--- title: "OpenID Connect" description: "Sign users in through an OpenID Connect provider: basic setup and PKCE, filters by domain, email or group, group sync, claims, and per-provider notes." --- Slopscale supports authentication via external identity providers using OpenID Connect (OIDC). It features: - Auto configuration via OpenID Connect Discovery Protocol - [Proof Key for Code Exchange (PKCE) code verification](#enable-pkce-recommended) - [Authorization based on a user's domain, email address or group membership](#authorize-users-with-filters) - Synchronization of [standard OIDC claims](#supported-oidc-claims) - Sign-in to the [admin console](/slopscale/ref/console#signing-in) with the same provider and redirect URI See [limitations](#limitations) for known issues. ## Configuration OpenID requires configuration in Slopscale and your identity provider: - Slopscale: The `oidc` section of the Slopscale [configuration](/slopscale/ref/configuration) contains all available configuration options along with a description and their default values. - Identity provider: the provider's own documentation has the exact steps. Additionally, there might be some useful hints in the [Identity provider specific configuration](#identity-provider-specific-configuration) section below. ### Basic configuration A basic configuration connects Slopscale to an identity provider and typically requires: - OpenID Connect Issuer URL from the identity provider. Slopscale uses the OpenID Connect Discovery Protocol 1.0 to automatically obtain OpenID configuration parameters (example: `https://sso.example.com`). - Client ID from the identity provider (example: `slopscale`). - Client secret generated by the identity provider (example: `generated-secret`). - Redirect URI for your identity provider (example: `https://slopscale.example.com/oidc/callback`). **Slopscale** ```yaml oidc: issuer: "https://sso.example.com" client_id: "slopscale" client_secret: "generated-secret" ``` **Identity provider** - Create a new confidential client (`Client ID`, `Client secret`) - Add Slopscale's OIDC callback URL as valid redirect URL: `https://slopscale.example.com/oidc/callback` - Configure additional parameters to improve user experience such as: name, description, logo, … ### Enable PKCE (recommended) Proof Key for Code Exchange (PKCE) adds an additional layer of security to the OAuth 2.0 authorization code flow by preventing authorization code interception attacks, see: https://datatracker.ietf.org/doc/html/rfc7636. PKCE is recommended and needs to be configured for Slopscale and the identity provider alike: **Slopscale** ```yaml hl_lines="5-6" oidc: issuer: "https://sso.example.com" client_id: "slopscale" client_secret: "generated-secret" pkce: enabled: true ``` **Identity provider** - Enable PKCE for the slopscale client - Set the PKCE challenge method to "S256" ### Authorize users with filters Slopscale allows to filter for allowed users based on their domain, email address or group membership. These filters can be helpful to apply additional restrictions and control which users are allowed to join. Filters are disabled by default, users are allowed to join once the authentication with the identity provider succeeds. In case multiple filters are configured, a user needs to pass all of them. **Allowed domains** - Check the email domain of each authenticating user against the list of allowed domains and only authorize users whose email domain matches `example.com`. - A verified email address is required [unless email verification is disabled](#control-email-verification). - Access allowed: `alice@example.com` - Access denied: `bob@example.net` ```yaml hl_lines="5-6" oidc: issuer: "https://sso.example.com" client_id: "slopscale" client_secret: "generated-secret" allowed_domains: - "example.com" ``` **Allowed users/emails** - Check the email address of each authenticating user against the list of allowed email addresses and only authorize users whose email is part of the `allowed_users` list. - A verified email address is required [unless email verification is disabled](#control-email-verification). - Access allowed: `alice@example.com`, `bob@example.net` - Access denied: `mallory@example.net` ```yaml hl_lines="5-7" oidc: issuer: "https://sso.example.com" client_id: "slopscale" client_secret: "generated-secret" allowed_users: - "alice@example.com" - "bob@example.net" ``` **Administrators** - Users whose email address is in `admin_users` hold the `admin` [role](/slopscale/ref/roles) from their first sign-in, so the [admin console](/slopscale/ref/console#signing-in) can be administered without granting roles over the CLI first. - The list is checked on every sign-in and only promotes members; the owner and users who already hold a role are left alone, and removing an address does not demote anyone. - A verified email address is required [unless email verification is disabled](#control-email-verification). ```yaml hl_lines="5-6" oidc: issuer: "https://sso.example.com" client_id: "slopscale" client_secret: "generated-secret" admin_users: - "alice@example.com" ``` **Allowed groups** - Use the OIDC `groups` claim of each authenticating user to get their group membership and only authorize users which are members in at least one of the referenced groups. - Access allowed: users in the `slopscale_users` group - Access denied: users without groups, users with other groups ```yaml hl_lines="5-7" oidc: issuer: "https://sso.example.com" client_id: "slopscale" client_secret: "generated-secret" scope: ["openid", "profile", "email", "groups"] allowed_groups: - "slopscale_users" ``` **Synced groups** - With `groups.sync` on, every group in the user's `groups` claim becomes a slopscale [group](/slopscale/ref/access-control#groups) of the same name with the user as a member, and the user leaves the synced groups the claim no longer lists. The claim is read at every sign-in, so a change at the identity provider takes effect the next time the person signs in, the way Tailscale's user and group provisioning does. - `groups.prefix` limits the sync to the claims that start with it and strips it from the name, so `hs-eng` becomes `eng` and a provider's other groups stay out. - A synced group carries `source: oidc`; its users cannot be edited by hand, while machines can still be added directly and the group can be renamed, described, used in rules and deleted. A group an operator made is never taken over by name; a claim that collides with one is logged and skipped. ```yaml hl_lines="5-8" oidc: issuer: "https://sso.example.com" client_id: "slopscale" client_secret: "generated-secret" scope: ["openid", "profile", "email", "groups"] groups: sync: true prefix: "hs-" ``` ### Control email verification Slopscale uses the `email` claim from the identity provider to synchronize the email address to its user profile. By default, a user's email address is only synchronized when the identity provider reports the email address as verified via the `email_verified: true` claim. Unverified emails may be allowed in case an identity provider does not send the `email_verified` claim or email verification is not required. In that case, a user's email address is always synchronized to the user profile. ```yaml hl_lines="5" oidc: issuer: "https://sso.example.com" client_id: "slopscale" client_secret: "generated-secret" email_verified_required: false ``` ### Customize node expiration The node expiration is the amount of time a node is authenticated with OpenID Connect until it expires and needs to reauthenticate. The default node expiration can be configured via the top-level `node.expiry` setting. **Customize node expiration** ```yaml hl_lines="2" node: expiry: 30d # Use 0 to disable node expiration ``` **Use expiration from Access Token** The Access Token is typically a short-lived token that expires within a few minutes. You will have to configure token expiration in your identity provider to avoid frequent re-authentication. ```yaml hl_lines="5" oidc: issuer: "https://sso.example.com" client_id: "slopscale" client_secret: "generated-secret" use_expiry_from_token: true ``` :::tip[Expire a node and force re-authentication] A node can be expired immediately via: ```console slopscale node expire -i ``` ::: ### Reference a user in the policy You may refer to users in the Slopscale policy via: - Email address - Username - Provider identifier (this value is currently only available from the [API](/slopscale/ref/api), database or directly from your identity provider) :::note[A user identifier in the policy must contain a single @] The Slopscale policy requires a single `@` to reference a user. If the username or provider identifier doesn't already contain a single `@`, it needs to be appended at the end. For example: the Slopscale username `ssmith` has to be written as `ssmith@` to be correctly identified as user within the policy. Ensure that the Slopscale username itself does not end with `@`. ::: :::warning[Email address or username might be updated by users] Many identity providers allow users to update their own profile. Depending on the identity provider and its configuration, the values for username or email address might change over time. This might have unexpected consequences for Slopscale where a policy might no longer work or a user might obtain more access by hijacking an existing username or email address. ::: :::tip[Howto use the provider identifier in the policy] The provider identifier uniquely identifies an OIDC user and a well-behaving identity provider guarantees that this value never