167 lines
7.6 KiB
Markdown
167 lines
7.6 KiB
Markdown
# OpenID Connect (OIDC)
|
|
|
|
GoToSocial supports [OpenID Connect](https://openid.net/connect/), which is an identification protocol built on top of [OAuth 2.0](https://oauth.net/2/), an industry standard protocol for authorization.
|
|
|
|
This means that you can connect GoToSocial to an external OIDC provider like [Gitlab](https://docs.gitlab.com/ee/integration/openid_connect_provider.html), [Google](https://cloud.google.com/identity-platform/docs/web/oidc), [Keycloak](https://www.keycloak.org/), or [Dex](https://dexidp.io/) and allow users to sign in to GoToSocial using their credentials for that provider.
|
|
|
|
This is very convenient in the following cases:
|
|
|
|
- You're running multiple services on a platform (Matrix, Peertube, GoToSocial), and you want users to be able to use the same sign in page for all of them.
|
|
- You want to delegate management of users, accounts, passwords etc. to an external service to make admin easier for yourself.
|
|
- You already have a lot of users in an external system and you don't want to have to recreate them all in GoToSocial manually.
|
|
|
|
!!! tip
|
|
If a user doesn't exist yet, login will fail if your IdP doesn't return a non-empty `email` as part of the claims. The email needs to be unique on this instance. Though we use the `sub` claim to associate the external identity with a GtS user, when a user is created it needs an email associated with it.
|
|
|
|
## Settings
|
|
|
|
GoToSocial exposes the following configuration settings for OIDC, shown below with their default values.
|
|
|
|
```yaml
|
|
#######################
|
|
##### OIDC CONFIG #####
|
|
#######################
|
|
|
|
# Config for authentication with an external OIDC provider (Dex, Google, Auth0, etc).
|
|
|
|
# Bool. Enable authentication with external OIDC provider. If set to true, then
|
|
# the other OIDC options must be set as well. If this is set to false, then the standard
|
|
# internal oauth flow will be used, where users sign in to GtS with username/password.
|
|
# Options: [true, false]
|
|
# Default: false
|
|
oidc-enabled: false
|
|
|
|
# String. Name of the oidc idp (identity provider). This will be shown to users when
|
|
# they log in.
|
|
# Examples: ["Google", "Dex", "Auth0"]
|
|
# Default: ""
|
|
oidc-idp-name: ""
|
|
|
|
# Bool. Skip the normal verification flow of tokens returned from the OIDC provider, ie.,
|
|
# don't check the expiry or signature. This should only be used in debugging or testing,
|
|
# never ever in a production environment as it's extremely unsafe!
|
|
# Options: [true, false]
|
|
# Default: false
|
|
oidc-skip-verification: false
|
|
|
|
# String. The OIDC issuer URI. This is where GtS will redirect users to for login.
|
|
# Typically this will look like a standard web URL.
|
|
# Examples: ["https://auth.example.org", "https://example.org/auth"]
|
|
# Default: ""
|
|
oidc-issuer: ""
|
|
|
|
# String. The ID for this client as registered with the OIDC provider.
|
|
# Examples: ["some-client-id", "fda3772a-ad35-41c9-9a59-f1943ad18f54"]
|
|
# Default: ""
|
|
oidc-client-id: ""
|
|
|
|
# String. The secret for this client as registered with the OIDC provider.
|
|
# Examples: ["super-secret-business", "79379cf5-8057-426d-bb83-af504d98a7b0"]
|
|
# Default: ""
|
|
oidc-client-secret: ""
|
|
|
|
# Array of string. Scopes to request from the OIDC provider. The returned values will be used to
|
|
# populate users created in GtS as a result of the authentication flow. 'openid' and 'email' are required.
|
|
# 'profile' is used to extract a username for the newly created user.
|
|
# 'groups' is optional and can be used to determine if a user is an admin based on oidc-admin-groups.
|
|
# Examples: See eg., https://auth0.com/docs/scopes/openid-connect-scopes
|
|
# Default: ["openid", "email", "profile", "groups"]
|
|
oidc-scopes:
|
|
- "openid"
|
|
- "email"
|
|
- "profile"
|
|
- "groups"
