includes/rijndael.php
changeset 1 fe660c52c48f
child 40 723bb7acf914
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/includes/rijndael.php	Wed Jun 13 16:07:17 2007 -0400
@@ -0,0 +1,1052 @@
+<?php
+
+/**
+ * Phijndael - an implementation of the AES encryption standard in PHP
+ * Originally written by Fritz Schneider <fritz AT cd DOT ucsd DOT edu>
+ * Ported to PHP by Dan Fuhry <dan AT enano DOT homelinux DOT org>
+ * @package phijndael
+ * @author Fritz Schneider
+ * @author Dan Fuhry
+ * @license BSD-style license
+ */
+
+error_reporting(E_ALL);
+
+define ('ENC_HEX', 201);
+define ('ENC_BASE64', 202);
+define ('ENC_BINARY', 203);
+
+class AESCrypt {
+  
+  var $debug = false;
+  var $mcrypt = false;
+
+  // Rijndael parameters --  Valid values are 128, 192, or 256
+  
+  var $keySizeInBits = 128;
+  var $blockSizeInBits = 128;
+  
+  ///////  You shouldn't have to modify anything below this line except for
+  ///////  the function getRandomBytes().
+  //
+  // Note: in the following code the two dimensional arrays are indexed as
+  //       you would probably expect, as array[row][column]. The state arrays
+  //       are 2d arrays of the form state[4][Nb].
+  
+  
+  // The number of rounds for the cipher, indexed by [Nk][Nb]
+  var $roundsArray = Array(0,0,0,0,Array(0,0,0,0,10,0, 12,0, 14),0, 
+                               Array(0,0,0,0,12,0, 12,0, 14),0, 
+                               Array(0,0,0,0,14,0, 14,0, 14) );
+  
+  // The number of bytes to shift by in shiftRow, indexed by [Nb][row]
+  var $shiftOffsets = Array(0,0,0,0,Array(0,1, 2, 3),0,Array(0,1, 2, 3),0,Array(0,1, 3, 4) );
+  
+  // The round constants used in subkey expansion
+  var $Rcon = Array( 
+  0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 
+  0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 
+  0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 
+  0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 
+  0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91 );
+  
+  // Precomputed lookup table for the SBox
+  var $SBox = Array(
+   99, 124, 119, 123, 242, 107, 111, 197,  48,   1, 103,  43, 254, 215, 171, 
+  118, 202, 130, 201, 125, 250,  89,  71, 240, 173, 212, 162, 175, 156, 164, 
+  114, 192, 183, 253, 147,  38,  54,  63, 247, 204,  52, 165, 229, 241, 113, 
+  216,  49,  21,   4, 199,  35, 195,  24, 150,   5, 154,   7,  18, 128, 226, 
+  235,  39, 178, 117,   9, 131,  44,  26,  27, 110,  90, 160,  82,  59, 214, 
+  179,  41, 227,  47, 132,  83, 209,   0, 237,  32, 252, 177,  91, 106, 203, 
+  190,  57,  74,  76,  88, 207, 208, 239, 170, 251,  67,  77,  51, 133,  69, 
+  249,   2, 127,  80,  60, 159, 168,  81, 163,  64, 143, 146, 157,  56, 245, 
+  188, 182, 218,  33,  16, 255, 243, 210, 205,  12,  19, 236,  95, 151,  68,  
+  23,  196, 167, 126,  61, 100,  93,  25, 115,  96, 129,  79, 220,  34,  42, 
+  144, 136,  70, 238, 184,  20, 222,  94,  11, 219, 224,  50,  58,  10,  73,
+    6,  36,  92, 194, 211, 172,  98, 145, 149, 228, 121, 231, 200,  55, 109, 
+  141, 213,  78, 169, 108,  86, 244, 234, 101, 122, 174,   8, 186, 120,  37,  
+   46,  28, 166, 180, 198, 232, 221, 116,  31,  75, 189, 139, 138, 112,  62, 
+  181, 102,  72,   3, 246,  14,  97,  53,  87, 185, 134, 193,  29, 158, 225,
+  248, 152,  17, 105, 217, 142, 148, 155,  30, 135, 233, 206,  85,  40, 223,
+  140, 161, 137,  13, 191, 230,  66, 104,  65, 153,  45,  15, 176,  84, 187,  
+   22 );
+  
+  // Precomputed lookup table for the inverse SBox
+  var $SBoxInverse = Array(
+   82,   9, 106, 213,  48,  54, 165,  56, 191,  64, 163, 158, 129, 243, 215, 
+  251, 124, 227,  57, 130, 155,  47, 255, 135,  52, 142,  67,  68, 196, 222, 
+  233, 203,  84, 123, 148,  50, 166, 194,  35,  61, 238,  76, 149,  11,  66, 
+  250, 195,  78,   8,  46, 161, 102,  40, 217,  36, 178, 118,  91, 162,  73, 
+  109, 139, 209,  37, 114, 248, 246, 100, 134, 104, 152,  22, 212, 164,  92, 
+  204,  93, 101, 182, 146, 108, 112,  72,  80, 253, 237, 185, 218,  94,  21,  
+   70,  87, 167, 141, 157, 132, 144, 216, 171,   0, 140, 188, 211,  10, 247, 
+  228,  88,   5, 184, 179,  69,   6, 208,  44,  30, 143, 202,  63,  15,   2, 
+  193, 175, 189,   3,   1,  19, 138, 107,  58, 145,  17,  65,  79, 103, 220, 
+  234, 151, 242, 207, 206, 240, 180, 230, 115, 150, 172, 116,  34, 231, 173,
+   53, 133, 226, 249,  55, 232,  28, 117, 223, 110,  71, 241,  26, 113,  29, 
+   41, 197, 137, 111, 183,  98,  14, 170,  24, 190,  27, 252,  86,  62,  75, 
+  198, 210, 121,  32, 154, 219, 192, 254, 120, 205,  90, 244,  31, 221, 168,
+   51, 136,   7, 199,  49, 177,  18,  16,  89,  39, 128, 236,  95,  96,  81,
+  127, 169,  25, 181,  74,  13,  45, 229, 122, 159, 147, 201, 156, 239, 160,
+  224,  59,  77, 174,  42, 245, 176, 200, 235, 187,  60, 131,  83, 153,  97, 
+   23,  43,   4, 126, 186, 119, 214,  38, 225, 105,  20,  99,  85,  33,  12,
+  125 );
+  
+  function AESCrypt($ks = 128, $bs = 128, $debug = false)
+  {
+    $this->__construct($ks, $bs, $debug);
+  }
+  
+  function __construct($ks = 128, $bs = 128, $debug = false)
+  {
+    $this->keySizeInBits = $ks;
+    $this->blockSizeInBits = $bs;
+    
+    // Use the Mcrypt library? This speeds things up dramatically.
