You can use the DMZ Secure Proxy Server for IBM® WebSphere® Application Server to provide a secure platform for your proxy server.
The DMZ Secure Proxy Server for IBM WebSphere Application Server installation enables you to install your proxy server in the demilitarized zone (DMZ), while reducing the security risk that might occur if you choose to install an application server in the DMZ to host a proxy server. The risk is reduced by removing any functionality from the application server that is not required to host the proxy servers, but that could pose a security risk. Installing the secure proxy server in the DMZ rather than the secured zone presents new security challenges. However, the secure proxy server is equipped with capabilities to provide protection from these challenges.
You can change the secure proxy server process to run as an unprivileged user after startup. Although you must start the secure proxy server as a privileged user, changing the server process to run as an unprivileged user provides additional protection for local operating resources.
The secure proxy server can be configured to route requests to target servers based on static routing information or dynamic information. Static routing means the server obtains the routing information from local flat files. Dynamic routing means the server obtains the routing information from a Hypertext Transfer Protocol (HTTP) tunnel connection from the proxy server to a server in the secure zone. It is more secure to use static routing because dynamic routing requires an additional connection through the inner firewall. Static routing is only applicable to HTTP requests.
The secure proxy server does not contain a Web container, and therefore, is unable to host the administrative console. It is beneficial to not have a Web container on a DMZ Secure Proxy Server for IBM WebSphere Application Server, since hosting application artifacts is considered a security risk and adds an unnecessary footprint to the proxy server. The secure proxy server is installed separately and has multiple administrative options that have security implications.
Custom error pages can be used by the secure proxy server for specific error codes or groups of error codes. A custom error page application can be used to generate error messages or flat custom error page files can be stored locally on the file system and used during run time. Choosing to use flat custom error pages instead of a custom error application provides a higher level of security. Choosing this option limits the code path and eliminates the need for a potentially unauthorized application to be run when an error page is needed.
Denial of service protection is provided with the inclusion of two properties: Maximum request body buffer chunk size and Maximum response body buffer chunk size. These properties must be tuned to balance the level of protection with the performance overhead that might be experienced if these properties are set incorrectly.
Setting | Default value |
---|---|
Startup permissions | Run as a privileged user |
Routing | Dynamic routing |
Administration | Remote Administration |
Error handling | Local error page handling |
Setting | Default value |
---|---|
Startup permissions | Run as an unprivileged user |
Routing | Dynamic routing |
Administration | Local Administration |
Error handling | Local error page handling |
Setting | Default value |
---|---|
Startup permissions | Run as an unprivileged user |
Routing | Static routing |
Administration | Local Administration |
Error handling | Local error page handling |
In addition to these predefined settings, you can customize the settings for your requirements. If you choose to customize the settings, your DMZ Secure Proxy Server for IBM WebSphere Application Server is still be assigned a qualitative categorization of your security level called the current security level. Each custom setting has been assigned a value of High, Medium or Low. The current security level is equal to the value of the least secure setting being used. To achieve a current security level of High, only settings assigned the high value can be configured. To achieve a current security level of Medium, only settings with values of High or Medium can be used. A current security level of Low is used if any settings that are assigned the value of Low are set.
An additional change to enhance the protection for the DMZ Secure Proxy Server for IBM WebSphere Application Server is the switch from a Java Development Kit (JDK) to a Java Runtime Environment (JRE). Switching from a JDK to a JRE removes the inclusion of a compiler on the installation. This change is beneficial because the compiler might be used for malicious purposes in the event of a security breach.
No JRE currently is available for i5/OS® systems; therefore, a JDK is used. For protection against this type of threat you can manually remove the tools.jar file from the JDK installation root.