/php5-3/core/tools/secure/crypt/Base.class.php
PHP | 1934 lines | 1097 code | 95 blank | 742 comment | 102 complexity | 157b6d0e244a322a501f2630e0112207 MD5 | raw file
Possible License(s): MPL-2.0-no-copyleft-exception
- <?php
- namespace core\tools\secure\crypt;
- /**
- * Base Class for all Crypt_* cipher classes
- *
- * PHP versions 4 and 5
- *
- * Internally for phpseclib developers:
- * If you plan to add a new cipher class, please note following rules:
- *
- * - The new Crypt_* cipher class should extend Base
- *
- * - Following methods are then required to be overridden/overloaded:
- *
- * - _encryptBlock()
- *
- * - _decryptBlock()
- *
- * - _setupKey()
- *
- * - All other methods are optional to be overridden/overloaded
- *
- * - Look at the source code of the current ciphers how they extend Base
- * and take one of them as a start up for the new cipher class.
- *
- * - Please read all the other comments/notes/hints here also for each class var/method
- *
- * 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 Base
- * @author Jim Wigginton <terrafrost@php.net>
- * @author Hans-Juergen Petrich <petrich@tronic-media.com>
- * @copyright MMVII Jim Wigginton
- * @license http://www.opensource.org/licenses/mit-license.html MIT License
- * @link http://phpseclib.sourceforge.net
- */
- /* * #@+
- * @access public
- * @see Base::encrypt()
- * @see Base::decrypt()
- */
- /**
- * Base Class for all Crypt_* cipher classes
- *
- * @package Base
- * @author Jim Wigginton <terrafrost@php.net>
- * @author Hans-Juergen Petrich <petrich@tronic-media.com>
- * @access public
- */
- class Base{
- /**
- * The Encryption Mode
- *
- * @see Base::Base()
- * @var Integer
- * @access private
- */
- private $mode;
- /**
- * The Block Length of the block cipher
- *
- * @var Integer
- * @access private
- */
- protected $block_size = 16;
- /**
- * The Key
- *
- * @see Base::setKey()
- * @var String
- * @access private
- */
- protected $key = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
- /**
- * The Initialization Vector
- *
- * @see Base::setIV()
- * @var String
- * @access private
- */
- private $iv;
- /**
- * A "sliding" Initialization Vector
- *
- * @see Base::enableContinuousBuffer()
- * @see Base::_clearBuffers()
- * @var String
- * @access private
- */
- private $encryptIV;
- /**
- * A "sliding" Initialization Vector
- *
- * @see Base::enableContinuousBuffer()
- * @see Base::_clearBuffers()
- * @var String
- * @access private
- */
- private $decryptIV;
- /**
- * Continuous Buffer status
- *
- * @see Base::enableContinuousBuffer()
- * @var Boolean
- * @access private
- */
- private $continuousBuffer = false;
- /**
- * Encryption buffer for CTR, OFB and CFB modes
- *
- * @see Base::encrypt()
- * @see Base::_clearBuffers()
- * @var Array
- * @access private
- */
- private $enbuffer;
- /**
- * Decryption buffer for CTR, OFB and CFB modes
- *
- * @see Base::decrypt()
- * @see Base::_clearBuffers()
- * @var Array
- * @access private
- */
- private $debuffer;
- /**
- * 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 Base::encrypt()
- * @var Resource
- * @access private
- */
- private $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 Base::decrypt()
- * @var Resource
- * @access private
- */
- private $demcrypt;
- /**
- * Does the enmcrypt resource need to be (re)initialized?
- *
- * @see Crypt_Twofish::setKey()
- * @see Crypt_Twofish::setIV()
- * @var Boolean
- * @access private
- */
- private $enchanged = true;
- /**
- * Does the demcrypt resource need to be (re)initialized?
- *
- * @see Crypt_Twofish::setKey()
- * @see Crypt_Twofish::setIV()
- * @var Boolean
- * @access private
- */
- private $dechanged = true;
- /**
- * mcrypt resource for CFB mode
- *
- * mcrypt's CFB mode, in (and only in) buffered context,
- * is broken, so phpseclib implements the CFB mode by it self,
- * even when the mcrypt php extension is available.
- *
- * In order to do the CFB-mode work (fast) phpseclib
- * use a separate ECB-mode mcrypt resource.
- *
- * @link http://phpseclib.sourceforge.net/cfb-demo.phps
- * @see Base::encrypt()
- * @see Base::decrypt()
- * @see Base::_setupMcrypt()
- * @var Resource
- * @access private
- */
- private $ecb;
- /**
- * Optimizing value while CFB-encrypting
- *
- * Only relevant if $continuousBuffer enabled
- * and $engine == CRYPT_MODE_MCRYPT
- *
- * It's faster to re-init $enmcrypt if
- * $buffer bytes > $cfb_init_len than
- * using the $ecb resource furthermore.
- *
- * This value depends of the chosen cipher
- * and the time it would be needed for it's
- * initialization [by mcrypt_generic_init()]
- * which, typically, depends on the complexity
- * on its internaly Key-expanding algorithm.
- *
- * @see Base::encrypt()
- * @var Integer
- * @access private
- */
- private $cfb_init_len = 600;
- /**
- * Does internal cipher state need to be (re)initialized?
- *
- * @see setKey()
- * @see setIV()
- * @see disableContinuousBuffer()
- * @var Boolean
- * @access private
- */
- private $changed = true;
- /**
- * Padding status
- *
- * @see Base::enablePadding()
- * @var Boolean
- * @access private
- */
- private $padding = true;
- /**
- * Is the mode one that is paddable?
- *
- * @see Base::Base()
- * @var Boolean
- * @access private
- */
- private $paddable = false;
- /**
- * Holds which crypt engine internaly should be use,
- * which will be determined automatically on __construct()
- *
- * Currently available $engines are:
- * - CRYPT_MODE_MCRYPT (fast, php-extension: mcrypt, extension_loaded('mcrypt') required)
- * - CRYPT_MODE_INTERNAL (slower, pure php-engine, no php-extension required)
- *
- * In the pipeline... maybe. But currently not available:
- * - CRYPT_MODE_OPENSSL (very fast, php-extension: openssl, extension_loaded('openssl') required)
- *
- * If possible, CRYPT_MODE_MCRYPT will be used for each cipher.
- * Otherwise CRYPT_MODE_INTERNAL
- *
- * @see Base::encrypt()
- * @see Base::decrypt()
- * @var Integer
- * @access private
- */
- protected $engine;
- /**
- * The mcrypt specific name of the cipher
- *
- * Only used if $engine == CRYPT_MODE_MCRYPT
- *
- * @link http://www.php.net/mcrypt_module_open
- * @link http://www.php.net/mcrypt_list_algorithms
- * @see Base::_setupMcrypt()
- * @var String
- * @access private
- */
- private $cipher_name_mcrypt;
- /**
- * The default password key_size used by setPassword()
- *
- * @see Base::setPassword()
- * @var Integer
- * @access private
- */
- private $password_key_size = 32;
- /**
- * The default salt used by setPassword()
- *
- * @see Base::setPassword()
- * @var String
- * @access private
- */
- private $password_default_salt = 'phpseclib/salt';
- /**
- * The namespace used by the cipher for its constants.
- *
- * ie: AES.php is using CRYPT_AES_MODE_* for its constants
- * so $const_namespace is AES
- *
- * DES.php is using CRYPT_DES_MODE_* for its constants
- * so $const_namespace is DES... and so on
- *
- * All CRYPT_<$const_namespace>_MODE_* are aliases of
- * the generic CRYPT_MODE_* constants, so both could be used
- * for each cipher.