+    if(defined('MCRYPT_RIJNDAEL_' . $ks) && defined('MCRYPT_ACCEL'))
+    {
+      eval('$mcb = MCRYPT_RIJNDAEL_' . $ks.';');
+      $bks = mcrypt_module_get_algo_block_size($mcb);
+      $bks = $bks * 8;
+      if ( $bks != $bs )
+      {
+        $mcb = false;
+        echo (string)$bks;
+      }
+    }
+    else
+    {
+      $mcb = false;
+    }
+      
+    $this->mcrypt = $mcb;
+    
+    // Cipher parameters ... do not change these
+    $this->Nk = $this->keySizeInBits / 32;
+    $this->Nb = $this->blockSizeInBits / 32;
+    $this->Nr = $this->roundsArray[$this->Nk][$this->Nb];
+    $this->debug = $debug;
+  }
+  
+  // Error handler
+  
+  function trigger_error($text, $level = E_USER_NOTICE)
+  {
+    $bt = debug_backtrace();
+    $lastfunc =& $bt[1];
+    switch($level)
+    {
+      case E_USER_NOTICE:
+      default:
+        $desc = 'Notice';
+        break;
+      case E_USER_WARNING:
+        $desc = 'Warning';
+        break;
+      case E_USER_ERROR:
+        $desc = 'Fatal';
+        break;
+    }
+    ob_start();
+    if($this->debug || $level == E_USER_ERROR) echo "AES encryption: <b>{$desc}:</b> $text in {$lastfunc['file']} on line {$lastfunc['line']} in function {$lastfunc['function']}<br />";
+    if($this->debug)
+    {
+      //echo '<pre>'.enano_debug_print_backtrace(true).'</pre>';
+    }
+    ob_end_flush();
+    if($level == E_USER_ERROR)
+    {
+      echo '<p><b>This can sometimes happen if you are upgrading Enano to a new version and did not log out first.</b> <a href="'.$_SERVER['PHP_SELF'].'?do=diag&amp;sub=cookie_destroy">Click here</a> to force cookies to clear and try again. You will be logged out.</p>';
+      exit;
+    }
+  }
+  
+  function array_slice_js_compat($array, $start, $finish = 0)
+  {
+    $len = $finish - $start;
+    if($len < 0) $len = 0 - $len;
+    //if($this->debug) echo (string)$len . ' ';
+    //if(count($array) < $start + $len)
+    //  $this->trigger_error('Index out of range', E_USER_WARNING);
+    return array_slice($array, $start, $len);
+  }
+  
+  function concat($s1, $s2)
+  {
+    if(is_array($s1) && is_array($s2))
+      return array_merge($s1, $s2);
+    elseif( ( is_array($s1) && !is_array($s2) ) || ( !is_array($s1) && is_array($s2) ) )
+    {
+      $this->trigger_error('incompatible types - you can\'t combine a non-array with an array', E_USER_WARNING);
+      return false;
+    }
+    else
+      return $s1 . $s2;
+  }
+  
+  // This method circularly shifts the array left by the number of elements
+  // given in its parameter. It returns the resulting array and is used for 
+  // the ShiftRow step. Note that shift() and push() could be used for a more 
+  // elegant solution, but they require IE5.5+, so I chose to do it manually. 
+  
+  function cyclicShiftLeft($theArray, $positions) {
+    if(!is_int($positions))
+    {
+      $this->trigger_error('$positions is not an integer! Backtrace:<br /><pre>'.print_r(debug_backtrace(), true).'</pre>', E_USER_WARNING);
+      return false;
+    }
+    $second = array_slice($theArray, 0, $positions);
+    $first = array_slice($theArray, $positions);
+    $theArray = array_merge($first, $second);
+    return $theArray;
+  }
+  
+  // Multiplies the element "poly" of GF(2^8) by x. See the Rijndael spec.
+  
+  function xtime($poly) {
+    $poly <<= 1;
+    return (($poly & 0x100) ? ($poly ^ 0x11B) : ($poly));
+  }
+  
+  // Multiplies the two elements of GF(2^8) together and returns the result.