|
|
|
|
# Bool. Link OIDC authenticated users to existing ones based on their email address.
|
|
# This is mostly intended for migration purposes if you were running previous versions of GTS
|
|
# which only correlated users with their email address. Should be set to false for most usecases.
|
|
# Options: [true, false]
|
|
# Default: false
|
|
oidc-link-existing: false
|
|
|
|
# Array of string. If the returned ID token contains a 'groups' claim that matches one of the
|
|
# groups in oidc-admin-groups, then this user will be granted admin rights on the GtS instance
|
|
# Default: []
|
|
oidc-admin-groups: []
|
|
```
|
|
|
|
## Behavior
|
|
|
|
When OIDC is enabled on GoToSocial, the default sign-in page redirects automatically to the sign-in page for the OIDC provider.
|
|
|
|
This means that OIDC essentially *replaces* the normal GtS email/password sign-in flow.
|
|
|
|
Due to the way the ActivityPub standard works, you _cannot_ change your username
|
|
after it has been set. This conflicts with the OIDC spec which does not
|
|
guarantee that the `preferred_username` field is stable.
|
|
|
|
To work with this, we ask the user to provide a username on their first login
|
|
attempt. The field for this is pre-filled with the value of the `preferred_username` claim.
|
|
|
|
After authenticating, GtS stores the `sub` claim supplied by the OIDC provider.
|
|
On subsequent authentication attempts, the user is looked up using this claim
|
|
exclusively.
|
|
|
|
This then allows you to change the username on a provider level without losing
|
|
access to your GtS account.
|
|
|
|
### Group membership
|
|
|
|
Most OIDC providers allow for the concept of groups and group memberships in returned claims. GoToSocial can use group membership to determine whether or not a user returned from an OIDC flow should be created as an admin account or not.
|
|
|
|
If the returned OIDC groups information for a user contains membership of the groups configured in `oidc-admin-groups`, then that user will be created/signed in as though they are an admin.
|
|
|
|
## Migrating from old versions
|
|
|
|
If you're moving from an old version of GtS which used the unstable `email`
|
|
claim for unique user identification, you can set the `oidc-link-existing`
|
|
configuration to `true`. If no user can be found for the ID returned by the
|
|
provider, a lookup based on the `email` claim is performed instead. If this
|
|
succeeds, the stable id is added to the database for the matching user.
|
|
|
|
You should only use this for a limited time to avoid malicious account takeover.
|
|
|
|
## Provider Examples
|
|
|
|
### Dex
|
|
|
|
[Dex](https://dexidp.io/) is an open-source OIDC Provider that you can host yourself. The procedure for installing Dex is out of scope for this documentation, but you can check out the Dex docs [here](https://dexidp.io/docs/).
|
|
|
|
Dex is great because it's also written in Go, like GoToSocial, which means it's small and fast and works well on lower-powered systems.
|
|
|
|
To configure Dex and GoToSocial to work together, create the following client under the `staticClients` section of your Dex config:
|
|
|
|
```yaml
|
|
staticClients:
|
|
- id: 'gotosocial_client'
|
|
redirectURIs:
|
|
- 'https://gotosocial.example.org/auth/callback'
|
|
name: 'GoToSocial'
|
|
secret: 'some-client-secret'
|
|
```
|
|
|
|
Make sure to replace `gotosocial_client` with your desired client ID, and `secret` with a reasonably long and secure secret (a UUID for example). You should also replace `gotosocial.example.org` with the `host` of your GtS instance, but leave `/auth/callback` in place.
|
|
|
|
Now, edit the `oidc` section of your GoToSocial config.yaml as follows:
|
|
|
|
```yaml
|
|
oidc:
|
|
enabled: true
|
|
idpName: "Dex"
|
|
skipVerification: false
|
|
issuer: "https://auth.example.org"
|
|
clientID: "gotosocial_client"
|
|
clientSecret: "some-client-secret"
|
|
scopes:
|
|
- "openid"
|
|
- "email"
|
|
- "profile"
|
|
- "groups"
|
|
```
|
|
|
|
Make sure to replace the `issuer` variable with whatever your Dex issuer is set to. This should be the exact URI at which your Dex instance can be reached.
|
|
|
|
Now, restart both GoToSocial and Dex so that the new settings are in place.
|
|
|
|
When you next go to log in to GtS, you should be redirected to the sign in page for Dex. On a successful sign in, you'll be directed back to GoToSocial.
|