The configuration in Authelia is straightforwarded: Tailscale is just another `identity_provider/oidc` entry. Complicating things is the necessary WebFinger reply for your domain - see the following [Application](#application) section.
### Application
To configure [Tailscale] to utilize Authelia as an [OpenID Connect 1.0] Provider, you will need a public WebFinger reply for your domain (see [RFC 7033](https://www.rfc-editor.org/rfc/rfc7033#section-3.1)) and point it to Authelia. The steps necessary are outlined in the Tailscale documentation on [Custom OIDC providers](https://tailscale.com/kb/1240/sso-custom-oidc/). This WebFinger reply is not generated by Authelia, so your external webserver hosted at the root of your domain will need to generate the reponse (Check [See also](#see-also) for example implementations). The following steps are necessary to get Tailscale working with Authelia:
1. Your domain will need to reply to a WebFinger request for your Authelia account
2. Your domain root is `example.com` and the Authelia account in question is `user@example.com`, the WebFinger request will be: `https://example.com/.well-known/webfinger/?resource=acct:user@example.com` (the complete request is `https://example.com/.well-known/webfinger?rel=http%3A%2F%2Fopenid.net%2Fspecs%2Fconnect%2F1.0%2Fissuer&resource=acct%3Auser%40example.com`)
3. The WebFinger request needs to be answered with the following example reply:
4. For any other users that you want to add to Tailscale, you will need to to provide similar WebFinger replies (e.g. for `user2@example.com` or `user3@example.com`)
5. Once you have the WebFinger reply set up and your [Authelia OpenID Connect Discovery endpoint](https://www.authelia.com/integration/openid-connect/introduction/#well-known-discovery-endpoints) is working (e.g. `https://auth.example.com/.well-known/openid-configuration`), you can sign up for a **new Tailnet** (currently migration isn't supported) via the link: [Sign up with OIDC](https://login.tailscale.com/start/oidc) where you will see the following screen:
**Note:** Even though the WebFinger URL displayed is `https://example.com/.well-known/webfinger`, the actual GET request will be including request parameters, most importantly `resource`.
6. After clicking on **Get OIDC Issuer**, Tailscale will fetch the WebFinger reply via `https://example.com/.well-known/webfinger/?resource=acct:user@example.com` and follow the set `href` to `https://auth.example.com/.well-known/openid-configuration`.
7. On the next screen you will need to add your client ID & secret configured in Authelia to finish the OIDC provider registration in [Tailscale]. See the following example screenshot:
The following YAML configuration is an example __Authelia__
[client configuration](../../../configuration/identity-providers/open-id-connect.md#clients) for use with [Tailscale] which
will operate with the above example:
```yaml
identity_providers:
oidc:
## The other portions of the mandatory OpenID Connect 1.0 configuration go here.
## See: https://www.authelia.com/c/oidc
clients:
- id: tailscale
description: Tailscale SSO
secret: '$pbkdf2-sha512$310000$c8p78n7pUMln0jzvd4aK4Q$JNRBzwAo0ek5qKn50cFzzvE9RXV88h1wJn5KGiHrD0YKtZaR/nCb2CJPOsKaPK0hjf.9yHxzQGZziziccp6Yng' # The digest of 'insecure_secret'.
redirect_uris:
- https://login.tailscale.com/a/oauth_response
scopes:
- openid
- email
- profile
```
## See Also
- [Tailscale] [Custom OIDC Provider Knowledge Base entry](https://tailscale.com/kb/1240/sso-custom-oidc/):
- [RFC 7033, Identity Provider Discovery for OpenID Connect](https://www.rfc-editor.org/rfc/rfc7033#section-3.1)
- [WebFinger example implementations](https://webfinger.net/code/)
