Merge branch 'master' into stable

* master: (413 commits)
  release preparation
  fixed strict violation in ACL plugin
  Fix issues from teams:i18n:translation-check in localizations
  ensure locale is set back to the original value
  skip FS#2867 test if \s doesn't match \xA0 after attempting to change the locale
  unittests for auth_loadACL
  translation update
  allow charset for SSO to be configured FS#2148
  Mailer: avoid overlong headers in content ids FS#2868
  translation update
  translation update
  replace \s, \S with [ \t], [^ \t] in regexs used with acls
  translation update
  translation update
  translation update
  translation update
  Fix handling of the legacy subscription action name
  remove obsolete opera handling and session closing
  remove no longer used ajax.php
  fix proxy CONNECT where HTTP 1.1 answer is given
  ...

1 files changed, 1989 insertions, 0 deletions

diff --git a/inc/phpseclib/Crypt_Base.php b/inc/phpseclib/Crypt_Base.php
new file mode 100644
index 000000000..7c650ca72
--- /dev/null
+++ b/inc/phpseclib/Crypt_Base.php
@@ -0,0 +1,1989 @@
+<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Base Class for all Crypt_* cipher classes
+ *
+ * PHP versions 4 and 5
+ *
+ * Internally for phpseclib developers:
+ *  If you plan to add a new cipher class, please note following rules:
+ *
+ *  - The new Crypt_* cipher class should extend Crypt_Base
+ *
+ *  - Following methods are then required to be overridden/overloaded:
+ *
+ *    - _encryptBlock()
+ *
+ *    - _decryptBlock()
+ *
+ *    - _setupKey()
+ *
+ *  - All other methods are optional to be overridden/overloaded
+ *
+ *  - Look at the source code of the current ciphers how they extend Crypt_Base
+ *    and take one of them as a start up for the new cipher class.
+ *
+ *  - Please read all the other comments/notes/hints here also for each class var/method
+ *
+ * LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @category   Crypt
+ * @package    Crypt_Base
+ * @author     Jim Wigginton <terrafrost@php.net>
+ * @author     Hans-Juergen Petrich <petrich@tronic-media.com>
+ * @copyright  MMVII Jim Wigginton
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @version    1.0.1
+ * @link       http://phpseclib.sourceforge.net
+ */
+
+/**#@+
+ * @access public
+ * @see Crypt_Base::encrypt()
+ * @see Crypt_Base::decrypt()
+ */
+/**
+ * Encrypt / decrypt using the Counter mode.
+ *
+ * Set to -1 since that's what Crypt/Random.php uses to index the CTR mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Counter_.28CTR.29
+ */
+define('CRYPT_MODE_CTR', -1);
+/**
+ * Encrypt / decrypt using the Electronic Code Book mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29
+ */
+define('CRYPT_MODE_ECB', 1);
+/**
+ * Encrypt / decrypt using the Code Book Chaining mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher-block_chaining_.28CBC.29
+ */
+define('CRYPT_MODE_CBC', 2);
+/**
+ * Encrypt / decrypt using the Cipher Feedback mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher_feedback_.28CFB.29
+ */
+define('CRYPT_MODE_CFB', 3);
+/**
+ * Encrypt / decrypt using the Output Feedback mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Output_feedback_.28OFB.29
+ */
+define('CRYPT_MODE_OFB', 4);
+/**
+ * Encrypt / decrypt using streaming mode.
+ *
+ */
+define('CRYPT_MODE_STREAM', 5);
+/**#@-*/
+
+/**#@+
+ * @access private
+ * @see Crypt_Base::Crypt_Base()
+ */
+/**
+ * Base value for the internal implementation $engine switch
+ */
+define('CRYPT_MODE_INTERNAL', 1);
+/**
+ * Base value for the mcrypt implementation $engine switch
+ */
+define('CRYPT_MODE_MCRYPT', 2);
+/**#@-*/
+
+/**
+ * Base Class for all Crypt_* cipher classes
+ *
+ * @author  Jim Wigginton <terrafrost@php.net>
+ * @author  Hans-Juergen Petrich <petrich@tronic-media.com>
+ * @version 1.0.0
+ * @access  public
+ * @package Crypt_Base
+ */
+class Crypt_Base {
+    /**
+     * The Encryption Mode
+     *
+     * @see Crypt_Base::Crypt_Base()
+     * @var Integer
+     * @access private
+     */
+    var $mode;
+
+    /**
+     * The Block Length of the block cipher
+     *
+     * @var Integer
+     * @access private
+     */
+    var $block_size = 16;
+
+    /**
+     * The Key
+     *
+     * @see Crypt_Base::setKey()
+     * @var String
+     * @access private
+     */
+    var $key = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
+
+    /**
+     * The Initialization Vector
+     *
+     * @see Crypt_Base::setIV()
+     * @var String
+     * @access private
+     */
+    var $iv;
+
+    /**
+     * A "sliding" Initialization Vector
+     *
+     * @see Crypt_Base::enableContinuousBuffer()
+     * @see Crypt_Base::_clearBuffers()
+     * @var String
+     * @access private
+     */
+    var $encryptIV;
+
+    /**
+     * A "sliding" Initialization Vector
+     *
+     * @see Crypt_Base::enableContinuousBuffer()
+     * @see Crypt_Base::_clearBuffers()
+     * @var String
+     * @access private
+     */
+    var $decryptIV;
+
+    /**
+     * Continuous Buffer status
+     *
+     * @see Crypt_Base::enableContinuousBuffer()
+     * @var Boolean
+     * @access private
+     */
+    var $continuousBuffer = false;
+
+    /**
+     * Encryption buffer for CTR, OFB and CFB modes
+     *
+     * @see Crypt_Base::encrypt()
+     * @see Crypt_Base::_clearBuffers()
+     * @var Array
+     * @access private
+     */
+    var $enbuffer;
+
+    /**
+     * Decryption buffer for CTR, OFB and CFB modes
+     *
+     * @see Crypt_Base::decrypt()
+     * @see Crypt_Base::_clearBuffers()
+     * @var Array
+     * @access private
+     */
+    var $debuffer;
+
+    /**
+     * mcrypt resource for encryption
+     *
+     * The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
+     * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
+     *
+     * @see Crypt_Base::encrypt()
+     * @var Resource
+     * @access private
+     */
+    var $enmcrypt;
+
+    /**
+     * mcrypt resource for decryption
+     *
+     * The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
+     * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
+     *
+     * @see Crypt_Base::decrypt()
+     * @var Resource
+     * @access private
+     */
+    var $demcrypt;
+
+    /**
+     * Does the enmcrypt resource need to be (re)initialized?
+     *
+     * @see Crypt_Twofish::setKey()
+     * @see Crypt_Twofish::setIV()
+     * @var Boolean
+     * @access private
+     */
+    var $enchanged = true;
+
+    /**
+     * Does the demcrypt resource need to be (re)initialized?
+     *
+     * @see Crypt_Twofish::setKey()
+     * @see Crypt_Twofish::setIV()
+     * @var Boolean
+     * @access private
+     */
+    var $dechanged = true;
+
+    /**
+     * mcrypt resource for CFB mode
+     *
+     * mcrypt's CFB mode, in (and only in) buffered context,
+     * is broken, so phpseclib implements the CFB mode by it self,
+     * even when the mcrypt php extension is available.
+     *
+     * In order to do the CFB-mode work (fast) phpseclib
+     * use a separate ECB-mode mcrypt resource.
+     *
+     * @link http://phpseclib.sourceforge.net/cfb-demo.phps
+     * @see Crypt_Base::encrypt()
+     * @see Crypt_Base::decrypt()
+     * @see Crypt_Base::_setupMcrypt()
+     * @var Resource
+     * @access private
+     */
+    var $ecb;
+
+    /**
+     * Optimizing value while CFB-encrypting
+     *
+     * Only relevant if $continuousBuffer enabled
+     * and $engine == CRYPT_MODE_MCRYPT
+     *
+     * It's faster to re-init $enmcrypt if
+     * $buffer bytes > $cfb_init_len than
+     * using the $ecb resource furthermore.
+     *
+     * This value depends of the choosen cipher
+     * and the time it would be needed for it's
+     * initialization [by mcrypt_generic_init()]
+     * which, typically, depends on the complexity
+     * on its internaly Key-expanding algorithm.
+     *
+     * @see Crypt_Base::encrypt()
+     * @var Integer
+     * @access private
+     */
+    var $cfb_init_len = 600;
+
+    /**
+     * Does internal cipher state need to be (re)initialized?