+  // See the Rijndael spec, but should be straightforward: for each power of
+  // the indeterminant that has a 1 coefficient in x, add y times that power
+  // to the result. x and y should be bytes representing elements of GF(2^8)
+  
+  function mult_GF256($x, $y) {
+    $result = 0;
+    
+    for ($bit = 1; $bit < 256; $bit *= 2, $y = $this->xtime($y)) {
+      if ($x & $bit) 
+        $result ^= $y;
+    }
+    return $result;
+  }
+  
+  // Performs the substitution step of the cipher. State is the 2d array of
+  // state information (see spec) and direction is string indicating whether
+  // we are performing the forward substitution ("encrypt") or inverse 
+  // substitution (anything else)
+  
+  function byteSub(&$state, $direction) {
+    //global $this->SBox, $this->SBoxInverse, $this->Nb;
+    if ($direction == "encrypt")           // Point S to the SBox we're using
+      $S =& $this->SBox;
+    else
+      $S =& $this->SBoxInverse;
+    for ($i = 0; $i < 4; $i++)           // Substitute for every byte in state
+      for ($j = 0; $j < $this->Nb; $j++)
+         $state[$i][$j] = $S[$state[$i][$j]];
+  }
+  
+  // Performs the row shifting step of the cipher.
+  
+  function shiftRow(&$state, $direction) {
+    //global $this->Nb, $this->shiftOffsets;
+    for ($i=1; $i<4; $i++)               // Row 0 never shifts
+      if ($direction == "encrypt")
+         $state[$i] = $this->cyclicShiftLeft($state[$i], $this->shiftOffsets[$this->Nb][$i]);
+      else
+         $state[$i] = $this->cyclicShiftLeft($state[$i], $this->Nb - $this->shiftOffsets[$this->Nb][$i]);
+  
+  }
+  
+  // Performs the column mixing step of the cipher. Most of these steps can
+  // be combined into table lookups on 32bit values (at least for encryption)
+  // to greatly increase the speed. 
+  
+  function mixColumn(&$state, $direction) {
+    //global $this->Nb;
+    $b = Array();                                  // Result of matrix multiplications
+    for ($j = 0; $j < $this->Nb; $j++) {                 // Go through each column...
+      for ($i = 0; $i < 4; $i++) {                 // and for each row in the column...
+        if ($direction == "encrypt")
+          $b[$i] = $this->mult_GF256($state[$i][$j], 2) ^ // perform mixing
+                   $this->mult_GF256($state[($i+1)%4][$j], 3) ^ 
+                   $state[($i+2)%4][$j] ^ 
+                   $state[($i+3)%4][$j];
+        else 
+          $b[$i] = $this->mult_GF256($state[$i][$j], 0xE) ^ 
+                   $this->mult_GF256($state[($i+1)%4][$j], 0xB) ^
+                   $this->mult_GF256($state[($i+2)%4][$j], 0xD) ^
+                   $this->mult_GF256($state[($i+3)%4][$j], 9);
+      }
+      for ($i = 0; $i < 4; $i++)          // Place result back into column
+        $state[$i][$j] = $b[$i];
+    }
+  }
+  
+  // Adds the current round key to the state information. Straightforward.
+  
+  function addRoundKey(&$state, $roundKey) {
+    //global $this->Nb;
+    for ($j = 0; $j < $this->Nb; $j++) {                      // Step through columns...
+      $state[0][$j] ^= ( $roundKey[$j] & 0xFF);         // and XOR
+      $state[1][$j] ^= (($roundKey[$j]>>8) & 0xFF);
+      $state[2][$j] ^= (($roundKey[$j]>>16) & 0xFF);
+      $state[3][$j] ^= (($roundKey[$j]>>24) & 0xFF);
+    }
+  }
+  
+  // This function creates the expanded key from the input (128/192/256-bit)
+  // key. The parameter key is an array of bytes holding the value of the key.
+  // The returned value is an array whose elements are the 32-bit words that 
+  // make up the expanded key.
+  
+  function keyExpansion($key) {
+    //global $this->keySizeInBits, $this->blockSizeInBits, $this->roundsArray, $this->Nk, $this->Nb, $this->Nr, $this->Nk, $this->SBox, $this->Rcon;
+    $expandedKey = Array();
+  
+    // in case the key size or parameters were changed...
+    $this->Nk = $this->keySizeInBits / 32;                   
+    $this->Nb = $this->blockSizeInBits / 32;
+    $this->Nr = $this->roundsArray[$this->Nk][$this->Nb];
+  
+    for ($j=0; $j < $this->Nk; $j++)     // Fill in input key first
+      $expandedKey[$j] = 
+        ($key[4*$j]) | ($key[4*$j+1]<<8) | ($key[4*$j+2]<<16) | ($key[4*$j+3]<<24);
+  
+    // Now walk down the rest of the array filling in expanded key bytes as
+    // per Rijndael's spec
+    for ($j = $this->Nk; $j < $this->Nb * ($this->Nr + 1); $j++) {    // For each word of expanded key
+      $temp = $expandedKey[$j - 1];
+      if ($j % $this->Nk == 0) 
+        $temp = ( ($this->SBox[($temp>>8) & 0xFF]) |
+                  ($this->SBox[($temp>>16) & 0xFF]<<8) |
+                  ($this->SBox[($temp>>24) & 0xFF]<<16) |
+                  ($this->SBox[$temp & 0xFF]<<24) ) ^ $this->Rcon[floor($j / $this->Nk) - 1];
+      elseif  ($this->Nk > 6 && $j % $this->Nk == 4)
+        $temp = ($this->SBox[($temp>>24) & 0xFF]<<24) |
+               ($this->SBox[($temp>>16) & 0xFF]<<16) |
+               ($this->SBox[($temp>>8) & 0xFF]<<8) |
+               ($this->SBox[ $temp & 0xFF]);
+      $expandedKey[$j] = $expandedKey[$j-$this->Nk] ^ $temp;
+    }
+    return $expandedKey;
+  }
+  
+  // Rijndael's round functions... 
