inc/classes/main/crypto/class_CryptoHelper.php

   1 <?php
   2 /**
   3  * A helper class for cryptographical things like hashing passwords and so on
   4  *
   5  * @author              Roland Haeder <webmaster@shipsimu.org>
   6  * @version             0.0.0
   7  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2013 Core Developer Team
   8  * @license             GNU GPL 3.0 or any newer version
   9  * @link                http://www.shipsimu.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 CryptoHelper extends BaseFrameworkSystem implements Cryptable {
  25         // Exception constants
  26         const EXCEPTION_ENCRYPT_MISSING = 0x1f0;
  27         const EXCEPTION_ENCRYPT_INVALID = 0x1f1;
  28
  29         /**
  30          * An instance of this own clas
  31          */
  32         private static $selfInstance = NULL;
  33
  34         /**
  35          * Instance of the crypto stream
  36          */
  37         private $cryptoStreamInstance = NULL;
  38
  39         /**
  40          * Salt for hashing operations
  41          */
  42         private $salt = '';
  43
  44         /**
  45          * Protected constructor
  46          *
  47          * @return      void
  48          */
  49         protected function __construct () {
  50                 // Call parent constructor
  51                 parent::__construct(__CLASS__);
  52         }
  53
  54         /**
  55          * Creates an instance of this class
  56          *
  57          * @return      $cryptoInstance         An instance of this crypto helper class
  58          */
  59         public static final function createCryptoHelper () {
  60                 // Get a new instance
  61                 $cryptoInstance = new CryptoHelper();
  62
  63                 // Initialize the hasher
  64                 $cryptoInstance->initHasher();
  65
  66                 // Attach a crypto stream
  67                 $cryptoInstance->attachCryptoStream();
  68
  69                 // Return the instance
  70                 return $cryptoInstance;
  71         }
  72
  73         /**
  74          * Get a singleton instance of this class
  75          *
  76          * @return      $selfInstance   An instance of this crypto helper class
  77          */
  78         public static final function getSelfInstance () {
  79                 // Is no instance there?
  80                 if (is_null(self::$selfInstance)) {
  81                         // Then get a new one
  82                         self::$selfInstance = self::createCryptoHelper();
  83                 } // END - if
  84
  85                 // Return the instance
  86                 return self::$selfInstance;
  87         }
  88
  89         /**
  90          * Attaches a crypto stream to this crypto helper by detecting loaded
  91          * modules.
  92          *
  93          * @return      void
  94          */
  95         protected function attachCryptoStream () {
  96                 // Do we have mcrypt loaded?
  97                 if ($this->isPhpExtensionLoaded('mcrypt')) {
  98                         // Then use it
  99                         $this->cryptoStreamInstance = ObjectFactory::createObjectByName('McryptStream', array($this->getRngInstance()));
 100                 } else {
 101                         // If nothing works ...
 102                         $this->cryptoStreamInstance = ObjectFactory::createObjectByName('NullCryptoStream');
 103                 }
 104         }
 105
 106         /**
 107          * Initializes the hasher for different purposes.
 108          *
 109          * @return      void
 110          */
 111         protected function initHasher () {
 112                 // Initialize the random number generator which is required by some crypto methods
 113                 $this->setRngInstance(ObjectFactory::createObjectByConfiguredName('rng_class'));
 114
 115                 // Generate a salt for the hasher
 116                 $this->generateSalt();
 117         }
 118
 119         /**
 120          * Generates the salt based on configured length
 121          *
 122          * @return      void
 123          */
 124         private function generateSalt () {
 125                 // Get a random string from the RNG
 126                 $randomString = $this->getRngInstance()->randomString() . $this->createUuid();
 127
 128                 // Get config entry for salt length
 129                 $length = $this->getConfigInstance()->getConfigEntry('salt_length');
 130
 131                 // Keep only defined number of characters
 132                 $this->salt = substr(sha1($randomString), -$length, $length);
 133         }
 134
 135         /**
 136          * Returns a UUID (Universal Unique IDentifier) if PECL extension uuid was
 137          * found or an empty string it not.
 138          *
 139          * @return      $uuid   UUID with leading dash or empty string
 140          */
 141         public function createUuid () {
 142                 // Init empty UUID
 143                 $uuid = '';
 144
 145                 // Is the UUID extension loaded? (see pecl)
 146                 if ((extension_loaded('uuid')) && (function_exists('uuid_create'))) {
 147                         // Then add it as well
 148                         $uuid = uuid_create();
 149                 } // END - if
 150
 151                 // Return it
 152                 return $uuid;
 153         }
 154
 155         /**
 156          * Hashes a string with salt and returns the hash. If an old previous hash
 157          * is supplied the method will use the first X chars of that hash for hashing
 158          * the password. This is useful if you want to check if password is identical
 159          * for authorization purposes.
 160          *
 161          * @param       $str            Unhashed string
 162          * @param       $oldHash        A hash from previous hashed string
 163          * @param       $withFixed      Whether to include a fixed salt (not recommended in p2p applications)
 164          * @return      $hashed         The hashed and salted string
 165          */
 166         public function hashString ($str, $oldHash = '', $withFixed = TRUE) {
 167                 // Cast the string
 168                 $str = (string) $str;
 169
 170                 // Default is the default salt ;-)
 171                 $salt = $this->salt;
 172
 173                 // Is the old password set?
 174                 if (!empty($oldHash)) {
 175                         // Use the salt from hash, first get length
 176                         $length = $this->getConfigInstance()->getConfigEntry('salt_length');
 177
 178                         // Then extract the X first characters from the hash as our salt
 179                         $salt = substr($oldHash, 0, $length);
 180                 } // END - if
 181
 182                 // Hash the password with salt
 183                 //* DEBUG: */ echo "salt=".$salt."/plain=".$str."<br />\n";
 184                 if ($withFixed === TRUE) {
 185                         // Use additional fixed salt
 186                         $hashed = $salt . md5(sprintf($this->getConfigInstance()->getConfigEntry('hash_extra_mask'),
 187                                 $salt,
 188                                 $this->getRngInstance()->getFixedSalt(),
 189                                 $str
 190                         ));
 191                 } else {
 192                         // Use salt+string to hash
 193                         $hashed = $salt . md5(sprintf($this->getConfigInstance()->getConfigEntry('hash_normal_mask'),
 194                                 $salt,
 195                                 $str
 196                         ));
 197                 }
 198
 199                 // And return it
 200                 return $hashed;
 201         }
 202
 203         /**
 204          * Encrypt the string with fixed salt
 205          *
 206          * @param       $str            The unencrypted string
 207          * @param       $key            Optional key, if none provided, a random key will be generated
 208          * @return      $encrypted      Encrypted string
 209          */
 210         public function encryptString ($str, $key = NULL) {
 211                 // Encrypt the string through the stream
 212                 $encrypted = $this->cryptoStreamInstance->encryptStream($str, $key);
 213
 214                 // Return the string
 215                 return $encrypted;
 216         }
 217
 218         /**
 219          * Decrypt the string with fixed salt
 220          *
 221          * @param       $encrypted      Encrypted string
 222          * @return      $str            The unencrypted string
 223          */
 224         public function decryptString ($encrypted) {
 225                 // Encrypt the string through the stream
 226                 $str = $this->cryptoStreamInstance->decryptStream($encrypted);
 227
 228                 // Return the string
 229                 return $str;
 230         }
 231 }
 232
 233 // [EOF]
 234 ?>