SAML v2 IdP Initiated Identity Provider

Overview

This FusionAuth Identity Provider allows you to configure FusionAuth to accept a SAML request initiated by a SAMLv2 identity provider. With this Identity Provider, FusionAuth is acting as the SAMLv2 service provider (SP).

Typically, a SAML flow begins at a service provider such as FusionAuth. In a service provider initiated login, the SAML Authentication Response is returned to the service provider in response to an authentication request. FusionAuth can validate certain parameters and only accept a response for a request that FusionAuth initiated.

In contrast, during an identity provider initiated login, the third-party identity provider sends FusionAuth a SAML Authentication Response indicating a user has been authenticated. FusionAuth did not initiate this request so it is unexpected and FusionAuth does not have the full context. This limits what can be verified and requires FusionAuth to allow a cross site request from this third party.

• Create a SAML v2 IdP Initiated Identity Provider

• Integration Details

• CORS Configuration

• Troubleshooting

We also provide specific examples for configuring SAML with some providers whose implementation requires unique configuration. If you’d like us to provide additional examples, please open a request on GitHub.

• Configure SAML v2 IdP Initiated SSO for Okta

Once you have completed this configuration you will be able to log in to FusionAuth directly from a SAMLv2 IdP.

Create a SAML v2 IdP Initiated Identity Provider

To create an Identity Provider navigate to Settings → Identity Providers and click Add provider and select SAML v2 IdP Initiated.

This will take you to the Add SAML v2 IdP Initiated panel. Here you will need to fill out the required fields.

Options

Form Fields

Reconcile lambda Optional

A lambda maps custom claims returned from the SAML response into the FusionAuth User and Registration. To learn more about creating a lambda, view the SAML v2 Reconcile lambda documentation.

To configure a lambda, navigate to Settings → Lambdas.

Debug Optional

Some identity providers are not compliant with the SAML and XML signing specifications. This makes it challenging to get them working with FusionAuth.

If you are running into integration issues, toggle this setting on and FusionAuth will output debugging information into the Event Log during a SAML login. You can find the event log in System → Event Log.

Integration Details

After configuring the Identity Provider, FusionAuth will display values likely required by your SAML v2 Identity Provider to trust FusionAuth as a relying party. Do so by navigating to Settings → Identity Providers and click the green magnifying glass on your SAML provider.

When viewing the details, scroll to the SAML v2 Integration details section. There you will find the necessary values to configure an integration with a SAMLv2 IdP.

SAML v2 Integration Details

Fields

Callback URL (ACS)

An Assertion Consumer Service (or ACS) is the location at a service provider that accepts messages to establish a session based on the assertion.

By default the redirect URI will be the first Authorized redirect URI found in the FusionAuth Application OAuth configuration. To specify a redirect URI send the authorized URI in the RelayState parameter. Support for using the RelayState in this manner is supported in FusionAuth version greater than or equal to 1.41.0. In prior versions, append a query parameter named redirect_uri to the ACS in the IdP configuration.

Note: For IdP initiated logins in order to receive a refresh token the query parameter ?scope=offline_access will need to be appended to the url. When logging into the FusionAuth Admin application this parameter is included by default and does not need to be supplied.

Issuer

The service provider EntityId. This is a URL.

Metadata URL

The URL where the service provider metadata resides. :idp_init!:

CORS Configuration

To complete the login request, the SAML v2 identity provider will make an HTTP POST request to the callback URL in FusionAuth. In order for this request to be allowed through the CORS filter you will need to navigate to Settings → System → CORS and add the SAML IdP origin as an Allowed Origin the CORS configuration.

Troubleshooting

To troubleshoot, turn on the Debug option and then navigate to System → Event Log.

Proceed through the SAML flow and review the Event log entries to see if there are any configuration issues.