8.1.3 Denial of service

In a denial of service attack, the attacker's goal is to prevent the directory from providing service to its clients. For example, an attacker might use all the system's resources, thereby preventing these resources from being used by anyone else.

Directory Server can prevent denial of service attacks by setting limits on the resources allocated to a particular bind DN. For more information about setting resource limits based on the user's bind DN, see the "User Account Management" chapter in the HP-UX Directory Server administrator guide.

8.2 Analyzing security needs

Analyze the environment and users to identify specific security needs. The site survey in Chapter 3 “Designing the directory schema” clarifies some basic decisions about who can read and write the individual pieces of data in the directory. This information forms the basis of the security design.

The way security is implemented also depends on how the directory service is used to support the business. A directory that serves an intranet does not require the same security measures as a directory that supports an extranet or e-commerce applications that are open to the Internet.

If the directory only serves an intranet, consider what level of access is needed for information:

•How to provide users and applications with access to the information they need to perform their jobs.

•How to protect sensitive data regarding employees or the business from general access.

If the directory serves an extranet or supports e-commerce applications over the Internet, there are additional points to consider:

•How to offer customers a guarantee of privacy.•How to guarantee information integrity.The following sections provide information about analyzing security needs.

8.2.1 Determining access rights

The data analysis identifies what information users, groups, partners, customers, and applications need to access the directory service.

Access rights can be granted in one of two ways:

•Grant all categories of users as many rights as possible while still protecting sensitive data.

An open method requires accurately determining what data are sensitive or critical to the business.

•Grant each category of users the minimum access they require to do their jobs.

A restrictive method requires minutely understanding the information needs of each category of user inside, and possibly outside, of the organization.

Irrespective of the method used to determine access rights, create a simple table that lists the categories of users in the organization and the access rights granted to each. Consider creating a table that lists the sensitive data held in the directory and, for each piece of data, the steps taken to protect it.

For information about checking the identity of users, see “Selecting appropriate authentication methods”. For information about restricting access to directory information, see “Designing access control”

104 Designing a secure directory