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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 and Dex. 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, Auth0 or 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, such as Github.
Preparing Synapse
The OpenID integration in Synapse uses the
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 a section to the oidc_providers
setting in your configuration file (or uncomment one of the existing examples).
See 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.
Microsoft Azure Active Directory
Azure AD can act as an OpenID Connect Provider. Register a new application under
App registrations in the Azure AD management console. The RedirectURI for your
application should point to your matrix server: [synapse public baseurl]/_synapse/oidc/callback
Go to Certificates & secrets and register a new client secret. Make note of your
Directory (tenant) ID as it will be used in the Azure links.
Edit your Synapse config file and change the oidc_config
section:
oidc_providers:
- idp_id: microsoft
idp_name: Microsoft
issuer: "https://login.microsoftonline.com/<tenant id>/v2.0"
client_id: "<client id>"
client_secret: "<client secret>"
scopes: ["openid", "profile"]
authorization_endpoint: "https://login.microsoftonline.com/<tenant id>/oauth2/v2.0/authorize"
token_endpoint: "https://login.microsoftonline.com/<tenant id>/oauth2/v2.0/token"
userinfo_endpoint: "https://graph.microsoft.com/oidc/userinfo"
user_mapping_provider:
config:
localpart_template: "{{ user.preferred_username.split('@')[0] }}"
display_name_template: "{{ user.name }}"
Dex
Dex 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 to install Dex.
Edit examples/config-dev.yaml
config file from the Dex repo to add a client:
staticClients:
- id: synapse
secret: secret
redirectURIs:
- '[synapse public baseurl]/_synapse/oidc/callback'
name: 'Synapse'
Run with dex serve examples/config-dev.yaml
.
Synapse config:
oidc_providers:
- idp_id: dex
idp_name: "My Dex server"
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 is an opensource IdP maintained by Red Hat.
Follow the Getting Started Guide to install Keycloak and set up a realm.
-
Click
Clients
in the sidebar and clickCreate
-
Fill in the fields as below:
Field | Value |
---|---|
Client ID | synapse |
Client Protocol | openid-connect |
- Click
Save
- 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 |
- Click
Save
- On the Credentials tab, update the fields:
Field | Value |
---|---|
Client Authenticator | Client ID and Secret |
- Click
Regenerate Secret
- Copy Secret
oidc_providers:
- idp_id: keycloak
idp_name: "My KeyCloak server"
issuer: "https://127.0.0.1:8443/auth/realms/{realm_name}"
client_id: "synapse"
client_secret: "copy secret generated from above"
scopes: ["openid", "profile"]
user_mapping_provider:
config:
localpart_template: "{{ user.preferred_username }}"
display_name_template: "{{ user.name }}"
Auth0
-
Create a regular web application for Synapse
-
Set the Allowed Callback URLs to
[synapse public baseurl]/_synapse/oidc/callback
-
Add a rule to add the
preferred_username
claim.Code sample
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:
oidc_providers:
- idp_id: auth0
idp_name: Auth0
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
can be used to retrieve information on the authenticated user. As the Synapse
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.
- Create a new OAuth application: https://github.com/settings/applications/new.
- Set the callback URL to
[synapse public baseurl]/_synapse/oidc/callback
.
Synapse config:
oidc_providers:
- idp_id: github
idp_name: Github
idp_brand: "org.matrix.github" # optional: styling hint for clients
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 }}"
- Set up a project in the Google API Console (see https://developers.google.com/identity/protocols/oauth2/openid-connect#appsetup).
- add an "OAuth Client ID" for a Web Application under "Credentials".
- Copy the Client ID and Client Secret, and add the following to your synapse config:
oidc_providers: - idp_id: google idp_name: Google idp_brand: "org.matrix.google" # optional: styling hint for clients 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 }}"
- Back in the Google console, add this Authorized redirect URI:
[synapse public baseurl]/_synapse/oidc/callback
.
Twitch
- Setup a developer account on Twitch
- Obtain the OAuth 2.0 credentials by creating an app
- Add this OAuth Redirect URL:
[synapse public baseurl]/_synapse/oidc/callback
Synapse config:
oidc_providers:
- idp_id: twitch
idp_name: Twitch
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
- Create a new application.
- Add the
read_user
andopenid
scopes. - Add this Callback URL:
[synapse public baseurl]/_synapse/oidc/callback
Synapse config:
oidc_providers:
- idp_id: gitlab
idp_name: Gitlab
idp_brand: "org.matrix.gitlab" # optional: styling hint for clients
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 }}'
Like Github, Facebook provide a custom OAuth2 API rather than an OIDC-compliant one so requires a little more configuration.
- You will need a Facebook developer account. You can register for one here.
- On the apps page of the developer console, "Create App", and choose "Build Connected Experiences".
- Once the app is created, add "Facebook Login" and choose "Web". You don't need to go through the whole form here.
- In the left-hand menu, open "Products"/"Facebook Login"/"Settings".
- Add
[synapse public baseurl]/_synapse/oidc/callback
as an OAuth Redirect URL.
- Add
- In the left-hand menu, open "Settings/Basic". Here you can copy the "App ID" and "App Secret" for use below.
Synapse config:
- idp_id: facebook
idp_name: Facebook
idp_brand: "org.matrix.facebook" # optional: styling hint for clients
discover: false
issuer: "https://facebook.com"
client_id: "your-client-id" # TO BE FILLED
client_secret: "your-client-secret" # TO BE FILLED
scopes: ["openid", "email"]
authorization_endpoint: https://facebook.com/dialog/oauth
token_endpoint: https://graph.facebook.com/v9.0/oauth/access_token
user_profile_method: "userinfo_endpoint"
userinfo_endpoint: "https://graph.facebook.com/v9.0/me?fields=id,name,email,picture"
user_mapping_provider:
config:
subject_claim: "id"
display_name_template: "{{ user.name }}"
Relevant documents:
- https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow
- Using Facebook's Graph API: https://developers.facebook.com/docs/graph-api/using-graph-api/
- Reference to the User endpoint: https://developers.facebook.com/docs/graph-api/reference/user