# Configuring Synapse to authenticate against an OpenID Connect provider Synapse can be configured to use an OpenID Connect Provider (OP) for authentication, instead of its own local password database. Any OP should work with Synapse, as long as it supports the authorization code flow. There are a few options for that: - start a local OP. Synapse has been tested with [Hydra][hydra] and [Dex][dex-idp]. Note that for an OP to work, it should be served under a secure (HTTPS) origin. A certificate signed with a self-signed, locally trusted CA should work. In that case, start Synapse with a `SSL_CERT_FILE` environment variable set to the path of the CA. - set up a SaaS OP, like [Google][google-idp], [Auth0][auth0] or [Okta][okta]. Synapse has been tested with Auth0 and Google. It may also be possible to use other OAuth2 providers which provide the [authorization code grant type](https://tools.ietf.org/html/rfc6749#section-4.1), such as [Github][github-idp]. [google-idp]: https://developers.google.com/identity/protocols/oauth2/openid-connect [auth0]: https://auth0.com/ [okta]: https://www.okta.com/ [dex-idp]: https://github.com/dexidp/dex [keycloak-idp]: https://www.keycloak.org/docs/latest/server_admin/#sso-protocols [hydra]: https://www.ory.sh/docs/hydra/ [github-idp]: https://developer.github.com/apps/building-oauth-apps/authorizing-oauth-apps ## Preparing Synapse The OpenID integration in Synapse uses the [`authlib`](https://pypi.org/project/Authlib/) library, which must be installed as follows: * The relevant libraries are included in the Docker images and Debian packages provided by `matrix.org` so no further action is needed. * If you installed Synapse into a virtualenv, run `/path/to/env/bin/pip install matrix-synapse[oidc]` to install the necessary dependencies. * For other installation mechanisms, see the documentation provided by the maintainer. To enable the OpenID integration, you should then add an `oidc_config` section to your configuration file (or uncomment the `enabled: true` line in the existing section). See [sample_config.yaml](./sample_config.yaml) for some sample settings, as well as the text below for example configurations for specific providers. ## Sample configs Here are a few configs for providers that should work with Synapse. ### [Dex][dex-idp] [Dex][dex-idp] is a simple, open-source, certified OpenID Connect Provider. Although it is designed to help building a full-blown provider with an external database, it can be configured with static passwords in a config file. Follow the [Getting Started guide](https://dexidp.io/docs/getting-started/) to install Dex. Edit `examples/config-dev.yaml` config file from the Dex repo to add a client: ```yaml staticClients: - id: synapse secret: secret redirectURIs: - '[synapse public baseurl]/_synapse/oidc/callback' name: 'Synapse' ``` Run with `dex serve examples/config-dev.yaml`. Synapse config: ```yaml oidc_config: enabled: true skip_verification: true # This is needed as Dex is served on an insecure endpoint issuer: "http://127.0.0.1:5556/dex" client_id: "synapse" client_secret: "secret" scopes: ["openid", "profile"] user_mapping_provider: config: localpart_template: "{{ user.name }}" display_name_template: "{{ user.name|capitalize }}" ``` ### [Keycloak][keycloak-idp] [Keycloak][keycloak-idp] is an opensource IdP maintained by Red Hat. Follow the [Getting Started Guide](https://www.keycloak.org/getting-started) to install Keycloak and set up a realm. 1. Click `Clients` in the sidebar and click `Create` 2. Fill in the fields as below: | Field | Value | |-----------|-----------| | Client ID | `synapse` | | Client Protocol | `openid-connect` | 3. Click `Save` 4. Fill in the fields as below: | Field | Value | |-----------|-----------| | Client ID | `synapse` | | Enabled | `On` | | Client Protocol | `openid-connect` | | Access Type | `confidential` | | Valid Redirect URIs | `[synapse public baseurl]/_synapse/oidc/callback` | 5. Click `Save` 6. On the Credentials tab, update the fields: | Field | Value | |-------|-------| | Client Authenticator | `Client ID and Secret` | 7. Click `Regenerate Secret` 8. Copy Secret ```yaml oidc_config: enabled: true issuer: "https://127.0.0.1:8443/auth/realms/{realm_name}" client_id: "synapse" client_secret: "copy secret generated from above" scopes: ["openid", "profile"] ``` ### [Auth0][auth0] 1. Create a regular web application for Synapse 2. Set the Allowed Callback URLs to `[synapse public baseurl]/_synapse/oidc/callback` 3. Add a rule to add the `preferred_username` claim.
