Base.php
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0
| php
Geri
<?php /** * Base Class for all \phpseclib\Crypt\* cipher classes * * PHP version 5 * * Internally for phpseclib developers: * If you plan to add a new cipher class, please note following rules: * * - The new \phpseclib\Crypt\* cipher class should extend \phpseclib\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 \phpseclib\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 * * @category Crypt * @package Base * @author Jim Wigginton <terrafrost@php.net> * @author Hans-Juergen Petrich <petrich@tronic-media.com> * @copyright 2007 Jim Wigginton * @license http://www.opensource.org/licenses/mit-license.html MIT License * @link http://phpseclib.sourceforge.net */ namespace phpseclib\Crypt; /** * Base Class for all \phpseclib\Crypt\* cipher classes * * @package Base * @author Jim Wigginton <terrafrost@php.net> * @author Hans-Juergen Petrich <petrich@tronic-media.com> */ abstract class Base { /**#@+ * @access public * @see \phpseclib\Crypt\Base::encrypt() * @see \phpseclib\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 */ const 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 */ const 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 */ const 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 */ const MODE_CFB = 3; /** * Encrypt / decrypt using the Cipher Feedback mode (8bit) */ const MODE_CFB8 = 38; /** * Encrypt / decrypt using the Output Feedback mode. * * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Output_feedback_.28OFB.29 */ const MODE_OFB = 4; /** * Encrypt / decrypt using streaming mode. */ const MODE_STREAM = 5; /**#@-*/ /** * Whirlpool available flag * * @see \phpseclib\Crypt\Base::_hashInlineCryptFunction() * @var bool * @access private */ static $WHIRLPOOL_AVAILABLE; /**#@+ * @access private * @see \phpseclib\Crypt\Base::__construct() */ /** * Base value for the internal implementation $engine switch */ const ENGINE_INTERNAL = 1; /** * Base value for the mcrypt implementation $engine switch */ const ENGINE_MCRYPT = 2; /** * Base value for the mcrypt implementation $engine switch */ const ENGINE_OPENSSL = 3; /**#@-*/ /** * The Encryption Mode * * @see self::__construct() * @var int * @access private */ var $mode; /** * The Block Length of the block cipher * * @var int * @access private */ var $block_size = 16; /** * The Key * * @see self::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 self::setIV() * @var string * @access private */ var $iv; /** * A "sliding" Initialization Vector * * @see self::enableContinuousBuffer() * @see self::_clearBuffers() * @var string * @access private */ var $encryptIV; /** * A "sliding" Initialization Vector * * @see self::enableContinuousBuffer() * @see self::_clearBuffers() * @var string * @access private */ var $decryptIV; /** * Continuous Buffer status * * @see self::enableContinuousBuffer() * @var bool * @access private */ var $continuousBuffer = false; /** * Encryption buffer for CTR, OFB and CFB modes * * @see self::encrypt() * @see self::_clearBuffers() * @var array * @access private */ var $enbuffer; /** * Decryption buffer for CTR, OFB and CFB modes * * @see self::decrypt() * @see self::_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 self::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 self::decrypt() * @var resource * @access private */ var $demcrypt; /** * Does the enmcrypt resource need to be (re)initialized? * * @see \phpseclib\Crypt\Twofish::setKey() * @see \phpseclib\Crypt\Twofish::setIV() * @var bool * @access private */ var $enchanged = true; /** * Does the demcrypt resource need to be (re)initialized? * * @see \phpseclib\Crypt\Twofish::setKey() * @see \phpseclib\Crypt\Twofish::setIV() * @var bool * @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 self::encrypt() * @see self::decrypt() * @see self::_setupMcrypt() * @var resource * @access private */ var $ecb; /** * Optimizing value while CFB-encrypting * * Only relevant if $continuousBuffer enabled * and $engine == self::ENGINE_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 self::encrypt() * @var int * @access private */ var $cfb_init_len = 600; /** * Does internal cipher state need to be (re)initialized? * * @see self::setKey() * @see self::setIV() * @see self::disableContinuousBuffer() * @var bool * @access private */ var $changed = true; /** * Padding status * * @see self::enablePadding() * @var bool * @access private */ var $padding = true; /** * Is the mode one that is paddable? * * @see self::__construct() * @var bool * @access private */ var $paddable = false; /** * Holds which crypt engine internaly should be use, * which will be determined automatically on __construct() * * Currently available $engines are: * - self::ENGINE_OPENSSL (very fast, php-extension: openssl, extension_loaded('openssl') required) * - self::ENGINE_MCRYPT (fast, php-extension: mcrypt, extension_loaded('mcrypt') required) * - self::ENGINE_INTERNAL (slower, pure php-engine, no php-extension required) * * @see self::_setEngine() * @see self::encrypt() * @see self::decrypt() * @var int * @access private */ var $engine; /** * Holds the preferred crypt engine * * @see self::_setEngine() * @see