<?php

$servername = "localhost";
$username = "whatever";
$password = "whatever";
$dbname = "whatever";

try {

    $db = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);


    $db->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);


    $salt = bin2hex(random_bytes(strlen($_POST["providedpass"])));
    $hashpsw = hash('sha256', $_POST["providedpass"].$salt);

    $name = $_POST["usrnm"];


    $stmt = $db->prepare("INSERT INTO users (username, password, salt, level) VALUES (?,?,?,?)");

    if ($stmt->execute(array($name,$hashpsw, $salt, 1))) {

        echo "USER CREATED";
    }


    $db = null;

} catch (PDOException $e){

    echo "Error: " . $e->getMessage();
}


?>

<?php

$servername = "localhost";
$username = "whatever";
$password = "whatever";
$dbname = "whatever";

try {


    $db = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);



    $db->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);


    $stmt = $db->prepare("SELECT * FROM users WHERE username = ?");



    $providedname= $_POST["usrnm"];

    $stmt->execute(array($providedname));

    while($row = $stmt->fetch(PDO::FETCH_OBJ)){

            echo "FOUND USER";

            $hashpsw = hash('sha256', $_POST["providedpass"].$row->salt);

            if($hashpsw == $row->password) {

                        echo "CORRECT CREDENTIALS";

            }





    }

    $db = null;

} catch (PDOException $e){

    echo "Error: " . $e->getMessage();

}
?>

<?php

$servername = "localhost";
$username = "whatever";
$password = "whatever";
$dbname = "whatever";
$charset = 'utf8mb4';

$options = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES   => false,
];
$dsn = "mysql:host=$servername;dbname=$dbname;charset=$charset";
try {
     $db = new PDO($dsn, $username, $password, $options);
} catch (PDOException $e) {
     throw new PDOException($e->getMessage(), (int)$e->getCode());
}

require 'db.php';
$hashpsw = password_hash($_POST["providedpass"],);

$stmt = $db->prepare("INSERT INTO users (username, password, level) VALUES (?,?,?)");
$stmt->execute(array($_POST["usrnm"], $hashpsw, 1));
echo "USER CREATED";

require 'db.php';
$stmt = $db->prepare("SELECT * FROM users WHERE username = ?");
$stmt->execute([$_POST['usrnm']]);
$user = $stmt->fetch();

if ($user && password_verify($_POST['providedpass'], $user['password']))
{
    echo "FOUND USER";
}