+     *
+     * @see setKey()
+     * @see setIV()
+     * @see disableContinuousBuffer()
+     * @var Boolean
+     * @access private
+     */
+    var $changed = true;
+
+    /**
+     * Padding status
+     *
+     * @see Crypt_Base::enablePadding()
+     * @var Boolean
+     * @access private
+     */
+    var $padding = true;
+
+    /**
+     * Is the mode one that is paddable?
+     *
+     * @see Crypt_Base::Crypt_Base()
+     * @var Boolean
+     * @access private
+     */
+    var $paddable = false;
+
+    /**
+     * Holds which crypt engine internaly should be use,
+     * which will be determined automatically on __construct()
+     *
+     * Currently available $engines are:
+     * - CRYPT_MODE_MCRYPT   (fast, php-extension: mcrypt, extension_loaded('mcrypt') required)
+     * - CRYPT_MODE_INTERNAL (slower, pure php-engine, no php-extension required)
+     *
+     * In the pipeline... maybe. But currently not available:
+     * - CRYPT_MODE_OPENSSL  (very fast, php-extension: openssl, extension_loaded('openssl') required)
+     *
+     * If possible, CRYPT_MODE_MCRYPT will be used for each cipher.
+     * Otherwise CRYPT_MODE_INTERNAL
+     *
+     * @see Crypt_Base::encrypt()
+     * @see Crypt_Base::decrypt()
+     * @var Integer
+     * @access private
+     */
+    var $engine;
+
+    /**
+     * The mcrypt specific name of the cipher
+     *
+     * Only used if $engine == CRYPT_MODE_MCRYPT
+     *
+     * @link http://www.php.net/mcrypt_module_open
+     * @link http://www.php.net/mcrypt_list_algorithms
+     * @see Crypt_Base::_setupMcrypt()
+     * @var String
+     * @access private
+     */
+    var $cipher_name_mcrypt;
+
+    /**
+     * The default password key_size used by setPassword()
+     *
+     * @see Crypt_Base::setPassword()
+     * @var Integer
+     * @access private
+     */
+    var $password_key_size = 32;
+
+    /**
+     * The default salt used by setPassword()
+     *
+     * @see Crypt_Base::setPassword()
+     * @var String
+     * @access private
+     */
+    var $password_default_salt = 'phpseclib/salt';
+
+    /**
+     * The namespace used by the cipher for its constants.
+     *
+     * ie: AES.php is using CRYPT_AES_MODE_* for its constants
+     *     so $const_namespace is AES
+     *
+     *     DES.php is using CRYPT_DES_MODE_* for its constants
+     *     so $const_namespace is DES... and so on
+     *
+     * All CRYPT_<$const_namespace>_MODE_* are aliases of
+     * the generic CRYPT_MODE_* constants, so both could be used
+     * for each cipher.
+     *
+     * Example:
+     * $aes = new Crypt_AES(CRYPT_AES_MODE_CFB); // $aes will operate in cfb mode
+     * $aes = new Crypt_AES(CRYPT_MODE_CFB);     // identical
+     *
+     * @see Crypt_Base::Crypt_Base()
+     * @var String
+     * @access private
+     */
+    var $const_namespace;
+
+    /**
+     * The name of the performance-optimized callback function
+     *
+     * Used by encrypt() / decrypt()
+     * only if $engine == CRYPT_MODE_INTERNAL
+     *
+     * @see Crypt_Base::encrypt()
+     * @see Crypt_Base::decrypt()
+     * @see Crypt_Base::_setupInlineCrypt()
+     * @see Crypt_Base::$use_inline_crypt
+     * @var Callback
+     * @access private
+     */
+    var $inline_crypt;
+
+    /**
+     * Holds whether performance-optimized $inline_crypt() can/should be used.
+     *
+     * @see Crypt_Base::encrypt()
+     * @see Crypt_Base::decrypt()
+     * @see Crypt_Base::inline_crypt
+     * @var mixed
+     * @access private
+     */
+    var $use_inline_crypt;
+
+    /**
+     * Default Constructor.
+     *
+     * Determines whether or not the mcrypt extension should be used.
+     *
+     * $mode could be:
+     *
+     * - CRYPT_MODE_ECB
+     *
+     * - CRYPT_MODE_CBC
+     *
+     * - CRYPT_MODE_CTR
+     *
+     * - CRYPT_MODE_CFB
+     *
+     * - CRYPT_MODE_OFB
+     *
+     * (or the alias constants of the choosen cipher, for example for AES: CRYPT_AES_MODE_ECB or CRYPT_AES_MODE_CBC ...)
+     *
+     * If not explictly set, CRYPT_MODE_CBC will be used.
+     *
+     * @param optional Integer $mode
+     * @access public
+     */
+    function Crypt_Base($mode = CRYPT_MODE_CBC)
+    {
+        $const_crypt_mode = 'CRYPT_' . $this->const_namespace . '_MODE';
+
+        // Determining the availibility of mcrypt support for the cipher
+        if (!defined($const_crypt_mode)) {
+            switch (true) {
+                case extension_loaded('mcrypt') && in_array($this->cipher_name_mcrypt, mcrypt_list_algorithms()):
+                    define($const_crypt_mode, CRYPT_MODE_MCRYPT);
+                    break;
+                default:
+                    define($const_crypt_mode, CRYPT_MODE_INTERNAL);
+            }
+        }
+
+        // Determining which internal $engine should be used.
+        // The fastes possible first.
+        switch (true) {
+            case empty($this->cipher_name_mcrypt): // The cipher module has no mcrypt-engine support at all so we force CRYPT_MODE_INTERNAL
+                $this->engine = CRYPT_MODE_INTERNAL;
+                break;
+            case constant($const_crypt_mode) == CRYPT_MODE_MCRYPT:
+                $this->engine = CRYPT_MODE_MCRYPT;
+                break;
+            default:
+                $this->engine = CRYPT_MODE_INTERNAL;
+        }
+
+        // $mode dependent settings
+        switch ($mode) {
+            case CRYPT_MODE_ECB:
+                $this->paddable = true;
+                $this->mode = $mode;
+                break;
+            case CRYPT_MODE_CTR:
+            case CRYPT_MODE_CFB:
+            case CRYPT_MODE_OFB:
+            case CRYPT_MODE_STREAM:
+                $this->mode = $mode;
+                break;
+            case CRYPT_MODE_CBC:
+            default:
+                $this->paddable = true;
+                $this->mode = CRYPT_MODE_CBC;
+        }
+
+        // Determining whether inline crypting can be used by the cipher
+        if ($this->use_inline_crypt !== false && function_exists('create_function')) {
+            $this->use_inline_crypt = true;
+        }
+    }
+
+    /**
+     * Sets the initialization vector. (optional)
+     *
+     * SetIV is not required when CRYPT_MODE_ECB (or ie for AES: CRYPT_AES_MODE_ECB) is being used.  If not explictly set, it'll be assumed
+     * to be all zero's.
+     *
+     * Note: Could, but not must, extend by the child Crypt_* class
+     *
+     * @access public
+     * @param String $iv
+     */
+    function setIV($iv)
+    {
+        if ($this->mode == CRYPT_MODE_ECB) {
+            return;
+        }
+
+        $this->iv = $iv;
+        $this->changed = true;
+    }
+
+    /**
+     * Sets the key.
+     *
+     * The min/max length(s) of the key depends on the cipher which is used.
+     * If the key not fits the length(s) of the cipher it will paded with null bytes
+     * up to the closest valid key length.  If the key is more than max length,
+     * we trim the excess bits.
+     *
+     * If the key is not explicitly set, it'll be assumed to be all null bytes.
+     *
+     * Note: Could, but not must, extend by the child Crypt_* class
+     *
+     * @access public
+     * @param String $key
+     */
+    function setKey($key)
+    {
+        $this->key = $key;
+        $this->changed = true;
+    }
+
+    /**
+     * Sets the password.
+     *
+     * Depending on what $method is set to, setPassword()'s (optional) parameters are as follows:
+     *     {@link http://en.wikipedia.org/wiki/PBKDF2 pbkdf2}:
+     *         $hash, $salt, $count, $dkLen
+     *
+     *         Where $hash (default = sha1) currently supports the following hashes: see: Crypt/Hash.php
+     *
+     * Note: Could, but not must, extend by the child Crypt_* class
+     *
+     * @see Crypt/Hash.php
+     * @param String $password
+     * @param optional String $method
+     * @access public
+     */
+    function setPassword($password, $method = 'pbkdf2')
+    {
+        $key = '';
+
+        switch ($method) {
+            default: // 'pbkdf2'
+                $func_args = func_get_args();
+
+                // Hash function
+                $hash = isset($func_args[2]) ? $func_args[2] : 'sha1';
+
+                // WPA and WPA2 use the SSID as the salt
+                $salt = isset($func_args[3]) ? $func_args[3] : $this->password_default_salt;
+
+                // RFC2898#section-4.2 uses 1,000 iterations by default
+                // WPA and WPA2 use 4,096.
