Protecting Your AS/400 Information
When configuring your Web Server, you should think about the kinds of
information on your AS/400 and to whom you want to make it available. There
are three basic categories, defined by their availability:
- Unavailable through the Web Server
-
This is information that you don't want anyone to view through the Web
Server. It may be personal or valuable information that is on the same AS/400
as the Web Server, but you don't want users to be able to access it
through the Web Server.
The two methods you have for protecting this information are OS/400
authority
and Web Server/400 scope control. OS/400 authority is very strong, but may be
hard to configure and maintain. Web Server/400 scope control should be easier
to maintain and is already set up when you install the server.
Note that a
third method, access control can also be used for this information. Access
control will be further described later.
- Available to all users who have access to the Web Server
-
This is information that you want generally available. It may include press
releases and other announcements or marketing material. If your Web Server is
only available through an internal network, you might include other
information here, such as company-wide announcements.
The same two methods as above are used to make information available (OS/400
authority and Web Server/400 scope control). The difference is that you would
use the methods to make this information available, rather than
unavailable.
- Available to a subset of users who have access to the Web Server
-
This is information that should be available to some users who have access to
the Web Server, but not all. It might include information only available to
customers, or information only available internally, even though the Web
Server itself if available to the public (e.g. through the Internet).
The method for protecting this information is access control. Using access
control, you can specify (on a per-directory basis if you like) who can access
information, either based on the on the machine they are using or based on a
user name and password they enter, or a combination of the two.
Note that this document only describes protecting your AS/400 information in
regards to Web Server/400. Other software such as Telnet and FTP pose
additional concerns which are not addressed here.
OS/400 Authority
This is
familiar to AS/400 system administrators and is very strong (it can be
configured to meet the requirements for C2 security, as defined by
the United States Department of Defense).
For OS/400 authority to be effective, your system's security level
(system value QSECURITY) should be
set to at least 30. Web Server/400 has been developed and tested at
security level 40.
The server jobs (daemon and request processors) that serve content run under
the configured server user profile. The server
user profile should have the following authorities:
-
*USE to any documents you want to make available to browsers.
-
*USE to any scripts the server should
be able to execute.
-
*USE to the
WWWSERVER/WWWDAEMON program and to the
QSYS/QSYSNOMAX job queue.
-
The server user profile must be registered in the system directory in
order to access Document Library Services (DLS) folders and documents.
To protect information from being accessed through Web Server/400 using
OS/400 authority, you must ensure that the server user profile does not have
access to it. You can do this by either specifically excluding the server
user profile, or by excluding *PUBLIC.
Web Server/400 Scope Control
Web Server scope control refers to configuration values that affect the scope
of the information the server will attempt to retrieve. Following are
references to more information related to those configuration values:
Web Server/400 Access Control
While OS/400 authority is very strong, it is inflexible because it is based
on the user profile of the person starting the server and on the server user
profile. The server user profile either has access to an object or not.
Access control takes into account information about the person requesting the
information, such as the workstation they are using and the user name and
password they enter.
You can find more information about access control in
the tutorial,
an
access control example
and a detailed
description of how limit sections are evaluated.
Modes For Evaluating Access
Access control is evaluated in one of two modes: normal mode or
administration mode.
Normal access control is governed by the
directory based configuration file. Administrative
access control is governed by the
administrative access configuration file.
By default, all hosts and users have normal access to all documents (that
OS/400 authority allows), and no hosts and users have administrative access to
any documents.
Ways Of Controlling Access
Web Server/400 allows access to be restricted in two ways, which may be used
separately or combined. For greatest security, both should be used together.
- Host filtering
-
Allows restriction of access to information based on the IP address or
domain name of the machine (host) requesting the information.
- User authentication
-
Allows restriction of access to information based on a user ID and
password the user enters.
Evaluating Web Server/400 access involves a two step process:
-
Host filtering will be checked first. If host filtering is not
configured or allows access, the server goes on to the next step. If host
filtering does not allow access, the server will forbid access.
-
User authentication is checked. If user authentication is not configured or
allows access, then access is granted. If user authentication does not allow
access, the server will forbid access.
Note that Web Server/400 access control is based entirely on files and their
relationship within IFS. Because Web Server/400 does not take into account
symbolic links, you must protect any symbolic links leading to a file in the
same way you protect the file itself.
Remember, even if Web Server/400 access control allows access, OS/400
authority must allow the server user profile access to information before it
can be sent back to a browser.
Further Information About Protecting Your AS/400
The following topics are related to protecting your AS/400: