Configure single sign-on using trust association interceptor ++

WAS v8.5 > Secure applications > Authenticate users > Implement single sign-on to minimize web user authentications > Configure single sign-on capability with Tivoli Access Manager or WebSEAL
Configure single sign-on using trust association interceptor ++

Perform this task to enable single sign-on using trust association interceptor ++. The steps involve setting up trust association and creating the interceptor properties.

LTPA (LTPA) is the default authentication mechanism for WebSphere Application Server. However, you may need to configure LTPA prior to configuring the TAMTrustAssociationInterceptorPlus. LTPA is the required authentication mechanism for all trust association interceptors. We can configure LTPA by clicking Security > Global security > Authentication mechanisms and expiration.
Enabling web security SSO is optional when we configure the TAMTrustAssociationInterceptorPlus. For more information, see Implement single sign-on to minimize web user authentications.
Although we can use Simple WebSphere Authentication Mechanism (SWAM) by selecting the Use SWAM-no authenticated communication between servers option on the Authentication mechanisms and expiration panel, SSO requires LTPA as the configured authentication mechanism.
To establish the trust association for the single sign-on, perform the following steps:
From the dmgr console for WAS, click Security Global security .
Under Web security, click Trust association.

Click Enable Trust Association.

Click Interceptors.

Click com.ibm.ws.security.web.TAMTrustAssociationInterceptorPlus to use a WebSEAL interceptor. This interceptor is one of two WebSEAL interceptors that are supplied for the use. You choose to use this interceptor by supplying properties as described in the next step.
WAS attempts to initialize both of these interceptors even if you only supplied properties for the com.ibm.ws.security.web.TAMTrustAssociationInterceptorPlus interceptor. As a result, messages AWXRB0008E and SECJ0384E can appear during initialization to indicate the interceptor you did not choose has failed to initialize. This is normal processing and does not affect the initialization of the interceptor you did select. To inhibit the display of messages AWXRB0008E and SECJ0384E, we can delete the interceptor we do not want to use prior to beginning the initialization. We can add that interceptor back later if the environment changes.

Click Custom Properties.
Click New to enter the property name and value pairs. Ensure the following parameters are set:
Custom properties.
This table describes the TAI custom properties.
Option Description
com.ibm.websphere.security.
webseal.checkViaHeader
We can configure TAI so the via header can be ignored when validating trust for a request. Set to false if none of the hosts in the via header need to be trusted. When false we do not need to set the trusted host names and host ports properties. The only mandatory property to check when via header is false is com.ibm.websphere.security.webseal.loginId.
The default value of the check via header property is false. When using Tivoli Access Manager plug-in for web servers, set this property to false.
The via header is part of the standard HTTP header that records the server names the request that passed through.
com.ibm.websphere.security.
webseal.loginId
The WebSEAL trusted user as created in Create a trusted user account in Tivoli Access Manager The format of the username is the short name representation. This property is mandatory. If it is not set in WAS, the TAI initialization fails.
com.ibm.websphere.security.
webseal.id
A comma-separated list of headers that exists in the request. If all of the configured headers do not exist in the request, trust cannot be established. The default value for the ID property is iv-creds. Any other values set in WAS are added to the list along with iv-creds, separated by commas.
com.ibm.websphere.security.
webseal.hostnames
Do not set this property if using Tivoli Access Manager Plug-in for Web Servers. The property specifies the host names (case sensitive) that are trusted and expected in the request header. Requests arriving from un-listed hosts might not be trusted. If the checkViaHeader property is not set or is set to false then the trusted host names property has no influence. If the checkViaHeader property is set to true, and the trusted host names property is not set, TAI initialization fails.
com.ibm.websphere.security.
webseal.ports
Do not set this property if using Tivoli Access Manager plug-in for web servers. This property is a comma-separated list of trusted host ports. Requests that arrive from unlisted ports might not be trusted. If the checkViaHeader property is not set, or is set to false this property has no influence. If the checkViaHeader property is set to true, and the trusted host ports property is not set in WAS, the TAI initialization fails.
com.ibm.websphere.security.
webseal.viaDepth
A positive integer that specifies the number of source hosts in the via header to check for trust. By default, every host in the via header is checked, and if any host is not trusted, trust cannot be established. The via depth property is used when only some of the hosts in the via header have to be trusted. The setting indicates the number of hosts required to be trusted.
As an example, consider the following header:
Via: HTTP/1.1 webseal1:7002, 1.1 webseal2:7001

