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tgseclib/phpseclib/Crypt/Base.php
Andreas Fischer d9e9504fba Merge branch 'PSR2-1.0' into PSR2-2.0 
* PSR2-1.0:
  Fix indentation phpcbf did not fix.
  Remove PSR2.Methods.FunctionCallSignature.SpaceAfterOpenBracket exception.
  Use phpcbf to fix PHP code to ruleset.
  Ignore coding guidelines in ANSI switch block.
  Base code sniffer ruleset on PSR2 rather than PEAR.
  Update PHP Code Sniffer to 2.3.3

Conflicts:
	build/code-sniffer-ruleset-tests.xml
	build/code-sniffer-ruleset.xml
	composer.lock
	phpseclib/Crypt/DES.php
	phpseclib/Crypt/Hash.php
	phpseclib/Crypt/RSA.php
	phpseclib/File/X509.php
	phpseclib/Math/BigInteger.php
	phpseclib/Net/SFTP.php
	phpseclib/Net/SSH1.php
	phpseclib/Net/SSH2.php
	tests/Functional/Net/SFTPUserStoryTest.php
	tests/Unit/Crypt/TwofishTest.php
2015-07-17 13:41:59 +02:00

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<?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;
use phpseclib\Crypt\Hash;
/**
* 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 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 Boolean
* @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 \phpseclib\Crypt\Base::__construct()
* @var Integer
* @access private
*/
var $mode;
/**
* The Block Length of the block cipher
*
* @var Integer
* @access private
*/
var $block_size = 16;
/**
* The Key
*
* @see \phpseclib\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 \phpseclib\Crypt\Base::setIV()
* @var String
* @access private
*/
var $iv;
/**
* A "sliding" Initialization Vector
*
* @see \phpseclib\Crypt\Base::enableContinuousBuffer()
* @see \phpseclib\Crypt\Base::_clearBuffers()
* @var String
* @access private
*/
var $encryptIV;
/**
* A "sliding" Initialization Vector
*
* @see \phpseclib\Crypt\Base::enableContinuousBuffer()
* @see \phpseclib\Crypt\Base::_clearBuffers()
* @var String
* @access private
*/
var $decryptIV;
/**
* Continuous Buffer status
*
* @see \phpseclib\Crypt\Base::enableContinuousBuffer()
* @var Boolean
* @access private
*/
var $continuousBuffer = false;
/**
* Encryption buffer for CTR, OFB and CFB modes
*
* @see \phpseclib\Crypt\Base::encrypt()
* @see \phpseclib\Crypt\Base::_clearBuffers()
* @var Array
* @access private
*/
var $enbuffer;
/**
* Decryption buffer for CTR, OFB and CFB modes
*
* @see \phpseclib\Crypt\Base::decrypt()
* @see \phpseclib\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 \phpseclib\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 \phpseclib\Crypt\Base::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 Boolean
* @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 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 \phpseclib\Crypt\Base::encrypt()
* @see \phpseclib\Crypt\Base::decrypt()
* @see \phpseclib\Crypt\Base::_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 \phpseclib\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 \phpseclib\Crypt\Base::enablePadding()
* @var Boolean
* @access private
*/
var $padding = true;
/**
* Is the mode one that is paddable?
*
* @see \phpseclib\Crypt\Base::__construct()
* @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:
* - 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 \phpseclib\Crypt\Base::_setEngine()
* @see \phpseclib\Crypt\Base::encrypt()
* @see \phpseclib\Crypt\Base::decrypt()
* @var Integer
* @access private
*/
var $engine;
/**
* Holds the preferred crypt engine
*
* @see \phpseclib\Crypt\Base::_setEngine()
* @see \phpseclib\Crypt\Base::setPreferredEngine()
* @var Integer
* @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 \phpseclib\Crypt\Base::_setupMcrypt()
* @var String
* @access private
*/
var $cipher_name_mcrypt;
/**
* The openssl specific name of the cipher
*
* Only used if $engine == CRYPT_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 password key_size used by setPassword()
*
* @see \phpseclib\Crypt\Base::setPassword()
* @var Integer
* @access private
*/
var $password_key_size = 32;
/**
* The default salt used by setPassword()
*
* @see \phpseclib\Crypt\Base::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 $engine == self::ENGINE_INTERNAL
*
* @see \phpseclib\Crypt\Base::encrypt()
* @see \phpseclib\Crypt\Base::decrypt()
* @see \phpseclib\Crypt\Base::_setupInlineCrypt()
* @see \phpseclib\Crypt\Base::$use_inline_crypt
* @var Callback
* @access private
*/
var $inline_crypt;
/**
* Holds whether performance-optimized $inline_crypt() can/should be used.
