php<input 修改

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $username = $_POST['username'];
    $password = $_POST['password'];
    echo "Username: " . $username . "<br>";
    echo "Password: " . $password;
}
?>
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
  Username: <input type="text" name="username"><br>
  Password: <input type="password" name="password"><br>
  <input type="submit">
</form>

<?php
session_start();
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    if ($_POST['token'] == $_SESSION['token']) {
        // 处理表单数据
        unset($_SESSION['token']);
    } else {
        echo "Invalid token!";
    }
}
$token = bin2hex(random_bytes(32));
$_SESSION['token'] = $token;
?>
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
  Username: <input type="text" name="username"><br>
  Password: <input type="password" name="password"><br>
  <input type="hidden" name="token" value="<?php echo $token; ?>">
  <input type="submit">
</form>