self::setPreferredEngine() * @var int * @access private */ var $preferredEngine; /** * The mcrypt specific name of the cipher * * Only used if $engine == self::ENGINE_MCRYPT * * @link http://www.php.net/mcrypt_module_open * @link http://www.php.net/mcrypt_list_algorithms * @see self::_setupMcrypt() * @var string * @access private */ var $cipher_name_mcrypt; /** * The openssl specific name of the cipher * * Only used if $engine == self::ENGINE_OPENSSL * * @link http://www.php.net/openssl-get-cipher-methods * @var string * @access private */ var $cipher_name_openssl; /** * The openssl specific name of the cipher in ECB mode * * If OpenSSL does not support the mode we're trying to use (CTR) * it can still be emulated with ECB mode. * * @link http://www.php.net/openssl-get-cipher-methods * @var string * @access private */ var $cipher_name_openssl_ecb; /** * The default salt used by setPassword() * * @see self::setPassword() * @var string * @access private */ var $password_default_salt = 'phpseclib/salt'; /** * The name of the performance-optimized callback function * * Used by encrypt() / decrypt() * only if $engine == self::ENGINE_INTERNAL * * @see self::encrypt() * @see self::decrypt() * @see self::_setupInlineCrypt() * @see self::$use_inline_crypt * @var Callback * @access private */ var $inline_crypt; /** * Holds whether performance-optimized $inline_crypt() can/should be used. * * @see self::encrypt() * @see self::decrypt() * @see self::inline_crypt * @var mixed * @access private */ var $use_inline_crypt = true; /** * If OpenSSL can be used in ECB but not in CTR we can emulate CTR * * @see self::_openssl_ctr_process() * @var bool * @access private */ var $openssl_emulate_ctr = false; /** * Determines what options are passed to openssl_encrypt/decrypt * * @see self::isValidEngine() * @var mixed * @access private */ var $openssl_options; /** * Has the key length explicitly been set or should it be derived from the key, itself? * * @see self::setKeyLength() * @var bool * @access private */ var $explicit_key_length = false; /** * Don't truncate / null pad key * * @see self::_clearBuffers() * @var bool * @access private */ var $skip_key_adjustment = false; /** * Default Constructor. * * Determines whether or not the mcrypt extension should be used. * * $mode could be: * * - self::MODE_ECB * * - self::MODE_CBC * * - self::MODE_CTR * * - self::MODE_CFB * * - self::MODE_OFB * * If not explicitly set, self::MODE_CBC will be used. * * @param int $mode * @access public */ function __construct($mode = self::MODE_CBC) { // $mode dependent settings switch ($mode) { case self::MODE_ECB: $this->paddable = true; $this->mode = self::MODE_ECB; break; case self::MODE_CTR: case self::MODE_CFB: case self::MODE_CFB8: case self::MODE_OFB: case self::MODE_STREAM: $this->mode = $mode; break; case self::MODE_CBC: default: $this->paddable = true; $this->mode = self::MODE_CBC; } $this->_setEngine(); } /** * Sets the initialization vector. (optional) * * SetIV is not required when self::MODE_ECB (or ie for AES: \phpseclib\Crypt\AES::MODE_ECB) is being used. If not explicitly set, it'll be assumed * to be all zero's. * * @access public * @param string $iv * @internal Can be overwritten by a sub class, but does not have to be */ function setIV($iv) { if ($this->mode == self::MODE_ECB) { return; } $this->iv = $iv; $this->changed = true; } /** * Sets the key length. * * Keys with explicitly set lengths need to be treated accordingly * * @access public * @param int $length */ function setKeyLength($length) { $this->explicit_key_length = true; $this->changed = true; $this->_setEngine(); } /** * Returns the current key length in bits * * @access public * @return int */ function getKeyLength() { return $this->key_length << 3; } /** * Returns the current block length in bits * * @access public * @return int */ function getBlockLength() { return $this->block_size << 3; } /** * 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. * * @access public * @param string $key * @internal Could, but not must, extend by the child Crypt_* class */ function setKey($key) { if (!$this->explicit_key_length) { $this->setKeyLength(strlen($key) << 3); $this->explicit_key_length = false; } $this->key = $key; $this->changed = true; $this->_setEngine(); } /** * 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 * * @see Crypt/Hash.php * @param string $password * @param string $method * @return bool * @access public * @internal Could, but not must, extend by the child Crypt_* class */ function setPassword($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->key_length : $this->key_length; } switch (true) { case $method == 'pbkdf1': $hashObj = new 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()): $i = 1; $hmac = new Hash(); $hmac->setHash($hash); $hmac->setKey($password); while (strlen($key) < $dkLen) { $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. * * @see self::decrypt() * @access public * @param string $plaintext * @return string $ciphertext * @internal Could, but not must, extend by the child Crypt_* class */ function encrypt($plaintext) { if ($this->paddable) { $plaintext = $this->_pad($plaintext); } if ($this->engine === self::ENGINE_OPENSSL) { if ($this->changed) { $this->_clearBuffers(); $this->changed = false; } switch ($this->mode) { case self::MODE_STREAM: return openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, $this->openssl_options); case self::MODE_ECB: $result = @openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, $this->openssl_options); return !defined('OPENSSL_RAW_DATA') ? substr($result, 0, -$this->block_size) : $result; case self::MODE_CBC: $result = openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, $this->openssl_options, $this->encryptIV); if (!defined('OPENSSL_RAW_DATA')) { $result = substr($result, 0, -$this->block_size); } if ($this->continuousBuffer) { $this->encryptIV = substr($result, -$this->block_size); } return $result; case self::MODE_CTR: return $this->_openssl_ctr_process($plaintext, $this->encryptIV, $this->enbuffer); case self::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} $ciphertext = ''; if ($this->continuousBuffer) { $iv = &$this->encryptIV; $pos = &$this->enbuffer['pos']; } else { $iv = $this->encryptIV; $pos = 0; } $len = strlen($plaintext); $i = 0; if ($pos) { $orig_pos = $pos; $max = $this->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); $plaintext = substr($plaintext, $i); } $overflow = $len % $this->block_size; if ($overflow) { $ciphertext.= openssl_encrypt(substr($plaintext, 0, -$overflow) . str_repeat("\0", $this->block_size), $this->cipher_name_openssl, $this->key, $this->openssl_options, $iv); $iv = $this->_string_pop($ciphertext, $this->block_size); $size = $len - $overflow; $block = $iv ^ substr($plaintext, -$overflow); $iv = substr_replace($iv, $block, 0, $overflow); $ciphertext.= $block; $pos = $overflow; } elseif ($len) { $ciphertext = openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, $this->openssl_options, $iv); $iv = substr($ciphertext, -$this->block_size); } return $ciphertext; case self::MODE_CFB8: $ciphertext = openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, $this->openssl_options, $this->encryptIV); if ($this->continuousBuffer) { if (($len = strlen($ciphertext)) >= $this->block_size) { $this->encryptIV = substr($ciphertext, -$this->block_size); } else { $this->encryptIV = substr($this->encryptIV, $len - $this->block_size) . substr($ciphertext, -$len); } } return $ciphertext; case self::MODE_OFB: return $this->_openssl_ofb_process($plaintext, $this->encryptIV, $this->enbuffer); } } if ($this->engine === self::ENGINE_MCRYPT) { set_error_handler(array($this, 'do_nothing')); if ($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 == self::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; } restore_error_handler(); return $ciphertext; } $ciphertext = mcrypt_generic($this->enmcrypt, $plaintext); if (!$this->continuousBuffer) { mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV); } restore_error_handler(); return $ciphertext; } if ($this->changed) { $this->_setup(); $this->changed = false; } if ($this->use_inline_crypt) { $inline = $this->inline_crypt; return $inline('encrypt', $this, $plaintext); } $buffer = &$this->enbuffer; $block_size = $this->block_size; $ciphertext = ''; switch ($this->mode) { case self::MODE_ECB: for ($i = 0; $i < strlen($plaintext); $i+=$block_size) { $ciphertext.= $this->_encryptBlock(substr($plaintext, $i, $block_size)); } break; case self::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 self::MODE_CTR: $xor = $this->encryptIV; if (strlen($buffer['ciphertext'])) { for ($i = 0; $i < strlen($plaintext); $i+=$block_size) { $block = substr($plaintext, $i, $block_size); if (strlen($block) > strlen($buffer['ciphertext'])) { $buffer['ciphertext'].= $this->_encryptBlock($xor); } $this->_increment_str($xor); $key = $this->_string_shift($buffer['ciphertext'], $block_size); $ciphertext.= $block ^ $key; } } else { for ($i = 0; $i < strlen($plaintext); $i+=$block_size) { $block = substr($plaintext, $i, $block_size); $key = $this->_encryptBlock($xor); $this->_increment_str($xor); $ciphertext.= $block ^ $key; } } if ($this->continuousBuffer) { $this->encryptIV = $xor; if ($start = strlen($plaintext) % $block_size) { $buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext']; } } break; case self::MODE_CFB: // cfb loosely routines inspired by openssl's: // {@link http://cvs.openssl.org/fileview?f=openssl/crypto/modes/cfb128.c&v=1.3.2.2.2.1} if ($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 self::MODE_CFB8: $ciphertext = ''; $len = strlen($plaintext); $iv = $this->encryptIV; for ($i = 0; $i < $len; ++$i) { $ciphertext .= ($c = $plaintext[$i] ^ $this->_encryptBlock($iv)); $iv = substr($iv, 1) . $c; } if ($this->continuousBuffer) { if ($len >= $block_size) { $this->encryptIV = substr($ciphertext, -$block_size); } else { $this->encryptIV = substr($this->encryptIV, $len - $block_size) . substr($ciphertext, -$len); } } break; case self::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 = $this->_string_shift($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 self::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. * * @see self::encrypt() * @access public * @param string $ciphertext * @return string $plaintext * @internal Could, but not must, extend by the child Crypt_* class */ function decrypt($ciphertext) { 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($ciphertext) + ($this->block_size - strlen($ciphertext) % $this->block_size) % $this->block_size, chr(0)); } if ($this->engine === self::ENGINE_OPENSSL) { if ($this->changed) { $this->_clearBuffers(); $this->changed = false; } switch ($this->mode) { case self::MODE_STREAM: $plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, $this->openssl_options); break; case self::MODE_ECB: if (!defined('OPENSSL_RAW_DATA')) { $ciphertext.