Enabling SSO support using OpenId Connect

Important

‼️ ‼️ ‼️
SSO is currently only available in the :testing tagged images!
The current stable v1.34.3 does not contain the SSO feature.
‼️ ‼️ ‼️

SSO using OpenId Connect

To use an external source of authentication your SSO will need to support OpenID Connect :

• An OpenID Connect Discovery endpoint should be available
• Client authentication will be done using Id and Secret.

A master password will still be required and not controlled by the SSO (depending on your point of view this might be a feature ;). This introduces another way to control who can use the vault without having to use invitation or using an LDAP.

Configuration

The following configurations are available

• SSO_ENABLED : Activate the SSO
• SSO_ONLY : disable email+Master password authentication
• SSO_SIGNUPS_MATCH_EMAIL: On SSO Signup if a user with a matching email already exists make the association (default true)
• SSO_ALLOW_UNKNOWN_EMAIL_VERIFICATION: Allow unknown email verification status (default false). Allowing this with SSO_SIGNUPS_MATCH_EMAIL open potential account takeover.
• SSO_AUTHORITY : the OpenID Connect Discovery endpoint of your SSO
  • Should not include the /.well-known/openid-configuration part and no trailing /
  • $SSO_AUTHORITY/.well-known/openid-configuration should return the a json document: https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderConfigurationResponse
• SSO_SCOPES : Optional, allow to override scopes if needed (default "email profile")
• SSO_AUTHORIZE_EXTRA_PARAMS : Optional, allow to add extra parameter to the authorize redirection (default "")
• SSO_PKCE: Activate PKCE for the Auth Code flow (default true).
• SSO_AUDIENCE_TRUSTED: Optional, Regex to trust additional audience for the IdToken (client_id is always trusted). Use single quote when writing the regex: '^$'.
• SSO_CLIENT_ID : Client Id
• SSO_CLIENT_SECRET : Client Secret
• SSO_MASTER_PASSWORD_POLICY: Optional Master password policy (enforceOnLogin is not supported).
• SSO_AUTH_ONLY_NOT_SESSION: Enable to use SSO only for authentication not session lifecycle
• SSO_CLIENT_CACHE_EXPIRATION: Cache calls to the discovery endpoint, duration in seconds, 0 to disable (default 0);
• SSO_DEBUG_TOKENS: Log all tokens for easier debugging (default false, LOG_LEVEL=debug or LOG_LEVEL=info,vaultwarden::sso=debug need to be set)

The callback url is : https://your.domain/identity/connect/oidc-signin

Account and Email handling

When logging in with SSO an identifier ({iss}/{sub} claims from the IdToken) is saved in a separate table (sso_users). This is used to link to the SSO provider identifier without changing the default user uuid. This is needed because:

• Storing the SSO identifier is important to prevent account takeover due to email change.
• We can't use the identifier as the User uuid since it's way longer (Max 255 chars for the sub part, cf spec).
• We want to be able to associate existing account based on email but only when the user logs in for the first time (controlled by SSO_SIGNUPS_MATCH_EMAIL).
• We need to be able to associate with existing stub account, such as the one created when inviting a user to an org (association is possible only if the user does not have a private key).

Additionally:

• Signup will be blocked if the Provider reports the email as unverified.
• Changing the email needs to be done by the user since it requires updating the key. On login if the email returned by the provider is not the one saved an email will be sent to the user to ask him to update it.
• If set, SIGNUPS_DOMAINS_WHITELIST is applied on SSO signup and when attempting to change the email.

This means that if you ever need to change the provider url or the provider itself; you'll have to first delete the association then ensure that SSO_SIGNUPS_MATCH_EMAIL is activated to allow a new association.

To delete the association (this has no impact on the Vaultwarden user):

TRUNCATE TABLE sso_users;

On SSO_ALLOW_UNKNOWN_EMAIL_VERIFICATION

If your provider does not send the verification status of emails (email_verified claim) you will need to activate this setting.

If set with SSO_SIGNUPS_MATCH_EMAIL=true (the default), then a user can associate with an existing, non-SSO account, even if they do not control the email address. This allow a user to gain access to sensitive information but the master password is still required to read the passwords.

As such when using SSO_ALLOW_UNKNOWN_EMAIL_VERIFICATION it is recommended to disable SSO_SIGNUPS_MATCH_EMAIL. If you need to associate non sso users try to keep both settings activated for the shortest time possible.

Client Cache

By default the client cache is disabled since it can cause issues with the signing keys.
This means that the discovery endpoint will be called again each time we need to interact with the provider (generating authorize_url, exchange the authorize code, refresh tokens). This is suboptimal so the SSO_CLIENT_CACHE_EXPIRATION allows you to configure an expiration that should work for your provider.

As a protection against a misconfigured expiration if the validation of the IdToken fails then the client cache is invalidated (but you'll periodically have an unlucky user ^^).