+                $count = isset($func_args[4]) ? $func_args[4] : 1000;
+
+                // Keylength
+                $dkLen = isset($func_args[5]) ? $func_args[5] : $this->password_key_size;
+
+                // Determining if php[>=5.5.0]'s hash_pbkdf2() function avail- and useable
+                switch (true) {
+                    case !function_exists('hash_pbkdf2'):
+                    case !function_exists('hash_algos'):
+                    case !in_array($hash, hash_algos()):
+                        if (!class_exists('Crypt_Hash')) {
+                            require_once('Crypt/Hash.php');
+                        }
+                        $i = 1;
+                        while (strlen($key) < $dkLen) {
+                            $hmac = new Crypt_Hash();
+                            $hmac->setHash($hash);
+                            $hmac->setKey($password);
+                            $f = $u = $hmac->hash($salt . pack('N', $i++));
+                            for ($j = 2; $j <= $count; ++$j) {
+                                $u = $hmac->hash($u);
+                                $f^= $u;
+                            }
+                            $key.= $f;
+                        }
+                        $key = substr($key, 0, $dkLen);
+                        break;
+                    default:
+                        $key = hash_pbkdf2($hash, $password, $salt, $count, $dkLen, true);
+                }
+        }
+
+        $this->setKey($key);
+    }
+
+    /**
+     * Encrypts a message.
+     *
+     * $plaintext will be padded with additional bytes such that it's length is a multiple of the block size. Other cipher
+     * implementations may or may not pad in the same manner.  Other common approaches to padding and the reasons why it's
+     * necessary are discussed in the following
+     * URL:
+     *
+     * {@link http://www.di-mgt.com.au/cryptopad.html http://www.di-mgt.com.au/cryptopad.html}
+     *
+     * An alternative to padding is to, separately, send the length of the file.  This is what SSH, in fact, does.
+     * strlen($plaintext) will still need to be a multiple of the block size, however, arbitrary values can be added to make it that
+     * length.
+     *
+     * Note: Could, but not must, extend by the child Crypt_* class
+     *
+     * @see Crypt_Base::decrypt()
+     * @access public
+     * @param String $plaintext
+     * @return String $cipertext
+     */
+    function encrypt($plaintext)
+    {
+        if ($this->engine == CRYPT_MODE_MCRYPT) {
+            if ($this->changed) {
+                $this->_setupMcrypt();
+                $this->changed = false;
+            }
+            if ($this->enchanged) {
+                mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV);
+                $this->enchanged = false;
+            }
+
+            // re: {@link http://phpseclib.sourceforge.net/cfb-demo.phps}
+            // using mcrypt's default handing of CFB the above would output two different things.  using phpseclib's
+            // rewritten CFB implementation the above outputs the same thing twice.
+            if ($this->mode == CRYPT_MODE_CFB && $this->continuousBuffer) {
+                $block_size = $this->block_size;
+                $iv = &$this->encryptIV;
+                $pos = &$this->enbuffer['pos'];
+                $len = strlen($plaintext);
+                $ciphertext = '';
+                $i = 0;
+                if ($pos) {
+                    $orig_pos = $pos;
+                    $max = $block_size - $pos;
+                    if ($len >= $max) {
+                        $i = $max;
+                        $len-= $max;
+                        $pos = 0;
+                    } else {
+                        $i = $len;
+                        $pos+= $len;
+                        $len = 0;
+                    }
+                    $ciphertext = substr($iv, $orig_pos) ^ $plaintext;
+                    $iv = substr_replace($iv, $ciphertext, $orig_pos, $i);
+                    $this->enbuffer['enmcrypt_init'] = true;
+                }
+                if ($len >= $block_size) {
+                    if ($this->enbuffer['enmcrypt_init'] === false || $len > $this->cfb_init_len) {
+                        if ($this->enbuffer['enmcrypt_init'] === true) {
+                            mcrypt_generic_init($this->enmcrypt, $this->key, $iv);
+                            $this->enbuffer['enmcrypt_init'] = false;
+                        }
+                        $ciphertext.= mcrypt_generic($this->enmcrypt, substr($plaintext, $i, $len - $len % $block_size));
+                        $iv = substr($ciphertext, -$block_size);
+                        $len%= $block_size;
+                    } else {
+                        while ($len >= $block_size) {
+                            $iv = mcrypt_generic($this->ecb, $iv) ^ substr($plaintext, $i, $block_size);
+                            $ciphertext.= $iv;
+                            $len-= $block_size;
+                            $i+= $block_size;
+                        }
+                    }
+                }
+
+                if ($len) {
+                    $iv = mcrypt_generic($this->ecb, $iv);
+                    $block = $iv ^ substr($plaintext, -$len);
+                    $iv = substr_replace($iv, $block, 0, $len);
+                    $ciphertext.= $block;
+                    $pos = $len;
+                }
+
+                return $ciphertext;
+            }
+
+            if ($this->paddable) {
+                $plaintext = $this->_pad($plaintext);
+            }
+
+            $ciphertext = mcrypt_generic($this->enmcrypt, $plaintext);
+
+            if (!$this->continuousBuffer) {
+                mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV);
+            }
+
+            return $ciphertext;
+        }
+
+        if ($this->changed) {
+            $this->_setup();
+            $this->changed = false;
+        }
+        if ($this->use_inline_crypt) {
+            $inline = $this->inline_crypt;
+            return $inline('encrypt', $this, $plaintext);
+        }
+        if ($this->paddable) {
+            $plaintext = $this->_pad($plaintext);
+        }
+
+        $buffer = &$this->enbuffer;
+        $block_size = $this->block_size;
+        $ciphertext = '';
+        switch ($this->mode) {
+            case CRYPT_MODE_ECB:
+                for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                    $ciphertext.= $this->_encryptBlock(substr($plaintext, $i, $block_size));
+                }
+                break;
+            case CRYPT_MODE_CBC:
+                $xor = $this->encryptIV;
+                for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                    $block = substr($plaintext, $i, $block_size);
+                    $block = $this->_encryptBlock($block ^ $xor);
+                    $xor = $block;
+                    $ciphertext.= $block;
+                }
+                if ($this->continuousBuffer) {
+                    $this->encryptIV = $xor;
+                }
+                break;
+            case CRYPT_MODE_CTR:
+                $xor = $this->encryptIV;
+                if (strlen($buffer['encrypted'])) {
+                    for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                        $block = substr($plaintext, $i, $block_size);
+                        if (strlen($block) > strlen($buffer['encrypted'])) {
+                            $buffer['encrypted'].= $this->_encryptBlock($this->_generateXor($xor, $block_size));
+                        }
+                        $key = $this->_stringShift($buffer['encrypted'], $block_size);
+                        $ciphertext.= $block ^ $key;
+                    }
+                } else {
+                    for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                        $block = substr($plaintext, $i, $block_size);
+                        $key = $this->_encryptBlock($this->_generateXor($xor, $block_size));
+                        $ciphertext.= $block ^ $key;
+                    }
+                }
+                if ($this->continuousBuffer) {
+                    $this->encryptIV = $xor;
+                    if ($start = strlen($plaintext) % $block_size) {
+                        $buffer['encrypted'] = substr($key, $start) . $buffer['encrypted'];
+                    }
+                }
+                break;
+            case CRYPT_MODE_CFB:
+                // cfb loosely routines inspired by openssl's:
+                // {@link http://cvs.openssl.org/fileview?f=openssl/crypto/modes/cfb128.c&v=1.3.2.2.2.1}
+                if ($this->continuousBuffer) {
+                    $iv = &$this->encryptIV;
+                    $pos = &$buffer['pos'];
+                } else {
+                    $iv = $this->encryptIV;
+                    $pos = 0;
+                }
+                $len = strlen($plaintext);
+                $i = 0;
+                if ($pos) {
+                    $orig_pos = $pos;
+                    $max = $block_size - $pos;
+                    if ($len >= $max) {
+                        $i = $max;
+                        $len-= $max;
+                        $pos = 0;
+                    } else {
+                        $i = $len;
+                        $pos+= $len;
+                        $len = 0;
+                    }
+                    // ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize
+                    $ciphertext = substr($iv, $orig_pos) ^ $plaintext;
+                    $iv = substr_replace($iv, $ciphertext, $orig_pos, $i);
+                }
+                while ($len >= $block_size) {
+                    $iv = $this->_encryptBlock($iv) ^ substr($plaintext, $i, $block_size);
+                    $ciphertext.= $iv;
+                    $len-= $block_size;
+                    $i+= $block_size;
+                }
+                if ($len) {
+                    $iv = $this->_encryptBlock($iv);
+                    $block = $iv ^ substr($plaintext, $i);
+                    $iv = substr_replace($iv, $block, 0, $len);
+                    $ciphertext.= $block;
+                    $pos = $len;
+                }
+                break;
+            case CRYPT_MODE_OFB:
+                $xor = $this->encryptIV;
+                if (strlen($buffer['xor'])) {
+                    for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                        $block = substr($plaintext, $i, $block_size);
+                        if (strlen($block) > strlen($buffer['xor'])) {
+                            $xor = $this->_encryptBlock($xor);
+                            $buffer['xor'].= $xor;
+                        }
+                        $key = $this->_stringShift($buffer['xor'], $block_size);
+                        $ciphertext.= $block ^ $key;
+                    }
+                } else {
+                    for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                        $xor = $this->_encryptBlock($xor);
+                        $ciphertext.= substr($plaintext, $i, $block_size) ^ $xor;
+                    }
+                    $key = $xor;
+                }
+                if ($this->continuousBuffer) {
+                    $this->encryptIV = $xor;
+                    if ($start = strlen($plaintext) % $block_size) {
+                         $buffer['xor'] = substr($key, $start) . $buffer['xor'];
+                    }
+                }
+                break;
+            case CRYPT_MODE_STREAM:
+                $ciphertext = $this->_encryptBlock($plaintext);
+                break;
+        }
+
+        return $ciphertext;
+    }
+
+    /**
+     * Decrypts a message.