changes for a particular user. It is usually an opaque and long string and its value is currently only available from the [API](/slopscale/ref/api), database or directly from your identity provider). Use the [API](/slopscale/ref/api) with the `/api/v1/user` endpoint to fetch the provider identifier (`providerId`). The value (be sure to append an `@` in case the provider identifier doesn't already contain an `@` somewhere) can be used directly to reference a user in the policy. To improve readability of the policy, one may use the `groups` section as an alias: ```json { "groups": { "group:alice": [ "https://sso.example.com/oauth2/openid/59ac9125-c31b-46c5-814e-06242908cf57@" ] }, "grants": [ { "src": ["group:alice"], "dst": ["*"], "ip": ["*"] } ] } ``` ::: ## Supported OIDC claims Slopscale uses [the standard OIDC claims](https://openid.net/specs/openid-connect-core-1_0.html#StandardClaims) to populate and update its local user profile on each login. OIDC claims are read from the ID Token and from the UserInfo endpoint. | Slopscale profile | OIDC claim | Notes / examples | | ------------------- | -------------------- | ------------------------------------------------------------------------------------------------- | | email address | `email` | Only verified emails are synchronized, unless `email_verified_required: false` is configured | | display name | `name` | eg: `Sam Smith` | | username | `preferred_username` | Depends on identity provider, eg: `ssmith`, `ssmith@idp.example.com`, `\\example.com\ssmith` | | profile picture | `picture` | URL to a profile picture or avatar | | provider identifier | `iss`, `sub` | A stable and unique identifier for a user, typically a combination of `iss` and `sub` OIDC claims | | | `groups` | [Only used to filter for allowed groups](#authorize-users-with-filters) | ## Limitations - Support for OpenID Connect aims to be generic and vendor independent. It offers only limited support for quirks of specific identity providers. - OIDC groups are not visible to the policy file: `groups` in the file are defined in the file. With [`groups.sync`](#authorize-users-with-filters) on, a provider's groups become slopscale groups that [access rules](/slopscale/ref/access-control) can name. - The username provided by the identity provider needs to adhere to this pattern: - The username must be at least two characters long. - It must only contain letters, digits, hyphens, dots, underscores, and up to a single `@`. - The username must start with a letter. See the [GitHub label "OIDC"](https://github.com/aislopware/slopscale/labels/OIDC) for OIDC related issues. ## Identity provider specific configuration :::warning[Third-party software and services] This section of the documentation is specific for third-party software and services. We recommend users read the third-party documentation on how to configure and integrate an OIDC client. See the [Configuration section](#configuration) for a description of Slopscale's OIDC related configuration settings. ::: Any identity provider with OpenID Connect support should "just work" with Slopscale. The following identity providers are known to work: - [Authelia](#authelia) - [Authentik](#authentik) - [Kanidm](#kanidm) - [Keycloak](#keycloak) ### Authelia Authelia is fully supported by Slopscale. ### Authentik - Authentik is fully supported by Slopscale. - [Slopscale does not support JSON Web Encryption](https://github.com/juanfont/headscale/issues/2446). Leave the field `Encryption Key` in the providers section unset. - See Authentik's [Integrate with Slopscale](https://integrations.goauthentik.io/networking/slopscale/) ### Google OAuth :::warning[No username due to missing preferred_username claim] Google OAuth does not send the `preferred_username` claim when the `profile` scope is requested. The username in Slopscale will be blank/not set. ::: In order to integrate Slopscale with Google, you'll need to have a [Google Cloud Console](https://console.cloud.google.com) account. Google OAuth has a [verification process](https://support.google.com/cloud/answer/9110914?hl=en) if you need to have users authenticate who are outside of your domain. If you only need to authenticate users from your domain name (ie `@example.com`), you don't need to go through the verification process. However if you don't have a domain, or need to add users outside of your domain, you can manually add emails via Google Console. #### Steps 1. Go to [Google Console](https://console.cloud.google.com) and login or create an account if you don't have one. 1. Create a project (if you don't already have one). 