Set single sign-on using trust association interceptor++
To enable single sign-on using TAI++ we...
- Set up trust association
- Set interceptor properties
Single sign-on requires LTPA as the authentication mechanism.
To establish the trust association for the single sign-on...
- Go to...
Enable Trust Association | Interceptors | com.ibm.ws.security.web.TAMTrustAssociationInterceptorPlus...which is one of two WebSEAL interceptors bundled with WAS v7.
By default, WAS attempts to initialize both of these interceptors even if we only supplied properties for one. As a result, messages AWXRB0008E and SECJ0384E can appear during initialization to indicate that 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 these messages, delete the interceptor you do not want to use prior to beginning the initialization. We can add that interceptor back later if the environment changes.
- Go to...
Custom Properties | NewVerify the following parameters are set..
- com.ibm.websphere.security.webseal.checkViaHeader
Configure TAI so that the via header can be ignored when validating trust for a request. Set this property to false if none of the hosts in the via header need to be trusted. When set to false you 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 TAM 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 TAM The format of the username is the short name representation. 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 TAM 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 TAM plug-in for Web servers. 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 that are required to be trusted.
For example, consider the following header:
Via: HTTP/1.1 webseal1:7002, 1.1 webseal2:7001If 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 = 7002,7001If 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 = 7001The 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 TAM 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 that 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 that the SvrSslCfg run for the Java Virtual Machine on the appserver 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_INSTALL_ROOT}/java/jre/PdPerm.properties- Click OK.
- Save the configuration and log out.
- Restart WAS.
 
Related concepts
Trust associations
Related tasks
Integrating third-party HTTP reverse proxy servers
Set single sign-on capability with TAM or WebSEAL