $state = array(
+ $state['word1'] ^ $w[0][0],
+ $state['word2'] ^ $w[0][1],
+ $state['word3'] ^ $w[0][2],
+ $state['word4'] ^ $w[0][3]
+ );
+
+ // shiftRows + subWord + mixColumns + addRoundKey
+ // we could loop unroll this and use if statements to do more rounds as necessary, but, in my tests, that yields
+ // only a marginal improvement. since that also, imho, hinders the readability of the code, i've opted not to do it.
+ for ($round = 1; $round < $this->Nr; $round++) {
+ $state = array(
+ $t0[$state[0] & 0xFF000000] ^ $t1[$state[1] & 0x00FF0000] ^ $t2[$state[2] & 0x0000FF00] ^ $t3[$state[3] & 0x000000FF] ^ $w[$round][0],
+ $t0[$state[1] & 0xFF000000] ^ $t1[$state[2] & 0x00FF0000] ^ $t2[$state[3] & 0x0000FF00] ^ $t3[$state[0] & 0x000000FF] ^ $w[$round][1],
+ $t0[$state[2] & 0xFF000000] ^ $t1[$state[3] & 0x00FF0000] ^ $t2[$state[0] & 0x0000FF00] ^ $t3[$state[1] & 0x000000FF] ^ $w[$round][2],
+ $t0[$state[3] & 0xFF000000] ^ $t1[$state[0] & 0x00FF0000] ^ $t2[$state[1] & 0x0000FF00] ^ $t3[$state[2] & 0x000000FF] ^ $w[$round][3]
+ );
+
+ }
+
+ // subWord
+ $state = array(
+ $this->_subWord($state[0]),
+ $this->_subWord($state[1]),
+ $this->_subWord($state[2]),
+ $this->_subWord($state[3])
+ );
+
+ // shiftRows + addRoundKey
+ $state = array(
+ ($state[0] & 0xFF000000) ^ ($state[1] & 0x00FF0000) ^ ($state[2] & 0x0000FF00) ^ ($state[3] & 0x000000FF) ^ $this->w[$this->Nr][0],
+ ($state[1] & 0xFF000000) ^ ($state[2] & 0x00FF0000) ^ ($state[3] & 0x0000FF00) ^ ($state[0] & 0x000000FF) ^ $this->w[$this->Nr][1],
+ ($state[2] & 0xFF000000) ^ ($state[3] & 0x00FF0000) ^ ($state[0] & 0x0000FF00) ^ ($state[1] & 0x000000FF) ^ $this->w[$this->Nr][2],
+ ($state[3] & 0xFF000000) ^ ($state[0] & 0x00FF0000) ^ ($state[1] & 0x0000FF00) ^ ($state[2] & 0x000000FF) ^ $this->w[$this->Nr][3]
+ );
+
+ return pack('N*', $state[0], $state[1], $state[2], $state[3]);
+ }
+
+ /**
+ * Decrypts a block
+ *
+ * Optimized over Crypt_Rijndael's implementation by means of loop unrolling.
+ *
+ * @see Crypt_Rijndael::_decryptBlock()
+ * @access private
+ * @param String $in
+ * @return String
+ */
+ function _decryptBlock($in)
+ {
+ $state = unpack('N*word', $in);
+
+ $Nr = $this->Nr;
+ $dw = $this->dw;
+ $dt0 = $this->dt0;
+ $dt1 = $this->dt1;
+ $dt2 = $this->dt2;
+ $dt3 = $this->dt3;
+
+ // addRoundKey and reindex $state
+ $state = array(
+ $state['word1'] ^ $dw[$this->Nr][0],
+ $state['word2'] ^ $dw[$this->Nr][1],
+ $state['word3'] ^ $dw[$this->Nr][2],
+ $state['word4'] ^ $dw[$this->Nr][3]
+ );
+
+
+ // invShiftRows + invSubBytes + invMixColumns + addRoundKey
+ for ($round = $this->Nr - 1; $round > 0; $round--) {
+ $state = array(
+ $dt0[$state[0] & 0xFF000000] ^ $dt1[$state[3] & 0x00FF0000] ^ $dt2[$state[2] & 0x0000FF00] ^ $dt3[$state[1] & 0x000000FF] ^ $dw[$round][0],
+ $dt0[$state[1] & 0xFF000000] ^ $dt1[$state[0] & 0x00FF0000] ^ $dt2[$state[3] & 0x0000FF00] ^ $dt3[$state[2] & 0x000000FF] ^ $dw[$round][1],
+ $dt0[$state[2] & 0xFF000000] ^ $dt1[$state[1] & 0x00FF0000] ^ $dt2[$state[0] & 0x0000FF00] ^ $dt3[$state[3] & 0x000000FF] ^ $dw[$round][2],
+ $dt0[$state[3] & 0xFF000000] ^ $dt1[$state[2] & 0x00FF0000] ^ $dt2[$state[1] & 0x0000FF00] ^ $dt3[$state[0] & 0x000000FF] ^ $dw[$round][3]
+ );
+ }
+
+ // invShiftRows + invSubWord + addRoundKey
+ $state = array(
+ $this->_invSubWord(($state[0] & 0xFF000000) ^ ($state[3] & 0x00FF0000) ^ ($state[2] & 0x0000FF00) ^ ($state[1] & 0x000000FF)) ^ $dw[0][0],
+ $this->_invSubWord(($state[1] & 0xFF000000) ^ ($state[0] & 0x00FF0000) ^ ($state[3] & 0x0000FF00) ^ ($state[2] & 0x000000FF)) ^ $dw[0][1],
+ $this->_invSubWord(($state[2] & 0xFF000000) ^ ($state[1] & 0x00FF0000) ^ ($state[0] & 0x0000FF00) ^ ($state[3] & 0x000000FF)) ^ $dw[0][2],
+ $this->_invSubWord(($state[3] & 0xFF000000) ^ ($state[2] & 0x00FF0000) ^ ($state[1] & 0x0000FF00) ^ ($state[0] & 0x000000FF)) ^ $dw[0][3]
+ );
+
+ return pack('N*', $state[0], $state[1], $state[2], $state[3]);
+ }
+}
+
+// vim: ts=4:sw=4:et:
+// vim6: fdl=1:
\ No newline at end of file |