= @openssl_encrypt('', $this->cipher_name_openssl_ecb, $this->key, true); } $plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, $this->openssl_options); break; case self::MODE_CBC: if (!defined('OPENSSL_RAW_DATA')) { $padding = str_repeat(chr($this->block_size), $this->block_size) ^ substr($ciphertext, -$this->block_size); $ciphertext.= substr(@openssl_encrypt($padding, $this->cipher_name_openssl_ecb, $this->key, true), 0, $this->block_size); $offset = 2 * $this->block_size; } else { $offset = $this->block_size; } $plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, $this->openssl_options, $this->decryptIV); if ($this->continuousBuffer) { $this->decryptIV = substr($ciphertext, -$offset, $this->block_size); } break; case self::MODE_CTR: $plaintext = $this->_openssl_ctr_process($ciphertext, $this->decryptIV, $this->debuffer); break; case self::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} $plaintext = ''; if ($this->continuousBuffer) { $iv = &$this->decryptIV; $pos = &$this->buffer['pos']; } else { $iv = $this->decryptIV; $pos = 0; } $len = strlen($ciphertext); $i = 0; if ($pos) { $orig_pos = $pos; $max = $this->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%= $this->blocksize $plaintext = substr($iv, $orig_pos) ^ $ciphertext; $iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i); $ciphertext = substr($ciphertext, $i); } $overflow = $len % $this->block_size; if ($overflow) { $plaintext.= openssl_decrypt(substr($ciphertext, 0, -$overflow), $this->cipher_name_openssl, $this->key, $this->openssl_options, $iv); if ($len - $overflow) { $iv = substr($ciphertext, -$overflow - $this->block_size, -$overflow); } $iv = openssl_encrypt(str_repeat("\0", $this->block_size), $this->cipher_name_openssl, $this->key, $this->openssl_options, $iv); $plaintext.= $iv ^ substr($ciphertext, -$overflow); $iv = substr_replace($iv, substr($ciphertext, -$overflow), 0, $overflow); $pos = $overflow; } elseif ($len) { $plaintext.= openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, $this->openssl_options, $iv); $iv = substr($ciphertext, -$this->block_size); } break; case self::MODE_CFB8: $plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, $this->openssl_options, $this->decryptIV); if ($this->continuousBuffer) { if (($len = strlen($ciphertext)) >= $this->block_size) { $this->decryptIV = substr($ciphertext, -$this->block_size); } else { $this->decryptIV = substr($this->decryptIV, $len - $this->block_size) . substr($ciphertext, -$len); } } break; case self::MODE_OFB: $plaintext = $this->_openssl_ofb_process($ciphertext, $this->decryptIV, $this->debuffer); } return $this->paddable ? $this->_unpad($plaintext) : $plaintext; } if ($this->engine === self::ENGINE_MCRYPT) { set_error_handler(array($this, 'do_nothing')); $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 == self::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; } restore_error_handler(); return $plaintext; } $plaintext = mdecrypt_generic($this->demcrypt, $ciphertext); if (!$this->continuousBuffer) { mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV); } restore_error_handler(); 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; $buffer = &$this->debuffer; $plaintext = ''; switch ($this->mode) { case self::MODE_ECB: for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) { $plaintext.= $this->_decryptBlock(substr($ciphertext, $i, $block_size)); } break; case self::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 self::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'].= $this->_encryptBlock($xor); $this->_increment_str($xor); } $key = $this->_string_shift($buffer['ciphertext'], $block_size); $plaintext.= $block ^ $key; } } else { for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) { $block = substr($ciphertext, $i, $block_size); $key = $this->_encryptBlock($xor); $this->_increment_str($xor); $plaintext.= $block ^ $key; } } if ($this->continuousBuffer) { $this->decryptIV = $xor; if ($start = strlen($ciphertext) % $block_size) { $buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext']; } } break; case self::MODE_CFB: if ($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 self::MODE_CFB8: $plaintext = ''; $len = strlen($ciphertext); $iv = $this->decryptIV; for ($i = 0; $i < $len; ++$i) { $plaintext .