README

redirecttoken

PHP Package to generate tokens for validating redirections

Description

Track clicks to external links on your site by linking to a local file that handles redirection.

From

<a href="https://someothersite.com/">Click me</a>

<a href="/redirect?uri=<remoteurl>&token=<validationtoken>">Click me</a>

This package provides the means to generate a validation token so that unscrupulous bots don't use your redirect as a redirect for nefarious means.

Installation

• Add the paclage to composer with the following

  composer require alasdairkeyes/redirecttoken
  

Example

Generate Token for URL to redirect

    # Or any other Class that implements Psr\Http\Message\UriInterface
use GuzzleHttp\Psr7\Uri;
use RedirectToken\Generator;

$secretKey = 'fgsdkjghsekugkserg';
$uriDestination = new Uri('https://www.google.co.uk/');

// Instantiate token generator and create token
$generator = new Generator($secretKey);
$token = $generator->generateToken($uriDestination);

$validRedirectUri = 'redirect.php?' . http_build_query([ 'uri' => (string)$uriDestination, 'token' => $token ], '', '&');

// Output
print '<a href="' . $validRedirectUri . '">Valid redirect</a>' . PHP_EOL;

Validate Token

    # Or any other Class that implements Psr\Http\Message\UriInterface
use GuzzleHttp\Psr7\Uri;
use RedirectToken\Validator;

// Parse the URI Query
parse_str($_SERVER["QUERY_STRING"], $q);

$redirectUri = new Uri($q['uri']);
$token = $q['token'];

// Instantiate validator
$validator = new Validator($secretKey);

if ($validator->validateUriToken($redirectUri, $token)) {
    header('Location: ' . $redirectUri, true, 302);
} else {
    print "Invalid request";
}

Prebuilt

If you've cloned the repository, you can test with PHP's builtin webserver

cd example
php -S localhost:8080

Goto localhost:8080 in a web browser

Changelog

• 2018-12-18 :: 1.0.0 :: Move to stable release
• 2017-10-29 :: 0.1.0 :: First Release

Site

https://gitlab.com/alasdairkeyes/redirecttoken

Author

• Alasdair Keyes - https://akeyes.co.uk/

License

Released under GPL V3 - See included license file.