Registering OAuth2 Client Credentials¶
The Raven OAuth2 service allows websites to authenticate using the OAuth2 protocol. In order to make use of the OAuth2 protocol you will need to register some client credentials.
The user experience for Raven OAuth2 may differ from the user experience shown by legacy Raven services. In particular users will be asked for consent on the first sign in. Please see the notice to IT professionals on the UIS website for more information.
OAuth2 requires that an application authenticating a user identify itself to the authentication service. Client credentials are the way in which your website identifies itself to Raven when requesting user sign in.
Client credentials consist of two parts. The client id, sometimes called the client key, is the equivalent of a username identifying your application. The client secret is the equivalent of a password. As the name suggests, it should be kept secret.
Google account types¶
Raven makes use of OAuth2 client credentials managed by Google. There are, somewhat confusingly, several forms of identity in the Google ecosystem:
An ordinary Google account is the sort of Google account you can register for free at https://google.com/. All that you need to register an ordinary Google account is the ability to receive email. An ordinary Google account is associated with an email address.
A Google Workspace account is like an ordinary Google account but (for the University of Cambridge tenacy) the associated email address ends in
@cam.ac.uk. Google Workspace accounts use Raven to authenticate rather than giving a password to Google. A Google Workspace account is associated with a single individual.
A service account is an account associated with a particular “project” in Google’s Cloud console. They are not associated with individuals. They do have email addresses associated with them which end with
.gserviceaccount.com. There is no mailbox behind the email address associated with service accounts.
Which account to use¶
In order to register new OAuth2 client credentials you will need to create a project in Google Cloud. Which account you use to create this account depends on the purpose of the site.
If the website you are configuring is an official University (not College) site and you are a member of staff (marked as 'staff' in Lookup) then you will be able to create projects using your CRSid@cam.ac.uk Google Workspace account.
If it does not already exist, a folder for your institution in the
cam.ac.uk Google Cloud organisation will need creating (by request to firstname.lastname@example.org). You can tell if this is the case by signing in to the Cloud Resource Manager (with your CRSid@cam.ac.uk account) and looking for an appropriately named institution folder under the
cam.ac.uk > Institutions folder.
Enable Google Cloud Platform
Depending on what they're doing, Google Workspace users may have to opt in to Google Cloud Platform for their account.
If the website you are configuring is a College site, for experimenting or for any personal reason, then you will need to create an ordinary Google account (or use an existing one). We strongly recommend that you create a shared ordinary Google account for a role address. For example, the COs of St Botolph's college would create a Google account for
email@example.com and store the credentials like they do with any other shared secrets. By using a role address, you can have some confidence that access to the Google account can be recovered in future as people join or leave your team.
Create a Google project¶
Once you've determined which account to use, sign in, open the Google Cloud console and create a new project for your service; click Select a project, then NEW PROJECT, enter a name for the project and, optionally, edit the provided project ID. For projects in the
cam.ac.uk Organisation make sure that is selected and change the Location to your institutional folder (or create a subfolder in that folder first). Finally click Create.
You will first need to add an initial set of administrators:
- Navigate to the IAM page of the Google developer console for your project.
- Use the Add button at the top of the page to add Lookup groups to the project and give them the Project Owner role (only the Project Editor role is permitted for projects outside the
cam.ac.ukorganisation). Lookup groups are identified via the email address
[groupid]is the numeric group id for the group visible on the Lookup page for that group. Alternatively, members may be added individually via their
- If logged in with an ordinary Google account, sign out and proceed using one of the Google Workspace accounts you just added as editor to the project (via Lookup group or individually).
All project administration should now be done as a Google Workspace user
It is best practice to use a shared ordinary Google account sparingly. As people join or leave your team, their corresponding Google Workspace user can be added or removed to the set of project editors, ideally by simple Lookup group membership.
Sign in details for the shared ordinary account should be kept securely for disaster recovery purposes or for adding project editors if all existing project editors are unavailable.
Create the client credentials¶
Once you have a new Google project, you can create some OAuth2 client credentials for your first application.
- Open the Google API Console Credentials page.
- On the Credentials page, select Create credentials, then OAuth client ID.
- You may be prompted to set a product name on the Consent screen; if so, click Configure consent screen and supply the information requested on that page. Projects created within the
cam.ac.ukorganisation should use "Internal", those outside the organisation ("No Organisation" in Google terms) should use "External" user authentication. You will also need to add the domain name of any websites providing Raven OAuth2 sign in, and set the Authorised Domain to "cam.ac.uk".
Leave the set of scopes as the default set. Click "Save" to return to the Credentials screen.
- Click Create.
- On the page that appears, make a note of the client ID and client secret. You will need them to configure your site.
Changing the support email address
When configuring the Consent screen, you can only select yourself as the support email address. It may be necessary to sign in with an ordinary Google account (creating first if not already done above) to edit this. If this isn't the account used to create the project then you will need at add the account as a Project Editor beforehand.