= $ciphertext[$i] ^ $this->_encryptBlock($iv); $iv = substr($iv, 1) . $ciphertext[$i]; } if ($this->continuousBuffer) { if ($len >= $block_size) { $this->decryptIV = substr($ciphertext, -$block_size); } else { $this->decryptIV = substr($this->decryptIV, $len - $block_size) . substr($ciphertext, -$len); } } break; case self::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 = $this->_string_shift($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 self::MODE_STREAM: $plaintext = $this->_decryptBlock($ciphertext); break; } return $this->paddable ? $this->_unpad($plaintext) : $plaintext; } /** * OpenSSL CTR Processor * * PHP's OpenSSL bindings do not operate in continuous mode so we'll wrap around it. Since the keystream * for CTR is the same for both encrypting and decrypting this function is re-used by both Base::encrypt() * and Base::decrypt(). Also, OpenSSL doesn't implement CTR for all of it's symmetric ciphers so this * function will emulate CTR with ECB when necessary. * * @see self::encrypt() * @see self::decrypt() * @param string $plaintext * @param string $encryptIV * @param array $buffer * @return string * @access private */ function _openssl_ctr_process($plaintext, &$encryptIV, &$buffer) { $ciphertext = ''; $block_size = $this->block_size; $key = $this->key; if ($this->openssl_emulate_ctr) { $xor = $encryptIV; if (strlen($buffer['ciphertext'])) { for ($i = 0; $i < strlen($plaintext); $i+=$block_size) { $block = substr($plaintext, $i, $block_size); if (strlen($block) > strlen($buffer['ciphertext'])) { $result = @openssl_encrypt($xor, $this->cipher_name_openssl_ecb, $key, $this->openssl_options); $result = !defined('OPENSSL_RAW_DATA') ? substr($result, 0, -$this->block_size) : $result; $buffer['ciphertext'].= $result; } $this->_increment_str($xor); $otp = $this->_string_shift($buffer['ciphertext'], $block_size); $ciphertext.= $block ^ $otp; } } else { for ($i = 0; $i < strlen($plaintext); $i+=$block_size) { $block = substr($plaintext, $i, $block_size); $otp = @openssl_encrypt($xor, $this->cipher_name_openssl_ecb, $key, $this->openssl_options); $otp = !defined('OPENSSL_RAW_DATA') ? substr($otp, 0, -$this->block_size) : $otp; $this->_increment_str($xor); $ciphertext.= $block ^ $otp; } } if ($this->continuousBuffer) { $encryptIV = $xor; if ($start = strlen($plaintext) % $block_size) { $buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext']; } } return $ciphertext; } if (strlen($buffer['ciphertext'])) { $ciphertext = $plaintext ^ $this->_string_shift($buffer['ciphertext'], strlen($plaintext)); $plaintext = substr($plaintext, strlen($ciphertext)); if (!strlen($plaintext)) { return $ciphertext; } } $overflow = strlen($plaintext) % $block_size; if ($overflow) { $plaintext2 = $this->_string_pop($plaintext, $overflow); // ie. trim $plaintext to a multiple of $block_size and put rest of $plaintext in $plaintext2 $encrypted = openssl_encrypt($plaintext . str_repeat("\0", $block_size), $this->cipher_name_openssl, $key, $this->openssl_options, $encryptIV); $temp = $this->_string_pop($encrypted, $block_size); $ciphertext.= $encrypted . ($plaintext2 ^ $temp); if ($this->continuousBuffer) { $buffer['ciphertext'] = substr($temp, $overflow); $encryptIV = $temp; } } elseif (!strlen($buffer['ciphertext'])) { $ciphertext.= openssl_encrypt($plaintext . str_repeat("\0", $block_size), $this->cipher_name_openssl, $key, $this->openssl_options, $encryptIV); $temp = $this->_string_pop($ciphertext, $block_size); if ($this->continuousBuffer) { $encryptIV = $temp; } } if ($this->continuousBuffer) { if (!defined('OPENSSL_RAW_DATA')) { $encryptIV.= @openssl_encrypt('', $this->cipher_name_openssl_ecb, $key, $this->openssl_options); } $encryptIV = openssl_decrypt($encryptIV, $this->cipher_name_openssl_ecb, $key, $this->openssl_options); if ($overflow) { $this->_increment_str($encryptIV); } } return $ciphertext; } /** * OpenSSL OFB Processor * * PHP's OpenSSL bindings do not operate in continuous mode so we'll wrap around it. Since the keystream * for OFB is the same for both encrypting and decrypting this function is re-used by both Base::encrypt() * and Base::decrypt(). * * @see self::encrypt() * @see self::decrypt() * @param string $plaintext * @param string $encryptIV * @param array $buffer * @return string * @access private */ function _openssl_ofb_process($plaintext, &$encryptIV, &$buffer) { if (strlen($buffer['xor'])) { $ciphertext = $plaintext ^ $buffer['xor']; $buffer['xor'] = substr($buffer['xor'], strlen($ciphertext)); $plaintext = substr($plaintext, strlen($ciphertext)); } else { $ciphertext = ''; } $block_size = $this->block_size; $len = strlen($plaintext); $key = $this->key; $overflow = $len % $block_size; if (strlen($plaintext)) { if ($overflow) { $ciphertext.= openssl_encrypt(substr($plaintext, 0, -$overflow) . str_repeat("\0", $block_size), $this->cipher_name_openssl, $key, $this->openssl_options, $encryptIV); $xor = $this->_string_pop($ciphertext, $block_size); if ($this->continuousBuffer) { $encryptIV = $xor; } $ciphertext.