Requirement

You should read this documentation to understand the concept of Authentication and Authorization with OIDC and OAuth2 before trying to implement it.

Abstract

In order to create an OIDC client, see 1. Registering an OIDC client. After creating the OIDC client, you have a corresponding access token and secret.

For the example below, we consider the case of someone wanting to provide access to https://www.getpostman.com as an app for Collaboratory users to access from their collabs. You should replace that URL by the one of your own app.

The redirect_uri is set with the URL of your application to which your users will be redirected after having been authenticated by their EBRAINS account. For example when you login to this wiki, the redirect URI is https://wiki.ebrains.eu/*

The whole authentication flow presented here is based on the official OAuth2 RFC described in the section 4.1.

https://tools.ietf.org/html/rfc6749#section-4.1

Authentication flow

Authorization Code Request

The first step of the authentication protocol is to fetch an authorization code for your client and your user. This is done by directing your users to the URL of the EBRAINS login page (IAM) where they can enter their username and password.

Request

The authorization code is fetched by an HTTP request:

/GET: https://iam.ebrains.eu/auth/realms/hbp/protocol/openid-connect/auth

with the following parameters:

• response_type=code
• login=true
• client_id=community-apps-tutorial
• redirect_uri=https://www.getpostman.com/oauth2/callback
• scope=openid+group+team

with the italics indicating the fields you customize for your own app. The URL will look like:

https://iam.ebrains.eu/auth/realms/hbp/protocol/openid-connect/auth?response_type=code&login=true&client_id=community-apps-tutorial&redirect_uri=https://www.getpostman.com/oauth2/callback&scope=openid+group+team

The scope parameter can include a combination of several values. Each user will be asked to consent to sharing that scope with your app upon first access.

• openid: This scope is required because we use the OIDC protocol. It will give your app access to the user's basic information such as username, email and full name.
• profile (optional): More information on user if provided by the user
• email (optional): The verified email of the user, should be add in addition of openid and/or profile to get the email.
• group (optional): If you request this scope, the future access token generated will authorize your app to identify which units and groups the user belongs to.
• team (optional): This scope is like the group scope lets your app identify the permissions of the user, but by identifying what collabs the user has access to and with what roles.
• clb.wiki.read (optional): access to GET Collab API
• clb.wiki.write (optional): access to DELETE/PUT/POST Collab API
• collab.drive (optional): access to GET/POST/PUT/DELETE drive API
• offline_access (optional): provide refresh token
• quota : User's quota usage around EBRAINS services

The group and team scopes are a simple way for your app to grant permissions to its services and resources when you want to grant access to a very few units, groups, or collab teams. For more complex permission management, contact support.

Response

Once the user has logged in, your app gets an HTTP 301 redirection followed by an HTTP 200 success response with an authorization code inside. A typical response might look like:

https://www.getpostman.com/oauth2/callback?session_state=a0ff8a68-2654-43ef-977a-6c15ce343546&code=f3f04f93-hbp-482d-ac3d-demo.turtorial.7122c1d9-3f7e-4d80-9c4f-dcd244bc2ec7

The authorization code is the part in bold in the response above.

Access Token Request

Now that your app has the authorization code for a user, it can fetch the user ID Token and Access Token

Request

/POST: https://iam.ebrains.eu/auth/realms/hbp/protocol/openid-connect/token

with the following parameters:

• grant_type: authorization_code
• code: f3f04f93-hbp-482d-ac3d-demo.turtorial.7122c1d9-3f7e-4d80-9c4f-dcd244bc2ec7
• redirect_uri: https://www.getpostman.com/oauth2/callback
• client_id: community-apps-tutorial
• client_secret: your client secret obtained during client creation

The image below shows a sample POST request generated from the Postman tool. [The fact that this page is based on getpostman.com as an example is pure coincidence.]

Response

200 OK

{
    "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCIgOiAi...pP5vaNwvvsaNGEA",
    "expires_in": 604773,
    "refresh_expires_in": 604773,
    "refresh_token": "eyJh...vC5eIR1rNhRJ4d8",
    "token_type": "bearer",
    "id_token": "eyJ...YOwdQ",
    "not-before-policy": 0,
    "session_state": "76e553bf-ba2e-45b6-8c6c-c867772b40ec",
    "scope": "openid"
}

Your app gets a response containing the access token, the refresh token, the id token and other information. The ID Token should be use by developer on their backend to read user informations such as username, first name, last name etc. The ID Token should be use internally, into your app only, the app which triggered the authentication. The access token will be use to reach APIs, the access token can be see as a card to access an ATM. ID Token is for Authentication, Access token is for Authorization. Refresh token is to re-ask a valid access token after expiration.