- *
- * Example:
- * $aes = new Crypt_AES(CRYPT_AES_MODE_CFB); // $aes will operate in cfb mode
- * $aes = new Crypt_AES(CRYPT_MODE_CFB); // identical
- *
- * @see Base::Base()
- * @var String
- * @access private
- */
- protected $const_namespace;
- /**
- * The name of the performance-optimized callback function
- *
- * Used by encrypt() / decrypt()
- * only if $engine == CRYPT_MODE_INTERNAL
- *
- * @see Base::encrypt()
- * @see Base::decrypt()
- * @see Base::_setupInlineCrypt()
- * @see Base::$use_inline_crypt
- * @var Callback
- * @access private
- */
- private $inline_crypt;
- /**
- * Holds whether performance-optimized $inline_crypt() can/should be used.
- *
- * @see Base::encrypt()
- * @see Base::decrypt()
- * @see Base::inline_crypt
- * @var mixed
- * @access private
- */
- protected $use_inline_crypt;
- /**
- * Default Constructor.
- *
- * Determines whether or not the mcrypt extension should be used.
- *
- * $mode could be:
- *
- * - CRYPT_MODE_ECB
- *
- * - CRYPT_MODE_CBC
- *
- * - CRYPT_MODE_CTR
- *
- * - CRYPT_MODE_CFB
- *
- * - CRYPT_MODE_OFB
- *
- * (or the alias constants of the chosen cipher, for example for AES: CRYPT_AES_MODE_ECB or CRYPT_AES_MODE_CBC ...)
- *
- * If not explicitly set, CRYPT_MODE_CBC will be used.
- *
- * @param optional Integer $mode
- * @access public
- */
- public function __construct($mode = CRYPT_MODE_CBC){
- $const_crypt_mode = 'CRYPT_' . $this->const_namespace . '_MODE';
- // Determining the availibility of mcrypt support for the cipher
- if(!defined($const_crypt_mode)){
- switch(true){
- case extension_loaded('mcrypt') && in_array($this->cipher_name_mcrypt, mcrypt_list_algorithms()):
- define($const_crypt_mode, CRYPT_MODE_MCRYPT);
- break;
- default:
- define($const_crypt_mode, CRYPT_MODE_INTERNAL);
- }
- }
- // Determining which internal $engine should be used.
- // The fastes possible first.
- switch(true){
- case empty($this->cipher_name_mcrypt): // The cipher module has no mcrypt-engine support at all so we force CRYPT_MODE_INTERNAL
- $this->engine = CRYPT_MODE_INTERNAL;
- break;
- case constant($const_crypt_mode) == CRYPT_MODE_MCRYPT:
- $this->engine = CRYPT_MODE_MCRYPT;
- break;
- default:
- $this->engine = CRYPT_MODE_INTERNAL;
- }
- // $mode dependent settings
- switch($mode){
- case CRYPT_MODE_ECB:
- $this->paddable = true;
- $this->mode = $mode;
- break;
- case CRYPT_MODE_CTR:
- case CRYPT_MODE_CFB:
- case CRYPT_MODE_OFB:
- case CRYPT_MODE_STREAM:
- $this->mode = $mode;
- break;
- case CRYPT_MODE_CBC:
- default:
- $this->paddable = true;
- $this->mode = CRYPT_MODE_CBC;
- }
- // Determining whether inline crypting can be used by the cipher
- if($this->use_inline_crypt !== false && function_exists('create_function')){
- $this->use_inline_crypt = true;
- }
- }
- /**
- * Sets the initialization vector. (optional)
- *
- * SetIV is not required when CRYPT_MODE_ECB (or ie for AES: CRYPT_AES_MODE_ECB) is being used. If not explicitly set, it'll be assumed
- * to be all zero's.
- *
- * Note: Could, but not must, extend by the child Crypt_* class
- *
- * @access public
- * @param String $iv
- */
- public function setIV($iv){
- if($this->mode == CRYPT_MODE_ECB){
- return;
- }
- $this->iv = $iv;
- $this->changed = true;
- }
- /**
- * Sets the key.
- *
- * The min/max length(s) of the key depends on the cipher which is used.
- * If the key not fits the length(s) of the cipher it will paded with null bytes
- * up to the closest valid key length. If the key is more than max length,
- * we trim the excess bits.
- *
- * If the key is not explicitly set, it'll be assumed to be all null bytes.
- *
- * Note: Could, but not must, extend by the child Crypt_* class
- *
- * @access public
- * @param String $key
- */
- public function setKey($key){
- $this->key = $key;
- $this->changed = true;
- }
- /**
- * Sets the password.
- *
- * Depending on what $method is set to, setPassword()'s (optional) parameters are as follows:
- * {@link http://en.wikipedia.org/wiki/PBKDF2 pbkdf2} or pbkdf1:
- * $hash, $salt, $count, $dkLen
- *
- * Where $hash (default = sha1) currently supports the following hashes: see: Crypt/Hash.php
- *
- * Note: Could, but not must, extend by the child Crypt_* class
- *
- * @see Crypt/Hash.php
- * @param String $password
- * @param optional String $method
- * @return Boolean
- * @access public
- */
- public function setPassword($password, $method = 'pbkdf2'){
- $key = '';
- switch($method){
- default: // 'pbkdf2' or 'pbkdf1'
- $func_args = func_get_args();
- // Hash function
- $hash = isset($func_args[2]) ? $func_args[2] : 'sha1';
- // WPA and WPA2 use the SSID as the salt
- $salt = isset($func_args[3]) ? $func_args[3] : $this->password_default_salt;
- // RFC2898#section-4.2 uses 1,000 iterations by default
- // WPA and WPA2 use 4,096.
- $count = isset($func_args[4]) ? $func_args[4] : 1000;
- // Keylength
- if(isset($func_args[5])){
- $dkLen = $func_args[5];
- }else{
- $dkLen = $method == 'pbkdf1' ? 2 * $this->password_key_size : $this->password_key_size;
- }
- switch(true){
- case $method == 'pbkdf1':
- if(!class_exists('Crypt_Hash')){
- include_once 'Crypt/Hash.php';
- }
- $hashObj = new Crypt_Hash();
- $hashObj->setHash($hash);
- if($dkLen > $hashObj->getLength()){
- user_error('Derived key too long');
- return false;
- }
- $t = $password . $salt;
- for($i = 0; $i < $count; ++$i){
- $t = $hashObj->hash($t);
- }
- $key = substr($t, 0, $dkLen);
- $this->setKey(substr($key, 0, $dkLen >> 1));
- $this->setIV(substr($key, $dkLen >> 1));
- return true;
- // Determining if php[>=5.5.0]'s hash_pbkdf2() function avail- and useable
- case!function_exists('hash_pbkdf2'):
- case!function_exists('hash_algos'):
- case!in_array($hash, hash_algos()):
- if(!class_exists('Crypt_Hash')){
- include_once 'Crypt/Hash.php';
- }
- $i = 1;
- while(strlen($key) < $dkLen){
- $hmac = new Crypt_Hash();
- $hmac->setHash($hash);
- $hmac->setKey($password);
- $f = $u = $hmac->hash($salt . pack('N', $i++));
- for($j = 2; $j <= $count; ++$j){
- $u = $hmac->hash($u);
- $f^= $u;
- }
- $key.= $f;
- }
- $key = substr($key, 0, $dkLen);
- break;
- default:
- $key = hash_pbkdf2($hash, $password, $salt, $count, $dkLen, true);
- }
- }
- $this->setKey($key);
- return true;
- }
- /**
- * Encrypts a message.
- *
- * $plaintext will be padded with additional bytes such that it's length is a multiple of the block size. Other cipher
- * implementations may or may not pad in the same manner. Other common approaches to padding and the reasons why it's
- * necessary are discussed in the following
- * URL:
- *
- * {@link http://www.di-mgt.com.au/cryptopad.html http://www.di-mgt.com.au/cryptopad.html}
- *
- * An alternative to padding is to, separately, send the length of the file. This is what SSH, in fact, does.
- * strlen($plaintext) will still need to be a multiple of the block size, however, arbitrary values can be added to make it that
- * length.
- *
- * Note: Could, but not must, extend by the child Crypt_* class
- *
- * @see Base::decrypt()
- * @access public
- * @param String $plaintext
- * @return String $cipertext
- */
- public function encrypt($plaintext){
- if($this->engine == CRYPT_MODE_MCRYPT){
- if($this->changed){
- $this->_setupMcrypt();
- $this->changed = false;
- }
- if($this->enchanged){
- mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV);
- $this->enchanged = false;
- }
- // re: {@link http://phpseclib.sourceforge.net/cfb-demo.phps}
- // using mcrypt's default handing of CFB the above would output two different things. using phpseclib's
- // rewritten CFB implementation the above outputs the same thing twice.
- if($this->mode == CRYPT_MODE_CFB && $this->continuousBuffer){
- $block_size = $this->block_size;
- $iv = &$this->encryptIV;
- $pos = &$this->enbuffer['pos'];
- $len = strlen($plaintext);
- $ciphertext = '';
- $i = 0;
- if($pos){
- $orig_pos = $pos;
- $max = $block_size - $pos;
- if($len >= $max){
- $i = $max;
- $len-= $max;
- $pos = 0;
- }else{
- $i = $len;
- $pos+= $len;
- $len = 0;
- }
- $ciphertext = substr($iv, $orig_pos) ^ $plaintext;
- $iv = substr_replace($iv, $ciphertext, $orig_pos, $i);
- $this->enbuffer['enmcrypt_init'] = true;
- }
- if($len >= $block_size){
- if($this->enbuffer['enmcrypt_init'] === false || $len > $this->cfb_init_len){
- if($this->enbuffer['enmcrypt_init'] === true){
- mcrypt_generic_init($this->enmcrypt, $this->key, $iv);
- $this->enbuffer['enmcrypt_init'] = false;
- }
- $ciphertext.= mcrypt_generic($this->enmcrypt, substr($plaintext, $i, $len - $len % $block_size));
- $iv = substr($ciphertext, -$block_size);
- $len%= $block_size;
- }else{
- while($len >= $block_size){
- $iv = mcrypt_generic($this->ecb, $iv) ^ substr($plaintext, $i, $block_size);
- $ciphertext.= $iv;
- $len-= $block_size;
- $i+= $block_size;
- }
- }
- }
- if($len){
- $iv = mcrypt_generic($this->ecb, $iv);
- $block = $iv ^ substr($plaintext, -$len);
- $iv = substr_replace($iv, $block, 0, $len);
- $ciphertext.= $block;
- $pos = $len;
- }
- return $ciphertext;
- }
- if($this->paddable){
- $plaintext = $this->_pad($plaintext);
- }
- $ciphertext = mcrypt_generic($this->enmcrypt, $plaintext);
- if(!$this->continuousBuffer){
- mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV);
- }
- return $ciphertext;
- }
- if($this->changed){
- $this->_setup();
- $this->changed = false;
- }
- if($this->use_inline_crypt){
- $inline = $this->inline_crypt;
- return $inline('encrypt', $this, $plaintext);
- }
- if($this->paddable){
- $plaintext = $this->_pad($plaintext);
- }
- $buffer = &$this->enbuffer;
- $block_size = $this->block_size;
- $ciphertext = '';
- switch($this->mode){
- case CRYPT_MODE_ECB:
- for($i = 0; $i < strlen($plaintext); $i+=$block_size){
- $ciphertext.= $this->_encryptBlock(substr($plaintext, $i, $block_size));
- }
- break;
- case CRYPT_MODE_CBC:
- $xor = $this->encryptIV;
- for($i = 0; $i < strlen($plaintext); $i+=$block_size){
- $block = substr($plaintext, $i, $block_size);
- $block = $this->_encryptBlock($block ^ $xor);
- $xor = $block;
- $ciphertext.= $block;
- }
- if($this->continuousBuffer){
- $this->encryptIV = $xor;
- }
- break;
- case CRYPT_MODE_CTR:
- $xor = $this->encryptIV;
- if(strlen($buffer['encrypted'])){
- for($i = 0; $i < strlen($plaintext); $i+=$block_size){
- $block = substr($plaintext, $i, $block_size);
- if(strlen($block) > strlen($buffer['encrypted'])){
- $buffer['encrypted'].= $this->_encryptBlock($this->_generateXor($xor, $block_size));
- }
- $key = $this->_stringShift($buffer['encrypted'], $block_size);
- $ciphertext.= $block ^ $key;
- }
- }else{
- for($i = 0; $i < strlen($plaintext); $i+=$block_size){
- $block = substr($plaintext, $i, $block_size);
- $key = $this->_encryptBlock($this->_generateXor($xor, $block_size));
- $ciphertext.= $block ^ $key;
- }
- }
- if($this->continuousBuffer){
- $this->encryptIV = $xor;
- if($start = strlen($plaintext) % $block_size){
- $buffer['encrypted'] = substr($key, $start) . $buffer['encrypted'];
- }
- }
- break;
- case CRYPT_MODE_CFB:
- // cfb loosely routines inspired by openssl's:
- // {@link http://cvs.openssl.org/fileview?f=openssl/crypto/modes/cfb128.c&v=1.3.2.2.2.1}
- if($this->continuousBuffer){
- $iv = &$this->encryptIV;
- $pos = &$buffer['pos'];
- }else{
- $iv = $this->encryptIV;
- $pos = 0;
- }
- $len = strlen($plaintext);
- $i = 0;
- if($pos){
- $orig_pos = $pos;
- $max = $block_size - $pos;
- if($len >= $max){
- $i = $max;
- $len-= $max;
- $pos = 0;
- }else{
- $i = $len;
- $pos+= $len;
- $len = 0;
- }
- // ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize
- $ciphertext = substr($iv, $orig_pos) ^ $plaintext;
- $iv = substr_replace($iv, $ciphertext, $orig_pos, $i);
- }
- while($len >= $block_size){
- $iv = $this->_encryptBlock($iv) ^ substr($plaintext, $i, $block_size);
- $ciphertext.= $iv;
- $len-= $block_size;
- $i+= $block_size;
- }
- if($len){
- $iv = $this->_encryptBlock($iv);
- $block = $iv ^ substr($plaintext, $i);
- $iv = substr_replace($iv, $block, 0, $len);
- $ciphertext.= $block;
- $pos = $len;
- }
- break;
- case CRYPT_MODE_OFB:
- $xor = $this->encryptIV;
- if(strlen($buffer['xor'])){
- for($i = 0; $i < strlen($plaintext); $i+=$block_size){
- $block = substr($plaintext, $i, $block_size);
- if(strlen($block) > strlen($buffer['xor'])){
- $xor = $this->_encryptBlock($xor);
- $buffer['xor'].= $xor;
- }
- $key = $this->_stringShift($buffer['xor'], $block_size);
- $ciphertext.= $block ^ $key;
- }
- }else{
- for($i = 0; $i < strlen($plaintext); $i+=$block_size){
- $xor = $this->_encryptBlock($xor);
- $ciphertext.= substr($plaintext, $i, $block_size) ^ $xor;
- }
- $key = $xor;
- }
- if($this->continuousBuffer){
- $this->encryptIV = $xor;
- if($start = strlen($plaintext) % $block_size){
- $buffer['xor'] = substr($key, $start) . $buffer['xor'];
- }
- }
- break;
- case CRYPT_MODE_STREAM:
- $ciphertext = $this->_encryptBlock($plaintext);
- break;
- }
- return $ciphertext;
- }
- /**
- * Decrypts a message.
- *
- * If strlen($ciphertext) is not a multiple of the block size, null bytes will be added to the end of the string until
- * it is.
- *
- * Note: Could, but not must, extend by the child Crypt_* class
- *
- * @see Base::encrypt()
- * @access public
- * @param String $ciphertext
- * @return String $plaintext
- */
- public function decrypt($ciphertext){
- if($this->engine == CRYPT_MODE_MCRYPT){
- $block_size = $this->block_size;
- if($this->changed){
- $this->_setupMcrypt();
- $this->changed = false;
- }
- if($this->dechanged){
- mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV);
- $this->dechanged = false;
- }
- if($this->mode == CRYPT_MODE_CFB && $this->continuousBuffer){
- $iv = &$this->decryptIV;
- $pos = &$this->debuffer['pos'];
- $len = strlen($ciphertext);
- $plaintext = '';
- $i = 0;
- if($pos){
- $orig_pos = $pos;
- $max = $block_size - $pos;
- if($len >= $max){
- $i = $max;
- $len-= $max;
- $pos = 0;
- }else{
- $i = $len;
- $pos+= $len;
- $len = 0;
- }
- // ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize
- $plaintext = substr($iv, $orig_pos) ^ $ciphertext;
- $iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i);
- }
- if($len >= $block_size){
- $cb = substr($ciphertext, $i, $len - $len % $block_size);
- $plaintext.= mcrypt_generic($this->ecb, $iv . $cb) ^ $cb;
- $iv = substr($cb, -$block_size);
- $len%= $block_size;
- }
- if($len){
- $iv = mcrypt_generic($this->ecb, $iv);
- $plaintext.= $iv ^ substr($ciphertext, -$len);
- $iv = substr_replace($iv, substr($ciphertext, -$len), 0, $len);
- $pos = $len;
- }
- return $plaintext;
- }
- if($this->paddable){
- // we pad with chr(0) since that's what mcrypt_generic does. to quote from {@link http://www.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($ciphertext) + ($block_size - strlen($ciphertext) % $block_size) % $block_size, chr(0));
- }
- $plaintext = mdecrypt_generic($this->demcrypt, $ciphertext);
- if(!$this->continuousBuffer){
- mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV);
- }
- return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
- }
- if($this->changed){
- $this->_setup();
- $this->changed = false;
- }
- if($this->use_inline_crypt){
- $inline = $this->inline_crypt;
- return $inline('decrypt', $this, $ciphertext);
- }
- $block_size = $this->block_size;
- if($this->paddable){
- // we pad with chr(0) since that's what mcrypt_generic does [...]
- $ciphertext = str_pad($ciphertext, strlen($ciphertext) + ($block_size - strlen($ciphertext) % $block_size) % $block_size, chr(0));
- }
- $buffer = &$this->debuffer;
- $plaintext = '';
- switch($this->mode){
- case CRYPT_MODE_ECB:
- for($i = 0; $i < strlen($ciphertext); $i+=$block_size){
- $plaintext.= $this->_decryptBlock(substr($ciphertext, $i, $block_size));
- }
- break;
- case CRYPT_MODE_CBC:
- $xor = $this->decryptIV;
- for($i = 0; $i < strlen($ciphertext); $i+=$block_size){
- $block = substr($ciphertext, $i, $block_size);
- $plaintext.= $this->_decryptBlock($block) ^ $xor;
- $xor = $block;
- }
- if($this->continuousBuffer){
- $this->decryptIV = $xor;
- }
- break;
- case CRYPT_MODE_CTR:
- $xor = $this->decryptIV;
- if(strlen($buffer['ciphertext'])){
- for($i = 0; $i < strlen($ciphertext); $i+=$block_size){
- $block = substr($ciphertext, $i, $block_size);
- if(strlen($block) > strlen($buffer['ciphertext'])){
- $buffer['ciphertext'].= $this->_encryptBlock($this->_generateXor($xor, $block_size));
- }
- $key = $this->_stringShift($buffer['ciphertext'], $block_size);
- $plaintext.= $block ^ $key;
- }
- }else{
- for($i = 0; $i < strlen($ciphertext); $i+=$block_size){
- $block = substr($ciphertext, $i, $block_size);
- $key = $this->_encryptBlock($this->_generateXor($xor, $block_size));
- $plaintext.= $block ^ $key;
- }
- }
- if($this->continuousBuffer){
- $this->decryptIV = $xor;
- if($start = strlen($ciphertext) % $block_size){
- $buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext'];
- }
- }
- break;
- case CRYPT_MODE_CFB:
- if($this->continuousBuffer){
- $iv = &$this->decryptIV;
- $pos = &$buffer['pos'];
- }else{
- $iv = $this->decryptIV;
- $pos = 0;
- }
- $len = strlen($ciphertext);
- $i = 0;
- if($pos){
- $orig_pos = $pos;
- $max = $block_size - $pos;
- if($len >= $max){
- $i = $max;
- $len-= $max;
- $pos = 0;
- }else{
- $i = $len;
- $pos+= $len;
- $len = 0;
- }
- // ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize
- $plaintext = substr($iv, $orig_pos) ^ $ciphertext;
- $iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i);
- }
- while($len >= $block_size){
- $iv = $this->_encryptBlock($iv);
- $cb = substr($ciphertext, $i, $block_size);
- $plaintext.= $iv ^ $cb;
- $iv = $cb;
- $len-= $block_size;
- $i+= $block_size;
- }
- if($len){
- $iv = $this->_encryptBlock($iv);
- $plaintext.= $iv ^ substr($ciphertext, $i);
- $iv = substr_replace($iv, substr($ciphertext, $i), 0, $len);
- $pos = $len;
- }
- break;
- case CRYPT_MODE_OFB:
- $xor = $this->decryptIV;
- if(strlen($buffer['xor'])){
- for($i = 0; $i < strlen($ciphertext); $i+=$block_size){
- $block = substr($ciphertext, $i, $block_size);
- if(strlen($block) > strlen($buffer['xor'])){
- $xor = $this->_encryptBlock($xor);
- $buffer['xor'].= $xor;
- }
- $key = $this->_stringShift($buffer['xor'], $block_size);
- $plaintext.= $block ^ $key;
- }
- }else{
- for($i = 0; $i < strlen($ciphertext); $i+=$block_size){
- $xor = $this->_encryptBlock($xor);
- $plaintext.= substr($ciphertext, $i, $block_size) ^ $xor;
- }
- $key = $xor;
- }
- if($this->continuousBuffer){
- $this->decryptIV = $xor;
- if($start = strlen($ciphertext) % $block_size){
- $buffer['xor'] = substr($key, $start) . $buffer['xor'];
- }
- }
- break;
- case CRYPT_MODE_STREAM:
- $plaintext = $this->_decryptBlock($ciphertext);
- break;
- }
- return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
- }
- /**
- * Pad "packets".
