Pages returned to the client
from back-end application servers
often contain links to resources located on those servers. It is important
these URLs are constructed to correctly direct any client requests
back to these resources.
For example, in a non-WebSEAL environment,
the URL entered by a
client for a resource on an application server might appear as follows:
http://www.example.com/file.html
WebSEAL,
as a front-end reverse proxy, provides security services
to back-end application servers via the WebSEAL junctioning feature.
This feature requires the original URLs to these resources be
modified to include the junction information.
The standard
junction feature of WebSEAL changes the server and
path information that must be used to access resources on junctioned
back-end systems. A link to a resource on a back-end junctioned server succeeds only if the URL contains the identity of the junction.
If
this same back-end server is a junctioned server in a WebSEAL
environment, the URL used to access the same resource on a junctioned
back-end application server must appear as follows:
http://webseal.example.com/jct/file.html
To support the standard junction feature and maintain the integrity
of URLs, WebSEAL must, where possible:
Modify the URLs
(links) found in responses sent
to clients
Modify requests for resources
resulting
from URLs (links) that WebSEAL could not change
WebSEAL's
rules and mechanisms for modifying URLs
do not apply to links that point to resources external to the ISAM junctioned
environment.
The following diagram summarizes the solutions
available to WebSEAL
for modifying URLs to junctioned back-end resources:
Figure 1. Summary: Modifying URLs to back-end resources