+  
+  function RijndaelRound(&$state, $roundKey) {
+    $this->byteSub($state, "encrypt");
+    $this->shiftRow($state, "encrypt");
+    $this->mixColumn($state, "encrypt");
+    $this->addRoundKey($state, $roundKey);
+  }
+  
+  function InverseRijndaelRound(&$state, $roundKey) {
+    $this->addRoundKey($state, $roundKey);
+    $this->mixColumn($state, "decrypt");
+    $this->shiftRow($state, "decrypt");
+    $this->byteSub($state, "decrypt");
+  }
+  
+  function FinalRijndaelRound(&$state, $roundKey) {
+    $this->byteSub($state, "encrypt");
+    $this->shiftRow($state, "encrypt");
+    $this->addRoundKey($state, $roundKey);
+  }
+  
+  function InverseFinalRijndaelRound(&$state, $roundKey){
+    $this->addRoundKey($state, $roundKey);
+    $this->shiftRow($state, "decrypt");
+    $this->byteSub($state, "decrypt");  
+  }
+  
+  // encrypt is the basic encryption function. It takes parameters
+  // block, an array of bytes representing a plaintext block, and expandedKey,
+  // an array of words representing the expanded key previously returned by
+  // keyExpansion(). The ciphertext block is returned as an array of bytes.
+  
+  function cryptBlock($block, $expandedKey) {
+    //global $this->blockSizeInBits, $this->Nb, $this->Nr;
+    $t=count($block)*8;
+    if (!is_array($block) || count($block)*8 != $this->blockSizeInBits)
+    {
+      $this->trigger_error('block is bad or block size is wrong<pre>'.print_r($block, true).'</pre><p>Aiming for size '.$this->blockSizeInBits.', got '.$t.'.', E_USER_WARNING); 
+      return false;
+    }
+    if (!$expandedKey)
+      return;
+  
+    $block = $this->packBytes($block);
+    $this->addRoundKey($block, $expandedKey);
+    for ($i=1; $i<$this->Nr; $i++) 
+      $this->RijndaelRound($block, $this->array_slice_js_compat($expandedKey, $this->Nb*$i, $this->Nb*($i+1)));
+    $this->FinalRijndaelRound($block, $this->array_slice_js_compat($expandedKey, $this->Nb*$this->Nr));
+    $ret = $this->unpackBytes($block);
+    return $ret;
+  }
+  
+  // decrypt is the basic decryption function. It takes parameters
+  // block, an array of bytes representing a ciphertext block, and expandedKey,
+  // an array of words representing the expanded key previously returned by
+  // keyExpansion(). The decrypted block is returned as an array of bytes.
+  
+  function unCryptBlock($block, $expandedKey) {
+    $t = count($block)*8;
+    if (!is_array($block) || count($block)*8 != $this->blockSizeInBits)
+    {
+      $this->trigger_error('$block is not a valid rijndael-block array: '.$this->byteArrayToHex($block).'<pre>'.print_r($block, true).'</pre><p>Block size is '.$t.', should be '.$this->blockSizeInBits.'</p>', E_USER_WARNING);
+      return false;
+    }
+    if (!$expandedKey)
+    {
+      $this->trigger_error('$expandedKey is invalid', E_USER_WARNING);
+      return false;
+    }
+  
+    $block = $this->packBytes($block);
+    $this->InverseFinalRijndaelRound($block, $this->array_slice_js_compat($expandedKey, $this->Nb*$this->Nr)); 
+    for ($i = $this->Nr - 1; $i>0; $i--) 
+    {
+      $this->InverseRijndaelRound($block, $this->array_slice_js_compat($expandedKey, $this->Nb*$i, $this->Nb*($i+1)));
+    }
+    $this->addRoundKey($block, $expandedKey);
+    $ret = $this->unpackBytes($block);
+    if(!is_array($ret))
+    {
+      $this->trigger_error('$ret is not an array', E_USER_WARNING);
+    }
+    return $ret;
+  }
+  
+  // This method takes a byte array (byteArray) and converts it to a string by
+  // applying String.fromCharCode() to each value and concatenating the result.
+  // The resulting string is returned. Note that this function SKIPS zero bytes
+  // under the assumption that they are padding added in formatPlaintext().
+  // Obviously, do not invoke this method on raw data that can contain zero
+  // bytes. It is really only appropriate for printable ASCII/Latin-1 
+  // values. Roll your own function for more robust functionality :)
+  
+  function byteArrayToString($byteArray) {
+    $result = "";
+    for($i=0; $i<count($byteArray); $i++)
+      if ($byteArray[$i] != 0) 
+        $result .= chr($byteArray[$i]);
+    return $result;
+  }
+  
+  // This function takes an array of bytes (byteArray) and converts them
+  // to a hexadecimal string. Array element 0 is found at the beginning of 
+  // the resulting string, high nibble first. Consecutive elements follow
+  // similarly, for example [16, 255] --> "10ff". The function returns a 
+  // string.
