8 Designing a secure directory

How the data in HP-UX Directory Server is secured affects all the previous design areas. Any security design needs to protect the data contained by the directory and meet the security and privacy needs of the users and applications.

This chapter describes how to analyze the security needs and explains how to design the directory to meet these needs.

8.1 About security threats

There are many potential threats to the security of the directory. Understanding the most common threats helps outline the overall security design. Threats to directory security fall into three main categories:

•Unauthorized access

•Unauthorized tampering

•Denial of service

8.1.1Unauthorized access

Protecting the directory from unauthorized access may seem straightforward, but implementing a secure solution may be more complex than it first appears. A number of potential access points exist on the directory information delivery path where an unauthorized client may gain access to data.

For example, an unauthorized client can use another client's credentials to access the data. This is particularly likely when the directory uses unprotected passwords. An unauthorized client can also eavesdrop on the information exchanged between a legitimate client and Directory Server.

Unauthorized access can occur from inside the company or, if the company is connected to an extranet or to the Internet, from outside the company.

The following scenarios describe just a few examples of how an unauthorized client might access the directory data.

The authentication methods, password policies, and access control mechanisms provided by the Directory Server offer efficient ways of preventing unauthorized access. See the following sections for more information:

•“Selecting appropriate authentication methods”

•“Designing a password policy”

•“Designing access control”

8.1.2Unauthorized tampering

If intruders gain access to the directory or intercept communications between Directory Server and a client application, they have the potential to modify (or tamper with) the directory data. The directory service is useless if the data can no longer be trusted by clients or if the directory itself cannot trust the modifications and queries it receives from clients.

For example, if the directory cannot detect tampering, an attacker could change a client's request to the server (or not forward it) and change the server's response to the client. SSL and similar technologies can solve this problem by signing information at either end of the connection. For more information about using SSL with Directory Server, see “Securing server to server connections”.

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