= $this->_string_shift($xor, $overflow) ^ substr($plaintext, -$overflow); if ($this->continuousBuffer) { $buffer['xor'] = $xor; } } else { $ciphertext = openssl_encrypt($plaintext, $this->cipher_name_openssl, $key, $this->openssl_options, $encryptIV); if ($this->continuousBuffer) { $encryptIV = substr($ciphertext, -$block_size) ^ substr($plaintext, -$block_size); } } } return $ciphertext; } /** * phpseclib <-> OpenSSL Mode Mapper * * May need to be overwritten by classes extending this one in some cases * * @return int * @access private */ function _openssl_translate_mode() { switch ($this->mode) { case self::MODE_ECB: return 'ecb'; case self::MODE_CBC: return 'cbc'; case self::MODE_CTR: return 'ctr'; case self::MODE_CFB: return 'cfb'; case self::MODE_CFB8: return 'cfb8'; case self::MODE_OFB: return 'ofb'; } } /** * 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 self::disablePadding() * @access public */ function enablePadding() { $this->padding = true; } /** * Do not pad packets. * * @see self::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($plaintext, 16, 16))); * </code> * * With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different * outputs. The reason is due to the fact that the initialization vector's change after every encryption / * decryption round when the continuous buffer is enabled. When it's disabled, they remain constant. * * Put another way, when the continuous buffer is enabled, the state of the \phpseclib\Crypt\*() object changes after each * encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that * continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them), * however, they are also less intuitive and more likely to cause you problems. * * @see self::disableContinuousBuffer() * @access public * @internal Could, but not must, extend by the child Crypt_* class */ function enableContinuousBuffer() { if ($this->mode == self::MODE_ECB) { return; } $this->continuousBuffer = true; $this->_setEngine(); } /** * Treat consecutive packets as if they are a discontinuous buffer. * * The default behavior. * * @see self::enableContinuousBuffer() * @access public * @internal Could, but not must, extend by the child Crypt_* class */ function disableContinuousBuffer() { if ($this->mode == self::MODE_ECB) { return; } if (!$this->continuousBuffer) { return; } $this->continuousBuffer = false; $this->changed = true; $this->_setEngine(); } /** * Test for engine validity * * @see self::__construct() * @param int $engine * @access public * @return bool */ function isValidEngine($engine) { switch ($engine) { case self::ENGINE_OPENSSL: if ($this->mode == self::MODE_STREAM && $this->continuousBuffer) { return false; } $this->openssl_emulate_ctr = false; $result = $this->cipher_name_openssl && extension_loaded('openssl') && // PHP 5.3.0 - 5.3.2 did not let you set IV's version_compare(PHP_VERSION, '5.3.3', '>='); if (!$result) { return false; } // prior to PHP 5.4.0 OPENSSL_RAW_DATA and OPENSSL_ZERO_PADDING were not defined. instead of expecting an integer // $options openssl_encrypt expected a boolean $raw_data. if (!defined('OPENSSL_RAW_DATA')) { $this->openssl_options = true; } else { $this->openssl_options = OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING; } $methods = openssl_get_cipher_methods(); if (in_array($this->cipher_name_openssl, $methods)) { return true; } // not all of openssl's symmetric cipher's support ctr. for those // that don't we'll emulate it switch ($this->mode) { case self::MODE_CTR: if (in_array($this->cipher_name_openssl_ecb, $methods)) { $this->openssl_emulate_ctr = true; return true; } } return false; case self::ENGINE_MCRYPT: set_error_handler(array($this, 'do_nothing')); $result = $this->cipher_name_mcrypt && extension_loaded('mcrypt') && in_array($this->cipher_name_mcrypt, mcrypt_list_algorithms()); restore_error_handler(); return $result; case self::ENGINE_INTERNAL: return true; } return false; } /** * Sets the preferred crypt engine * * Currently, $engine could be: * * - \phpseclib\Crypt\Base::ENGINE_OPENSSL [very fast] * * - \phpseclib\Crypt\Base::ENGINE_MCRYPT [fast] * * - \phpseclib\Crypt\Base::ENGINE_INTERNAL [slow] * * If the preferred crypt engine is not available the fastest available one will be used * * @see self::__construct() * @param int $engine * @access public */ function setPreferredEngine($engine) { switch ($engine) { //case self::ENGINE_OPENSSL; case self::ENGINE_MCRYPT: case self::ENGINE_INTERNAL: $this->preferredEngine = $engine; break; default: $this->preferredEngine = self::ENGINE_OPENSSL; } $this->_setEngine(); } /** * Returns the engine currently being utilized * * @see self::_setEngine() * @access public */ function getEngine() { return $this->engine; } /** * Sets the engine as appropriate * * @see self::__construct() * @access private */ function _setEngine() { $this->engine = null; $candidateEngines = array( $this->preferredEngine, self::ENGINE_OPENSSL, self::ENGINE_MCRYPT ); foreach ($candidateEngines as $engine) { if ($this->isValidEngine($engine)) { $this->engine = $engine; break; } } if (!