Code base merged from ship-simu repos

[hub.git] / inc / classes / main / crypto / class_CryptoHelper.php

diff --git a/inc/classes/main/crypto/class_CryptoHelper.php b/inc/classes/main/crypto/class_CryptoHelper.php
new file mode 100644 (file)
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+++ b/inc/classes/main/crypto/class_CryptoHelper.php
@@ -0,0 +1,157 @@
+<?php
+/**
+ * A helper class for cryptographical things like hashing passwords and so on
+ *
+ * @author             Roland Haeder <webmaster@ship-simu.org>
+ * @version            0.3.0
+ * @copyright  Copyright(c) 2007, 2008 Roland Haeder, this is free software
+ * @license            GNU GPL 3.0 or any newer version
+ * @link               http://www.mxchange.org
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+class CryptoHelper extends BaseFrameworkSystem {
+       /**
+        * An instance of this own clas
+        */
+       private static $selfInstance = null;
+
+       /**
+        * Instance of the random number generator
+        */
+       private $rngInstance = null;
+
+       /**
+        * Salt for hashing operations
+        */
+       private $salt = "";
+
+       /**
+        * Protected constructor
+        *
+        * @return      void
+        */
+       protected function __construct () {
+               // Call parent constructor
+               parent::__construct(__CLASS__);
+
+               // Set part description
+               $this->setObjectDescription("Cryptographical helper");
+
+               // Create unique ID number
+               $this->generateUniqueId();
+
+               // Clean up a little
+               $this->removeNumberFormaters();
+               $this->removeSystemArray();
+       }
+
+       /**
+        * Creates an instance of this class
+        *
+        * @return      $cryptoInstance         An instance of this crypto helper class
+        */
+       public final static function createCryptoHelper () {
+               // Get a new instance
+               $cryptoInstance = self::getInstance();
+
+               // Initialize the hasher
+               $cryptoInstance->initHasher();
+
+               // Return the instance
+               return $cryptoInstance;
+       }
+
+       /**
+        * Get a singleton instance of this class
+        *
+        * @return      $selfInstance   An instance of this crypto helper class
+        */
+       public final static function getInstance () {
+               // Is no instance there?
+               if (is_null(self::$selfInstance)) {
+                       // Then get a new one
+                       self::$selfInstance = new CryptoHelper();
+               }
+
+               // Return the instance
+               return self::$selfInstance;
+       }
+
+       /**
+        * Initializes the hasher for different purposes.
+        *
+        * @return      void
+        */
+       protected function initHasher () {
+               // Initialize the random number generator which is required by some crypto methods
+               $this->rngInstance = ObjectFactory::createObjectByConfiguredName('rng_class');
+
+               // Generate a salt for the hasher
+               $this->generateSalt();
+       }
+
+       /**
+        * Generates the salt based on configured length
+        *
+        * @return      void
+        */
+       private function generateSalt () {
+               // Get a random string from the RNG
+               $randomString = $this->rngInstance->makeRandomString();
+
+               // Get config entry for salt length
+               $length = $this->getConfigInstance()->readConfig('salt_length');
+
+               // Keep only defined number of characters
+               $this->salt = substr(sha1($randomString), -$length, $length);
+       }
+
+       /**
+        * Hashes a password with salt and returns the hash. If an old previous hash
+        * is supplied the method will use the first X chars of that hash for hashing
+        * the password. This is useful if you want to check if the password is
+        * identical for authorization purposes.
+        *
+        * @param       $plainPassword  The plain password to use
+        * @param       $oldHash                A previously hashed password
+        * @return      $hashed                 The hashed and salted password
+        */
+       public function hashPassword ($plainPassword, $oldHash = "") {
+               // Is the old password set?
+               if (empty($oldHash)) {
+                       // No, then use the current salt
+                       $salt = $this->salt;
+               } else {
+                       // Use the salt from hash, first get length
+                       $length = $this->getConfigInstance()->readConfig('salt_length');
+
+                       // Then extract the X first characters from the hash as our salt
+                       $salt = substr($oldHash, 0, $length);
+               }
+
+               // Hash the password with salt
+               $hashed = $salt . md5(sprintf($this->getConfigInstance()->readConfig('hash_mask'),
+                       $salt,
+                       $this->rngInstance->getExtraSalt(),
+                       $plainPassword
+               ));
+
+               // And return it
+               return $hashed;
+       }
+}
+
+// [EOF]
+?>