+     *
+     * If strlen($ciphertext) is not a multiple of the block size, null bytes will be added to the end of the string until
+     * it is.
+     *
+     * Note: Could, but not must, extend by the child Crypt_* class
+     *
+     * @see Crypt_Base::encrypt()
+     * @access public
+     * @param String $ciphertext
+     * @return String $plaintext
+     */
+    function decrypt($ciphertext)
+    {
+        if ($this->engine == CRYPT_MODE_MCRYPT) {
+            $block_size = $this->block_size;
+            if ($this->changed) {
+                $this->_setupMcrypt();
+                $this->changed = false;
+            }
+            if ($this->dechanged) {
+                mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV);
+                $this->dechanged = false;
+            }
+
+            if ($this->mode == CRYPT_MODE_CFB && $this->continuousBuffer) {
+                $iv = &$this->decryptIV;
+                $pos = &$this->debuffer['pos'];
+                $len = strlen($ciphertext);
+                $plaintext = '';
+                $i = 0;
+                if ($pos) {
+                    $orig_pos = $pos;
+                    $max = $block_size - $pos;
+                    if ($len >= $max) {
+                        $i = $max;
+                        $len-= $max;
+                        $pos = 0;
+                    } else {
+                        $i = $len;
+                        $pos+= $len;
+                        $len = 0;
+                    }
+                    // ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize
+                    $plaintext = substr($iv, $orig_pos) ^ $ciphertext;
+                    $iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i);
+                }
+                if ($len >= $block_size) {
+                    $cb = substr($ciphertext, $i, $len - $len % $block_size);
+                    $plaintext.= mcrypt_generic($this->ecb, $iv . $cb) ^ $cb;
+                    $iv = substr($cb, -$block_size);
+                    $len%= $block_size;
+                }
+                if ($len) {
+                    $iv = mcrypt_generic($this->ecb, $iv);
+                    $plaintext.= $iv ^ substr($ciphertext, -$len);
+                    $iv = substr_replace($iv, substr($ciphertext, -$len), 0, $len);
+                    $pos = $len;
+                }
+
+                return $plaintext;
+            }
+
+            if ($this->paddable) {
+                // we pad with chr(0) since that's what mcrypt_generic does.  to quote from {@link http://www.php.net/function.mcrypt-generic}:
+                // "The data is padded with "\0" to make sure the length of the data is n * blocksize."
+                $ciphertext = str_pad($ciphertext, strlen($ciphertext) + ($block_size - strlen($ciphertext) % $block_size) % $block_size, chr(0));
+            }
+
+            $plaintext = mdecrypt_generic($this->demcrypt, $ciphertext);
+
+            if (!$this->continuousBuffer) {
+                mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV);
+            }
+
+            return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
+        }
+
+        if ($this->changed) {
+            $this->_setup();
+            $this->changed = false;
+        }
+        if ($this->use_inline_crypt) {
+            $inline = $this->inline_crypt;
+            return $inline('decrypt', $this, $ciphertext);
+        }
+
+        $block_size = $this->block_size;
+        if ($this->paddable) {
+            // we pad with chr(0) since that's what mcrypt_generic does [...]
+            $ciphertext = str_pad($ciphertext, strlen($ciphertext) + ($block_size - strlen($ciphertext) % $block_size) % $block_size, chr(0));
+        }
+
+        $buffer = &$this->debuffer;
+        $plaintext = '';
+        switch ($this->mode) {
+            case CRYPT_MODE_ECB:
+                for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                    $plaintext.= $this->_decryptBlock(substr($ciphertext, $i, $block_size));
+                }
+                break;
+            case CRYPT_MODE_CBC:
+                $xor = $this->decryptIV;
+                for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                    $block = substr($ciphertext, $i, $block_size);
+                    $plaintext.= $this->_decryptBlock($block) ^ $xor;
+                    $xor = $block;
+                }
+                if ($this->continuousBuffer) {
+                    $this->decryptIV = $xor;
+                }
+                break;
+            case CRYPT_MODE_CTR:
+                $xor = $this->decryptIV;
+                if (strlen($buffer['ciphertext'])) {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                        $block = substr($ciphertext, $i, $block_size);
+                        if (strlen($block) > strlen($buffer['ciphertext'])) {
+                            $buffer['ciphertext'].= $this->_encryptBlock($this->_generateXor($xor, $block_size));
+                        }
+                        $key = $this->_stringShift($buffer['ciphertext'], $block_size);
+                        $plaintext.= $block ^ $key;
+                    }
+                } else {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                        $block = substr($ciphertext, $i, $block_size);
+                        $key = $this->_encryptBlock($this->_generateXor($xor, $block_size));
+                        $plaintext.= $block ^ $key;
+                    }
+                }
+                if ($this->continuousBuffer) {
+                    $this->decryptIV = $xor;
+                    if ($start = strlen($ciphertext) % $block_size) {
+                        $buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext'];
+                    }
+                }
+                break;
+            case CRYPT_MODE_CFB:
+                if ($this->continuousBuffer) {
+                    $iv = &$this->decryptIV;
+                    $pos = &$buffer['pos'];
+                } else {
+                    $iv = $this->decryptIV;
+                    $pos = 0;
+                }
+                $len = strlen($ciphertext);
+                $i = 0;
+                if ($pos) {
+                    $orig_pos = $pos;
+                    $max = $block_size - $pos;
+                    if ($len >= $max) {
+                        $i = $max;
+                        $len-= $max;
+                        $pos = 0;
+                    } else {
+                        $i = $len;
+                        $pos+= $len;
+                        $len = 0;
+                    }
+                    // ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize
+                    $plaintext = substr($iv, $orig_pos) ^ $ciphertext;
+                    $iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i);
+                }
+                while ($len >= $block_size) {
+                    $iv = $this->_encryptBlock($iv);
+                    $cb = substr($ciphertext, $i, $block_size);
+                    $plaintext.= $iv ^ $cb;
+                    $iv = $cb;
+                    $len-= $block_size;
+                    $i+= $block_size;
+                }
+                if ($len) {
+                    $iv = $this->_encryptBlock($iv);
+                    $plaintext.= $iv ^ substr($ciphertext, $i);
+                    $iv = substr_replace($iv, substr($ciphertext, $i), 0, $len);
+                    $pos = $len;
+                }
+                break;
+            case CRYPT_MODE_OFB:
+                $xor = $this->decryptIV;
+                if (strlen($buffer['xor'])) {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                        $block = substr($ciphertext, $i, $block_size);
+                        if (strlen($block) > strlen($buffer['xor'])) {
+                            $xor = $this->_encryptBlock($xor);
+                            $buffer['xor'].= $xor;
+                        }
+                        $key = $this->_stringShift($buffer['xor'], $block_size);
+                        $plaintext.= $block ^ $key;
+                    }
+                } else {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                        $xor = $this->_encryptBlock($xor);
+                        $plaintext.= substr($ciphertext, $i, $block_size) ^ $xor;
+                    }
+                    $key = $xor;
+                }
+                if ($this->continuousBuffer) {
+                    $this->decryptIV = $xor;
+                    if ($start = strlen($ciphertext) % $block_size) {
+                         $buffer['xor'] = substr($key, $start) . $buffer['xor'];
+                    }
+                }
+                break;
+            case CRYPT_MODE_STREAM:
+                $plaintext = $this->_decryptBlock($ciphertext);
+                break;
+        }
+        return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
+    }
+
+    /**
+     * Pad "packets".