$this->engine) { $this->engine = self::ENGINE_INTERNAL; } if ($this->engine != self::ENGINE_MCRYPT && $this->enmcrypt) { set_error_handler(array($this, 'do_nothing')); // Closing the current mcrypt resource(s). _mcryptSetup() will, if needed, // (re)open them with the module named in $this->cipher_name_mcrypt mcrypt_module_close($this->enmcrypt); mcrypt_module_close($this->demcrypt); $this->enmcrypt = null; $this->demcrypt = null; if ($this->ecb) { mcrypt_module_close($this->ecb); $this->ecb = null; } restore_error_handler(); } $this->changed = true; } /** * Encrypts a block * * Note: Must be extended by the child \phpseclib\Crypt\* class * * @access private * @param string $in * @return string */ abstract function _encryptBlock($in); /** * Decrypts a block * * Note: Must be extended by the child \phpseclib\Crypt\* class * * @access private * @param string $in * @return string */ abstract function _decryptBlock($in); /** * Setup the key (expansion) * * Only used if $engine == self::ENGINE_INTERNAL * * Note: Must extend by the child \phpseclib\Crypt\* class * * @see self::_setup() * @access private */ abstract function _setupKey(); /** * Setup the self::ENGINE_INTERNAL $engine * * (re)init, if necessary, the internal cipher $engine and flush all $buffers * Used (only) if $engine == self::ENGINE_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 * * @see self::setKey() * @see self::setIV() * @see self::disableContinuousBuffer() * @access private * @internal _setup() is always called before en/decryption. * @internal Could, but not must, extend by the child Crypt_* class */ function _setup() { $this->_clearBuffers(); $this->_setupKey(); if ($this->use_inline_crypt) { $this->_setupInlineCrypt(); } } /** * Setup the self::ENGINE_MCRYPT $engine * * (re)init, if necessary, the (ext)mcrypt resources and flush all $buffers * Used (only) if $engine = self::ENGINE_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() * * @see self::setKey() * @see self::setIV() * @see self::disableContinuousBuffer() * @access private * @internal Could, but not must, extend by the child Crypt_* class */ function _setupMcrypt() { $this->_clearBuffers(); $this->enchanged = $this->dechanged = true; if (!isset($this->enmcrypt)) { static $mcrypt_modes = array( self::MODE_CTR => 'ctr', self::MODE_ECB => MCRYPT_MODE_ECB, self::MODE_CBC => MCRYPT_MODE_CBC, self::MODE_CFB => 'ncfb', self::MODE_CFB8 => MCRYPT_MODE_CFB, self::MODE_OFB => MCRYPT_MODE_NOFB, self::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 == self::MODE_CFB) { $this->ecb = mcrypt_module_open($this->cipher_name_mcrypt, '', MCRYPT_MODE_ECB, ''); } } // else should mcrypt_generic_deinit be called? if ($this->mode == self::MODE_CFB) { mcrypt_generic_init($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 self::_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 self::_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() * * @access public * @internal Could, but not must, extend by the child Crypt_* class */ function _clearBuffers() { $this->enbuffer = $this->debuffer = array('ciphertext' => '', 'xor' => '', 'pos' => 0, 'enmcrypt_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), $this->block_size, "\0"); if (!$this->skip_key_adjustment) { $this->key = str_pad(substr($this->key, 0, $this->key_length), $this->key_length, "\0"); } } /** * String Shift * * Inspired by array_shift * * @param string $string * @param int $index * @access private * @return string */ function _string_shift(&$string, $index = 1) { $substr = substr($string, 0, $index); $string = substr($string, $index); return $substr; } /** * String Pop * * Inspired by array_pop * * @param string $string * @param int $index * @access private * @return string */ function _string_pop(&$string, $index = 1) { $substr = substr($string, -$index); $string = substr($string, 0, -$index); return $substr; } /** * Increment the current string * * @see self::decrypt() * @see self::encrypt() * @param string $var * @access private */ function _increment_str(&$var) { for ($i = 4; $i <= strlen($var); $i+= 4) { $temp = substr($var, -$i, 4); switch ($temp) { case "\xFF\xFF\xFF\xFF": $var = substr_replace($var, "\x00\x00\x00\x00", -$i, 4); break; case "\x7F\xFF\xFF\xFF": $var = substr_replace($var, "\x80\x00\x00\x00", -$i, 4); return; default: $temp = unpack('Nnum', $temp); $var = substr_replace($var, pack('N', $temp['num'] + 1), -$i, 4); return; } } $remainder = strlen($var) % 4; if ($remainder == 0) { return; } $temp = unpack('Nnum', str_pad(substr($var, 0, $remainder), 4, "\0", STR_PAD_LEFT)); $temp = substr(pack('N', $temp['num'] + 1), -$remainder); $var = substr_replace($var, $temp, 0, $remainder); } /** * 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 == self::ENGINE_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 \phpseclib\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 self::_setup() * @see self::_createInlineCryptFunction() * @see self::encrypt() * @see self::decrypt() * @access private * @internal If a Crypt_* class providing inline crypting it must extend _setupInlineCrypt() */ function _setupInlineCrypt() { // If, for any reason, an extending \phpseclib\Crypt\Base() \phpseclib\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 \phpseclib\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 \phpseclib\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 self::_setupInlineCrypt() * @see self::encrypt() * @see self::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 self::MODE_ECB: $encrypt = $init_encrypt . ' $_ciphertext = ""; $_plaintext_len = strlen($_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 self::MODE_CTR: $encrypt = $init_encrypt . ' $_ciphertext = ""; $_plaintext_len = strlen($_text); $_xor = $self->encryptIV; $_buffer = &$self->enbuffer; if (strlen($_buffer["ciphertext"])) { for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') { $_block = substr($_text, $_i, '.