How to protect file using user agent in php with script

 

Protecting files based on the user agent in PHP can be a useful security measure to prevent direct access to specific files from unauthorized sources. To achieve this, you can check the user agent of incoming HTTP requests and serve the file only if the user agent matches a predefined value. Here's a sample PHP script that demonstrates how to protect a file based on the user agent:

php
 

<?php
// Define the allowed user agent
$allowedUserAgent = "Your-User-Agent-String"; // Replace with the desired user agent

// Get the user agent from the HTTP request
$userAgent = $_SERVER['HTTP_USER_AGENT'];

// Check if the user agent matches the allowed value
if ($userAgent === $allowedUserAgent) {
    // Serve the protected file
    $fileToProtect = 'protected-file.pdf'; // Replace with the actual file path
    if (file_exists($fileToProtect)) {
        header('Content-Type: application/pdf');
        header('Content-Disposition: inline; filename="protected-file.pdf"');
        readfile($fileToProtect);
    } else {
        echo 'File not found.';
    }
} else {
    // Send a forbidden response
    http_response_code(403);
    echo 'Access Denied';
}
 
 

In this script:

1. Set the $allowedUserAgent variable to the desired user agent string that is allowed to access the protected file. Replace "Your-User-Agent-String" with the actual user agent string.

2. Retrieve the user agent from the HTTP request using $_SERVER['HTTP_USER_AGENT'].

3. Check if the user agent in the request matches the allowed user agent string. If there's a match, the script proceeds to serve the protected file.

4. If the user agent doesn't match the allowed value, the script sends a "403 Forbidden" response, denying access to the protected file.

Make sure to replace "protected-file.pdf" with the actual file path you want to protect.

Keep in mind that user agent strings can be easily spoofed, so this method is not foolproof and should not be the sole security measure for protecting files. Additional security measures, such as proper authentication and authorization, are recommended for more robust protection.

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