+     *
+     * Block ciphers working by encrypting between their specified [$this->]block_size at a time
+     * If you ever need to encrypt or decrypt something that isn't of the proper length, it becomes necessary to
+     * pad the input so that it is of the proper length.
+     *
+     * Padding is enabled by default.  Sometimes, however, it is undesirable to pad strings.  Such is the case in SSH,
+     * where "packets" are padded with random bytes before being encrypted.  Unpad these packets and you risk stripping
+     * away characters that shouldn't be stripped away. (SSH knows how many bytes are added because the length is
+     * transmitted separately)
+     *
+     * @see Crypt_Base::disablePadding()
+     * @access public
+     */
+    function enablePadding()
+    {
+        $this->padding = true;
+    }
+
+    /**
+     * Do not pad packets.
+     *
+     * @see Crypt_Base::enablePadding()
+     * @access public
+     */
+    function disablePadding()
+    {
+        $this->padding = false;
+    }
+
+    /**
+     * Treat consecutive "packets" as if they are a continuous buffer.
+     *
+     * Say you have a 32-byte plaintext $plaintext.  Using the default behavior, the two following code snippets
+     * will yield different outputs:
+     *
+     * <code>
+     *    echo $rijndael->encrypt(substr($plaintext,  0, 16));
+     *    echo $rijndael->encrypt(substr($plaintext, 16, 16));
+     * </code>
+     * <code>
+     *    echo $rijndael->encrypt($plaintext);
+     * </code>
+     *
+     * The solution is to enable the continuous buffer.  Although this will resolve the above discrepancy, it creates
+     * another, as demonstrated with the following:
+     *
+     * <code>
+     *    $rijndael->encrypt(substr($plaintext, 0, 16));
+     *    echo $rijndael->decrypt($rijndael->encrypt(substr($plaintext, 16, 16)));
+     * </code>
+     * <code>
+     *    echo $rijndael->decrypt($rijndael->encrypt(substr($plaintext, 16, 16)));
+     * </code>
+     *
+     * With the continuous buffer disabled, these would yield the same output.  With it enabled, they yield different
+     * outputs.  The reason is due to the fact that the initialization vector's change after every encryption /
+     * decryption round when the continuous buffer is enabled.  When it's disabled, they remain constant.
+     *
+     * Put another way, when the continuous buffer is enabled, the state of the Crypt_*() object changes after each
+     * encryption / decryption round, whereas otherwise, it'd remain constant.  For this reason, it's recommended that
+     * continuous buffers not be used.  They do offer better security and are, in fact, sometimes required (SSH uses them),
+     * however, they are also less intuitive and more likely to cause you problems.
+     *
+     * Note: Could, but not must, extend by the child Crypt_* class
+     *
+     * @see Crypt_Base::disableContinuousBuffer()
+     * @access public
+     */
+    function enableContinuousBuffer()
+    {
+        if ($this->mode == CRYPT_MODE_ECB) {
+            return;
+        }
+
+        $this->continuousBuffer = true;
+    }
+
+    /**
+     * Treat consecutive packets as if they are a discontinuous buffer.
+     *
+     * The default behavior.
+     *
+     * Note: Could, but not must, extend by the child Crypt_* class
+     *
+     * @see Crypt_Base::enableContinuousBuffer()
+     * @access public
+     */
+    function disableContinuousBuffer()
+    {
+        if ($this->mode == CRYPT_MODE_ECB) {
+            return;
+        }
+        if (!$this->continuousBuffer) {
+            return;
+        }
+
+        $this->continuousBuffer = false;
+        $this->changed = true;
+    }
+
+    /**
+     * Encrypts a block
+     *
+     * Note: Must extend by the child Crypt_* class
+     *
+     * @access private
+     * @param String $in
+     * @return String
+     */
+    function _encryptBlock($in)
+    {
+        user_error((version_compare(PHP_VERSION, '5.0.0', '>=')  ? __METHOD__ : __FUNCTION__)  . '() must extend by class ' . get_class($this), E_USER_ERROR);
+    }
+
+    /**
+     * Decrypts a block
+     *
+     * Note: Must extend by the child Crypt_* class
+     *
+     * @access private
+     * @param String $in
+     * @return String
+     */
+    function _decryptBlock($in)
+    {
+        user_error((version_compare(PHP_VERSION, '5.0.0', '>=')  ? __METHOD__ : __FUNCTION__)  . '() must extend by class ' . get_class($this), E_USER_ERROR);
+    }
+
+    /**
+     * Setup the key (expansion)
+     *
+     * Only used if $engine == CRYPT_MODE_INTERNAL
+     *
+     * Note: Must extend by the child Crypt_* class
+     *
+     * @see Crypt_Base::_setup()
+     * @access private
+     */
+    function _setupKey()
+    {
+        user_error((version_compare(PHP_VERSION, '5.0.0', '>=')  ? __METHOD__ : __FUNCTION__)  . '() must extend by class ' . get_class($this), E_USER_ERROR);
+    }
+
+    /**
+     * Setup the CRYPT_MODE_INTERNAL $engine
+     *
+     * (re)init, if necessary, the internal cipher $engine and flush all $buffers
+     * Used (only) if $engine == CRYPT_MODE_INTERNAL
+     *
+     * _setup() will be called each time if $changed === true
+     * typically this happens when using one or more of following public methods:
+     *
+     * - setKey()
+     *
+     * - setIV()
+     *
+     * - disableContinuousBuffer()
+     *
+     * - First run of encrypt() / decrypt() with no init-settings
+     *
+     * Internally: _setup() is called always before(!) en/decryption.
+     *
+     * Note: Could, but not must, extend by the child Crypt_* class
+     *
+     * @see setKey()
+     * @see setIV()
+     * @see disableContinuousBuffer()
+     * @access private
+     */
+    function _setup()
+    {
+        $this->_clearBuffers();
+        $this->_setupKey();
+
+        if ($this->use_inline_crypt) {
+            $this->_setupInlineCrypt();
+        }
+    }
+
+    /**
+     * Setup the CRYPT_MODE_MCRYPT $engine
+     *
+     * (re)init, if necessary, the (ext)mcrypt resources and flush all $buffers
+     * Used (only) if $engine = CRYPT_MODE_MCRYPT
+     *
+     * _setupMcrypt() will be called each time if $changed === true
+     * typically this happens when using one or more of following public methods:
+     *
+     * - setKey()
+     *
+     * - setIV()
+     *
+     * - disableContinuousBuffer()
+     *
+     * - First run of encrypt() / decrypt()
+     *
+     *
+     * Note: Could, but not must, extend by the child Crypt_* class
+     *
+     * @see setKey()
+     * @see setIV()
+     * @see disableContinuousBuffer()
+     * @access private
+     */
+    function _setupMcrypt()
+    {
+        $this->_clearBuffers();
+        $this->enchanged = $this->dechanged = true;
+
+        if (!isset($this->enmcrypt)) {
+            static $mcrypt_modes = array(
+                CRYPT_MODE_CTR    => 'ctr',
+                CRYPT_MODE_ECB    => MCRYPT_MODE_ECB,
+                CRYPT_MODE_CBC    => MCRYPT_MODE_CBC,
+                CRYPT_MODE_CFB    => 'ncfb',
+                CRYPT_MODE_OFB    => MCRYPT_MODE_NOFB,
+                CRYPT_MODE_STREAM => MCRYPT_MODE_STREAM,
+            );
+
+            $this->demcrypt = mcrypt_module_open($this->cipher_name_mcrypt, '', $mcrypt_modes[$this->mode], '');
+            $this->enmcrypt = mcrypt_module_open($this->cipher_name_mcrypt, '', $mcrypt_modes[$this->mode], '');
+
+            // we need the $ecb mcrypt resource (only) in MODE_CFB with enableContinuousBuffer()
+            // to workaround mcrypt's broken ncfb implementation in buffered mode
+            // see: {@link http://phpseclib.sourceforge.net/cfb-demo.phps}
+            if ($this->mode == CRYPT_MODE_CFB) {
+                $this->ecb = mcrypt_module_open($this->cipher_name_mcrypt, '', MCRYPT_MODE_ECB, '');
+            }
+
+        } // else should mcrypt_generic_deinit be called?
+
+        if ($this->mode == CRYPT_MODE_CFB) {
+            mcrypt_generic_init($this->ecb, $this->key, str_repeat("\0", $this->block_size));
+        }
+    }
+
+    /**
+     * Pads a string
+     *
+     * Pads a string using the RSA PKCS padding standards so that its length is a multiple of the blocksize.
