Help with encrypt/decrypt using a combination of md5 and initilization vector.

[facarroll]

Hi.

I  purchased software for a PayPal subscription management system, and it relies on user verification by way of a username (email address) and a hashed password.

 

I have also developed my own login scripts for an application which also uses a hashed md5 password and all that works fine. I want to integrate my scripts with the purchased software using the supplied mySql database tables.

 

My problem is that the supplied software goes a step further than a hashed md5 password by applying initializing vectors to the hashed password. I cannot figure out how to modify my login code to accommodate the encrypted password that appears in the database.

 

It is beyond my current abilities to work this out on my own. I'd really appreciate it if anyone can help.

 

I've attached my own login script below, and Ive attached what I believe is the decryption code that comes with the purchased software. There is also a database file that relates to this.

 

Hope someone can help me.

 

<?php
session_start();
if ($_POST['password']) {
//Connect to the database 
    include_once "db_connect.php";    
$email = stripslashes($_POST['payer_email']);
$email = strip_tags($email);
$email = mysql_real_escape_string($email);
$password = preg_replace("/[^A-Za-z0-9]/", "", $_POST['password']); // filter everything but numbers and letters
$password = md5($password);
// Make query and then register all relevant database data into SESSION variables.
$sql = mysql_query("SELECT * FROM sec_tblusers WHERE payer_email='$email' AND password='$password' AND signedup='1'") or die("failed"); 
$login_check = mysql_num_rows($sql);
if($login_check > 0){ 
    while($row = mysql_fetch_array($sql)){ 
        // Get member data into a session variable
        $id = $row["recid"];   
        session_register('recid'); 
        $_SESSION['recid'] = $id;
   
        $payer_email = $row["payer_email"]; 
        session_register('payer_email'); 
        $_SESSION['payer_email'] = $payer_email;
        
        $password = $row["password"]; 
        session_register('password'); 
        $_SESSION['password'] = $password;        
           
        $iv = $row["iv"]; 
        session_register('iv'); 
        $_SESSION['iv'] = $iv;
         
        $signedup = $row["signedup"]; 
        session_register('signedup'); 
        $_SESSION['signedup'] = $signedup;
         
        $lastlogin = $row["lastlogin"]; 
        session_register('lastlogin'); 
        $_SESSION['lastlogin'] = $lastlogin;
    
        // Update last_log_date field for this member now
        mysql_query("UPDATE sec_tblusers SET lastlogin=now() WHERE recid='$id'");
        // Print success message here then exit the script
        //header("location: member_profile.php?id=$id"); 
        header("location: adduser.php?id=$id"); 
        exit();
    } // close while
} else {
// Print login failure message to the user and link them back to your login page
  print '<br /><br /><font color="#FF0000">You do not show in our records as a subscriber. Has the subscription expired?</font><br />
<br /><a href="../main.php">Click here</a> to go back.';
  exit();
}
}// close if post
?> 

 

What I think is the decrypting code that comes with the purchased software goes like this.

 

<?php 
//---------------------------------------
//Given the payer_email address, return the decrypted password
function getpassword($payer_email, $dbhost, $dbusername, $dbpass, $dbname, $dbprefix, &$message) {

    $dl = new DataLayer();
    $dl->debug=false;
    $dl->connect( $dbhost, $dbusername, $dbpass, $dbname )  or die ( "Database connection error " . $dl->geterror() );
       
    //SELECT password, iv FROM sec_tblusers WHERE payer_email = '" . $payer_email . "'"
    $cols = array("password", "iv");
    $table = $dl->select( $dbprefix."sec_tblusers", "", $cols, "payer_email = '$payer_email'", "" );

    if ($dl->geterror()) {
        $message = "SQL error - user.php ref 58 " . $dl->geterror();
        exit;
    }

    $IV = $table[0]['iv'];
    $password = $table[0]['password'];

    $decryption = new password($IV, $password);
    $decryption->decode();
    $decode = $decryption->getdecodedtext();

    return $decode;

}


//------------------------------------
?> 

 

The database table is here.

 

-- Table structure for table `sec_tblusers`
--

CREATE TABLE `sec_tblusers` (
  `recid` int(11) NOT NULL AUTO_INCREMENT,
  `payer_email` varchar(100) NOT NULL,
  `password` varchar(50) DEFAULT NULL,
  `iv` int(11) DEFAULT NULL,
  `signedup` int(11) NOT NULL DEFAULT '0',
  `signupdate` datetime NOT NULL,
  `lastlogin` datetime NOT NULL,
  PRIMARY KEY (`recid`),
  UNIQUE KEY `payer_email` (`payer_email`),
  KEY `password` (`password`),
  KEY `signedup` (`signedup`),
  KEY `lastlogin` (`lastlogin`),
  KEY `signupdate` (`signupdate`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=22 ;

--
-- Dumping data for table `sec_tblusers`
--

INSERT INTO `sec_tblusers` (`recid`, `payer_email`, `password`, `iv`, `signedup`, `signupdate`, `lastlogin`) VALUES
(5, 'someone@gmail.com', 'cRbeAWgN3 ', 316, 1, '0000-00-00 00:00:00', '2010-11-10 22:29:06'),
(6, 'someoneelse@gmail.com', 'cRbeAWgN3 ', 269, 1, '0000-00-00 00:00:00', '0000-00-00 00:00:00');

 

I suspect that there may be some other relevant code in the purchased software, and I could hunt that up if someone could tell me what I should look for.

 

Anyway, I'm really in need of some help, or some advice.

 

Cheers, everyone.

[btherl]

It looks like the "password" object from the purchased software is the critical part.  It takes the IV and the encrypted password and returns the decrypted one.

[facarroll]

I think you are correct, but the trouble is, I just don't understand the code well enough to apply it.