+  
+  /*
+  function byteArrayToHex($byteArray) {
+    $result = "";
+    if (!$byteArray)
+      return;
+    for ($i=0; $i<count($byteArray); $i++)
+      $result .= (($byteArray[$i]<16) ? "0" : "") + toString($byteArray[$i]); // magic number here is 16, not sure how to handle this...
+  
+    return $result;
+  }
+  */
+  function byteArrayToHex($arr)
+  {
+    $ret = '';
+    foreach($arr as $a)
+    {
+      $nibble = (string)dechex(intval($a));
+      if(strlen($nibble) == 1) $nibble = '0' . $nibble;
+      $ret .= $nibble;
+    }
+    return $ret;
+  }
+  
+  // PHP equivalent of Javascript's toString()
+  function toString($bool)
+  {
+    if(is_bool($bool))
+      return ($bool) ? 'true' : 'false';
+    elseif(is_array($bool))
+      return implode(',', $bool);
+    else
+      return (string)$bool;
+  }
+  
+  // This function converts a string containing hexadecimal digits to an 
+  // array of bytes. The resulting byte array is filled in the order the
+  // values occur in the string, for example "10FF" --> [16, 255]. This
+  // function returns an array. 
+  
+  /*
+  function hexToByteArray($hexString) {
+    $byteArray = Array();
+    if (strlen($hexString) % 2)             // must have even length
+      return;
+    if (strstr($hexString, "0x") == $hexString || strstr($hexString, "0X") == $hexString)
+      $hexString = substr($hexString, 2);
+    for ($i = 0; $i<strlen($hexString); $i++,$i++) 
+      $byteArray[floor($i/2)] = intval(substr($hexString, $i, 2)); // again, that strange magic number: 16
+    return $byteArray;
+  }
+  */
+  function hexToByteArray($str)
+  {
+    if(substr($str, 0, 2) == '0x' || substr($str, 0, 2) == '0X')
+      $str = substr($str, 2);
+    $arr = Array();
+    $str = $this->enano_str_split($str, 2);
+    foreach($str as $s)
+    {
+      $arr[] = intval(hexdec($s));
+    }
+    return $arr;
+  }
+  
+  // This function packs an array of bytes into the four row form defined by
+  // Rijndael. It assumes the length of the array of bytes is divisible by
+  // four. Bytes are filled in according to the Rijndael spec (starting with
+  // column 0, row 0 to 3). This function returns a 2d array.
+  
+  function packBytes($octets) {
+    $state = Array();
+    if (!$octets || count($octets) % 4)
+      return;
+  
+    $state[0] = Array(); $state[1] = Array(); 
+    $state[2] = Array(); $state[3] = Array();
+    for ($j=0; $j<count($octets); $j = $j+4) {
+       $state[0][$j/4] = $octets[$j];
+       $state[1][$j/4] = $octets[$j+1];
+       $state[2][$j/4] = $octets[$j+2];
+       $state[3][$j/4] = $octets[$j+3];
+    }
+    return $state;
+  }
+  
+  // This function unpacks an array of bytes from the four row format preferred
+  // by Rijndael into a single 1d array of bytes. It assumes the input "packed"
+  // is a packed array. Bytes are filled in according to the Rijndael spec. 
+  // This function returns a 1d array of bytes.
+  
+  function unpackBytes($packed) {
+    $result = Array();
+    for ($j=0; $j<count($packed[0]); $j++) {
+      $result[] = $packed[0][$j];
+      $result[] = $packed[1][$j];
+      $result[] = $packed[2][$j];
+      $result[] = $packed[3][$j];
+    }
+    return $result;
+  }
+  
+  function charCodeAt($str, $i)
+  {
+    return ord(substr($str, $i, 1));
+  }
+  
+  function fromCharCode($str)
+  {
+    return chr($str);
+  }
+  
+  // This function takes a prospective plaintext (string or array of bytes)
+  // and pads it with zero bytes if its length is not a multiple of the block 
+  // size. If plaintext is a string, it is converted to an array of bytes
+  // in the process. The type checking can be made much nicer using the 
+  // instanceof operator, but this operator is not available until IE5.0 so I 
+  // chose to use the heuristic below. 
+  
+  function formatPlaintext($plaintext) {
+    //global $this->blockSizeInBits;
+    $bpb = $this->blockSizeInBits / 8;               // bytes per block
+  
+    // if primitive string or String instance
+    if (is_string($plaintext)) {
+      $plaintext = $this->enano_str_split($plaintext);
+      // Unicode issues here (ignoring high byte)
+      for ($i=0; $i<sizeof($plaintext); $i++)
+        $plaintext[$i] = $this->charCodeAt($plaintext[$i], 0) & 0xFF;
+    } 
+  
+    for ($i = $bpb - (sizeof($plaintext) % $bpb); $i > 0 && $i < $bpb; $i--) 
+      $plaintext[] = 0;
+    
+    return $plaintext;
+  }
+  
+  // Returns an array containing "howMany" random bytes. YOU SHOULD CHANGE THIS
+  // TO RETURN HIGHER QUALITY RANDOM BYTES IF YOU ARE USING THIS FOR A "REAL"
+  // APPLICATION. (edit: done, mt_rand() is relatively secure)
+  
+  function getRandomBytes($howMany) {
+    $bytes = Array();
+    for ($i=0; $i<$howMany; $i++)
+      $bytes[$i] = mt_rand(0, 255);
+    return $bytes;
+  }
+  
+  // rijndaelEncrypt(plaintext, key, mode)
+  // Encrypts the plaintext using the given key and in the given mode. 