+     * $this->block_size - (strlen($text) % $this->block_size) bytes are added, each of which is equal to
+     * chr($this->block_size - (strlen($text) % $this->block_size)
+     *
+     * If padding is disabled and $text is not a multiple of the blocksize, the string will be padded regardless
+     * and padding will, hence forth, be enabled.
+     *
+     * @see Crypt_Base::_unpad()
+     * @param String $text
+     * @access private
+     * @return String
+     */
+    function _pad($text)
+    {
+        $length = strlen($text);
+
+        if (!$this->padding) {
+            if ($length % $this->block_size == 0) {
+                return $text;
+            } else {
+                user_error("The plaintext's length ($length) is not a multiple of the block size ({$this->block_size})");
+                $this->padding = true;
+            }
+        }
+
+        $pad = $this->block_size - ($length % $this->block_size);
+
+        return str_pad($text, $length + $pad, chr($pad));
+    }
+
+    /**
+     * Unpads a string.
+     *
+     * If padding is enabled and the reported padding length is invalid the encryption key will be assumed to be wrong
+     * and false will be returned.
+     *
+     * @see Crypt_Base::_pad()
+     * @param String $text
+     * @access private
+     * @return String
+     */
+    function _unpad($text)
+    {
+        if (!$this->padding) {
+            return $text;
+        }
+
+        $length = ord($text[strlen($text) - 1]);
+
+        if (!$length || $length > $this->block_size) {
+            return false;
+        }
+
+        return substr($text, 0, -$length);
+    }
+
+    /**
+     * Clears internal buffers
+     *
+     * Clearing/resetting the internal buffers is done everytime
+     * after disableContinuousBuffer() or on cipher $engine (re)init
+     * ie after setKey() or setIV()
+     *
+     * Note: Could, but not must, extend by the child Crypt_* class
+     *
+     * @access public
+     */
+    function _clearBuffers()
+    {
+        $this->enbuffer = array('encrypted'  => '', 'xor' => '', 'pos' => 0, 'enmcrypt_init' => true);
+        $this->debuffer = array('ciphertext' => '', 'xor' => '', 'pos' => 0, 'demcrypt_init' => true);
+
+        // mcrypt's handling of invalid's $iv:
+        // $this->encryptIV = $this->decryptIV = strlen($this->iv) == $this->block_size ? $this->iv : str_repeat("\0", $this->block_size);
+        $this->encryptIV = $this->decryptIV = str_pad(substr($this->iv, 0, $this->block_size), $this->block_size, "\0");
+    }
+
+    /**
+     * String Shift
+     *
+     * Inspired by array_shift
+     *
+     * @param String $string
+     * @param optional Integer $index
+     * @access private
+     * @return String
+     */
+    function _stringShift(&$string, $index = 1)
+    {
+        $substr = substr($string, 0, $index);
+        $string = substr($string, $index);
+        return $substr;
+    }
+
+    /**
+     * Generate CTR XOR encryption key
+     *
+     * Encrypt the output of this and XOR it against the ciphertext / plaintext to get the
+     * plaintext / ciphertext in CTR mode.
+     *
+     * @see Crypt_Base::decrypt()
+     * @see Crypt_Base::encrypt()
+     * @param String $iv
+     * @param Integer $length
+     * @access private
+     * @return String $xor
+     */
+    function _generateXor(&$iv, $length)
+    {
+        $xor = '';
+        $block_size = $this->block_size;
+        $num_blocks = floor(($length + ($block_size - 1)) / $block_size);
+        for ($i = 0; $i < $num_blocks; $i++) {
+            $xor.= $iv;
+            for ($j = 4; $j <= $block_size; $j+= 4) {
+                $temp = substr($iv, -$j, 4);
+                switch ($temp) {
+                    case "\xFF\xFF\xFF\xFF":
+                        $iv = substr_replace($iv, "\x00\x00\x00\x00", -$j, 4);
+                        break;
+                    case "\x7F\xFF\xFF\xFF":
+                        $iv = substr_replace($iv, "\x80\x00\x00\x00", -$j, 4);
+                        break 2;
+                    default:
+                        extract(unpack('Ncount', $temp));
+                        $iv = substr_replace($iv, pack('N', $count + 1), -$j, 4);
+                        break 2;
+                }
+            }
+        }
+
+        return $xor;
+    }
+
+    /**
+     * Setup the performance-optimized function for de/encrypt()
+     *
+     * Stores the created (or existing) callback function-name
+     * in $this->inline_crypt
+     *
+     * Internally for phpseclib developers:
+     *
+     *     _setupInlineCrypt() would be called only if:
+     *
+     *     - $engine == CRYPT_MODE_INTERNAL and
+     *
+     *     - $use_inline_crypt === true
+     *
+     *     - each time on _setup(), after(!) _setupKey()
+     *
+     *
+     *     This ensures that _setupInlineCrypt() has allways a
+     *     full ready2go initializated internal cipher $engine state
+     *     where, for example, the keys allready expanded,
+     *     keys/block_size calculated and such.
+     *
+     *     It is, each time if called, the responsibility of _setupInlineCrypt():
+     *
+     *     - to set $this->inline_crypt to a valid and fully working callback function
+     *       as a (faster) replacement for encrypt() / decrypt()
+     *
+     *     - NOT to create unlimited callback functions (for memory reasons!)
+     *       no matter how often _setupInlineCrypt() would be called. At some
+     *       point of amount they must be generic re-useable.
+     *
+     *     - the code of _setupInlineCrypt() it self,
+     *       and the generated callback code,
+     *       must be, in following order:
+     *       - 100% safe
+     *       - 100% compatible to encrypt()/decrypt()
+     *       - using only php5+ features/lang-constructs/php-extensions if
+     *         compatibility (down to php4) or fallback is provided
+     *       - readable/maintainable/understandable/commented and... not-cryptic-styled-code :-)
+     *       - >= 10% faster than encrypt()/decrypt() [which is, by the way,
+     *         the reason for the existence of _setupInlineCrypt() :-)]
+     *       - memory-nice
+     *       - short (as good as possible)
+     *
+     * Note: - _setupInlineCrypt() is using _createInlineCryptFunction() to create the full callback function code.
+     *       - In case of using inline crypting, _setupInlineCrypt() must extend by the child Crypt_* class.
+     *       - The following variable names are reserved:
+     *         - $_*  (all variable names prefixed with an underscore)
+     *         - $self (object reference to it self. Do not use $this, but $self instead)
+     *         - $in (the content of $in has to en/decrypt by the generated code)
+     *       - The callback function should not use the 'return' statement, but en/decrypt'ing the content of $in only
+     *
+     *
+     * @see Crypt_Base::_setup()
+     * @see Crypt_Base::_createInlineCryptFunction()
+     * @see Crypt_Base::encrypt()
+     * @see Crypt_Base::decrypt()
+     * @access private
+     */
+    function _setupInlineCrypt()
+    {
+        // If a Crypt_* class providing inline crypting it must extend _setupInlineCrypt()
+
+        // If, for any reason, an extending Crypt_Base() Crypt_* class
+        // not using inline crypting then it must be ensured that: $this->use_inline_crypt = false
+        // ie in the class var declaration of $use_inline_crypt in general for the Crypt_* class,
+        // in the constructor at object instance-time
+        // or, if it's runtime-specific, at runtime
+
+        $this->use_inline_crypt = false;
+    }
+
+    /**
+     * Creates the performance-optimized function for en/decrypt()
+     *
+     * Internally for phpseclib developers:
+     *
+     *    _createInlineCryptFunction():
+     *
+     *    - merge the $cipher_code [setup'ed by _setupInlineCrypt()]
+     *      with the current [$this->]mode of operation code
+     *
+     *    - create the $inline function, which called by encrypt() / decrypt()
+     *      as its replacement to speed up the en/decryption operations.
+     *
+     *    - return the name of the created $inline callback function
+     *
+     *    - used to speed up en/decryption
+     *
+     *
+     *
+     *    The main reason why can speed up things [up to 50%] this way are:
+     *
+     *    - using variables more effective then regular.
+     *      (ie no use of expensive arrays but integers $k_0, $k_1 ...
+     *      or even, for example, the pure $key[] values hardcoded)
+     *
+     *    - avoiding 1000's of function calls of ie _encryptBlock()
+     *      but inlining the crypt operations.
+     *      in the mode of operation for() loop.
+     *
+     *    - full loop unroll the (sometimes key-dependent) rounds
+     *      avoiding this way ++$i counters and runtime-if's etc...
