--- /dev/null
+<?php
+
+/**
+ * Pure-PHP implementation of Triple DES.
+ *
+ * Uses mcrypt, if available, and an internal implementation, otherwise. Operates in the EDE3 mode (encrypt-decrypt-encrypt).
+ *
+ * PHP versions 4 and 5
+ *
+ * Here's a short example of how to use this library:
+ * <code>
+ * <?php
+ * include 'Crypt/TripleDES.php';
+ *
+ * $des = new Crypt_TripleDES();
+ *
+ * $des->setKey('abcdefghijklmnopqrstuvwx');
+ *
+ * $size = 10 * 1024;
+ * $plaintext = '';
+ * for ($i = 0; $i < $size; $i++) {
+ * $plaintext.= 'a';
+ * }
+ *
+ * echo $des->decrypt($des->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_TripleDES
+ * @author Jim Wigginton <terrafrost@php.net>
+ * @copyright 2007 Jim Wigginton
+ * @license http://www.opensource.org/licenses/mit-license.html MIT License
+ * @link http://phpseclib.sourceforge.net
+ */
+
+/**
+ * Include Crypt_DES
+ */
+if (!class_exists('Crypt_DES')) {
+ include_once 'DES.php';
+}
+
+/**
+ * Encrypt / decrypt using inner chaining
+ *
+ * Inner chaining is used by SSH-1 and is generally considered to be less secure then outer chaining (CRYPT_DES_MODE_CBC3).
+ */
+define('CRYPT_DES_MODE_3CBC', -2);
+
+/**
+ * Encrypt / decrypt using outer chaining
+ *
+ * Outer chaining is used by SSH-2 and when the mode is set to CRYPT_DES_MODE_CBC.
+ */
+define('CRYPT_DES_MODE_CBC3', CRYPT_DES_MODE_CBC);
+
+/**
+ * Pure-PHP implementation of Triple DES.
+ *
+ * @package Crypt_TripleDES
+ * @author Jim Wigginton <terrafrost@php.net>
+ * @access public
+ */
+class Crypt_TripleDES extends Crypt_DES
+{
+ /**
+ * The default password key_size used by setPassword()
+ *
+ * @see Crypt_DES::password_key_size
+ * @see Crypt_Base::password_key_size
+ * @see Crypt_Base::setPassword()
+ * @var Integer
+ * @access private
+ */
+ var $password_key_size = 24;
+
+ /**
+ * The default salt used by setPassword()
+ *
+ * @see Crypt_Base::password_default_salt
+ * @see Crypt_Base::setPassword()
+ * @var String
+ * @access private
+ */
+ var $password_default_salt = 'phpseclib';
+
+ /**
+ * The namespace used by the cipher for its constants.
+ *
+ * @see Crypt_DES::const_namespace
+ * @see Crypt_Base::const_namespace
+ * @var String
+ * @access private
+ */
+ var $const_namespace = 'DES';
+
+ /**
+ * The mcrypt specific name of the cipher
+ *
+ * @see Crypt_DES::cipher_name_mcrypt
+ * @see Crypt_Base::cipher_name_mcrypt
+ * @var String
+ * @access private
+ */
+ var $cipher_name_mcrypt = 'tripledes';
+
+ /**
+ * Optimizing value while CFB-encrypting
+ *
+ * @see Crypt_Base::cfb_init_len
+ * @var Integer
+ * @access private
+ */
+ var $cfb_init_len = 750;
+
+ /**
+ * max possible size of $key
+ *
+ * @see Crypt_TripleDES::setKey()
+ * @see Crypt_DES::setKey()
+ * @var String
+ * @access private
+ */
+ var $key_size_max = 24;
+
+ /**
+ * Internal flag whether using CRYPT_DES_MODE_3CBC or not
+ *
+ * @var Boolean
+ * @access private
+ */
+ var $mode_3cbc;
+
+ /**
+ * The Crypt_DES objects
+ *
+ * Used only if $mode_3cbc === true
+ *
+ * @var Array
+ * @access private
+ */
+ var $des;
+
+ /**
+ * Default Constructor.
+ *
+ * Determines whether or not the mcrypt extension should be used.
+ *
+ * $mode could be:
+ *
+ * - CRYPT_DES_MODE_ECB
+ *
+ * - CRYPT_DES_MODE_CBC
+ *
+ * - CRYPT_DES_MODE_CTR
+ *
+ * - CRYPT_DES_MODE_CFB
+ *
+ * - CRYPT_DES_MODE_OFB
+ *
+ * - CRYPT_DES_MODE_3CBC
+ *
+ * If not explicitly set, CRYPT_DES_MODE_CBC will be used.