+  // The parameter "plaintext" can either be a string or an array of bytes. 
+  // The parameter "key" must be an array of key bytes. If you have a hex 
+  // string representing the key, invoke hexToByteArray() on it to convert it 
+  // to an array of bytes. The third parameter "mode" is a string indicating
+  // the encryption mode to use, either "ECB" or "CBC". If the parameter is
+  // omitted, ECB is assumed.
+  // 
+  // An array of bytes representing the cihpertext is returned. To convert 
+  // this array to hex, invoke byteArrayToHex() on it. If you are using this 
+  // "for real" it is a good idea to change the function getRandomBytes() to 
+  // something that returns truly random bits.
+  
+  function rijndaelEncrypt($plaintext, $key, $mode = 'ECB') {
+    //global $this->blockSizeInBits, $this->keySizeInBits;
+    $bpb = $this->blockSizeInBits / 8;          // bytes per block
+    // var ct;                                 // ciphertext
+  
+    if($mode == 'CBC')
+    {
+      if (!is_string($plaintext) || !is_array($key))
+      {
+        $this->trigger_error('In CBC mode the first and second parameters should be strings', E_USER_WARNING);
+        return false;
+      }
+    } else {
+      if (!is_array($plaintext) || !is_array($key))
+      {
+        $this->trigger_error('In ECB mode the first and second parameters should be byte arrays', E_USER_WARNING);
+        return false;
+      }
+    }
+    if (sizeof($key)*8 != $this->keySizeInBits)
+    {
+      $this->trigger_error('The key needs to be '. ( $this->keySizeInBits / 8 ) .' bytes in length', E_USER_WARNING);
+      return false;
+    }
+    if ($mode == "CBC")
+      $ct = $this->getRandomBytes($bpb);             // get IV
+    else {
+      $mode = "ECB";
+      $ct = Array();
+    }
+    
+    // convert plaintext to byte array and pad with zeros if necessary. 
+    $plaintext = $this->formatPlaintext($plaintext);
+    
+    $expandedKey = $this->keyExpansion($key);
+    
+    for ($block=0; $block<sizeof($plaintext) / $bpb; $block++) {
+      $aBlock = $this->array_slice_js_compat($plaintext, $block*$bpb, ($block+1)*$bpb);
+      if ($mode == "CBC")
+      {
+        for ($i=0; $i<$bpb; $i++)
+        {
+          $aBlock[$i] ^= $ct[$block*$bpb + $i];
+        }
+      }
+      $cp = $this->cryptBlock($aBlock, $expandedKey);
+      $ct = $this->concat($ct, $cp);
+    }
+  
+    return $ct;
+  }
+  
+  // rijndaelDecrypt(ciphertext, key, mode)
+  // Decrypts the using the given key and mode. The parameter "ciphertext" 
+  // must be an array of bytes. The parameter "key" must be an array of key 
+  // bytes. If you have a hex string representing the ciphertext or key, 
+  // invoke hexToByteArray() on it to convert it to an array of bytes. The
+  // parameter "mode" is a string, either "CBC" or "ECB".
+  // 
+  // An array of bytes representing the plaintext is returned. To convert 
+  // this array to a hex string, invoke byteArrayToHex() on it. To convert it 
+  // to a string of characters, you can use byteArrayToString().
+  
+  function rijndaelDecrypt($ciphertext, $key, $mode = 'ECB') {
+    //global $this->blockSizeInBits, $this->keySizeInBits;
+    $bpb = $this->blockSizeInBits / 8;          // bytes per block
+    $pt = Array();                   // plaintext array
+    // $aBlock;                             // a decrypted block
+    // $block;                              // current block number
+  
+    if (!$ciphertext)
+    {
+      $this->trigger_error('$ciphertext should be a byte array', E_USER_WARNING);
+      return false;
+    }
+    if(  !is_array($key) )
+    {
+      $this->trigger_error('$key should be a byte array', E_USER_WARNING);
+      return false;
+    }
+    if( is_string($ciphertext) )
+    {
+      $this->trigger_error('$ciphertext should be a byte array', E_USER_WARNING);
+      return false;
+    }
+    if (sizeof($key)*8 != $this->keySizeInBits)
+    {
+      $this->trigger_error('Encryption key is the wrong length', E_USER_WARNING);
+      return false;
+    }
+    if (!$mode)
+      $mode = "ECB";                         // assume ECB if mode omitted
+  
+    $expandedKey = $this->keyExpansion($key);
+   
+    // work backwards to accomodate CBC mode 
+    for ($block=(sizeof($ciphertext) / $bpb)-1; $block>0; $block--)
+    {
+      if( ( $block*$bpb ) + ( ($block+1)*$bpb ) > count($ciphertext) )
+      {
+        //$this->trigger_error('$ciphertext index out of bounds', E_USER_ERROR);
+      }
+      $current_block = $this->array_slice_js_compat($ciphertext, $block*$bpb, ($block+1)*$bpb);
+      if(count($current_block) * 8 != $this->blockSizeInBits)
+      {
+        // $c=count($current_block)*8;
+        // $this->trigger_error('We got a '.$c.'-bit block, instead of '.$this->blockSizeInBits.'', E_USER_ERROR);
+      }
+      $aBlock = $this->uncryptBlock($current_block, $expandedKey);
+      if(!$aBlock)
+      {
+        $this->trigger_error('Shared block decryption routine returned false', E_USER_WARNING);
+        return false;
+      }
+      if ($mode == "CBC")
+        for ($i=0; $i<$bpb; $i++) 
+          $pt[($block-1)*$bpb + $i] = $aBlock[$i] ^ $ciphertext[($block-1)*$bpb + $i];
+      else
+        $pt = $this->concat($aBlock, $pt);
+    }
+  
+    // do last block if ECB (skips the IV in CBC)
+    if ($mode == "ECB")
+    {
+      $x = $this->uncryptBlock($this->array_slice_js_compat($ciphertext, 0, $bpb), $expandedKey);
+      if(!$x)
+      {
+        $this->trigger_error('ECB block decryption routine returned false', E_USER_WARNING);
+        return false;
+      }
+      $pt = $this->concat($x, $pt);
+      if(!$pt)
+      {
+        $this->trigger_error('ECB concatenation routine returned false', E_USER_WARNING);
+        return false;
+      }
+    }
+  
+    return $pt;
+  }
+  
+  /**
+   * Wrapper for encryption.
+   * @param string $text the text to encrypt
+   * @param string $key the raw binary key to encrypt with
+   * @param int $return_encoding optional - can be ENC_BINARY, ENC_HEX or ENC_BASE64
+   */
+   
+  function encrypt($text, $key, $return_encoding = ENC_HEX)
+  {
+    if ( $this->mcrypt && $this->blockSizeInBits == mcrypt_module_get_algo_block_size(eval('return MCRYPT_RIJNDAEL_'.$this->keySizeInBits.';')) )
+    {
+      $iv_size = mcrypt_get_iv_size($this->mcrypt, MCRYPT_MODE_ECB);
+      $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
+      $cryptext = mcrypt_encrypt($this->mcrypt, $key, $text, MCRYPT_MODE_ECB, $iv);
+      switch($return_encoding)
+      {
+        case ENC_HEX:
+        default:
+          $cryptext = $this->strtohex($cryptext);
+          break;
+        case ENC_BINARY:
+          $cryptext = $cryptext;
+          break;
+        case ENC_BASE64:
+          $cryptext = base64_encode($cryptext);
+          break;
+      }
+    }
+    else
+    {
+      $key = $this->prepare_string($key);
+      $text = $this->prepare_string($text);
+      $cryptext = $this->rijndaelEncrypt($text, $key, 'ECB');
+      if(!is_array($cryptext))
+      {
+        echo 'Warning: encryption failed for string: '.$text.'<br />';
+        return false;
+      }
+      switch($return_encoding)
+      {
+        case ENC_HEX:
+        default:
+          $cryptext = $this->byteArrayToHex($cryptext);
+          break;
+        case ENC_BINARY:
+          $cryptext = $this->byteArrayToString($cryptext);
+          break;
+        case ENC_BASE64:
+          $cryptext = base64_encode($this->byteArrayToString($cryptext));
+          break;
+      }
+    }
+    return $cryptext;
+  }
+  
+  /**
+   * Wrapper for decryption.
+   * @param string $text the encrypted text
+   * @param string $key the raw binary key used to encrypt the text
+   * @param int $input_encoding the encoding used for the encrypted string. Can be ENC_BINARY, ENC_HEX, or ENC_BASE64.
+   * @return string
+   */
+   
+  function decrypt($text, $key, $input_encoding = ENC_HEX)
+  {
+    switch($input_encoding)
+    {
+      case ENC_BINARY:
+      default:
+        break;
+      case ENC_HEX:
+        $text = $this->hextostring($text);
+        break;
+      case ENC_BASE64:
+        $text = base64_decode($text);
+        break;
+    }
+    //$mod = strlen($text) % $this->blockSizeInBits;
+    //if($mod != 96)
+      //die('modulus check failed: '.$mod);
+    if ( $this->mcrypt )
+    {
+      $iv_size = mcrypt_get_iv_size($this->mcrypt, MCRYPT_MODE_ECB);
+      $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
+      $dypt = mcrypt_decrypt($this->mcrypt, $key, $text, MCRYPT_MODE_ECB, $iv);
+    }
+    else
+    {
+      $etext = $this->prepare_string($text);
+      $ekey  = $this->prepare_string($key);
+      $mod = count($etext) % $this->blockSizeInBits;
+      $dypt = $this->rijndaelDecrypt($etext, $ekey, 'ECB');
+      if(!$dypt)
+      {
+        echo '<pre>'.print_r($dypt, true).'</pre>';
+        $this->trigger_error('Rijndael main decryption routine failed', E_USER_ERROR);
+      }
+      $dypt = $this->byteArrayToString($dypt);
+    }
+    return $dypt;
+  }
+  
+  /**
+   * Enano-ese equivalent of str_split() which is only found in PHP5
+   * @param $text string the text to split
+   * @param $inc int size of each block
+   * @return array
+   */
+   
+  function enano_str_split($text, $inc = 1)
+  {
+    if($inc < 1) return false;
+    if($inc >= strlen($text)) return Array($text);
+    $len = ceil(strlen($text) / $inc);
+    $ret = Array();
+    for($i=0;$i<strlen($text);$i=$i+$inc)
+    {
+      $ret[] = substr($text, $i, $inc);
+    }
+    return $ret;
+  }
+  
+  /**
+   * Generates a random key suitable for encryption
+   * @param int $len the length of the key, in bytes
+   * @return string a BINARY key
+   */
+  
+  function randkey($len = 32)
+  {
+    $key = '';
+    for($i=0;$i<$len;$i++)
+    {
+      $key .= chr(mt_rand(0, 255));
+    }
+    return $key;
+  }
+  
+  /*
+  function byteArrayToString($arr)
+  {
+    if(!is_array($arr))
+    {
+      $this->trigger_error('First parameter should be an array', E_USER_WARNING);
+      return false;
+    }
+    $ret = '';
+    foreach($arr as $a)
+    {
+      if($a != 0) $ret .= chr($a);
+    }
+    return $ret;
+  }
+  */
+  
+  function strtohex($str)
+  {
+    $str = $this->enano_str_split($str);
+    $ret = '';
+    foreach($str as $s)
+    {
+      $chr = dechex(ord($s));
+      if(strlen($chr) < 2) $chr = '0' . $chr;
+      $ret .= $chr;
+    }
+    return $ret;
+  }
+  
+  function gen_readymade_key()
+  {
+    $key = $this->strtohex($this->randkey($this->keySizeInBits / 8));
+    return $key;
+  }
+  
+  function prepare_string($text)
+  {
+    $ret = $this->hexToByteArray($this->strtohex($text));
+    if(count($ret) != strlen($text))
+      die('problem seems to be the hex conversion');
+    return $ret;
+  }
+  
+  /**
+   * Decodes a hex string.
+   * @param string $hex The hex code to decode
+   * @return string
+   */
+  
+  function hextostring($hex)
+  {
+    $hex = $this->enano_str_split($hex, 2);
+    $bin_key = '';
+    foreach($hex as $nibble)
+    {
+      $byte = chr(hexdec($nibble));
+      $bin_key .= $byte;
+    }
+    return $bin_key;
+  }
+}
+
+/**
+ * XXTEA encryption arithmetic library.
+ *
+ * Copyright (C) 2006 Ma Bingyao <andot@ujn.edu.cn>
+ * Version:      1.5
+ * LastModified: Dec 5, 2006
+ * This library is free.  You can redistribute it and/or modify it.
+ * 
+ * From dandaman32: I am treating this code as GPL, as implied by the license statement above.
+ */
+class TEACrypt extends AESCrypt {
+  function long2str($v, $w) {
+      $len = count($v);
+      $n = ($len - 1) << 2;
+      if ($w) {
+          $m = $v[$len - 1];
+          if (($m < $n - 3) || ($m > $n)) return false;
+          $n = $m;
+      }
+      $s = array();
+      for ($i = 0; $i < $len; $i++) {
+          $s[$i] = pack("V", $v[$i]);
+      }
+      if ($w) {
+          return substr(join('', $s), 0, $n);
+      }
+      else {
+          return join('', $s);
+      }
+  }
+   
+  function str2long($s, $w) {
+      $v = unpack("V*", $s. str_repeat("\0", (4 - strlen($s) % 4) & 3));
+      $v = array_values($v);
+      if ($w) {
+          $v[count($v)] = strlen($s);
+      }
+      return $v;
+  }
+   
+  function int32($n) {
+      while ($n >= 2147483648) $n -= 4294967296;
+      while ($n <= -2147483649) $n += 4294967296;
+      return (int)$n;
+  }
+   
+  function encrypt($str, $key) {
+      if ($str == "") {
+          return "";
+      }
+      $v = $this->str2long($str, true);
+      $k = $this->str2long($key, false);
+      if (count($k) < 4) {
+          for ($i = count($k); $i < 4; $i++) {
+              $k[$i] = 0;
+          }
+      }
+      $n = count($v) - 1;
+   
+      $z = $v[$n];
+      $y = $v[0];
+      $delta = 0x9E3779B9;
+      $q = floor(6 + 52 / ($n + 1));
+      $sum = 0;
+      while (0 < $q--) {
+          $sum = $this->int32($sum + $delta);
+          $e = $sum >> 2 & 3;
+          for ($p = 0; $p < $n; $p++) {
+              $y = $v[$p + 1];
+              $mx = $this->int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ $this->int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
+              $z = $v[$p] = $this->int32($v[$p] + $mx);
+          }
+          $y = $v[0];
+          $mx = $this->int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ $this->int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
+          $z = $v[$n] = $this->int32($v[$n] + $mx);
+      }
+      return $this->long2str($v, false);
+  }
+   
+  function decrypt($str, $key) {
+      if ($str == "") {
+          return "";
+      }
+      $v = $this->str2long($str, false);
+      $k = $this->str2long($key, false);
+      if (count($k) < 4) {
+          for ($i = count($k); $i < 4; $i++) {
+              $k[$i] = 0;
+          }
+      }
+      $n = count($v) - 1;
+   
+      $z = $v[$n];
+      $y = $v[0];
+      $delta = 0x9E3779B9;
+      $q = floor(6 + 52 / ($n + 1));
+      $sum = $this->int32($q * $delta);
+      while ($sum != 0) {
+          $e = $sum >> 2 & 3;
+          for ($p = $n; $p > 0; $p--) {
+              $z = $v[$p - 1];
+              $mx = $this->int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ $this->int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
+              $y = $v[$p] = $this->int32($v[$p] - $mx);
+          }
+          $z = $v[$n];
+          $mx = $this->int32((($z >> 5 & 0x07ffffff) ^ $y << 2) + (($y >> 3 & 0x1fffffff) ^ $z << 4)) ^ $this->int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
+          $y = $v[0] = $this->int32($v[0] - $mx);
+          $sum = $this->int32($sum - $delta);
+      }
+      return $this->long2str($v, true);
+  }
+}
+
+?>