+     *
+     *    The basic code architectur of the generated $inline en/decrypt()
+     *    lambda function, in pseudo php, is:
+     *
+     *    <code>
+     *    +----------------------------------------------------------------------------------------------+
+     *    | callback $inline = create_function:                                                          |
+     *    | lambda_function_0001_crypt_ECB($action, $text)                                               |
+     *    | {                                                                                            |
+     *    |     INSERT PHP CODE OF:                                                                      |
+     *    |     $cipher_code['init_crypt'];                  // general init code.                       |
+     *    |                                                  // ie: $sbox'es declarations used for       |
+     *    |                                                  //     encrypt and decrypt'ing.             |
+     *    |                                                                                              |
+     *    |     switch ($action) {                                                                       |
+     *    |         case 'encrypt':                                                                      |
+     *    |             INSERT PHP CODE OF:                                                              |
+     *    |             $cipher_code['init_encrypt'];       // encrypt sepcific init code.               |
+     *    |                                                    ie: specified $key or $box                |
+     *    |                                                        declarations for encrypt'ing.         |
+     *    |                                                                                              |
+     *    |             foreach ($ciphertext) {                                                          |
+     *    |                 $in = $block_size of $ciphertext;                                            |
+     *    |                                                                                              |
+     *    |                 INSERT PHP CODE OF:                                                          |
+     *    |                 $cipher_code['encrypt_block'];  // encrypt's (string) $in, which is always:  |
+     *    |                                                 // strlen($in) == $this->block_size          |
+     *    |                                                 // here comes the cipher algorithm in action |
+     *    |                                                 // for encryption.                           |
+     *    |                                                 // $cipher_code['encrypt_block'] has to      |
+     *    |                                                 // encrypt the content of the $in variable   |
+     *    |                                                                                              |
+     *    |                 $plaintext .= $in;                                                           |
+     *    |             }                                                                                |
+     *    |             return $plaintext;                                                               |
+     *    |                                                                                              |
+     *    |         case 'decrypt':                                                                      |
+     *    |             INSERT PHP CODE OF:                                                              |
+     *    |             $cipher_code['init_decrypt'];       // decrypt sepcific init code                |
+     *    |                                                    ie: specified $key or $box                |
+     *    |                                                        declarations for decrypt'ing.         |
+     *    |             foreach ($plaintext) {                                                           |
+     *    |                 $in = $block_size of $plaintext;                                             |
+     *    |                                                                                              |
+     *    |                 INSERT PHP CODE OF:                                                          |
+     *    |                 $cipher_code['decrypt_block'];  // decrypt's (string) $in, which is always   |
+     *    |                                                 // strlen($in) == $this->block_size          |
+     *    |                                                 // here comes the cipher algorithm in action |
+     *    |                                                 // for decryption.                           |
+     *    |                                                 // $cipher_code['decrypt_block'] has to      |
+     *    |                                                 // decrypt the content of the $in variable   |
+     *    |                 $ciphertext .= $in;                                                          |
+     *    |             }                                                                                |
+     *    |             return $ciphertext;                                                              |
+     *    |     }                                                                                        |
+     *    | }                                                                                            |
+     *    +----------------------------------------------------------------------------------------------+
+     *    </code>
+     *
+     *    See also the Crypt_*::_setupInlineCrypt()'s for
+     *    productive inline $cipher_code's how they works.
+     *
+     *    Structure of:
+     *    <code>
+     *    $cipher_code = array(
+     *        'init_crypt'    => (string) '', // optional
+     *        'init_encrypt'  => (string) '', // optional
+     *        'init_decrypt'  => (string) '', // optional
+     *        'encrypt_block' => (string) '', // required
+     *        'decrypt_block' => (string) ''  // required
+     *    );
+     *    </code>
+     *
+     * @see Crypt_Base::_setupInlineCrypt()
+     * @see Crypt_Base::encrypt()
+     * @see Crypt_Base::decrypt()
+     * @param Array $cipher_code
+     * @access private
+     * @return String (the name of the created callback function)
+     */
+    function _createInlineCryptFunction($cipher_code)
+    {
+        $block_size = $this->block_size;
+
+        // optional
+        $init_crypt    = isset($cipher_code['init_crypt'])    ? $cipher_code['init_crypt']    : '';
+        $init_encrypt  = isset($cipher_code['init_encrypt'])  ? $cipher_code['init_encrypt']  : '';
+        $init_decrypt  = isset($cipher_code['init_decrypt'])  ? $cipher_code['init_decrypt']  : '';
+        // required
+        $encrypt_block = $cipher_code['encrypt_block'];
+        $decrypt_block = $cipher_code['decrypt_block'];
+
+        // Generating mode of operation inline code,
+        // merged with the $cipher_code algorithm
+        // for encrypt- and decryption.
+        switch ($this->mode) {
+            case CRYPT_MODE_ECB:
+                $encrypt = $init_encrypt . '
+                    $_ciphertext = "";
+                    $_text = $self->_pad($_text);
+                    $_plaintext_len = strlen($_text);
+
+                    for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
+                        $in = substr($_text, $_i, '.$block_size.');
+                        '.$encrypt_block.'
+                        $_ciphertext.= $in;
+                    }
+
+                    return $_ciphertext;
+                    ';
+
+                $decrypt = $init_decrypt . '
+                    $_plaintext = "";
+                    $_text = str_pad($_text, strlen($_text) + ('.$block_size.' - strlen($_text) % '.$block_size.') % '.$block_size.', chr(0));
+                    $_ciphertext_len = strlen($_text);
+
+                    for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
+                        $in = substr($_text, $_i, '.$block_size.');
+                        '.$decrypt_block.'
+                        $_plaintext.= $in;
+                    }
+
+                    return $self->_unpad($_plaintext);
+                    ';
+                break;
+            case CRYPT_MODE_CTR:
+                $encrypt = $init_encrypt . '
+                    $_ciphertext = "";
+                    $_plaintext_len = strlen($_text);
+                    $_xor = $self->encryptIV;
+                    $_buffer = &$self->enbuffer;
+
+                    if (strlen($_buffer["encrypted"])) {
+                        for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
+                            $_block = substr($_text, $_i, '.$block_size.');
+                            if (strlen($_block) > strlen($_buffer["encrypted"])) {
+                                $in = $self->_generateXor($_xor, '.$block_size.');
+                                '.$encrypt_block.'
+                                $_buffer["encrypted"].= $in;
+                            }
+                            $_key = $self->_stringShift($_buffer["encrypted"], '.$block_size.');
+                            $_ciphertext.= $_block ^ $_key;
+                        }
+                    } else {
+                        for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
+                            $_block = substr($_text, $_i, '.$block_size.');
+                            $in = $self->_generateXor($_xor, '.$block_size.');
+                            '.$encrypt_block.'
+                            $_key = $in;
+                            $_ciphertext.= $_block ^ $_key;
+                        }
+                    }
+                    if ($self->continuousBuffer) {
+                        $self->encryptIV = $_xor;
+                        if ($_start = $_plaintext_len % '.$block_size.') {
+                            $_buffer["encrypted"] = substr($_key, $_start) . $_buffer["encrypted"];
+                        }
+                    }
+
+                    return $_ciphertext;
+                ';
+
+                $decrypt = $init_encrypt . '
+                    $_plaintext = "";
+                    $_ciphertext_len = strlen($_text);
+                    $_xor = $self->decryptIV;
+                    $_buffer = &$self->debuffer;
+
+                    if (strlen($_buffer["ciphertext"])) {
+                        for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
+                            $_block = substr($_text, $_i, '.$block_size.');
+                            if (strlen($_block) > strlen($_buffer["ciphertext"])) {
+                                $in = $self->_generateXor($_xor, '.$block_size.');
+                                '.$encrypt_block.'
+                                $_buffer["ciphertext"].= $in;
+                            }
+                            $_key = $self->_stringShift($_buffer["ciphertext"], '.$block_size.');
+                            $_plaintext.= $_block ^ $_key;
+                        }
+                    } else {
+                        for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
+                            $_block = substr($_text, $_i, '.$block_size.');
+                            $in = $self->_generateXor($_xor, '.$block_size.');
+                            '.$encrypt_block.'