1. On the left hand menu, go to `APIs and services` -> `Credentials` 1. Click `Create Credentials` -> `OAuth client ID` 1. Under `Application Type`, choose `Web Application` 1. For `Name`, enter whatever you like 1. Under `Authorised redirect URIs`, add Slopscale's OIDC callback URL: `https://slopscale.example.com/oidc/callback` 1. Click `Save` at the bottom of the form 1. Take note of the `Client ID` and `Client secret`, you can also download it for reference if you need it. 1. [Configure Slopscale following the "Basic configuration" steps](#basic-configuration). The issuer URL for Google OAuth is: `https://accounts.google.com`. The client ID and secret may also come from the environment as `SLOPSCALE_OIDC_CLIENT_ID` and `SLOPSCALE_OIDC_CLIENT_SECRET`. 1. The same client signs operators in to the [admin console](/slopscale/ref/console#signing-in); no further redirect URI is needed. List the addresses that should administer it in `admin_users` (or `SLOPSCALE_OIDC_ADMIN_USERS`) so they sign in as admins right away. ### Kanidm - Kanidm is fully supported by Slopscale. - Groups for the [allowed groups filter](#authorize-users-with-filters) need to be specified with their full SPN, for example: `slopscale_users@sso.example.com`. - Kanidm sends the full SPN (`alice@sso.example.com`) as `preferred_username` by default. Slopscale stores this value as username which might be confusing as the username and email fields now contain values that look like an email address. [Kanidm can be configured to send the short username as `preferred_username` attribute instead](https://kanidm.github.io/kanidm/stable/integrations/oauth2.html#short-names): ```console kanidm system oauth2 prefer-short-username ``` Once configured, the short username in Slopscale will be `alice` and can be referred to as `alice@` in the policy. ### Keycloak Keycloak is fully supported by Slopscale. #### Additional configuration to use the allowed groups filter Keycloak has no built-in client scope for the OIDC `groups` claim. This extra configuration step is **only** needed if you need to [authorize access based on group membership](#authorize-users-with-filters). - Create a new client scope `groups` for OpenID Connect: - Configure a `Group Membership` mapper with name `groups` and the token claim name `groups`. - Add the mapper to at least the UserInfo endpoint. - Configure the new client scope for your Slopscale client: - Edit the Slopscale client. - Search for the client scope `group`. - Add it with assigned type `Default`. - [Configure the allowed groups in Slopscale](#authorize-users-with-filters). How groups need to be specified depends on Keycloak's `Full group path` option: - `Full group path` is enabled: groups contain their full path, e.g. `/top/group1` - `Full group path` is disabled: only the name of the group is used, e.g. `group1` ### Microsoft Entra ID In order to integrate Slopscale with Microsoft Entra ID, you'll need to provision an App Registration with the correct scopes and redirect URI. [Configure Slopscale following the "Basic configuration" steps](#basic-configuration). The issuer URL for Microsoft Entra ID is: `https://login.microsoftonline.com//v2.0`. The following `extra_params` might be useful: - `domain_hint: example.com` to use your own domain - `prompt: select_account` to force an account picker during login When using Microsoft Entra ID together with the [allowed groups filter](#authorize-users-with-filters), configure the Slopscale OIDC scope without the `groups` claim, for example: ```yaml oidc: scope: ["openid", "profile", "email"] ``` Groups for the [allowed groups filter](#authorize-users-with-filters) need to be specified with their group ID(UUID) instead of the group name. ## Switching OIDC providers Slopscale only supports a single OIDC provider in its configuration, but it does store the provider identifier of each user. When switching providers, all user details (name, email, groups) might be identical with the new provider, but the identifier will differ. Slopscale will be unable to create a new user as the name and email will already be in use for the existing users. Set `oidc.match_by_email: true` while migrating. A login whose identifier is unknown is then matched to the existing OIDC user with the same email, that user takes over the new identifier, and the machines stay with it. The switch is recorded in the audit log as `user.provider.switch` with the old and the new identifier. Only a verified email (or any email when `email_verified_required` is off) is matched, and a login is refused when several users share the email. Turn the setting off again once every user has logged in through the new provider. Without the setting you need to manually update the `provider_identifier` column in the `users` table for each user with the appropriate value for the new provider. The identifier is built from the `iss` and `sub` claims of the OIDC ID token, for example `https://id.example.com/12340987`.