- *
- * Block ciphers working by encrypting between their specified [$this->]block_size at a time
- * If you ever need to encrypt or decrypt something that isn't of the proper length, it becomes necessary to
- * pad the input so that it is of the proper length.
- *
- * Padding is enabled by default. Sometimes, however, it is undesirable to pad strings. Such is the case in SSH,
- * where "packets" are padded with random bytes before being encrypted. Unpad these packets and you risk stripping
- * away characters that shouldn't be stripped away. (SSH knows how many bytes are added because the length is
- * transmitted separately)
- *
- * @see Base::disablePadding()
- * @access public
- */
- public function enablePadding(){
- $this->padding = true;
- }
- /**
- * Do not pad packets.
- *
- * @see Base::enablePadding()
- * @access public
- */
- public function disablePadding(){
- $this->padding = false;
- }
- /**
- * Treat consecutive "packets" as if they are a continuous buffer.
- *
- * Say you have a 32-byte plaintext $plaintext. Using the default behavior, the two following code snippets
- * will yield different outputs:
- *
- * <code>
- * echo $rijndael->encrypt(substr($plaintext, 0, 16));
- * echo $rijndael->encrypt(substr($plaintext, 16, 16));
- * </code>
- * <code>
- * echo $rijndael->encrypt($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>
- * $rijndael->encrypt(substr($plaintext, 0, 16));
- * echo $rijndael->decrypt($rijndael->encrypt(substr($plaintext, 16, 16)));
- * </code>
- * <code>
- * echo $rijndael->decrypt($rijndael->encrypt(substr($plaintext, 16, 16)));
- * </code>
- *
- * With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different
- * outputs. The reason is due to the fact that the initialization vector's change after every encryption /
- * decryption round when the continuous buffer is enabled. When it's disabled, they remain constant.
- *
- * Put another way, when the continuous buffer is enabled, the state of the Crypt_*() object changes after each
- * encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that
- * continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them),
- * however, they are also less intuitive and more likely to cause you problems.
- *
- * Note: Could, but not must, extend by the child Crypt_* class
- *
- * @see Base::disableContinuousBuffer()
- * @access public
- */
- public function enableContinuousBuffer(){
- if($this->mode == CRYPT_MODE_ECB){
- return;
- }
- $this->continuousBuffer = true;
- }
- /**
- * Treat consecutive packets as if they are a discontinuous buffer.
- *
- * The default behavior.
- *
- * Note: Could, but not must, extend by the child Crypt_* class
- *
- * @see Base::enableContinuousBuffer()
- * @access public
- */
- public function disableContinuousBuffer(){
- if($this->mode == CRYPT_MODE_ECB){
- return;
- }
- if(!$this->continuousBuffer){
- return;
- }
- $this->continuousBuffer = false;
- $this->changed = true;
- }
- /**
- * Encrypts a block
- *
- * Note: Must extend by the child Crypt_* class
- *
- * @access private
- * @param String $in
- * @return String
- */
- protected function _encryptBlock($in){
- user_error((version_compare(PHP_VERSION, '5.0.0', '>=') ? __METHOD__ : __FUNCTION__) . '() must extend by class ' . get_class($this), E_USER_ERROR);
- }
- /**
- * Decrypts a block
- *
- * Note: Must extend by the child Crypt_* class
- *
- * @access private
- * @param String $in
- * @return String
- */
- protected function _decryptBlock($in){
- user_error((version_compare(PHP_VERSION, '5.0.0', '>=') ? __METHOD__ : __FUNCTION__) . '() must extend by class ' . get_class($this), E_USER_ERROR);
- }
- /**
- * Setup the key (expansion)
- *
- * Only used if $engine == CRYPT_MODE_INTERNAL
- *
- * Note: Must extend by the child Crypt_* class
- *
- * @see Base::_setup()
- * @access private
- */
- protected function _setupKey(){
- user_error((version_compare(PHP_VERSION, '5.0.0', '>=') ? __METHOD__ : __FUNCTION__) . '() must extend by class ' . get_class($this), E_USER_ERROR);
- }
- /**
- * Setup the CRYPT_MODE_INTERNAL $engine
- *
- * (re)init, if necessary, the internal cipher $engine and flush all $buffers
- * Used (only) if $engine == CRYPT_MODE_INTERNAL
- *
- * _setup() will be called each time if $changed === true
- * typically this happens when using one or more of following public methods:
- *
- * - setKey()
- *
- * - setIV()
- *
- * - disableContinuousBuffer()
- *
- * - First run of encrypt() / decrypt() with no init-settings
- *
- * Internally: _setup() is called always before(!) en/decryption.
- *
- * Note: Could, but not must, extend by the child Crypt_* class
- *
- * @see setKey()
- * @see setIV()
- * @see disableContinuousBuffer()
- * @access private
- */
- private function _setup(){
- $this->_clearBuffers();
- $this->_setupKey();
- if($this->use_inline_crypt){
- $this->_setupInlineCrypt();
- }
- }
- /**
- * Setup the CRYPT_MODE_MCRYPT $engine
- *
- * (re)init, if necessary, the (ext)mcrypt resources and flush all $buffers
- * Used (only) if $engine = CRYPT_MODE_MCRYPT
- *
- * _setupMcrypt() will be called each time if $changed === true
- * typically this happens when using one or more of following public methods:
- *
- * - setKey()
- *
- * - setIV()
- *
- * - disableContinuousBuffer()
- *
- * - First run of encrypt() / decrypt()
- *
- *
- * Note: Could, but not must, extend by the child Crypt_* class
- *
- * @see setKey()
- * @see setIV()
- * @see disableContinuousBuffer()
- * @access private
- */
- private function _setupMcrypt(){
- $this->_clearBuffers();
- $this->enchanged = $this->dechanged = true;
- if(!isset($this->enmcrypt)){
- static $mcrypt_modes = array(
- CRYPT_MODE_CTR => 'ctr',
- CRYPT_MODE_ECB => MCRYPT_MODE_ECB,
- CRYPT_MODE_CBC => MCRYPT_MODE_CBC,
- CRYPT_MODE_CFB => 'ncfb',
- CRYPT_MODE_OFB => MCRYPT_MODE_NOFB,
- CRYPT_MODE_STREAM => MCRYPT_MODE_STREAM,
- );
- echo $this->cipher_name_mcrypt;
- $this->demcrypt = mcrypt_module_open($this->cipher_name_mcrypt, '', $mcrypt_modes[$this->mode], '');
- $this->enmcrypt = mcrypt_module_open($this->cipher_name_mcrypt, '', $mcrypt_modes[$this->mode], '');
- // we need the $ecb mcrypt resource (only) in MODE_CFB with enableContinuousBuffer()
- // to workaround mcrypt's broken ncfb implementation in buffered mode
- // see: {@link http://phpseclib.sourceforge.net/cfb-demo.phps}
- if($this->mode == CRYPT_MODE_CFB){
- $this->ecb = mcrypt_module_open($this->cipher_name_mcrypt, '', MCRYPT_MODE_ECB, '');
- }
- } // else should mcrypt_generic_deinit be called?
- if($this->mode == CRYPT_MODE_CFB){
- mcrypt_generic_init($this->ecb, $this->key, str_repeat("\0", $this->block_size));
- }
- }
- /**
- * Pads a string
- *
- * Pads a string using the RSA PKCS padding standards so that its length is a multiple of the blocksize.