$block_size.'); if (strlen($_block) > strlen($_buffer["ciphertext"])) { $in = $_xor; '.$encrypt_block.' $self->_increment_str($_xor); $_buffer["ciphertext"].= $in; } $_key = $self->_string_shift($_buffer["ciphertext"], '.$block_size.'); $_ciphertext.= $_block ^ $_key; } } else { for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') { $_block = substr($_text, $_i, '.$block_size.'); $in = $_xor; '.$encrypt_block.' $self->_increment_str($_xor); $_key = $in; $_ciphertext.= $_block ^ $_key; } } if ($self->continuousBuffer) { $self->encryptIV = $_xor; if ($_start = $_plaintext_len % '.$block_size.') { $_buffer["ciphertext"] = substr($_key, $_start) . $_buffer["ciphertext"]; } } 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 = $_xor; '.$encrypt_block.' $self->_increment_str($_xor); $_buffer["ciphertext"].= $in; } $_key = $self->_string_shift($_buffer["ciphertext"], '.$block_size.'); $_plaintext.= $_block ^ $_key; } } else { for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') { $_block = substr($_text, $_i, '.$block_size.'); $in = $_xor; '.$encrypt_block.' $self->_increment_str($_xor); $_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 self::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 self::MODE_CFB8: $encrypt = $init_encrypt . ' $_ciphertext = ""; $_len = strlen($_text); $_iv = $self->encryptIV; for ($_i = 0; $_i < $_len; ++$_i) { $in = $_iv; '.$encrypt_block.' $_ciphertext .= ($_c = $_text[$_i] ^ $in); $_iv = substr($_iv, 1) . $_c; } if ($self->continuousBuffer) { if ($_len >= '.$block_size.') { $self->encryptIV = substr($_ciphertext, -'.$block_size.'); } else { $self->encryptIV = substr($self->encryptIV, $_len - '.$block_size.') . substr($_ciphertext, -$_len); } } return $_ciphertext; '; $decrypt = $init_encrypt . ' $_plaintext = ""; $_len = strlen($_text); $_iv = $self->decryptIV; for ($_i = 0; $_i < $_len; ++$_i) { $in = $_iv; '.$encrypt_block.' $_plaintext .= $_text[$_i] ^ $in; $_iv = substr($_iv, 1) . $_text[$_i]; } if ($self->continuousBuffer) { if ($_len >= '.$block_size.') { $self->decryptIV = substr($_text, -'.$block_size.'); } else { $self->decryptIV = substr($self->decryptIV, $_len - '.$block_size.') . substr($_text, -$_len); } } return $_plaintext; '; break; case self::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 = $self->_string_shift($_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 = $self->_string_shift($_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 self::MODE_STREAM: $encrypt = $init_encrypt . ' $_ciphertext = ""; '.$encrypt_block.' return $_ciphertext; '; $decrypt = $init_decrypt . ' $_plaintext = ""; '.$decrypt_block.' return $_plaintext; '; break; // case self::MODE_CBC: default: $encrypt = $init_encrypt . ' $_ciphertext = ""; $_plaintext_len = strlen($_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 $inline function and return its name as string. Ready to run! eval('$func = function ($_action, &$self, $_text) { ' . $init_crypt . 'if ($_action == "encrypt") { ' . $encrypt . ' } else { ' . $decrypt . ' } };'); return $func; } /** * 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 * unique value representing, at least, the $mode of * operation (or more... depends of the optimizing level) * for which $mode the lambda function was created. * * @access private * @return array &$functions */ function &_getLambdaFunctions() { static $functions = array(); return $functions; } /** * Generates a digest from $bytes * * @see self::_setupInlineCrypt() * @access private * @param string $bytes * @return string */ function _hashInlineCryptFunction($bytes) { if (!isset(self::$WHIRLPOOL_AVAILABLE)) { self::$WHIRLPOOL_AVAILABLE = extension_loaded('hash') && in_array('whirlpool', hash_algos()); } $result = ''; $hash = $bytes; switch (true) { case self::$WHIRLPOOL_AVAILABLE: foreach (str_split($bytes, 64) as $t) { $hash = hash('whirlpool', $hash, true); $result .= $t ^ $hash; } return $result . hash('whirlpool', $hash, true); default: $len = strlen($bytes); for ($i = 0; $i < $len; $i+=20) { $t = substr($bytes, $i, 20); $hash = pack('H*', sha1($hash)); $result .= $t ^ $hash; } return $result . pack('H*', sha1($hash)); } } /** * Convert float to int * * On ARM CPUs converting floats to ints doesn't always work * * @access private * @param string $x * @return int */ function safe_intval($x) { switch (true) { case is_int($x): // PHP 5.3, per http://php.net/releases/5_3_0.php, introduced "more consistent float rounding" case (php_uname('m') & "\xDF\xDF\xDF") != 'ARM': return $x; } return (fmod($x, 0x80000000) & 0x7FFFFFFF) | ((fmod(floor($x / 0x80000000), 2) & 1) << 31); } /** * eval()'able string for in-line float to int * * @access private * @return string */ function safe_intval_inline() { switch (true) { case defined('PHP_INT_SIZE') && PHP_INT_SIZE == 8: case (php_uname('m') & "\xDF\xDF\xDF") != 'ARM': return '%s'; break; default: $safeint = '(is_int($temp = %s) ? $temp : (fmod($temp, 0x80000000) & 0x7FFFFFFF) | '; return $safeint . '((fmod(floor($temp / 0x80000000), 2) & 1) << 31))'; } } /** * Dummy error handler to suppress mcrypt errors * * @access private */ function do_nothing() { } }
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