Google example (Rolling keys)

If we take Google as an example checking the discovery endpoint response headers we can see that the max-age of the cache control is set to 3600 seconds. And the jwk_uri response headers usually contain a max-age with an even bigger value. / Combined with user feedback we can conclude that Google will roll the signing keys each week.

Setting the cache expiration too high has diminishing return but using something like 600 (10 min) should provide plenty benefits.

Rolling keys manually

If you want to roll the used key, first add a new one but do not immediately start signing with it. Wait for the delay you configured in SSO_CLIENT_CACHE_EXPIRATION then you can start signing with it.

As mentioned in the Google example setting too high of a value has diminishing return even if you do not plan to roll the keys.

Keycloak

Default access token lifetime might be only 5min, set a longer value otherwise it will collide with Bitwarden front-end expiration detection which is also set at 5min.
At the realm level

• Realm settings / Tokens / Access Token Lifespan to at least 10min (accessTokenLifespan setting when using kcadm.sh).
• Realm settings / Sessions / SSO Session Idle/Max for the Refresh token lifetime

Or for a specific client in Clients / Client details / Advanced / Advanced settings you can find Access Token Lifespan and Client Session Idle/Max.

Server configuration, nothing specific just set:

• SSO_AUTHORITY=https://${domain}/realms/${realm_name}
• SSO_CLIENT_ID
• SSO_CLIENT_SECRET

Testing

If you want to run a testing instance of Keycloak the Playwright docker-compose can be used.
More details on how to use it in README.md.

Auth0

Not working due to the following issue https://github.com/ramosbugs/openidconnect-rs/issues/23 (they appear not to follow the spec). A feature flag is available (oidc-accept-rfc3339-timestamps) to bypass the issue but you will need to compile the server with it. There is no plan at the moment to either always activate the feature nor make a specific distribution for Auth0.

Authelia

To obtain a refresh_token to be able to extend session you'll need to add the offline_access scope.

Config will look like:

• SSO_SCOPES="email profile offline_access"

Authentik

Default access token lifetime might be only 5min, set a longer value otherwise it will collide with Bitwarden front-end expiration detection which is also set at 5min.
To change the tokens expiration go to Applications / Providers / Edit / Advanced protocol settings.

Starting with 2024.2 version you will need to add the offline_access scope and ensure it's selected in Applications / Providers / Edit / Advanced protocol settings / Scopes (Doc).

Server configuration should look like:

• SSO_AUTHORITY=https://${domain}/application/o/${application_name}/ : trailing / is important
• SSO_SCOPES="email profile offline_access"
• SSO_CLIENT_ID
• SSO_CLIENT_SECRET

Troubleshooting

• Failed to discover OpenID provider: Failed to parse server response:
  • First ensure that the Authority endpoint with /.well-known/openid-configuration appended is reacheable.
  • Next check that the document return id_token_signing_alg_values_supported: ["RS256"]
    If it returns HS256 then selecting the default signing key again should fix the issue (steps).
• Failed to contact token endpoint: Parse(Error ... Invalid JSON web token: found 5 parts:
  This error is probably due to an encrypted token (JWE), ensure that no encryption key is used (steps).

Casdoor

Since version v1.639.0 should work (Tested with version v1.686.0). When creating the application you will need to select the Token format -> JWT-Standard.

Then configure your server with:

• SSO_AUTHORITY=https://${provider_host}
• SSO_CLIENT_ID
• SSO_CLIENT_SECRET

GitLab

Create an application in your Gitlab Settings with

• redirectURI: https://your.domain/identity/connect/oidc-signin
• Confidential: true
• scopes: openid, profile, email

Then configure your server with

• SSO_AUTHORITY=https://gitlab.com
• SSO_CLIENT_ID
• SSO_CLIENT_SECRET

Google Auth

Google Documentation.
By default without extra configuration you won´t have a refresh_token and session will be limited to 1h.

Configure your server with :

• SSO_AUTHORITY=https://accounts.google.com
• SSO_AUTHORIZE_EXTRA_PARAMS="access_type=offline&prompt=consent"
• SSO_CLIENT_ID
• SSO_CLIENT_SECRET

Kanidm

Nothing specific should work with just SSO_AUTHORITY, SSO_CLIENT_ID and SSO_CLIENT_SECRET.

Microsoft Entra ID

1. Create an "App registration" in Entra ID following Identity | Applications | App registrations.
2. From the "Overview" of your "App registration", you'll need the "Directory (tenant) ID" for the SSO_AUTHORITY variable and the "Application (client) ID" as the SSO_CLIENT_ID value.
3. In "Certificates & Secrets" create an "App secret" , you'll need the "Secret Value" for the SSO_CLIENT_SECRET variable.
4. In "Authentication" add https://warden.example.org/identity/connect/oidc-signin as "Web Redirect URI".
5. In "API Permissions" make sure you have profile, email and offline_access listed under "API / Permission name" (offline_access is required, otherwise no refresh_token is returned, see https://github.com/MicrosoftDocs/azure-docs/issues/17134).

