This file checks user-entered access codes for validity, granting access if the code is correct, and prompting for re-entry if incorrect.

access_code_verification.php

<?php

// Check if a valid access code has been submitted
if (isset($_POST['access_code'])) {
    $stored_hash = 'a891af9b4934fe765b5778469d1f1f45'; // Replace with your actual MD5 hash
    $entered_code = $_POST['access_code'];
    $entered_hash = md5($entered_code); // Hash the entered code

    if ($entered_hash === $stored_hash) {
        // Display your link
        echo '<a href="https://www.google.com/" target="_blank">Requested link</a>';
        // You can also store access information in session or cookies
    } else {
        // Display error message
        echo 'Incorrect access code. Please try again.';
        // Display the code input form again
        display_code_form();
    }
} else {
    // Display the code input form
    display_code_form();
}

// Function to display the code input form
function display_code_form() {
    ?>
    <form method="post" action="">
        <label for="access_code">Enter access code:</label>
        <input type="text" name="access_code" id="access_code">
        <input type="submit" value="Submit">
    </form>
    <?php
}

?>