Identity Service

Introduction

The LFS Identity Service -based on Oauth2- allows you to integrate LFS user authentication into your own website and / or use the LFS API. Both purposes are often used together; your website can authenticate an LFS user visiting your own website to perform actions on your website, on behalf of the LFS user. These actions are performed using the LFS API. Though you can also use the LFS API alone via (back end) scripts, to fetch and / or update information related to your own LFS account.

You can find many explanations and further details about Oauth2 on the internet. A good introduction for example is the one from Digital Ocean.

The Application

In order to use the LFS Identity Service you must always register a so called Application. An Application is a record of your website or script that will perform LFS User authentication.

You must have at least one Application, but it is possible to register multiple Applications used for different purposes.

You can register your Applications at https://www.lfs.net/account/api

An Application is always required for Oauth2 authentications, one for each grant type (or flow) you will be using.

An Application must have a name and one redirect uri pointing to a callback endpoint on your website where authenticated users will return to after authentication. A redirect uri is also required even if you only use the LFS API for your own (back end) purposes. In that case you can enter a fictional redirect uri.

Once your Application is registered, you will receive a Client ID and a Client Secret that you must store in order to perform Identity Authentications later on. Note that the Client Secret will only be shown to you once, after Application registration.

Authentication Grant Types

There are 2 authorization grant types that can be used. Which you should use depends on your use case:

• Authorization Code Grant, used with server-side applications or websites
• Authorization Code Grant with Proof Key for Code Exchange (PKCE), used with Single Page Applications
• Client Credentials Grant, used with back end scripts

Server Side Application

If you have your own server side website or application (e.g. back end driven with PHP) where you want to allow your users to login using their own LFS credentials or just confirm their LFS identity to e.g. sign them up for races, you must use this grant type. You will also have the option of accessing certain information of these LFS accounts by using scopes during the authentication process.

For this purpose you should use the Authorization Code Grant.

How does that work?

... stuffs here ...

Single Page Application

If you have your own javascript driven website or application where you want to allow your users to login using their own LFS credentials or just confirm their LFS identity to e.g. sign them up for races, you must use this grant type. You will also have the option of accessing certain information of these LFS accounts by using scopes during the authentication process.

For this purpose you should use the Authorization Code Grant with PKCE.

How does that work?

... stuffs here ...

• https://id.lfs.net/oauth2/authorize?response_type=code&client_id=CLIENT_ID&redirect_uri=REDIRECT_URI&scope=openid%20profile&state=CSRFTOKEN
• receive redirect URI (goes to lfs.net's login page)
• client logs in if not already logged in
• client must accept scopes requested by Application
• client is redirected to id.lfs.net one final time
• client is redirected to Application redirect URI

Back End Scripting

For this purpose you should use the Client Credentials Grant.

How does that work?

... stuffs here ...

• POST to https://id.lfs.net/oauth2/access_token
  • grant_type => 'client_credentials',
  • client_id => 'CLIENT_ID',
  • client_secret => 'CLIENT_SECRET',
• receive access token immediately

Authentication Scopes

Scope information here.

Refresh Token Flow

... stuffs here ... normally used only with the Authorization Code Grant because for the Client Credentials Grant type you can simply perform a new Access Token request.

Usage Examples

examples (are these needed? Maybe the grant explanations above should be enough - I don't think I should start providing actual code examples here - there are plenty available out on the nets.)

Single Page Applications

example here

Back End Scripting

example here