+                            $_key = $in;
+                            $_plaintext.= $_block ^ $_key;
+                        }
+                    }
+                    if ($self->continuousBuffer) {
+                        $self->decryptIV = $_xor;
+                        if ($_start = $_ciphertext_len % '.$block_size.') {
+                            $_buffer["ciphertext"] = substr($_key, $_start) . $_buffer["ciphertext"];
+                        }
+                    }
+
+                    return $_plaintext;
+                    ';
+                break;
+            case CRYPT_MODE_CFB:
+                $encrypt = $init_encrypt . '
+                    $_ciphertext = "";
+                    $_buffer = &$self->enbuffer;
+
+                    if ($self->continuousBuffer) {
+                        $_iv = &$self->encryptIV;
+                        $_pos = &$_buffer["pos"];
+                    } else {
+                        $_iv = $self->encryptIV;
+                        $_pos = 0;
+                    }
+                    $_len = strlen($_text);
+                    $_i = 0;
+                    if ($_pos) {
+                        $_orig_pos = $_pos;
+                        $_max = '.$block_size.' - $_pos;
+                        if ($_len >= $_max) {
+                            $_i = $_max;
+                            $_len-= $_max;
+                            $_pos = 0;
+                        } else {
+                            $_i = $_len;
+                            $_pos+= $_len;
+                            $_len = 0;
+                        }
+                        $_ciphertext = substr($_iv, $_orig_pos) ^ $_text;
+                        $_iv = substr_replace($_iv, $_ciphertext, $_orig_pos, $_i);
+                    }
+                    while ($_len >= '.$block_size.') {
+                        $in = $_iv;
+                        '.$encrypt_block.';
+                        $_iv = $in ^ substr($_text, $_i, '.$block_size.');
+                        $_ciphertext.= $_iv;
+                        $_len-= '.$block_size.';
+                        $_i+= '.$block_size.';
+                    }
+                    if ($_len) {
+                        $in = $_iv;
+                        '.$encrypt_block.'
+                        $_iv = $in;
+                        $_block = $_iv ^ substr($_text, $_i);
+                        $_iv = substr_replace($_iv, $_block, 0, $_len);
+                        $_ciphertext.= $_block;
+                        $_pos = $_len;
+                    }
+                    return $_ciphertext;
+                ';
+
+                $decrypt = $init_encrypt . '
+                    $_plaintext = "";
+                    $_buffer = &$self->debuffer;
+
+                    if ($self->continuousBuffer) {
+                        $_iv = &$self->decryptIV;
+                        $_pos = &$_buffer["pos"];
+                    } else {
+                        $_iv = $self->decryptIV;
+                        $_pos = 0;
+                    }
+                    $_len = strlen($_text);
+                    $_i = 0;
+                    if ($_pos) {
+                        $_orig_pos = $_pos;
+                        $_max = '.$block_size.' - $_pos;
+                        if ($_len >= $_max) {
+                            $_i = $_max;
+                            $_len-= $_max;
+                            $_pos = 0;
+                        } else {
+                            $_i = $_len;
+                            $_pos+= $_len;
+                            $_len = 0;
+                        }
+                        $_plaintext = substr($_iv, $_orig_pos) ^ $_text;
+                        $_iv = substr_replace($_iv, substr($_text, 0, $_i), $_orig_pos, $_i);
+                    }
+                    while ($_len >= '.$block_size.') {
+                        $in = $_iv;
+                        '.$encrypt_block.'
+                        $_iv = $in;
+                        $cb = substr($_text, $_i, '.$block_size.');
+                        $_plaintext.= $_iv ^ $cb;
+                        $_iv = $cb;
+                        $_len-= '.$block_size.';
+                        $_i+= '.$block_size.';
+                    }
+                    if ($_len) {
+                        $in = $_iv;
+                        '.$encrypt_block.'
+                        $_iv = $in;
+                        $_plaintext.= $_iv ^ substr($_text, $_i);
+                        $_iv = substr_replace($_iv, substr($_text, $_i), 0, $_len);
+                        $_pos = $_len;
+                    }
+
+                    return $_plaintext;
+                    ';
+                break;
+            case CRYPT_MODE_OFB:
+                $encrypt = $init_encrypt . '
+                    $_ciphertext = "";
+                    $_plaintext_len = strlen($_text);
+                    $_xor = $self->encryptIV;
+                    $_buffer = &$self->enbuffer;
+
+                    if (strlen($_buffer["xor"])) {
+                        for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
+                            $_block = substr($_text, $_i, '.$block_size.');
+                            if (strlen($_block) > strlen($_buffer["xor"])) {
+                                $in = $_xor;
+                                '.$encrypt_block.'
+                                $_xor = $in;
+                                $_buffer["xor"].= $_xor;
+                            }
+                            $_key = $self->_stringShift($_buffer["xor"], '.$block_size.');
+                            $_ciphertext.= $_block ^ $_key;
+                        }
+                    } else {
+                        for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
+                            $in = $_xor;
+                            '.$encrypt_block.'
+                            $_xor = $in;
+                            $_ciphertext.= substr($_text, $_i, '.$block_size.') ^ $_xor;
+                        }
+                        $_key = $_xor;
+                    }
+                    if ($self->continuousBuffer) {
+                        $self->encryptIV = $_xor;
+                        if ($_start = $_plaintext_len % '.$block_size.') {
+                             $_buffer["xor"] = substr($_key, $_start) . $_buffer["xor"];
+                        }
+                    }
+                    return $_ciphertext;
+                    ';
+
+                $decrypt = $init_encrypt . '
+                    $_plaintext = "";
+                    $_ciphertext_len = strlen($_text);
+                    $_xor = $self->decryptIV;
+                    $_buffer = &$self->debuffer;
+
+                    if (strlen($_buffer["xor"])) {
+                        for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
+                            $_block = substr($_text, $_i, '.$block_size.');
+                            if (strlen($_block) > strlen($_buffer["xor"])) {
+                                $in = $_xor;
+                                '.$encrypt_block.'
+                                $_xor = $in;
+                                $_buffer["xor"].= $_xor;
+                            }
+                            $_key = $self->_stringShift($_buffer["xor"], '.$block_size.');
+                            $_plaintext.= $_block ^ $_key;
+                        }
+                    } else {
+                        for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
+                            $in = $_xor;
+                            '.$encrypt_block.'
+                            $_xor = $in;
+                            $_plaintext.= substr($_text, $_i, '.$block_size.') ^ $_xor;
+                        }
+                        $_key = $_xor;
+                    }
+                    if ($self->continuousBuffer) {
+                        $self->decryptIV = $_xor;
+                        if ($_start = $_ciphertext_len % '.$block_size.') {
+                             $_buffer["xor"] = substr($_key, $_start) . $_buffer["xor"];
+                        }
+                    }
+                    return $_plaintext;
+                    ';
+                break;
+            case CRYPT_MODE_STREAM:
+                $encrypt = $init_encrypt . '
+                    $_ciphertext = "";
+                    '.$encrypt_block.'
+                    return $_ciphertext;
+                    ';
+                $decrypt = $init_decrypt . '
+                    $_plaintext = "";
+                    '.$decrypt_block.'
+                    return $_plaintext;
+                    ';
+                break;
+            // case CRYPT_MODE_CBC:
+            default:
+                $encrypt = $init_encrypt . '
+                    $_ciphertext = "";
+                    $_text = $self->_pad($_text);
+                    $_plaintext_len = strlen($_text);
+
+                    $in = $self->encryptIV;
+
+                    for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
+                        $in = substr($_text, $_i, '.$block_size.') ^ $in;
+                        '.$encrypt_block.'
+                        $_ciphertext.= $in;
+                    }
+
+                    if ($self->continuousBuffer) {
+                        $self->encryptIV = $in;
+                    }
+
+                    return $_ciphertext;
+                    ';
+
+                $decrypt = $init_decrypt . '
+                    $_plaintext = "";
+                    $_text = str_pad($_text, strlen($_text) + ('.$block_size.' - strlen($_text) % '.$block_size.') % '.$block_size.', chr(0));
+                    $_ciphertext_len = strlen($_text);
+
+                    $_iv = $self->decryptIV;
+
+                    for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
+                        $in = $_block = substr($_text, $_i, '.$block_size.');
+                        '.$decrypt_block.'
+                        $_plaintext.= $in ^ $_iv;
+                        $_iv = $_block;
+                    }
+
+                    if ($self->continuousBuffer) {
+                        $self->decryptIV = $_iv;
+                    }
+
+                    return $self->_unpad($_plaintext);
+                    ';
+                break;
+        }
+
+        // Create the $inline function and return its name as string. Ready to run!
+        return create_function('$_action, &$self, $_text', $init_crypt . 'if ($_action == "encrypt") { ' . $encrypt . ' } else { ' . $decrypt . ' }');
+    }
+
+    /**
+     * Holds the lambda_functions table (classwide)
+     *
+     * Each name of the lambda function, created from
+     * _setupInlineCrypt() && _createInlineCryptFunction()
+     * is stored, classwide (!), here for reusing.
+     *
+     * The string-based index of $function is a classwide
+     * uniqe value representing, at least, the $mode of
+     * operation (or more... depends of the optimizing level)
+     * for which $mode the lambda function was created.
+     *
+     * @access private
+     * @return &Array
+     */
+    function &_getLambdaFunctions()
+    {
+        static $functions = array();
+        return $functions;
+    }
+}
+
+// vim: ts=4:sw=4:et:
+// vim6: fdl=1: