inc/classes/main/streams/crypto/class_McryptStream.php

   1 <?php
   2 /**
   3  * A mcrypt-based encryption stream
   4  *
   5  * @author              Roland Haeder <webmaster@ship-simu.org>
   6  * @version             0.0.0
   7  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2011 Core Developer Team
   8  * @license             GNU GPL 3.0 or any newer version
   9  * @link                http://www.ship-simu.org
  10  *
  11  * This program is free software: you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation, either version 3 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  23  */
  24 class McryptStream extends BaseStream implements EncryptableStream {
  25         /**
  26          * Seperator on many places
  27          */
  28         private $seperator = '|';
  29
  30         /**
  31          * Protected constructor
  32          *
  33          * @return      void
  34          */
  35         protected function __construct () {
  36                 // Call parent constructor
  37                 parent::__construct(__CLASS__);
  38         }
  39
  40         /**
  41          * Creates an instance of this node class
  42          *
  43          * @param       $rngInstance            An RNG instance
  44          * @return      $streamInstance         An instance of this node class
  45          */
  46         public static final function createMcryptStream (RandomNumberGenerator $rngInstance) {
  47                 // Get a new instance
  48                 $streamInstance = new McryptStream();
  49
  50                 // Set the RNG instance
  51                 $streamInstance->setRngInstance($rngInstance);
  52
  53                 // Return the instance
  54                 return $streamInstance;
  55         }
  56
  57         /**
  58          * Encrypt the string with fixed salt
  59          *
  60          * @param       $str            The unencrypted string
  61          * @return      $encrypted      Encrypted string
  62          */
  63         public function encryptStream ($str) {
  64                 // Init crypto module
  65                 $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
  66                 $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
  67
  68                 // Generate key
  69                 $key = $this->getRngInstance()->generateKey();
  70
  71                 // Add some "garbage" to the string
  72                 switch ($this->getRngInstance()->randomNumber(0, 8)) {
  73                         case 0:
  74                                 $garbageString = crc32($this->getRngInstance()->randomString(10)) . $this->seperator . base64_encode($str) . $this->seperator . crc32($this->getRngInstance()->randomString(20));
  75                                 break;
  76
  77                         case 1:
  78                                 $garbageString = crc32($this->getRngInstance()->randomString(10)) . $this->seperator . base64_encode($str) . $this->seperator . md5($this->getRngInstance()->randomString(20));
  79                                 break;
  80
  81                         case 2:
  82                                 $garbageString = crc32($this->getRngInstance()->randomString(10)) . $this->seperator . base64_encode($str) . $this->seperator . sha1($this->getRngInstance()->randomString(20));
  83                                 break;
  84
  85                         case 3:
  86                                 $garbageString = md5($this->getRngInstance()->randomString(10)) . $this->seperator . base64_encode($str) . $this->seperator . crc32($this->getRngInstance()->randomString(20));
  87                                 break;
  88
  89                         case 4:
  90                                 $garbageString = md5($this->getRngInstance()->randomString(10)) . $this->seperator . base64_encode($str) . $this->seperator . md5($this->getRngInstance()->randomString(20));
  91                                 break;
  92
  93                         case 5:
  94                                 $garbageString = md5($this->getRngInstance()->randomString(10)) . $this->seperator . base64_encode($str) . $this->seperator . sha1($this->getRngInstance()->randomString(20));
  95                                 break;
  96
  97                         case 6:
  98                                 $garbageString = sha1($this->getRngInstance()->randomString(10)) . $this->seperator . base64_encode($str) . $this->seperator . crc32($this->getRngInstance()->randomString(20));
  99                                 break;
 100
 101                         case 7:
 102                                 $garbageString = sha1($this->getRngInstance()->randomString(10)) . $this->seperator . base64_encode($str) . $this->seperator . md5($this->getRngInstance()->randomString(20));
 103                                 break;
 104
 105                         case 8:
 106                                 $garbageString = sha1($this->getRngInstance()->randomString(10)) . $this->seperator . base64_encode($str) . $this->seperator . sha1($this->getRngInstance()->randomString(20));
 107                                 break;
 108                 }
 109
 110                 // Encrypt the string
 111                 $encrypted = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $garbageString, MCRYPT_MODE_ECB, $iv);
 112
 113                 // Return the string
 114                 return $encrypted;
 115         }
 116
 117         /**
 118          * Decrypt the string with fixed salt
 119          *
 120          * @param       $encrypted      Encrypted string
 121          * @return      $str            The unencrypted string
 122          */
 123         public function decryptStream ($encrypted) {
 124                 // Init crypto module
 125                 $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
 126                 $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
 127
 128                 // Generate key
 129                 $key = $this->getRngInstance()->generateKey();
 130
 131                 // Decrypt the string
 132                 $garbageString = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key, $encrypted, MCRYPT_MODE_ECB, $iv);
 133
 134                 // Get the real string out
 135                 $strArray = explode($this->seperator, $garbageString);
 136
 137                 // Does the element count match?
 138                 assert(count($strArray) == 3);
 139
 140                 // Decode the string
 141                 $str = base64_decode($strArray[1]);
 142
 143                 // Trim trailing nulls away
 144                 $str = rtrim($str, "\0");
 145
 146                 // Return the string
 147                 return $str;
 148         }
 149 }
 150
 151 // [EOF]
 152 ?>