+ *
+ * @see Crypt_DES::Crypt_DES()
+ * @see Crypt_Base::Crypt_Base()
+ * @param optional Integer $mode
+ * @access public
+ */
+ function Crypt_TripleDES($mode = CRYPT_DES_MODE_CBC)
+ {
+ switch ($mode) {
+ // In case of CRYPT_DES_MODE_3CBC, we init as CRYPT_DES_MODE_CBC
+ // and additional flag us internally as 3CBC
+ case CRYPT_DES_MODE_3CBC:
+ parent::Crypt_Base(CRYPT_DES_MODE_CBC);
+ $this->mode_3cbc = true;
+
+ // This three $des'es will do the 3CBC work (if $key > 64bits)
+ $this->des = array(
+ new Crypt_DES(CRYPT_DES_MODE_CBC),
+ new Crypt_DES(CRYPT_DES_MODE_CBC),
+ new Crypt_DES(CRYPT_DES_MODE_CBC),
+ );
+
+ // we're going to be doing the padding, ourselves, so disable it in the Crypt_DES objects
+ $this->des[0]->disablePadding();
+ $this->des[1]->disablePadding();
+ $this->des[2]->disablePadding();
+ break;
+ // If not 3CBC, we init as usual
+ default:
+ parent::Crypt_Base($mode);
+ }
+ }
+
+ /**
+ * Sets the initialization vector. (optional)
+ *
+ * SetIV is not required when CRYPT_DES_MODE_ECB is being used. If not explicitly set, it'll be assumed
+ * to be all zero's.
+ *
+ * @see Crypt_Base::setIV()
+ * @access public
+ * @param String $iv
+ */
+ function setIV($iv)
+ {
+ parent::setIV($iv);
+ if ($this->mode_3cbc) {
+ $this->des[0]->setIV($iv);
+ $this->des[1]->setIV($iv);
+ $this->des[2]->setIV($iv);
+ }
+ }
+
+ /**
+ * Sets the key.
+ *
+ * Keys can be of any length. Triple DES, itself, can use 128-bit (eg. strlen($key) == 16) or
+ * 192-bit (eg. strlen($key) == 24) keys. This function pads and truncates $key as appropriate.
+ *
+ * DES also requires that every eighth bit be a parity bit, however, we'll ignore that.
+ *
+ * If the key is not explicitly set, it'll be assumed to be all null bytes.
+ *
+ * @access public
+ * @see Crypt_DES::setKey()
+ * @see Crypt_Base::setKey()
+ * @param String $key
+ */
+ function setKey($key)
+ {
+ $length = strlen($key);
+ if ($length > 8) {
+ $key = str_pad(substr($key, 0, 24), 24, chr(0));
+ // if $key is between 64 and 128-bits, use the first 64-bits as the last, per this:
+ // http://php.net/function.mcrypt-encrypt#47973
+ //$key = $length <= 16 ? substr_replace($key, substr($key, 0, 8), 16) : substr($key, 0, 24);
+ } else {
+ $key = str_pad($key, 8, chr(0));
+ }
+ parent::setKey($key);
+
+ // And in case of CRYPT_DES_MODE_3CBC:
+ // if key <= 64bits we not need the 3 $des to work,
+ // because we will then act as regular DES-CBC with just a <= 64bit key.
+ // So only if the key > 64bits (> 8 bytes) we will call setKey() for the 3 $des.
+ if ($this->mode_3cbc && $length > 8) {
+ $this->des[0]->setKey(substr($key, 0, 8));
+ $this->des[1]->setKey(substr($key, 8, 8));
+ $this->des[2]->setKey(substr($key, 16, 8));
+ }
+ }
+
+ /**
+ * Encrypts a message.
+ *
+ * @see Crypt_Base::encrypt()
+ * @access public
+ * @param String $plaintext
+ * @return String $cipertext
+ */
+ function encrypt($plaintext)
+ {
+ // parent::en/decrypt() is able to do all the work for all modes and keylengths,
+ // except for: CRYPT_DES_MODE_3CBC (inner chaining CBC) with a key > 64bits
+
+ // if the key is smaller then 8, do what we'd normally do
+ if ($this->mode_3cbc && strlen($this->key) > 8) {
+ return $this->des[2]->encrypt(
+ $this->des[1]->decrypt(
+ $this->des[0]->encrypt(
+ $this->_pad($plaintext)
+ )
+ )
+ );
+ }
+
+ return parent::encrypt($plaintext);
+ }
+
+ /**
+ * Decrypts a message.