- * $this->block_size - (strlen($text) % $this->block_size) bytes are added, each of which is equal to
- * chr($this->block_size - (strlen($text) % $this->block_size)
- *
- * If padding is disabled and $text is not a multiple of the blocksize, the string will be padded regardless
- * and padding will, hence forth, be enabled.
- *
- * @see Base::_unpad()
- * @param String $text
- * @access private
- * @return String
- */
- private function _pad($text){
- $length = strlen($text);
- if(!$this->padding){
- if($length % $this->block_size == 0){
- return $text;
- }else{
- user_error("The plaintext's length ($length) is not a multiple of the block size ({$this->block_size})");
- $this->padding = true;
- }
- }
- $pad = $this->block_size - ($length % $this->block_size);
- return str_pad($text, $length + $pad, chr($pad));
- }
- /**
- * Unpads a string.
- *
- * If padding is enabled and the reported padding length is invalid the encryption key will be assumed to be wrong
- * and false will be returned.
- *
- * @see Base::_pad()
- * @param String $text
- * @access private
- * @return String
- */
- private function _unpad($text){
- if(!$this->padding){
- return $text;
- }
- $length = ord($text[strlen($text) - 1]);
- if(!$length || $length > $this->block_size){
- return false;
- }
- return substr($text, 0, -$length);
- }
- /**
- * Clears internal buffers
- *
- * Clearing/resetting the internal buffers is done everytime
- * after disableContinuousBuffer() or on cipher $engine (re)init
- * ie after setKey() or setIV()
- *
- * Note: Could, but not must, extend by the child Crypt_* class
- *
- * @access public
- */
- private function _clearBuffers(){
- $this->enbuffer = array('encrypted' => '', 'xor' => '', 'pos' => 0, 'enmcrypt_init' => true);
- $this->debuffer = array('ciphertext' => '', 'xor' => '', 'pos' => 0, 'demcrypt_init' => true);
- // mcrypt's handling of invalid's $iv:
- // $this->encryptIV = $this->decryptIV = strlen($this->iv) == $this->block_size ? $this->iv : str_repeat("\0", $this->block_size);
- $this->encryptIV = $this->decryptIV = str_pad(substr($this->iv, 0, $this->block_size), $this->block_size, "\0");
- }
- /**
- * String Shift
- *
- * Inspired by array_shift
- *
- * @param String $string
- * @param optional Integer $index
- * @access private
- * @return String
- */
- private function _stringShift(&$string, $index = 1){
- $substr = substr($string, 0, $index);
- $string = substr($string, $index);
- return $substr;
- }
- /**
- * Generate CTR XOR encryption key
- *
- * Encrypt the output of this and XOR it against the ciphertext / plaintext to get the
- * plaintext / ciphertext in CTR mode.
- *
- * @see Base::decrypt()
- * @see Base::encrypt()
- * @param String $iv
- * @param Integer $length
- * @access private
- * @return String $xor
- */
- private function _generateXor(&$iv, $length){
- $xor = '';
- $block_size = $this->block_size;
- $num_blocks = floor(($length + ($block_size - 1)) / $block_size);
- for($i = 0; $i < $num_blocks; $i++){
- $xor.= $iv;
- for($j = 4; $j <= $block_size; $j+= 4){
- $temp = substr($iv, -$j, 4);
- switch($temp){
- case "\xFF\xFF\xFF\xFF":
- $iv = substr_replace($iv, "\x00\x00\x00\x00", -$j, 4);
- break;
- case "\x7F\xFF\xFF\xFF":
- $iv = substr_replace($iv, "\x80\x00\x00\x00", -$j, 4);
- break 2;
- default:
- extract(unpack('Ncount', $temp));
- $iv = substr_replace($iv, pack('N', $count + 1), -$j, 4);
- break 2;
- }
- }
- }
- return $xor;
- }
- /**
- * Setup the performance-optimized function for de/encrypt()
- *
- * Stores the created (or existing) callback function-name
- * in $this->inline_crypt
- *
- * Internally for phpseclib developers:
- *
- * _setupInlineCrypt() would be called only if:
- *
- * - $engine == CRYPT_MODE_INTERNAL and
- *
- * - $use_inline_crypt === true
- *
- * - each time on _setup(), after(!) _setupKey()
- *
- *
- * This ensures that _setupInlineCrypt() has always a
- * full ready2go initializated internal cipher $engine state
- * where, for example, the keys allready expanded,
- * keys/block_size calculated and such.
- *
- * It is, each time if called, the responsibility of _setupInlineCrypt():
- *
- * - to set $this->inline_crypt to a valid and fully working callback function
- * as a (faster) replacement for encrypt() / decrypt()
- *
- * - NOT to create unlimited callback functions (for memory reasons!)
- * no matter how often _setupInlineCrypt() would be called. At some
- * point of amount they must be generic re-useable.
- *
- * - the code of _setupInlineCrypt() it self,
- * and the generated callback code,
- * must be, in following order:
- * - 100% safe
- * - 100% compatible to encrypt()/decrypt()
- * - using only php5+ features/lang-constructs/php-extensions if
- * compatibility (down to php4) or fallback is provided
- * - readable/maintainable/understandable/commented and... not-cryptic-styled-code :-)
- * - >= 10% faster than encrypt()/decrypt() [which is, by the way,
- * the reason for the existence of _setupInlineCrypt() :-)]
- * - memory-nice
- * - short (as good as possible)
- *
- * Note: - _setupInlineCrypt() is using _createInlineCryptFunction() to create the full callback function code.
- * - In case of using inline crypting, _setupInlineCrypt() must extend by the child Crypt_* class.
- * - The following variable names are reserved:
- * - $_* (all variable names prefixed with an underscore)
- * - $self (object reference to it self. Do not use $this, but $self instead)
- * - $in (the content of $in has to en/decrypt by the generated code)
- * - The callback function should not use the 'return' statement, but en/decrypt'ing the content of $in only
- *
- *
- * @see Base::_setup()
- * @see Base::_createInlineCryptFunction()
- * @see Base::encrypt()
- * @see Base::decrypt()
- * @access private
- */
- private function _setupInlineCrypt(){
- // If a Crypt_* class providing inline crypting it must extend _setupInlineCrypt()
- // If, for any reason, an extending Base() Crypt_* class
- // not using inline crypting then it must be ensured that: $this->use_inline_crypt = false
- // ie in the class var declaration of $use_inline_crypt in general for the Crypt_* class,
- // in the constructor at object instance-time
- // or, if it's runtime-specific, at runtime
- $this->use_inline_crypt = false;
- }
- /**
- * Creates the performance-optimized function for en/decrypt()
- *
- * Internally for phpseclib developers:
- *
- * _createInlineCryptFunction():
- *
- * - merge the $cipher_code [setup'ed by _setupInlineCrypt()]
- * with the current [$this->]mode of operation code
- *
- * - create the $inline function, which called by encrypt() / decrypt()
- * as its replacement to speed up the en/decryption operations.
- *
- * - return the name of the created $inline callback function
- *
- * - used to speed up en/decryption
- *
- *
- *
- * The main reason why can speed up things [up to 50%] this way are:
- *
- * - using variables more effective then regular.
- * (ie no use of expensive arrays but integers $k_0, $k_1 ...
- * or even, for example, the pure $key[] values hardcoded)
- *
- * - avoiding 1000's of function calls of ie _encryptBlock()
- * but inlining the crypt operations.
- * in the mode of operation for() loop.
- *
- * - full loop unroll the (sometimes key-dependent) rounds
- * avoiding this way ++$i counters and runtime-if's etc...
