OIDC Auth for Home Assistant

Caution

This is an alpha release. I give no guarantees about code quality, error handling or security at this stage. Use at your own risk.

Provides an OpenID Connect (OIDC) implementation for Home Assistant through a custom component/integration. Through this integration, you can create an SSO (single-sign-on) environment within your self-hosted application stack / homelab.

Background

If you would like to read the background/open letter that lead to this component, please see https://community.home-assistant.io/t/open-letter-for-improving-home-assistants-authentication-system-oidc-sso/494223. It is currently one of the most upvoted feature requests for Home Assistant.

How to use

Installation

Add this repository to HACS.

Update your configuration.yaml file with

auth_oidc:
    client_id: ""
    discovery_url: ""

Register your client with your OIDC Provider (e.g. Authentik/Authelia) as a public client and get the client_id. Then, use the obtained client_id and discovery URLs to fill the fields in configuration.yaml.

For example:

auth_oidc:
    client_id: "someValueForTheClientId"
    discovery_url: "https://example.com/application/o/application/.well-known/openid-configuration"

Afterwards, restart Home Assistant.

You can find all possible configuration options below.

Login

You should now be able to see a second option on your login screen ("OpenID Connect (SSO)"). It provides you with a single input field.

To start, go to one of to one of these URLs (you may also set these as application URLs in your OIDC Provider):

• /auth/oidc/welcome (if you would like a nice welcome screen for your users)
• /auth/oidc/redirect (if you would like to just redirect them without a welcome screen)

So, for example, you may start at http://homeassistant.local:8123/auth/oidc/welcome.

Tip

You can use a different device to login instead. Open the /auth/oidc/welcome link on device A and then type the obtained code into the normal HA login on device B (can also be the mobile app) to login.

Tip

For a seamless user experience, configure a new domain on your proxy to redirect to the /auth/oidc/welcome path or configure that path on your homelab dashboard or in Authentik. Users will then always start on the OIDC welcome page, which will allow them to visit the dashboard if they are already logged in.

With the default configuration, a person entry will be created for every new OIDC user logging in. New OIDC users will get their own fresh user, linked to their persistent ID (subject) at the OpenID Connect provider. You may change your name, username or email at the provider and still have the same Home Assistant user profile.

Configuration Options

Option	Type	Required	Default	Description
client_id	string	Yes		The Client ID as registered with your OpenID Connect provider.
client_secret	string	No		The Client Secret for enabling confidential client mode.
discovery_url	string	Yes		The OIDC well-known configuration URL.
display_name	string	No	"OpenID Connect (SSO)"	The name to display on the login screen, both for the Home Assistant screen and the OIDC welcome screen.
id_token_signing_alg	string	No	RS256	The signing algorithm that is used for your id_tokens.
features.automatic_user_linking	boolean	No	false	Automatically links users to existing Home Assistant users based on the OIDC username claim. Disabled by default for security. When disabled, OIDC users will get their own new user profile upon first login.
features.automatic_person_creation	boolean	No	true	Automatically creates a person entry for new user profiles created by this integration. Recommended if you would like to assign presence detection to OIDC users.
features.disable_rfc7636	boolean	No	false	Disables PKCE (RFC 7636) for OIDC providers that don't support it. You should not need this with most providers.
claims.display_name	string	No	name	The claim to use to obtain the display name.
claims.username	string	No	preferred_username	The claim to use to obtain the username.
claims.groups	string	No	groups	The claim to use to obtain the user's group(s).

Example: Migrating from HA username/password users to OIDC users

If you already have users created within Home Assistant and would like to re-use the current user profile for your OIDC login, you can (temporarily) enable features.automatic_user_linking, with the following config (example):

auth_oidc:
    client_id: "someValueForTheClientId"
    discovery_url: "https://example.com/application/o/application/.well-known/openid-configuration"
    features:
        automatic_user_linking: true

Upon login, OIDC users will then automatically be linked to the HA user with the same username.

Important

It's recommended to only enable this temporarily as it may pose a security risk. Any OIDC user with a username corresponding to a user in Home Assistant can get access to that user, and it's existing rights (admin), even if MFA is currently enabled for that account. After you have migrated your users (and linked OIDC to all existing accounts) you can disable the feature and keep using the linked users.

Development

This project uses the Rye package manager for development. You can find installation instructions here: https://rye.astral.sh/guide/installation/. Start by installing the dependencies using rye sync and then point your editor towards the environment created in the .venv directory.

Help wanted

If you have any tips or would like to contribute, send me a message. You are also welcome to contribute a PR to fix any of the TODOs.

Currently, this is a pre-alpha, so I welcome issues but I cannot guarantee I can fix them (at least within a reasonable time). Please turn on watch for this repository to remain updated. When the component is in a beta stage, issues will likely get fixed more frequently.

TODOs

• Basic flow
• Implement a final link back to the main page from the finish page
• Improve welcome screen UI, should render a simple centered Tailwind UI instructing users that you should login externally to obtain a code.
• Improve finish screen UI, showing the code clearly with instructions to paste it into Home Assistant.
• Implement error handling on top of this proof of concept (discovery, JWKS, OIDC)
• Make id_token claim used for the group (admin/user) configurable
• Make id_token claim used for the username configurable
• Make id_token claim used for the name configurable
• Add instructions on how to deploy this with Authentik & Authelia
• Configure Github Actions to automatically lint and build the package
• Configure Dependabot for automatic updates
• Configure tests
• Consider use of setup UI instead of YAML (see #6)

Currently waiting on HA feature additions:

• Update the HA frontend code to allow a redirection to be requested from an auth provider instead of manually opening welcome page (possibly after home-assistant/frontend#23204)
• Implement this redirection logic to open a new tab on desktop (#23204 uses popup)
• Implement this redirection logic to open a Android Custom Tab (Android) / SFSafariViewController (iOS), instead of opening the link in the HA webview