README

A very minimalistic OpenID implementation that hardcodes it for Steam only, as using a generic OpenID library may do unnecessary steps of “discovering” OpenID servers, which will end up leaking your origin server address, and worse, leave your website open to vulnerabilities of claiming wrong Steam profiles if the implementation is bugged.

The described problems are not theoretical, LightOpenID has been proven to have implementation problems, and even if you use validate and use regex on the final identity it can be spoofed and a third-party server can be used to pass the validation.

This library aims to avoid these problems by implementing the bare minimum functionality required for validating Steam OpenID requests against the hardcoded Steam server. This library only implements validation, you will need to implement Steam WebAPI calls yourself to fetch user profile information.

Before using this library, please read Valve's terms here.

Installation

composer require xpaw/steam-openid

See Example.php file for example usage.

Basic usage

use xPaw\Steam\SteamOpenID;

$SteamOpenID = new SteamOpenID( $ReturnToUrl );

if( $SteamOpenID->ShouldValidate() )
{
	try
	{
		$CommunityID = $SteamOpenID->Validate();
		echo 'Logged in as ' . $SteamID;
	}
	catch( Exception $e )
	{
		echo 'Login failed';
	}
}
else
{
	header( 'Location: ' . $SteamOpenID->GetAuthUrl() );
}

If you want to parse SteamIDs, take a look at SteamID.php.

Advanced usage

Passing GET parameters manually

If you need to pass request parameters manually instead of using $_GET, you can provide them in the constructor:

$params = [
	'openid_mode' => $_GET['openid_mode'] ?? null,
	// etc...
];

$SteamOpenID = new SteamOpenID( $ReturnToUrl, $params );

Custom HTTP client

If you need to customize the HTTP request to Steam (e.g., using a different HTTP client, adding proxies, or custom timeouts), you can override the SendSteamRequest method:

class CustomSteamOpenID extends SteamOpenID
{
	public function SendSteamRequest( array $Arguments ) : array
	{
		// Use your preferred HTTP client here
		$httpClient = new YourHttpClient();

		$response = $httpClient->post( self::SERVER, [
			'form_params' => $Arguments,
			'timeout' => 10,
			'headers' => [
				'User-Agent' => 'Your Custom User Agent'
			]
		] );

		// array(http code as int, response as string)
		return [ $response->getStatusCode(), $response->getBody() ];
	}
}

$SteamOpenID = new CustomSteamOpenID( $ReturnToUrl );