- *
- * The basic code architectur of the generated $inline en/decrypt()
- * lambda function, in pseudo php, is:
- *
- * <code>
- * +----------------------------------------------------------------------------------------------+
- * | callback $inline = create_function: |
- * | lambda_function_0001_crypt_ECB($action, $text) |
- * | { |
- * | INSERT PHP CODE OF: |
- * | $cipher_code['init_crypt']; // general init code. |
- * | // ie: $sbox'es declarations used for |
- * | // encrypt and decrypt'ing. |
- * | |
- * | switch ($action) { |
- * | case 'encrypt': |
- * | INSERT PHP CODE OF: |
- * | $cipher_code['init_encrypt']; // encrypt sepcific init code. |
- * | ie: specified $key or $box |
- * | declarations for encrypt'ing. |
- * | |
- * | foreach ($ciphertext) { |
- * | $in = $block_size of $ciphertext; |
- * | |
- * | INSERT PHP CODE OF: |
- * | $cipher_code['encrypt_block']; // encrypt's (string) $in, which is always: |
- * | // strlen($in) == $this->block_size |
- * | // here comes the cipher algorithm in action |
- * | // for encryption. |
- * | // $cipher_code['encrypt_block'] has to |
- * | // encrypt the content of the $in variable |
- * | |
- * | $plaintext .= $in; |
- * | } |
- * | return $plaintext; |
- * | |
- * | case 'decrypt': |
- * | INSERT PHP CODE OF: |
- * | $cipher_code['init_decrypt']; // decrypt sepcific init code |
- * | ie: specified $key or $box |
- * | declarations for decrypt'ing. |
- * | foreach ($plaintext) { |
- * | $in = $block_size of $plaintext; |
- * | |
- * | INSERT PHP CODE OF: |
- * | $cipher_code['decrypt_block']; // decrypt's (string) $in, which is always |
- * | // strlen($in) == $this->block_size |
- * | // here comes the cipher algorithm in action |
- * | // for decryption. |
- * | // $cipher_code['decrypt_block'] has to |
- * | // decrypt the content of the $in variable |
- * | $ciphertext .= $in; |
- * | } |
- * | return $ciphertext; |
- * | } |
- * | } |
- * +----------------------------------------------------------------------------------------------+
- * </code>
- *
- * See also the Crypt_*::_setupInlineCrypt()'s for
- * productive inline $cipher_code's how they works.
- *
- * Structure of:
- * <code>
- * $cipher_code = array(
- * 'init_crypt' => (string) '', // optional
- * 'init_encrypt' => (string) '', // optional
- * 'init_decrypt' => (string) '', // optional
- * 'encrypt_block' => (string) '', // required
- * 'decrypt_block' => (string) '' // required
- * );
- * </code>
- *
- * @see Base::_setupInlineCrypt()
- * @see Base::encrypt()
- * @see Base::decrypt()
- * @param Array $cipher_code
- * @access private
- * @return String (the name of the created callback function)
- */
- private function _createInlineCryptFunction($cipher_code){
- $block_size = $this->block_size;
- // optional
- $init_crypt = isset($cipher_code['init_crypt']) ? $cipher_code['init_crypt'] : '';
- $init_encrypt = isset($cipher_code['init_encrypt']) ? $cipher_code['init_encrypt'] : '';
- $init_decrypt = isset($cipher_code['init_decrypt']) ? $cipher_code['init_decrypt'] : '';
- // required
- $encrypt_block = $cipher_code['encrypt_block'];
- $decrypt_block = $cipher_code['decrypt_block'];
- // Generating mode of operation inline code,
- // merged with the $cipher_code algorithm
- // for encrypt- and decryption.
- switch($this->mode){
- case CRYPT_MODE_ECB:
- $encrypt = $init_encrypt . '
- $_ciphertext = "";
- $_text = $self->_pad($_text);
- $_plaintext_len = strlen($_text);
- for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') {
- $in = substr($_text, $_i, ' . $block_size . ');
- ' . $encrypt_block . '
- $_ciphertext.= $in;
- }
- return $_ciphertext;
- ';
- $decrypt = $init_decrypt . '
- $_plaintext = "";
- $_text = str_pad($_text, strlen($_text) + (' . $block_size . ' - strlen($_text) % ' . $block_size . ') % ' . $block_size . ', chr(0));
- $_ciphertext_len = strlen($_text);
- for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') {
- $in = substr($_text, $_i, ' . $block_size . ');
- ' . $decrypt_block . '
- $_plaintext.= $in;
- }
- return $self->_unpad($_plaintext);
- ';
- break;
- case CRYPT_MODE_CTR:
- $encrypt = $init_encrypt . '
- $_ciphertext = "";
- $_plaintext_len = strlen($_text);
- $_xor = $self->encryptIV;
- $_buffer = &$self->enbuffer;
- if (strlen($_buffer["encrypted"])) {
- for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') {
- $_block = substr($_text, $_i, ' . $block_size . ');
- if (strlen($_block) > strlen($_buffer["encrypted"])) {
- $in = $self->_generateXor($_xor, ' . $block_size . ');
- ' . $encrypt_block . '
- $_buffer["encrypted"].= $in;
- }
- $_key = $self->_stringShift($_buffer["encrypted"], ' . $block_size . ');
- $_ciphertext.= $_block ^ $_key;
- }
- } else {
- for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') {
- $_block = substr($_text, $_i, ' . $block_size . ');
- $in = $self->_generateXor($_xor, ' . $block_size . ');
- ' . $encrypt_block . '
- $_key = $in;
- $_ciphertext.= $_block ^ $_key;
- }
- }
- if ($self->continuousBuffer) {
- $self->encryptIV = $_xor;
- if ($_start = $_plaintext_len % ' . $block_size . ') {
- $_buffer["encrypted"] = substr($_key, $_start) . $_buffer["encrypted"];
- }
- }
- return $_ciphertext;
- ';
- $decrypt = $init_encrypt . '
- $_plaintext = "";
- $_ciphertext_len = strlen($_text);
- $_xor = $self->decryptIV;
- $_buffer = &$self->debuffer;
- if (strlen($_buffer["ciphertext"])) {
- for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') {
- $_block = substr($_text, $_i, ' . $block_size . ');
- if (strlen($_block) > strlen($_buffer["ciphertext"])) {
- $in = $self->_generateXor($_xor, ' . $block_size . ');
- ' . $encrypt_block . '
- $_buffer["ciphertext"].= $in;
- }
- $_key = $self->_stringShift($_buffer["ciphertext"], ' . $block_size . ');
- $_plaintext.= $_block ^ $_key;
- }
- } else {
- for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') {
- $_block = substr($_text, $_i, ' . $block_size . ');
- $in = $self->_generateXor($_xor, ' . $block_size . ');
- ' . $encrypt_block . '
- $_key = $in;
- $_plaintext.= $_block ^ $_key;
- }
- }
- if ($self->continuousBuffer) {
- $self->decryptIV = $_xor;
- if ($_start = $_ciphertext_len % ' . $block_size . ') {
- $_buffer["ciphertext"] = substr($_key, $_start) . $_buffer["ciphertext"];