Code sample ```js function addPersistenceAttribute(user, context, callback) { user.user_metadata = user.user_metadata || {}; user.user_metadata.preferred_username = user.user_metadata.preferred_username || user.user_id; context.idToken.preferred_username = user.user_metadata.preferred_username; auth0.users.updateUserMetadata(user.user_id, user.user_metadata) .then(function(){ callback(null, user, context); }) .catch(function(err){ callback(err); }); } ```
Synapse config: ```yaml oidc_config: enabled: true issuer: "https://your-tier.eu.auth0.com/" # TO BE FILLED client_id: "your-client-id" # TO BE FILLED client_secret: "your-client-secret" # TO BE FILLED scopes: ["openid", "profile"] user_mapping_provider: config: localpart_template: "{{ user.preferred_username }}" display_name_template: "{{ user.name }}" ``` ### GitHub GitHub is a bit special as it is not an OpenID Connect compliant provider, but just a regular OAuth2 provider. The [`/user` API endpoint](https://developer.github.com/v3/users/#get-the-authenticated-user) can be used to retrieve information on the authenticated user. As the Synaspse login mechanism needs an attribute to uniquely identify users, and that endpoint does not return a `sub` property, an alternative `subject_claim` has to be set. 1. Create a new OAuth application: https://github.com/settings/applications/new. 2. Set the callback URL to `[synapse public baseurl]/_synapse/oidc/callback`. Synapse config: ```yaml oidc_config: enabled: true discover: false issuer: "https://github.com/" client_id: "your-client-id" # TO BE FILLED client_secret: "your-client-secret" # TO BE FILLED authorization_endpoint: "https://github.com/login/oauth/authorize" token_endpoint: "https://github.com/login/oauth/access_token" userinfo_endpoint: "https://api.github.com/user" scopes: ["read:user"] user_mapping_provider: config: subject_claim: "id" localpart_template: "{{ user.login }}" display_name_template: "{{ user.name }}" ``` ### [Google][google-idp] 1. Set up a project in the Google API Console (see https://developers.google.com/identity/protocols/oauth2/openid-connect#appsetup). 2. add an "OAuth Client ID" for a Web Application under "Credentials". 3. Copy the Client ID and Client Secret, and add the following to your synapse config: ```yaml oidc_config: enabled: true issuer: "https://accounts.google.com/" client_id: "your-client-id" # TO BE FILLED client_secret: "your-client-secret" # TO BE FILLED scopes: ["openid", "profile"] user_mapping_provider: config: localpart_template: "{{ user.given_name|lower }}" display_name_template: "{{ user.name }}" ``` 4. Back in the Google console, add this Authorized redirect URI: `[synapse public baseurl]/_synapse/oidc/callback`. ### Twitch 1. Setup a developer account on [Twitch](https://dev.twitch.tv/) 2. Obtain the OAuth 2.0 credentials by [creating an app](https://dev.twitch.tv/console/apps/) 3. Add this OAuth Redirect URL: `[synapse public baseurl]/_synapse/oidc/callback` Synapse config: ```yaml oidc_config: enabled: true issuer: "https://id.twitch.tv/oauth2/" client_id: "your-client-id" # TO BE FILLED client_secret: "your-client-secret" # TO BE FILLED client_auth_method: "client_secret_post" user_mapping_provider: config: localpart_template: "{{ user.preferred_username }}" display_name_template: "{{ user.name }}" ``` ### GitLab 1. Create a [new application](https://gitlab.com/profile/applications). 2. Add the `read_user` and `openid` scopes. 3. Add this Callback URL: `[synapse public baseurl]/_synapse/oidc/callback` Synapse config: ```yaml oidc_config: enabled: true issuer: "https://gitlab.com/" client_id: "your-client-id" # TO BE FILLED client_secret: "your-client-secret" # TO BE FILLED client_auth_method: "client_secret_post" scopes: ["openid", "read_user"] user_profile_method: "userinfo_endpoint" user_mapping_provider: config: localpart_template: '{{ user.nickname }}' display_name_template: '{{ user.name }}' ```