*
* @see \phpseclib\Crypt\Base::encrypt()
* @see \phpseclib\Crypt\Base::decrypt()
* @see \phpseclib\Crypt\Base::inline_crypt
* @var mixed
* @access private
*/
var $use_inline_crypt;
/**
* If OpenSSL can be used in ECB but not in CTR we can emulate CTR
*
* @see \phpseclib\Crypt\Base::_openssl_ctr_process()
* @var Boolean
* @access private
*/
var $openssl_emulate_ctr = false;
/**
* Determines what options are passed to openssl_encrypt/decrypt
*
* @see \phpseclib\Crypt\Base::isValidEngine()
* @var mixed
* @access private
*/
var $openssl_options;
/**
* 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
*
* (or the alias constants of the chosen cipher, for example for AES: CRYPT_AES_MODE_ECB or CRYPT_AES_MODE_CBC ...)
*
* If not explicitly set, self::MODE_CBC will be used.
*
* @param optional Integer $mode
* @access public
*/
function __construct($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_OFB:
case self::MODE_STREAM:
$this->mode = $mode;
break;
case self::MODE_CBC:
default:
$this->paddable = true;
$this->mode = self::MODE_CBC;
}
$this->_setEngine();
// Determining whether inline crypting can be used by the cipher
if ($this->use_inline_crypt !== false && function_exists('create_function')) {
$this->use_inline_crypt = true;
}
}
/**
* Sets the initialization vector. (optional)
*
* SetIV is not required when 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.
*
* 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)
{
$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 optional String $method
* @return Boolean
* @access public
* @internal Could, but not must, extend by the child Crypt_* class
*/
function setPassword($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->password_key_size : $this->password_key_size;
}
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()):
$i = 1;
while (strlen($key) < $dkLen) {
$hmac = new Hash();
$hmac->setHash($hash);
$hmac->setKey($password);
$f = $u = $hmac->hash($salt . pack('N', $i++));
for ($j = 2; $j <= $count; ++$j) {
$u = $hmac->hash($u);
$f^= $u;
}
$key.= $f;
}
$key = substr($key, 0, $dkLen);
break;
default:
$key = hash_pbkdf2($hash, $password, $salt, $count, $dkLen, true);
}
}
$this->setKey($key);
return true;
}
/**
* Encrypts a message.
*
* $plaintext will be padded with additional bytes such that it's length is a multiple of the block size. Other cipher
* implementations may or may not pad in the same manner. Other common approaches to padding and the reasons why it's
* necessary are discussed in the following
* URL:
*
* {@link http://www.di-mgt.com.au/cryptopad.html http://www.di-mgt.com.au/cryptopad.html}
*
* An alternative to padding is to, separately, send the length of the file. This is what SSH, in fact, does.
* strlen($plaintext) will still need to be a multiple of the block size, however, arbitrary values can be added to make it that
* length.
*
* @see \phpseclib\Crypt\Base::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, $this->encryptIV);
if ($this->continuousBuffer) {
$this->encryptIV = substr($result, -$this->block_size);
}
return !defined('OPENSSL_RAW_DATA') ? substr($result, 0, -$this->block_size) : $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_OFB:
return $this->_openssl_ofb_process($plaintext, $this->encryptIV, $this->enbuffer);
}
}
if ($this->engine === self::ENGINE_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 == 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;
}
return $ciphertext;
}
$ciphertext = mcrypt_generic($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);
}
$buffer = &$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_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 \phpseclib\Crypt\Base::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')) {
$ciphetext.= 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);
}
$plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, $this->openssl_options, $this->decryptIV);
if ($this->continuousBuffer) {
$this->decryptIV = substr($ciphertext, -$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_OFB:
$plaintext = $this->_openssl_ofb_process($ciphertext, $this->decryptIV, $this->debuffer);
}
return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
}
if ($this->engine === self::ENGINE_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 == 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;
}
return $plaintext;
}
$plaintext = mdecrypt_generic($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;
$buffer = &$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_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 Crypt_Base::encrypt()
* and Crypt_Base::decrypt(). Also, OpenSSL doesn't implement CTR for all of it's symmetric ciphers so this
* function will emulate CTR with ECB when necesary.
*
* @see Crypt_Base::encrypt()
* @see Crypt_Base::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 Crypt_Base::encrypt()
* and Crypt_Base::decrypt().
*
* @see Crypt_Base::encrypt()
* @see Crypt_Base::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 $ciphertext;
}
/**
* phpseclib <-> OpenSSL Mode Mapper
*
* May need to be overwritten by classes extending this one in some cases
*
* @return Integer
* @access private
*/
function _openssl_translate_mode()
{
switch ($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_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 \phpseclib\Crypt\Base::disablePadding()
* @access public
*/
function enablePadding()
{
$this->padding = true;
}
/**
* Do not pad packets.
*
* @see \phpseclib\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($plaintext, 16, 16)));
* </code>
*
* With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different
* outputs. The reason is due to the fact that the initialization vector's change after every encryption /
* decryption round when the continuous buffer is enabled. When it's disabled, they remain constant.
*
* Put another way, when the continuous buffer is enabled, the state of the \phpseclib\Crypt\*() object changes after each
* encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that
* continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them),
* however, they are also less intuitive and more likely to cause you problems.
*
* @see \phpseclib\Crypt\Base::disableContinuousBuffer()
* @access public
* @internal Could, but not must, extend by the child Crypt_* class
*/
function enableContinuousBuffer()
{
if ($this->mode == self::MODE_ECB) {
return;
}
$this->continuousBuffer = true;
$this->_setEngine();
}
/**
* Treat consecutive packets as if they are a discontinuous buffer.
*
* The default behavior.
*
* @see \phpseclib\Crypt\Base::enableContinuousBuffer()
* @access public
* @internal Could, but not must, extend by the child Crypt_* class
*/
function disableContinuousBuffer()
{
if ($this->mode == self::MODE_ECB) {
return;
}
if (!$this->continuousBuffer) {
return;
}
$this->continuousBuffer = false;
$this->changed = true;
$this->_setEngine();
}
/**
* Test for engine validity
*
* @see \phpseclib\Crypt\Base::Crypt_Base()
* @param Integer $engine
* @access public
* @return Boolean
*/
function isValidEngine($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:
return $this->cipher_name_mcrypt &&
extension_loaded('mcrypt') &&
in_array($this->cipher_name_mcrypt, mcrypt_list_algorithms());
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 \phpseclib\Crypt\Base::Crypt_Base()
* @param Integer $engine
* @access public
*/
function setPreferredEngine($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 \phpseclib\Crypt\Base::_setEngine()
* @access public
*/
function getEngine()
{
return $this->engine;
}
/**
* Sets the engine as appropriate
*
* @see \phpseclib\Crypt\Base::Crypt_Base()
* @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) {
// 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;
}
}
$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 \phpseclib\Crypt\Base::_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 setKey()
* @see setIV()
* @see 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 setKey()
* @see setIV()
* @see 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_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 \phpseclib\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 \phpseclib\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()
*
* @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");
}
/**
* String Shift
*
* Inspired by array_shift
*
* @param String $string
* @param optional Integer $index
* @access private
* @return String
*/
function _string_shift(&$string, $index = 1)
{
$substr = substr($string, 0, $index);
$string = substr($string, $index);
return $substr;
}
/**
* String Pop
*
* Inspired by array_pop
*
* @param String $string
* @param optional Integer $index
* @access private
* @return String
*/
function _string_pop(&$string, $index = 1)
{
$substr = substr($string, -$index);
$string = substr($string, 0, -$index);
return $substr;
}
/**
* Increment the current string
*
* @see \phpseclib\Crypt\Base::decrypt()
* @see \phpseclib\Crypt\Base::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 \phpseclib\Crypt\Base::_setup()
* @see \phpseclib\Crypt\Base::_createInlineCryptFunction()
* @see \phpseclib\Crypt\Base::encrypt()
* @see \phpseclib\Crypt\Base::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 \phpseclib\Crypt\Base::_setupInlineCrypt()
* @see \phpseclib\Crypt\Base::encrypt()
* @see \phpseclib\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 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_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 $inline function and return its name as string. Ready to run!
return create_function('$_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 $mode the lambda function was created.
*
* @access private
* @return Array &$functions
*/
function &_getLambdaFunctions()
{
static $functions = array();
return $functions;
}
/**
* Generates a digest from $bytes
*
* @see _setupInlineCrypt()
* @access private
* @param $bytes
* @return String
*/
function _hashInlineCryptFunction($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));
}
}
}
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