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Diffstat (limited to 'inc/phpseclib/Crypt_Base.php')
| -rw-r--r-- | inc/phpseclib/Crypt_Base.php | 1989 |
1 files changed, 1989 insertions, 0 deletions
diff --git a/inc/phpseclib/Crypt_Base.php b/inc/phpseclib/Crypt_Base.php new file mode 100644 index 000000000..7c650ca72 --- /dev/null +++ b/inc/phpseclib/Crypt_Base.php @@ -0,0 +1,1989 @@ +<?php +/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */ + +/** + * 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 Crypt_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 Crypt_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 Crypt_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 + * @version 1.0.1 + * @link http://phpseclib.sourceforge.net + */ + +/**#@+ + * @access public + * @see Crypt_Base::encrypt() + * @see Crypt_Base::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_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_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_MODE_CBC', 2); +/** + * Encrypt / decrypt using the Cipher Feedback mode. + * + * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher_feedback_.28CFB.29 + */ +define('CRYPT_MODE_CFB', 3); +/** + * Encrypt / decrypt using the Output Feedback mode. + * + * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Output_feedback_.28OFB.29 + */ +define('CRYPT_MODE_OFB', 4); +/** + * Encrypt / decrypt using streaming mode. + * + */ +define('CRYPT_MODE_STREAM', 5); +/**#@-*/ + +/**#@+ + * @access private + * @see Crypt_Base::Crypt_Base() + */ +/** + * Base value for the internal implementation $engine switch + */ +define('CRYPT_MODE_INTERNAL', 1); +/** + * Base value for the mcrypt implementation $engine switch + */ +define('CRYPT_MODE_MCRYPT', 2); +/**#@-*/ + +/** + * Base Class for all Crypt_* cipher classes + * + * @author Jim Wigginton <terrafrost@php.net> + * @author Hans-Juergen Petrich <petrich@tronic-media.com> + * @version 1.0.0 + * @access public + * @package Crypt_Base + */ +class Crypt_Base { + /** + * The Encryption Mode + * + * @see Crypt_Base::Crypt_Base() + * @var Integer + * @access private + */ + var $mode; + + /** + * The Block Length of the block cipher + * + * @var Integer + * @access private + */ + var $block_size = 16; + + /** + * The Key + * + * @see Crypt_Base::setKey() + * @var String + * @access private + */ + var $key = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"; + + /** + * The Initialization Vector + * + * @see Crypt_Base::setIV() + * @var String + * @access private + */ + var $iv; + + /** + * A "sliding" Initialization Vector + * + * @see Crypt_Base::enableContinuousBuffer() + * @see Crypt_Base::_clearBuffers() + * @var String + * @access private + */ + var $encryptIV; + + /** + * A "sliding" Initialization Vector + * + * @see Crypt_Base::enableContinuousBuffer() + * @see Crypt_Base::_clearBuffers() + * @var String + * @access private + */ + var $decryptIV; + + /** + * Continuous Buffer status + * + * @see Crypt_Base::enableContinuousBuffer() + * @var Boolean + * @access private + */ + var $continuousBuffer = false; + + /** + * Encryption buffer for CTR, OFB and CFB modes + * + * @see Crypt_Base::encrypt() + * @see Crypt_Base::_clearBuffers() + * @var Array + * @access private + */ + var $enbuffer; + + /** + * Decryption buffer for CTR, OFB and CFB modes + * + * @see Crypt_Base::decrypt() + * @see Crypt_Base::_clearBuffers() + * @var Array + * @access private + */ + var $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 Crypt_Base::encrypt() + * @var Resource + * @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_Base::decrypt() + * @var Resource + * @access private + */ + var $demcrypt; + + /** + * Does the enmcrypt resource need to be (re)initialized? + * + * @see Crypt_Twofish::setKey() + * @see Crypt_Twofish::setIV() + * @var Boolean + * @access private + */ + var $enchanged = true; + + /** + * Does the demcrypt resource need to be (re)initialized? + * + * @see Crypt_Twofish::setKey() + * @see Crypt_Twofish::setIV() + * @var Boolean + * @access private + */ + var $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 Crypt_Base::encrypt() + * @see Crypt_Base::decrypt() + * @see Crypt_Base::_setupMcrypt() + * @var Resource + * @access private + */ + var $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 choosen 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 Crypt_Base::encrypt() + * @var Integer + * @access private + */ + var $cfb_init_len = 600; + + /** + * Does internal cipher state need to be (re)initialized? + * + * @see setKey() + * @see setIV() + * @see disableContinuousBuffer() + * @var Boolean + * @access private + */ + var $changed = true; + + /** + * Padding status + * + * @see Crypt_Base::enablePadding() + * @var Boolean + * @access private + */ + var $padding = true; + + /** + * Is the mode one that is paddable? + * + * @see Crypt_Base::Crypt_Base() + * @var Boolean + * @access private + */ + var $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 Crypt_Base::encrypt() + * @see Crypt_Base::decrypt() + * @var Integer + * @access private + */ + var $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 Crypt_Base::_setupMcrypt() + * @var String + * @access private + */ + var $cipher_name_mcrypt; + + /** + * The default password key_size used by setPassword() + * + * @see Crypt_Base::setPassword() + * @var Integer + * @access private + */ + var $password_key_size = 32; + + /** + * The default salt used by setPassword() + * + * @see Crypt_Base::setPassword() + * @var String + * @access private + */ + var $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 Crypt_Base::Crypt_Base() + * @var String + * @access private + */ + var $const_namespace; + + /** + * The name of the performance-optimized callback function + * + * Used by encrypt() / decrypt() + * only if $engine == CRYPT_MODE_INTERNAL + * + * @see Crypt_Base::encrypt() + * @see Crypt_Base::decrypt() + * @see Crypt_Base::_setupInlineCrypt() + * @see Crypt_Base::$use_inline_crypt + * @var Callback + * @access private + */ + var $inline_crypt; + + /** + * Holds whether performance-optimized $inline_crypt() can/should be used. + * + * @see Crypt_Base::encrypt() + * @see Crypt_Base::decrypt() + * @see Crypt_Base::inline_crypt + * @var mixed + * @access private + */ + var $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 choosen cipher, for example for AES: CRYPT_AES_MODE_ECB or CRYPT_AES_MODE_CBC ...) + * + * If not explictly set, CRYPT_MODE_CBC will be used. + * + * @param optional Integer $mode + * @access public + */ + function Crypt_Base($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 explictly 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 $iv + */ + function setIV($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 $key + */ + function setKey($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}: + * $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 $method + * @access public + */ + function setPassword($password, $method = 'pbkdf2') + { + $key = ''; + + switch ($method) { + default: // 'pbkdf2' + $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 + $dkLen = isset($func_args[5]) ? $func_args[5] : $this->password_key_size; + + // Determining if php[>=5.5.0]'s hash_pbkdf2() function avail- and useable + switch (true) { + case !function_exists('hash_pbkdf2'): + case !function_exists('hash_algos'): + case !in_array($hash, hash_algos()): + if (!class_exists('Crypt_Hash')) { + require_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); + } + + /** + * 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 Crypt_Base::decrypt() + * @access public + * @param String $plaintext + * @return String $cipertext + */ + function encrypt($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 Crypt_Base::encrypt() + * @access public + * @param String $ciphertext + * @return String $plaintext + */ + function decrypt($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 Crypt_Base::disablePadding() + * @access public + */ + function enablePadding() + { + $this->padding = true; + } + + /** + * Do not pad packets. + * + * @see Crypt_Base::enablePadding() + * @access 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($plaintext, 16, 16))); + * </code> + * + * With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different + * outputs. The reason is due to the fact that the initialization vector's change after every encryption / + * decryption round when the continuous buffer is enabled. When it's disabled, they remain constant. + * + * Put another way, when the continuous buffer is enabled, the state of the Crypt_*() object changes after each + * encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that + * continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them), + * however, they are also less intuitive and more likely to cause you problems. + * + * Note: Could, but not must, extend by the child Crypt_* class + * + * @see Crypt_Base::disableContinuousBuffer() + * @access public + */ + function enableContinuousBuffer() + { + if ($this->mode == CRYPT_MODE_ECB) { + return; + } + + $this->continuousBuffer = true; + } + + /** + * Treat consecutive packets as if they are a discontinuous buffer. + * + * The default behavior. + * + * Note: Could, but not must, extend by the child Crypt_* class + * + * @see Crypt_Base::enableContinuousBuffer() + * @access public + */ + function disableContinuousBuffer() + { + if ($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 $in + * @return String + */ + function _encryptBlock($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 $in + * @return String + */ + function _decryptBlock($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 $engine == CRYPT_MODE_INTERNAL + * + * Note: Must extend by the child Crypt_* class + * + * @see Crypt_Base::_setup() + * @access private + */ + function _setupKey() + { + user_error((version_compare(PHP_VERSION, '5.0.0', '>=') ? __METHOD__ : __FUNCTION__) . '() must extend by class ' . get_class($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 + */ + 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 + */ + 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, + ); + + $this->demcrypt = mcrypt_module_open($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 Crypt_Base::_unpad() + * @param String $text + * @access private + * @return String + */ + function _pad($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 Crypt_Base::_pad() + * @param String $text + * @access private + * @return String + */ + function _unpad($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 + */ + 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 $index + * @access private + * @return String + */ + function _stringShift(&$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 Crypt_Base::decrypt() + * @see Crypt_Base::encrypt() + * @param String $iv + * @param Integer $length + * @access private + * @return String $xor + */ + function _generateXor(&$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 allways 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 Crypt_Base::_setup() + * @see Crypt_Base::_createInlineCryptFunction() + * @see Crypt_Base::encrypt() + * @see Crypt_Base::decrypt() + * @access private + */ + function _setupInlineCrypt() + { + // If a Crypt_* class providing inline crypting it must extend _setupInlineCrypt() + + // If, for any reason, an extending Crypt_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 Crypt_Base::_setupInlineCrypt() + * @see Crypt_Base::encrypt() + * @see Crypt_Base::decrypt() + * @param Array $cipher_code + * @access private + * @return String (the name of the created callback function) + */ + function _createInlineCryptFunction($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 + */ + function &_getLambdaFunctions() + { + static $functions = array(); + return $functions; + } +} + +// vim: ts=4:sw=4:et: +// vim6: fdl=1: |