Forgot password email reset php works, except neither original nor changed password allow login

Question

I have created a forgotten password change php function for my login system that sends an email to the user that has forgotten his/her password and gives a link utilizing a hashed token in order to change their password. Once email link is selected by the user, they are then able to change their password, which then updates mysql with their new hashed password.

Every aspect of the code seems to work properly until I try to login with the new password. I receive echo that "username/password combination incorrect" (found on LOGIN.PHP page). Trying the original password echos the same error as well on the LOGIN.PHP page.

Not exactly sure why my sql query is not matching the updated password with the existing username and allowing the login?

For ease of parsing thru the code, I have excluded parts I do not believe to be the issue. I have included 5 php files.

FORGOTPASSWORD.PHP

<?php
if (!isset($_GET['email'])) {
    echo '<form action="">//Form for password reset here</form>';
    exit();
}


define('DB_USER', '');
define('DB_PASS', '');
define('DB_NAME', '');

$email = $_GET['email'];

function connect()
{
//Connect to db
}
connect();

$q = "SELECT email FROM users WHERE LCASE(TRIM(email))='" . strtolower(trim($email)) . "'";
$r = mysql_query($q);
$n = mysql_num_rows($r);

if ($n == 0) {
    echo "Email id is not registered";
    die();

}

//token updated into sql db for user
    $token=getRandomString(10);
    $q="UPDATE users SET token=('".$token."') WHERE email=('".$email."')";
    mysql_query($q);

function getRandomString($length) 
   {

//token created
}
//email creation code here

RESET.PHP

<?php
session_start();

//Define db connection parameters

    $token=$_GET['token'];

function connect() {

//Connection to db executed
    }

connect();

if(!isset($_POST['password'])){
    $q="SELECT email FROM users WHERE token='".$token."' and used='0'";
    $r=mysql_query($q);
    while($row=mysql_fetch_array($r))
   {

$email=$row['email'];
   }

If ($email!=''){
      $_SESSION['email']=$email;
}

    else die("Invalid link or Password already changed");}

$password=$_POST['password'];
$email=$_SESSION['email'];

if(!isset($password)){

echo '
//Change password form
';}

if(isset($_POST['password'])&&isset($_SESSION['email']))
{

//Update sql db with newly created password
$q="UPDATE users SET password='".md5($password)."' WHERE email='".$email."'";
$r=mysql_query($q);

if($r)mysql_query("UPDATE users SET used='1' WHERE token='".$token."'");echo "Your password is changed successfully";
if(!$r)echo "An error occurred";
}
?>

LOGIN.PHP (displays the error messsage)

<div id="loginContainer">
<div id="loginMessage">
        <?php if ( $logged == 'invalid' ) : ?>
            <p class="name_pass">
                The username/password combination is incorrect. Try again.
            </p>
        <?php endif; ?>
        <?php if ( $_GET['reg'] == 'true' ) : ?>
            <p class="success">Your registration was successful, please login below.
            </p>
        <?php endif; ?>
        <?php if ( $_GET['action'] == 'logout' ) : ?>
            <?php if ( $loggedout == true ) : ?>
                <p class="log_out">You have been successfully logged out.
                </p>
            <?php else: ?>
                <p class="problem">There was a problem logging you out.
                </p>
            <?php endif; ?>
        <?php endif; ?>
        <?php if ( $_GET['msg'] == 'login' ) : ?>
            <p class="must_login">You must login to view this content. Please login below.
                </p>
        <?php endif; ?>
</div>

CLASS.PHP (login function)

        function login($redirect) {
        global $jdb;

        if ( !empty ( $_POST ) ) {


            $values = $jdb->clean($_POST);


            $subname = $values['username'];
            $subpass = $values['password'];


            $table = 'users';


            $sql = "SELECT * FROM $table WHERE username = '" . $subname . "'";
            $results = $jdb->select($sql);


            if (!$results) {
                die('Sorry, that username does not exist!');
            }


            $results = mysql_fetch_assoc( $results );


            $storeg = $results['date'];


            $stopass = $results['password'];


            $nonce = md5('registration-' . $subname . $storeg . NONCE_SALT);


            $subpass = $jdb->hash_password($subpass, $nonce);


            if ( $subpass == $stopass ) {


                $authnonce = md5('cookie-' . $subname . $storeg . AUTH_SALT);
                $authID = $jdb->hash_password($subpass, $authnonce);


                setcookie('logauth[user]', $subname, 0, '', '', '', true);
                setcookie('logauth[authID]', $authID, 0, '', '', '', true);


                $url = "http" . ((!empty($_SERVER['HTTPS'])) ? "s" : "") . "://".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];
                $redirect = str_replace('login.php', $redirect, $url);


                header("Location: $redirect");
                exit;   
            } else {
                return 'invalid';
            }
        } else {
            return 'empty';
        }
    }

INDEX.PHP (landing page following successful login)

<?php
require_once('load.php');
$logged = $j->checkLogin();

if ( $logged == false ) {
    //Build our redirect
    $url = "http" . ((!empty($_SERVER['HTTPS'])) ? "s" : "") . "://".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];
    $redirect = str_replace('index.php', 'login.php', $url);

    //Redirect to the home page
    header("Location: $redirect?msg=login");
    exit;
} else {
    //Grab our authorization cookie array
    $cookie = $_COOKIE['logauth'];

    //Set our user and authID variables
    $user = $cookie['user'];
    $authID = $cookie['authID'];

    //Query the database for the selected user
    $table = 'users';
    $sql = "SELECT * FROM $table WHERE username = '" . $user . "'";
    $results = $jdb->select($sql);

    //Kill the script if the submitted username doesn't exit
    if (!$results) {
        die('Sorry, that username does not exist!');
    }

    //Fetch our results into an associative array
    $results = mysql_fetch_assoc( $results );
?>

Thanks for any and all help. I appreciate anyone willing to take a look at the code to help me figure out this last part to my login process. Thanks.

Answer 1

In your reset.php file, you store an unsalted MD5 of the password...

$password=$_POST['password'];
$q="UPDATE users SET password='".md5($password)."' WHERE email='".$email."'";

...but then you compare it to something different...

$subpass = $values['password']; // seems to be the entered password
...
$stopass = $results['password']; // seems to be the stored MD5 password hash
...
$subpass = $jdb->hash_password($subpass, $nonce); // probably not an unsalted MD5
if ( $subpass == $stopass ) // comparison of different things

Even if you get this code to work, it will be a very unsafe solution. Instead you should absolutely switch to the password hash functions built in in PHP. The DB field should be varchar(255), the code could then look something like this:

// Hash a new password for storing in the database.
// The function automatically generates a cryptographically safe salt.
$hashToStoreInDb = password_hash($_POST['password'], PASSWORD_DEFAULT);
$q="UPDATE users SET password='".$hashToStoreInDb."' WHERE email='".$email."'";

To check the password you need to get the hash from the database and compare it with password_verify, so the comparison will be done with the same salt as was used to store the hash.

// Check if the hash of the entered login password, matches the stored hash.
// The salt and the cost factor will be extracted from $stopass.
$subpass = $values['password'];
...
$stopass = $results['password'];
...
$isPasswordCorrect = password_verify($subpass, $stopass);
if ($isPasswordCorrect)

Another problem in your code is SQL-injection, you could avoid this vulnerablity with using prepared statements. An example with MySqli or PDO you can find in another answer.