Only the v2 endpoint is compliant with the OpenID spec, see https://github.com/MicrosoftDocs/azure-docs/issues/38427 and https://github.com/ramosbugs/openidconnect-rs/issues/122.

Your configuration should look like this:

• SSO_AUTHORITY=https://login.microsoftonline.com/${Directory_ID}/v2.0 #tenant
• SSO_SCOPES=openid profile offline_access User.Read
• SSO_CLIENT_ID=${Application_ID} #client
• SSO_CLIENT_SECRET=${Secret_Value}

Rauthy

To use a provider controlled session you will need to run Rauthy with DISABLE_REFRESH_TOKEN_NBF=true otherwise the server will fail when trying to read a not yet valid refresh_token (Bitwarden clients will trigger a refresh even if the access_token is still valid. Details on rauthy side). Alternative is to use the default session handling with SSO_AUTH_ONLY_NOT_SESSION=true.

No specific config needed when creating the Client.

Your configuration should look like this:

• SSO_AUTHORITY=http://${provider_host}/auth/v1
• SSO_CLIENT_ID=${Client ID}
• SSO_CLIENT_SECRET=${Client Secret}
• SSO_AUTH_ONLY_NOT_SESSION=true Only needed if not running Rauthy with DISABLE_REFRESH_TOKEN_NBF=true

Slack

You will need to create an app in https://api.slack.com/apps/.

It appears that the access_token returned is not in JWT format and an expiration date is not sent with it. As such you will need to use the default session lifecycle.

Your configuration should look like this:

• SSO_AUTHORITY=https://slack.com
• SSO_CLIENT_ID=${Application Client ID}
• SSO_CLIENT_SECRET=${Application Client Secret}
• SSO_AUTH_ONLY_NOT_SESSION=true

Zitadel

To obtain a refresh_token to be able to extend session you'll need to add the offline_access scope.

Additionally Zitadel include the Project id and the Client Id in the audience of the Id Token. For the validation to work you will need to add the Resource Id as a trusted audience (Client Id is trusted by default). You can control the trusted audience with the config SSO_AUDIENCE_TRUSTED.

According to Zitadel#9200, id_token passes a list of trusted audiences including the Project Id. If you end up having many trusted aud strings, SSO_AUDIENCE_TRUSTED, may become unmanageable. In such cases, SSO_AUDIENCE_TRUSTED: '^\d{18}$' (18 is the size of each string in aud list, it may differ depending on your Zitadel implementation) would help you but it's safe to individually add all the aud strings like SSO_AUDIENCE_TRUSTED: '^abcd|def|xyz$'.

Since zitadel#721 PKCE should work with client secret. But older versions might have to disable it (SSO_PKCE=false).

Config will look like:

• SSO_AUTHORITY=https://${provider_host}
• SSO_SCOPES="email profile offline_access"
• SSO_CLIENT_ID
• SSO_CLIENT_SECRET
• SSO_AUDIENCE_TRUSTED='^${Project Id}$'

Session lifetime

Session lifetime is dependant on refresh token and access token returned after calling your SSO token endpoint (grant type authorization_code). If no refresh token is returned then the session will be limited to the access token lifetime.

Tokens are not persisted in the server but wrapped in JWT tokens and returned to the application (The refresh_token and access_token values returned by VW identity/connect/token endpoint). Note that the server will always return a refresh_token for compatibility reasons with the web front and it presence does not indicate that a refresh token was returned by your SSO (But you can decode its value with https://jwt.io and then check if the token field contain anything).

With a refresh token present, activity in the application will trigger a refresh of the access token when it's close to expiration (5min in web client).

Additionally for certain action a token check is performed, if we have a refresh token we will perform a refresh otherwise we'll call the user information endpoint to check the access token validity.

Disabling SSO session handling

If you are unable to obtain a refresh_token or for any other reason you can disable SSO session handling and revert to the default handling. You'll need to enable SSO_AUTH_ONLY_NOT_SESSION=true then access token will be valid for 2h and refresh token will allow for an idle time of 7 days (which can be indefinitely extended).

Debug information

Running with LOG_LEVEL=debug you'll be able to see information on token expiration.

Desktop Client

There is some issue to handle redirection from your browser (used for sso login) to the application.

Chrome

Some user report having (issues).

Firefox

On Windows you'll be presented with a prompt the first time you log to confirm which application should be launched (But there is a bug at the moment you might end-up with an empty vault after login atm).

On Linux it's a bit more tricky. First you'll need to add some config in about:config :

network.protocol-handler.expose.bitwarden=false
network.protocol-handler.external.bitwarden=true

If you have any doubt you can check mailto to see how it's configured.

The redirection will still not work since it appears that the association to an application can only be done on a link/click. You can trigger it with a dummy page such as:

data:text/html,<a href="bitwarden:///dummy">Click me to register Bitwarden</a>

From now on the redirection should now work. If you need to change the application launched you can now find it in Settings by using the search function and entering application.