title: Object of class .. could not be converted to string
body: <p>I made my first class and I'm having trouble converting the objects back into strings.</p>
  
  <pre><code>class Cryption
  {
      var $data;
      var $salt;
  
  function __construct($data, $salt)
  {
      $this-&gt;data = $data;
      $this-&gt;salt = $salt;
  }
  
  function sha512()
  {
      $sodium = 'Na';
      return hash_hmac("sha512", $this-&gt;data . $this-&gt;salt, $sodium);
  }
  
  function encrypt()
  {
      $salt = substr(sha512(($this-&gt;key), 'brownies'), 0, 30);
      return base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $salt, $this-&gt;data, MCRYPT_MODE_CBC, md5($salt)));
  }
  </code></pre>
  
  <p>When I use it:</p>
  
  <pre><code>$password = new Cryption(mysql_real_escape_string(trim($_POST['password'])), 'pepper');
  $password-&gt;sha512();
  </code></pre>
  
  <p>It says 'PHP Catchable fatal error:  Object of class Cryption could not be converted to string'</p>
  
  <p>I don't really know how to get it back into a string.  May someone please help me?</p>
  
  <p>Thank you.</p>
  
  <p>Edit: </p>
  
  <pre><code>&lt;?php
  require("config.php");
  include("includes/cryption/cryption.php");
  
  $username = mysql_real_escape_string(trim($_POST['username']));
  $password = new Cryption(mysql_real_escape_string(trim($_POST['password'])), 'pepper'); //use a different salt next time such as a special salt for each user
  $password-&gt;sha512();
  
  $result = mysql_query("SELECT * FROM `administrators` WHERE username='$username' and password='$password'");
  $row = mysql_fetch_row($result);
  $count = mysql_num_rows($result);
  
  if ($count == 1) {
      if (isset($_POST['remember'])) {
          session_start();
          $_SESSION['user'] = array(
              'id' =&gt; $row[0],
              'username' =&gt; $row[1],
              'password' =&gt; $row[2]
          );
          $userid = new Cryption($_SESSION['user']['id'], 'kkfishing');
          $session = new Cryption($_SESSION['user']['username'], 'kkfishing');
          $validated = new Cryption($_SESSION['user']['password'], 'kkfishing');
  
          setcookie("uniqueid", $userid-&gt;encrypt(), time() + 60 * 60 * 24 * 100, "/"); //100 days
          setcookie("kksessionid", $session-&gt;encrypt(), time() + 60 * 60 * 24 * 100, "/");
          setcookie("kkuserid", $validated-&gt;encrypt(), time() + 60 * 60 * 24 * 100, "/");//disguised cookie name
      }
      session_start();
      $_SESSION['authenticated'] = $row[0];
      echo '1'; //true
      exit;
  }
  else
  {
      echo '0'; //false
      exit;
  }
  ?&gt;
  </code></pre>