If the viaDepth property is not set, is set to 2 or is set to 0, and a request with the previous via header is received then both webseal1:7002 and webseal2:7001 need to be trusted. The following configuration applies:
com.ibm.websphere.security.webseal.hostnames = webseal1,webseal2
com.ibm.websphere.security.webseal.ports = 7002,7001
If the via depth property is set to 1, and the previous request is received, then only the last host in the via header needs to be trusted. The following configuration applies:
com.ibm.websphere.security.webseal.hostnames = webseal2 
com.ibm.websphere.security.webseal.ports = 7001
The viaDepth property is set to 0 by default, which means all of the hosts in the via header are checked for trust.
com.ibm.websphere.security.
webseal.ssoPwdExpiry
After trust is established for a request, the single sign-on user password is cached, eliminating the need to have the TAI re-authenticate the single sign-on user with Tivoli Access Manager for every request. We can modify the cache timeout period by setting the single sign-on password expiry property to the required time in seconds. If the password expiry property is set to 0, the cached password never expires. The default value for the password expiry property is 600.
com.ibm.websphere.security.
webseal.ignoreProxy
This property can be used to tell the TAI to ignore proxies as trusted hosts. If set to true the comments field of the hosts entry in the via header is checked to determine if a host is a proxy. Remember that not all proxies insert comments in the via header indicating they are proxies. The default value of the ignoreProxy property is false. If the checkViaHeader property is set to false then the ignoreProxy property has no influence in establishing trust.
com.ibm.websphere.security.
webseal.configURL
For the TAI to establish trust for a request, it requires the SvrSslCfg run for the Java Virtual Machine on the Application Server and result in the creation of a properties file. If this properties file is not at the default URL, which is file://java.home/PdPerm.properties, the correct URL of the properties file must be set in the configuration URL property. If this property is not set, and the SvrSslCfg-generated properties file is not in the default location, the TAI initialization fails. The default value for the config URL property is file://$WAS_HOME/java/jre/PdPerm.properties.
Click OK.

Save the configuration and log out.
Restart WAS.
Related concepts:

Trust associations

Related

Configure single sign-on capability with Tivoli Access Manager or WebSEAL
Integrating third-party HTTP reverse proxy servers

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Option	Description
com.ibm.websphere.security. webseal.checkViaHeader	We can configure TAI so the via header can be ignored when validating trust for a request. Set to false if none of the hosts in the via header need to be trusted. When false we do not need to set the trusted host names and host ports properties. The only mandatory property to check when via header is false is com.ibm.websphere.security.webseal.loginId. The default value of the check via header property is false. When using Tivoli Access Manager plug-in for web servers, set this property to false. The via header is part of the standard HTTP header that records the server names the request that passed through.
com.ibm.websphere.security. webseal.loginId	The WebSEAL trusted user as created in Create a trusted user account in Tivoli Access Manager The format of the username is the short name representation. This property is mandatory. If it is not set in WAS, the TAI initialization fails.
com.ibm.websphere.security. webseal.id	A comma-separated list of headers that exists in the request. If all of the configured headers do not exist in the request, trust cannot be established. The default value for the ID property is iv-creds. Any other values set in WAS are added to the list along with iv-creds, separated by commas.
com.ibm.websphere.security. webseal.hostnames	Do not set this property if using Tivoli Access Manager Plug-in for Web Servers. The property specifies the host names (case sensitive) that are trusted and expected in the request header. Requests arriving from un-listed hosts might not be trusted. If the checkViaHeader property is not set or is set to false then the trusted host names property has no influence. If the checkViaHeader property is set to true, and the trusted host names property is not set, TAI initialization fails.
com.ibm.websphere.security. webseal.ports	Do not set this property if using Tivoli Access Manager plug-in for web servers. This property is a comma-separated list of trusted host ports. Requests that arrive from unlisted ports might not be trusted. If the checkViaHeader property is not set, or is set to false this property has no influence. If the checkViaHeader property is set to true, and the trusted host ports property is not set in WAS, the TAI initialization fails.
com.ibm.websphere.security. webseal.viaDepth	A positive integer that specifies the number of source hosts in the via header to check for trust. By default, every host in the via header is checked, and if any host is not trusted, trust cannot be established. The via depth property is used when only some of the hosts in the via header have to be trusted. The setting indicates the number of hosts required to be trusted. As an example, consider the following header: Via: HTTP/1.1 webseal1:7002, 1.1 webseal2:7001 If the viaDepth property is not set, is set to 2 or is set to 0, and a request with the previous via header is received then both webseal1:7002 and webseal2:7001 need to be trusted. The following configuration applies: com.ibm.websphere.security.webseal.hostnames = webseal1,webseal2 com.ibm.websphere.security.webseal.ports = 7002,7001 If the via depth property is set to 1, and the previous request is received, then only the last host in the via header needs to be trusted. The following configuration applies: com.ibm.websphere.security.webseal.hostnames = webseal2 com.ibm.websphere.security.webseal.ports = 7001 The viaDepth property is set to 0 by default, which means all of the hosts in the via header are checked for trust.
com.ibm.websphere.security. webseal.ssoPwdExpiry	After trust is established for a request, the single sign-on user password is cached, eliminating the need to have the TAI re-authenticate the single sign-on user with Tivoli Access Manager for every request. We can modify the cache timeout period by setting the single sign-on password expiry property to the required time in seconds. If the password expiry property is set to 0, the cached password never expires. The default value for the password expiry property is 600.
com.ibm.websphere.security. webseal.ignoreProxy	This property can be used to tell the TAI to ignore proxies as trusted hosts. If set to true the comments field of the hosts entry in the via header is checked to determine if a host is a proxy. Remember that not all proxies insert comments in the via header indicating they are proxies. The default value of the ignoreProxy property is false. If the checkViaHeader property is set to false then the ignoreProxy property has no influence in establishing trust.
com.ibm.websphere.security. webseal.configURL	For the TAI to establish trust for a request, it requires the SvrSslCfg run for the Java Virtual Machine on the Application Server and result in the creation of a properties file. If this properties file is not at the default URL, which is file://java.home/PdPerm.properties, the correct URL of the properties file must be set in the configuration URL property. If this property is not set, and the SvrSslCfg-generated properties file is not in the default location, the TAI initialization fails. The default value for the config URL property is file://$WAS_HOME/java/jre/PdPerm.properties.