+ *
+ * @see Crypt_Base::decrypt()
+ * @access public
+ * @param String $ciphertext
+ * @return String $plaintext
+ */
+ function decrypt($ciphertext)
+ {
+ if ($this->mode_3cbc && strlen($this->key) > 8) {
+ return $this->_unpad(
+ $this->des[0]->decrypt(
+ $this->des[1]->encrypt(
+ $this->des[2]->decrypt(
+ str_pad($ciphertext, (strlen($ciphertext) + 7) & 0xFFFFFFF8, "\0")
+ )
+ )
+ )
+ );
+ }
+
+ return parent::decrypt($ciphertext);
+ }
+
+ /**
+ * Treat consecutive "packets" as if they are a continuous buffer.
+ *
+ * Say you have a 16-byte plaintext $plaintext. Using the default behavior, the two following code snippets
+ * will yield different outputs:
+ *
+ * <code>
+ * echo $des->encrypt(substr($plaintext, 0, 8));
+ * echo $des->encrypt(substr($plaintext, 8, 8));
+ * </code>
+ * <code>
+ * echo $des->encrypt($plaintext);
+ * </code>
+ *
+ * The solution is to enable the continuous buffer. Although this will resolve the above discrepancy, it creates
+ * another, as demonstrated with the following:
+ *
+ * <code>
+ * $des->encrypt(substr($plaintext, 0, 8));
+ * echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8)));
+ * </code>
+ * <code>
+ * echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8)));
+ * </code>
+ *
+ * With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different
+ * outputs. The reason is due to the fact that the initialization vector's change after every encryption /
+ * decryption round when the continuous buffer is enabled. When it's disabled, they remain constant.
+ *
+ * Put another way, when the continuous buffer is enabled, the state of the Crypt_DES() object changes after each
+ * encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that
+ * continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them),
+ * however, they are also less intuitive and more likely to cause you problems.
+ *
+ * @see Crypt_Base::enableContinuousBuffer()
+ * @see Crypt_TripleDES::disableContinuousBuffer()
+ * @access public
+ */
+ function enableContinuousBuffer()
+ {
+ parent::enableContinuousBuffer();
+ if ($this->mode_3cbc) {
+ $this->des[0]->enableContinuousBuffer();
+ $this->des[1]->enableContinuousBuffer();
+ $this->des[2]->enableContinuousBuffer();
+ }
+ }
+
+ /**
+ * Treat consecutive packets as if they are a discontinuous buffer.
+ *
+ * The default behavior.
+ *
+ * @see Crypt_Base::disableContinuousBuffer()
+ * @see Crypt_TripleDES::enableContinuousBuffer()
+ * @access public
+ */
+ function disableContinuousBuffer()
+ {
+ parent::disableContinuousBuffer();
+ if ($this->mode_3cbc) {
+ $this->des[0]->disableContinuousBuffer();
+ $this->des[1]->disableContinuousBuffer();
+ $this->des[2]->disableContinuousBuffer();
+ }
+ }
+
+ /**
+ * Creates the key schedule
+ *
+ * @see Crypt_DES::_setupKey()
+ * @see Crypt_Base::_setupKey()
+ * @access private
+ */
+ function _setupKey()
+ {
+ switch (true) {
+ // if $key <= 64bits we configure our internal pure-php cipher engine
+ // to act as regular [1]DES, not as 3DES. mcrypt.so::tripledes does the same.
+ case strlen($this->key) <= 8:
+ $this->des_rounds = 1;
+ break;
+
+ // otherwise, if $key > 64bits, we configure our engine to work as 3DES.
+ default:
+ $this->des_rounds = 3;
+
+ // (only) if 3CBC is used we have, of course, to setup the $des[0-2] keys also separately.
+ if ($this->mode_3cbc) {
+ $this->des[0]->_setupKey();
+ $this->des[1]->_setupKey();
+ $this->des[2]->_setupKey();
+
+ // because $des[0-2] will, now, do all the work we can return here
+ // not need unnecessary stress parent::_setupKey() with our, now unused, $key.
+ return;
+ }
+ }
+ // setup our key
+ parent::_setupKey();
+ }
+}
projects / friendica-addons.git / blobdiff