Question

This is an authentication script for a website. Is this safe? Is it recent programming? Is it obsolete? Are there “better more secure ways” I am very new but I don’t see too many places using header authorization.

Any help would be appreciated! This is the first login script I’ve ever made and also registration.. However I’m not sure I like the header authorization.

<?php
require_once('connectvars.php');
IF (!isset($_SERVER['PHP_AUTH_USER']) || !isset($_SERVER['PHP_AUTH_PW'])) {
header('HTTP/1.1 401 Unauthorized');
header('WWW-Authenticate: Basic realm="Register"');
exit('<h3> You must enter your username & password to continue');
}
$Dbc  = mysqli_connect('localhost', 'root', '', 'learn');
$user_username = mysqli_real_escape_string($Dbc, trim($_SERVER['PHP_AUTH_USER']));
$user_password = mysqli_real_escape_string($Dbc, trim($_SERVER['PHP_AUTH_PW']));
$query = "SELECT ID, Username from members where Username = '$user_username' AND " .
"Password = SHA1('$user_password')";
$data = mysqli_query($Dbc, $query);
if (mysqli_num_rows($data) == 1) {
$row = mysqli_fetch_array($data);
$user_id = $row['ID'];
$username = $row['Username'];
}
else {
header('http/1.1 401 unauthorized');
header('www-authenticate: basic realm="Register"');
}
echo ('<p class="Login"> yo are logged in as ' . $user_username . '.</p>'); 

if (isset($_POST['submit'])) {
$username = $_POST['username'];
$password = $_POST['password'];
$email = $_POST['email'];

if (empty($username) ){ 
echo "you forgot to enter a username.</br>";
}
if (empty($password)) {
echo "you forgot to enter a password.</br>";
}   
if (empty($email)) {
echo "you forgot to enter an email.</br>";
}

if(!empty($username) && !empty($password) && !empty($email))  {
$dbc = mysqli_connect('localhost', 'root', '', 'learn');
$checkusername = 'SELECT username FROM members where username = "'.$username.'"';
if (mysqli_num_rows(mysqli_query($dbc, $checkusername)) != 0) 
{
    echo "<font color = red> Username <font color = black><u>           $username</u></font> already exists in the database.</font></br>";

$checkemail = 'Select email FROM members where email = "'.$email.'"';
if (mysqli_num_rows(mysqli_query($dbc, $checkemail)) != 0)
        echo "<font color = red> Email <font color = black><u>     $email</u></font> already exists in the database.</font>";
    mysqli_close($dbc);
}
else 
{
$query = "INSERT INTO members VALUES (0, '$username', SHA1('$password'), '$email')";
mysqli_query($dbc, $query);
echo " Username: <font color = green ><u> $username</u></font> & Password: <font color = green><u> $password</u></font> have been added to the database.";
mysqli_close($dbc);
}
}   
}

?>

Answer 1

It’s wrong. mysqli supports parametrized queries; use them.