<?
require_once('../dbconfig.inc');
require_once('../dbconnect.inc');
define('SALT_LENGTH', 9);

function generateHash($plainText, $salt = null)
{
    if ($salt === null)
    {
        $salt = substr(md5(uniqid(rand(), true)), 0, SALT_LENGTH);
    }
    else
    {
        $salt = substr($salt, 0, SALT_LENGTH);
    }
    return $salt . sha1($salt . $plainText);
}

//username and password from form (in plain text)
$myusername = $_POST['myusername'];
$mypassword = $_POST['mypassword'];

//hash password with salt+sha-1 (first nine chars of the string = salt)
$result = mysql_query("SELECT * FROM members WHERE username = '$myusername'");
while ($row = mysql_fetch_array($result))
{
   $password = $row['password'];
   $salt = substr($password, 0, SALT_LENGTH);
   $encrypted_password = generateHash($mypassword, $salt);
}

//protect from mysql injections
$myusername = stripslashes($myusername);
$myusername = mysql_real_escape_string($myusername);

$mypassword = stripslashes($encrypted_password);
$mypassword = mysql_real_escape_string($encrypted_password);

//compare username and password with db-entry
$sql = "SELECT * FROM $table WHERE username = '$myusername' AND password = '$mypassword'";
$result = mysql_query($sql);

$count = mysql_num_rows($result);

if ($count == 1)
    //login ok
else
    //login failed

?>