Integrate with Matrix Synapse

What is Matrix Synapse

Matrix is an open source project that publishes the Matrix open standard for secure, decentralized, real-time communication, and its Apache licensed reference implementations.

-- https://matrix.org/

Preparation

The following placeholders are used in this guide:

• matrix.company is the FQDN of the Matrix installation.
• authentik.company is the FQDN of the authentik installation.

:::info This documentation lists only the settings that you need to change from their default values. Be aware that any changes other than those explicitly mentioned in this guide could cause issues accessing your application. :::

authentik configuration

To support the integration of Matrix Synapse with authentik, you need to create an application/provider pair in authentik.

Create an application and provider in authentik

1. Log in to authentik as an administrator and open the authentik Admin interface.
2. Navigate to Applications > Applications and click Create with Provider to create an application and provider pair. (Alternatively you can first create a provider separately, then create the application and connect it with the provider.)

• Application: provide a descriptive name, an optional group for the type of application, the policy engine mode, and optional UI settings.
• Choose a Provider type: select OAuth2/OpenID Connect as the provider type.
• Configure the Provider: provide a name (or accept the auto-provided name), the authorization flow to use for this provider, and the following required configurations.
  • Note the Client ID, Client Secret, and slug values because they will be required later.
  • Set a Strict redirect URI to https://matrix.company/_synapse/client/oidc/callback.
  • Select any available RSA signing key. Matrix Synapse doesn't support ECC keys.
  • Do not set an encryption key because this is not supported by Matrix Synapse.
• Configure Bindings (optional): you can create a binding (policy, group, or user) to manage the listing and access to applications on a user's My applications page.

3. Click Submit to save the new application and provider.

Matrix configuration

Add the following block to your Matrix config

:::info For more info, see https://matrix-org.github.io/synapse/latest/openid.html?highlight=authentik#authentik :::

oidc_providers:
    - idp_id: authentik
      idp_name: authentik
      discover: true
      issuer: "https://authentik.company/application/o/<application_slug>/"
      client_id: "*client_ID*"
      client_secret: "*client_secret*"
      scopes:
          - "openid"
          - "profile"
          - "email"
      user_mapping_provider:
          config:
              localpart_template: "{{ user.preferred_username }}"
              display_name_template: "{{ user.name|capitalize }}"
[...]
jwt_config:
    enabled: true
    secret: "*client_secret*"
    algorithm: "RS256"