The SAML (Security Assertion Markup Language) adapter provides Single Sign On (SSO) and Single Log Off (SLO) in your deployment. Each Liferay DXP instance serves as either the Service Provider (SP) or the Identity Provider (IdP). An identity provider is a trusted provider that provides single sign-on for users to access other websites. A service provider is a website that hosts applications and grants access only to identified users with proper credentials.
Below is background on how SAML works. To jump right to its configuration, see the articles on Setting Up SAML as an Identity Provider or Setting Up SAML as a Service Provider for instructions on using the SAML adapter. Use the instructions to make the conceptual magic from this article come to life!
What’s new in Liferay Connector to SAML 2.0
5.0.0 version of the application for Liferay DXP brings some long-awaited
- Liferay DXP acting as a Service Provider (SP) can now connect to multiple Identity Providers (IdP).
- Developers have an extension point for customizing which Identity Providers to users can use to sign in.
- Support for other Signature Algorithms (like
- Signature method algorithm URL’s can now be blacklisted from the metadata (for
Important SAML Paths
For reference, here are a few important SAML paths.
This URL is the default location of the metadata XML file:
Note that when configuring SAML, no importing of SAML certificates is required. Liferay DXP reads certificates from the SAML metadata XML file. If you want a third-party application like Salesforce to read a Liferay SAML certificate, you can export the Liferay DXP certificate from the keystore. The default keystore file is
You can change this path in System Settings → SSO → SAML Configuration → Key Store Path.
Single Sign On
Both the IdP and the SP can initiate the Single Sign On process, and the SSO flow is different depending on each one. Regardless of how it’s initiated, SSO is configured for HTTPS between the SP and IdP, so all transport-level communication is encrypted. SAML requests are signed using certificates configured in Liferay DXP, using the SAML Web Browser SSO profile as defined in the SAML 2.0 specification. In all cases, responses are sent using HTTP-POST or HTTP-Redirect. HTTP-POST is preferred because it reduces the risk that the URL is too long for a browser to handle.
Consider IdP initiated SSO first.
Identity Provider Initiated SSO
Sometimes a user enters the SSO cycle by sending a request directly from the browser to the IdP.
The SSO Request to the IdP
If Liferay DXP is the IdP, the IdP initiated SSO URL
- Must specify the path as
- Must include the
entityIdparameter which is the identifier to a previously configured Service Provider Connection (SPC).
- May include a
RelayStateparameter which contains a URL encoded value where the user is redirected upon successful authentication. This URL should point to a location on the desired SPC (according to the SAML 2.0 standards section 3.4.3, this value must not exceed 80 bytes in length). It is useful to specify a landing page after SSO has been executed.
For non-Liferay DXP IdPs (Siteminder, ADFS, etc.), consult the vendor’s documentation on constructing IdP initiated SSO URLs.
If the IdP determines that the user isn’t authenticated, it prompts the user with the appropriate login screen.
The SSO Response from the IdP
Upon successful authentication, the IdP constructs a SAML Response. It includes attribute statements configured in the designated Service Provider Connection (SPC; see the next article on setting up the SPC in Liferay DXP’s SAML adapter).
The IdP sends the response to the Assertion Consumer Service URL. The request
contains two parameters:
The SP Processes the SSO Response
The SP validates and processes the SAML Response. Liferay DXP’s SAML solution
SAMLResponse messages. This signature process ensures proper
identification for the IdP and prevents potential SAML Response spoofing.
- If one Liferay DXP instance is the IdP and another is the SP, make sure the SAML metadata XML file imported into the SP contains the IdP’s certificate.
- If Liferay DXP is the IdP and another application is the SP, export the certificate from the IdP and import it into the SP’s certificate store.
RelayState is included in the SAML Response, the user is redirected to
it. Otherwise the home page of the SP is served.
Service Provider Initiated SSO
Most of the time, authentication requests come from the Service Provider.
The SSO Request to the SP
When the user’s browser requests a protected resource or login URL on the SP,
it triggers the SP initiated SSO process. When Liferay DXP is the SAML SP, SSO is
initiated either by requesting
/c/portal/login URL or a protected resource
that requires authentication (for example, a document not viewable by the Guest
Role). If the user requests a protected resource, its URL is recorded in the
RelayState parameter. If the user requested
RelayState can be set by providing the
redirect parameter. Otherwise, if
the portal property
auth.forward.by.last.path is set to
true, the last accessed path is set as
RelayState. For non-Liferay DXP SPs, consult the vendor documentation on
The AuthnRequest to the IdP
The SP looks up the IdP’s Single Sign On service URL and sends an
AuthnRequest. When Liferay DXP is the SP it looks up the configured SAML Identity
Provider Connection and sends a SAML
AuthnRequest to the IdP’s Single Sign On
service URL as defined in the SAML metadata XML document. Liferay DXP supports
sending and receiving the
AuthnRequest using HTTP-POST or HTTP-Redirect
binding. HTTP-POST is preferred.
If the user doesn’t have an active session or if
ForceAuthn was requested by
the SP, the user must authenticate by providing credentials. When Liferay DXP is
the IdP, authentication occurs in the Login Portlet. Liferay DXP decodes and
AuthnRequest before requesting the user to authenticate.
The SSO Response from the IdP
After authentication, a SAML Response is constructed, sent to the Assertion Consumer Service URL of the SP, and verified. The IdP automatically makes this choice based on the SP metadata.
When Liferay DXP is configured as the IdP, any attributes configured on the Service Provider Connection are included in the response as attribute statements. The Assertion Consumer Service URL is looked up from the SAML metadata XML of the SP.
When Liferay DXP is configured as the SP, response and assertion signatures are verified. Liferay DXP requires the sender to be authenticated. This is done via whole message signature from the issuing IdP. Responses missing the signature are considered unauthenticated and the response is rejected. For non-Liferay DXP SP or IdP vendors, consult their documentation.
The user is redirected to the requested resource or to the URL contained in the
RelayState parameter (for example, the last page the user accessed before
Single Log Off
The Single Log Off request is sent from the user’s browser to the IdP or an SP, and the SLO flow differs in each case. First consider IdP initiated SLO.
Identity Provider Initiated SLO
The SLO Request to the IdP
An IdP initiated SLO request is sent directly to the IdP by the user’s browser. When Liferay DXP is the IdP, the IdP initiated SSO URL must specify the URL path as
If the user is signed on to any configured SP, the SAML plugin takes over the logout process, displaying all the signed on services. The single logout screen displays the authentication status of each SP and whether any SPs can’t be logged out of (for example, if the SP is down or doesn’t support SLO). For non-Liferay DXP IdPs (Siteminder, ADFS, etc.) consult the vendor’s documentation on constructing IdP initiated SLO URLs.
The IdP sends a SAML
LogoutRequest to the SP.
- When Liferay DXP is configured as the IdP, the
LogoutRequestis sent using either HTTP-POST, HTTP-Redirect, or SOAP binding. HTTP-Post binding is preferred but in its absence, the first available SLO endpoint with supported binding is selected.
- When Liferay DXP is configured as the SP, supported bindings for
LogoutRequestare HTTP-Post, HTTP-Redirect, or SOAP.
- For other IdPs or SPs, please consult the vendor’s documentation.
The SLO Response from the SP
The SP delivers a
LogoutResponse to the IdP.
The IdP sends a SAML
LogoutRequest to the second SP.
The second SP then delivers the
LogoutResponse to the IdP. The process is
repeated for all SPs the user is logged into. When Liferay DXP is the IdP,
Liferay DXP logs the user out after the last SP has delivered its
or has timed out.
Service Provider Initiated SLO
The SLO Request to the SP
In SP initiated SLO, the user’s browser sends a logout request directly to the SP. When Liferay DXP is configured as the SP, the SLO is initiated by requesting this logout URL:
For other SPs, consult the vendor’s documentation on initiating SLO.
LogoutRequest is sent to the Single Log Out service URL of the IdP.
If Liferay DXP serves as the SP, the
LogoutRequestis sent to the IdP configured by the IdP Connections tab of the SAML provider (see the next article to set up the IdP Connection) and the SLO service URL defined in the SAML metadata.
When Liferay DXP is the IdP, if the user has logged on to other SPs, the user is presented with a single logout screen with the status of each SP logout, flagging any that can’t be looged out of (some SPs might not support SLO or are currently down). If there are no other SPs to log out of, the SAML session terminates and the IdP destroys its session.
The SLO Response from the SP
If the user is logged in to additional SPs (beyond just the initiating SP), the
IdP sends the SAML
LogoutRequest to each one. When Liferay DXP is the IdP, the
LogoutResponse is sent using either HTTP-Post, HTTP-Redirect, or SOAP binding.
Each SP delivers its
LogoutResponse to the IdP. When Liferay DXP is the SP, the
LogoutResponse is sent using either HTTP-Post, HTTP-Redirect or direct
response to SOAP request.
After all additional SPs deliver their
LogoutResponses to the IdP, the IdP
destroys its SSO session. When Liferay DXP is the IdP, once the last SP has
LogoutResponse or has timed out, the IdP destroys the Liferay DXP
session, logging out the user.
Finally, the IdP sends a
LogoutResponse to the SP that initiated SLO. The
initiating SP terminates its SAML session and logs the user out.