- }
- }
- return $_plaintext;
- ';
- break;
- case CRYPT_MODE_CFB:
- $encrypt = $init_encrypt . '
- $_ciphertext = "";
- $_buffer = &$self->enbuffer;
- if ($self->continuousBuffer) {
- $_iv = &$self->encryptIV;
- $_pos = &$_buffer["pos"];
- } else {
- $_iv = $self->encryptIV;
- $_pos = 0;
- }
- $_len = strlen($_text);
- $_i = 0;
- if ($_pos) {
- $_orig_pos = $_pos;
- $_max = ' . $block_size . ' - $_pos;
- if ($_len >= $_max) {
- $_i = $_max;
- $_len-= $_max;
- $_pos = 0;
- } else {
- $_i = $_len;
- $_pos+= $_len;
- $_len = 0;
- }
- $_ciphertext = substr($_iv, $_orig_pos) ^ $_text;
- $_iv = substr_replace($_iv, $_ciphertext, $_orig_pos, $_i);
- }
- while ($_len >= ' . $block_size . ') {
- $in = $_iv;
- ' . $encrypt_block . ';
- $_iv = $in ^ substr($_text, $_i, ' . $block_size . ');
- $_ciphertext.= $_iv;
- $_len-= ' . $block_size . ';
- $_i+= ' . $block_size . ';
- }
- if ($_len) {
- $in = $_iv;
- ' . $encrypt_block . '
- $_iv = $in;
- $_block = $_iv ^ substr($_text, $_i);
- $_iv = substr_replace($_iv, $_block, 0, $_len);
- $_ciphertext.= $_block;
- $_pos = $_len;
- }
- return $_ciphertext;
- ';
- $decrypt = $init_encrypt . '
- $_plaintext = "";
- $_buffer = &$self->debuffer;
- if ($self->continuousBuffer) {
- $_iv = &$self->decryptIV;
- $_pos = &$_buffer["pos"];
- } else {
- $_iv = $self->decryptIV;
- $_pos = 0;
- }
- $_len = strlen($_text);
- $_i = 0;
- if ($_pos) {
- $_orig_pos = $_pos;
- $_max = ' . $block_size . ' - $_pos;
- if ($_len >= $_max) {
- $_i = $_max;
- $_len-= $_max;
- $_pos = 0;
- } else {
- $_i = $_len;
- $_pos+= $_len;
- $_len = 0;
- }
- $_plaintext = substr($_iv, $_orig_pos) ^ $_text;
- $_iv = substr_replace($_iv, substr($_text, 0, $_i), $_orig_pos, $_i);
- }
- while ($_len >= ' . $block_size . ') {
- $in = $_iv;
- ' . $encrypt_block . '
- $_iv = $in;
- $cb = substr($_text, $_i, ' . $block_size . ');
- $_plaintext.= $_iv ^ $cb;
- $_iv = $cb;
- $_len-= ' . $block_size . ';
- $_i+= ' . $block_size . ';
- }
- if ($_len) {
- $in = $_iv;
- ' . $encrypt_block . '
- $_iv = $in;
- $_plaintext.= $_iv ^ substr($_text, $_i);
- $_iv = substr_replace($_iv, substr($_text, $_i), 0, $_len);
- $_pos = $_len;
- }
- return $_plaintext;
- ';
- break;
- case CRYPT_MODE_OFB:
- $encrypt = $init_encrypt . '
- $_ciphertext = "";
- $_plaintext_len = strlen($_text);
- $_xor = $self->encryptIV;
- $_buffer = &$self->enbuffer;
- if (strlen($_buffer["xor"])) {
- for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') {
- $_block = substr($_text, $_i, ' . $block_size . ');
- if (strlen($_block) > strlen($_buffer["xor"])) {
- $in = $_xor;
- ' . $encrypt_block . '
- $_xor = $in;
- $_buffer["xor"].= $_xor;
- }
- $_key = $self->_stringShift($_buffer["xor"], ' . $block_size . ');
- $_ciphertext.= $_block ^ $_key;
- }
- } else {
- for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') {
- $in = $_xor;
- ' . $encrypt_block . '
- $_xor = $in;
- $_ciphertext.= substr($_text, $_i, ' . $block_size . ') ^ $_xor;
- }
- $_key = $_xor;
- }
- if ($self->continuousBuffer) {
- $self->encryptIV = $_xor;
- if ($_start = $_plaintext_len % ' . $block_size . ') {
- $_buffer["xor"] = substr($_key, $_start) . $_buffer["xor"];
- }
- }
- return $_ciphertext;
- ';
- $decrypt = $init_encrypt . '
- $_plaintext = "";
- $_ciphertext_len = strlen($_text);
- $_xor = $self->decryptIV;
- $_buffer = &$self->debuffer;
- if (strlen($_buffer["xor"])) {
- for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') {
- $_block = substr($_text, $_i, ' . $block_size . ');
- if (strlen($_block) > strlen($_buffer["xor"])) {
- $in = $_xor;
- ' . $encrypt_block . '
- $_xor = $in;
- $_buffer["xor"].= $_xor;
- }
- $_key = $self->_stringShift($_buffer["xor"], ' . $block_size . ');
- $_plaintext.= $_block ^ $_key;
- }
- } else {
- for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') {
- $in = $_xor;
- ' . $encrypt_block . '
- $_xor = $in;
- $_plaintext.= substr($_text, $_i, ' . $block_size . ') ^ $_xor;
- }
- $_key = $_xor;
- }
- if ($self->continuousBuffer) {
- $self->decryptIV = $_xor;
- if ($_start = $_ciphertext_len % ' . $block_size . ') {
- $_buffer["xor"] = substr($_key, $_start) . $_buffer["xor"];
- }
- }
- return $_plaintext;
- ';
- break;
- case CRYPT_MODE_STREAM:
- $encrypt = $init_encrypt . '
- $_ciphertext = "";
- ' . $encrypt_block . '
- return $_ciphertext;
- ';
- $decrypt = $init_decrypt . '
- $_plaintext = "";
- ' . $decrypt_block . '
- return $_plaintext;
- ';
- break;
- // case CRYPT_MODE_CBC:
- default:
- $encrypt = $init_encrypt . '
- $_ciphertext = "";
- $_text = $self->_pad($_text);
- $_plaintext_len = strlen($_text);
- $in = $self->encryptIV;
- for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') {
- $in = substr($_text, $_i, ' . $block_size . ') ^ $in;
- ' . $encrypt_block . '
- $_ciphertext.= $in;
- }
- if ($self->continuousBuffer) {
- $self->encryptIV = $in;
- }
- return $_ciphertext;
- ';
- $decrypt = $init_decrypt . '
- $_plaintext = "";
- $_text = str_pad($_text, strlen($_text) + (' . $block_size . ' - strlen($_text) % ' . $block_size . ') % ' . $block_size . ', chr(0));
- $_ciphertext_len = strlen($_text);
- $_iv = $self->decryptIV;
- for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') {
- $in = $_block = substr($_text, $_i, ' . $block_size . ');
- ' . $decrypt_block . '
- $_plaintext.= $in ^ $_iv;
- $_iv = $_block;
- }
- if ($self->continuousBuffer) {
- $self->decryptIV = $_iv;
- }
- return $self->_unpad($_plaintext);
- ';
- break;
- }
- // Create the $inline function and return its name as string. Ready to run!
- return create_function('$_action, &$self, $_text', $init_crypt . 'if ($_action == "encrypt") { ' . $encrypt . ' } else { ' . $decrypt . ' }');
- }
- /**
- * Holds the lambda_functions table (classwide)
- *
- * Each name of the lambda function, created from
- * _setupInlineCrypt() && _createInlineCryptFunction()
- * is stored, classwide (!), here for reusing.
- *
- * The string-based index of $function is a classwide
- * uniqe value representing, at least, the $mode of
- * operation (or more... depends of the optimizing level)
- * for which $mode the lambda function was created.
- *
- * @access private
- * @return &Array
- */
- private function &_getLambdaFunctions(){
- static $functions = array();
- return $functions;
- }
- }