Access user info

Now that your app has the access token of a user, it can fetch the user's info.

Request

/GET: https://iam.ebrains.eu/auth/realms/hbp/protocol/openid-connect/userinfo

with the following parameters:

• Authorization: the access token preceded by the string "Bearer "

The image below shows a sample GET request generated from the Postman tool. [The fact that this page is based on getpostman.com as an example is pure coincidence.]

Response

As response your app receives a JSON with all the information about the logged user

{
"sub": "fa2db206-3...0ebaba98e1",
  "preferred_username": "demoaccount",
    "unit": [
        "/all/institutions/switzerland/epfl",
        "/all/projects/hbp/consortium/SGA2/SP05",
        "/all/projects/hbp/consortium/SGA3/WP6/T6_11"
    ],
    "roles": {
        "jupyterhub": [
            "feature:authenticate"
        ],
        "xwiki": [
            "feature:authenticate"
        ],
        "team": [
            "collab-collaboratory-community-apps-editor"
        ],
        "group": [
            "group-collaboratory-developers",
            "unit-all-projects-hbp-consortium-sga2-sp05-administrator"
        ]
    },
    "mitreid-sub": "30...62"
}

The unit field above lists Collaboratory Units which the user is a member of, with the unit name using slashes instead of the colons you see in the Collaboratory UI.

jupyterhub and xwiki are OIDC clients with more advanced permission management.

The team field above lists Collaboratory Teams which the user is a member of, in the form "collab-collabname-role" where role is one of admin, editor, or viewer according to the user's role in collab collabname.

The group field above lists Collaboratory Groups which the user is a member of, in the form "group-groupname". It also lists Collaboratory Units which the user is an admin of, in the form "unit-unitname-administrator" with unitname using dashes instead of the colons you see in the Collaboratory UI.

Which unique identifier should you use for your users

We recommand you to use the "preferred_username" field (which is the username) to identify your users for every new users in your system. The "preferred_username*" is used by us as unique identifier in The Collaboratory, it's really friendly to use it and interact easily with our IDM Api. We are guaranting its unicity.

You can also use the "sub" provided by keycloak which is the OIDC/OAuth2 standard unique identifier for a user and might be consider as the good choice. If in addition you store the username associate to the sub you will still be able to use easily our IDM Api, if not you will maybe need to perform one more request to get the User object from your sub in the IDM Api

You can found additional information about userinfo fields and difference with previous Collaboratory 1 here.

OIDC Plugin configuration exemple

You will probably not reinvent the wheel and use an existing OIDC Library to establish the authentication. Often theses libary do all the above flow for you, you just have to fill a properties file.

OIDC Plugin Properties : Usefull link

All the link you need to know to fill the property file of your OIDC plugin are visibles here

https://iam.ebrains.eu/auth/realms/hbp/.well-known/openid-configuration

OIDC Plugin for Python : mozilla-django-oidc

We are using this plugin with our Django based project, a full documentation is available here
https://mozilla-django-oidc.readthedocs.io/en/stable/installation.html

Github demo project using mozilla-django-oidc
https://github.com/HumanBrainProject/mozilla-django-oidc-demo

You can found a very basic empty Django project using mozilla-django-oidc on this github. Clone it and follow the README instruction. In few minutes if you already have a clientId and clientSecret available you should be able to login in this demo application. Once you validated that your client works well, you can compare with your own code and debug your own code to made the login works.

In the future, I will add some branch in this project with advanced usage exemple as overriding default mozilla-django-oidc class and fetch team and groups/units of a user.

For now, you can found more advanced usage in the CodeJam#12 presentation

https://drive.ebrains.eu/lib/cf5b0375-4e07-4e62-847d-e2997eac3f30/file/CodeJam%20%2312%20(2021)/Presentations/Oidc_integration_for_python.pptx

You can see every function of the original mozilla-django-oidc on their github, so you can better understand what you can override and how

https://github.com/mozilla/mozilla-django-oidc/blob/master/mozilla_django_oidc/auth.py

mozilla-django-oidc sample config

OIDC Plugin for Python : flask-oidc

https://flask-oidc.readthedocs.io/en/latest/

You will need at the root of your project a "client_secrets.json" file.

client_secrets.json