Database encryption allows individual attributes to be encrypted as they are stored in the database. When configured, every instance of a particular attribute, even index data, is encrypted and can only be accessed via a secure channel, such as SSL/TLS.

For information on using database encryption, refer to the "Configuring Directory Databases" chapter in the HP-UX Directory Server administrator guide.

8.9 Securing server to server connections

After designing the authentication scheme for identified users and the access control scheme for protecting information in the directory, to design a way to protect the integrity of the information passed between servers and client applications.

For both server to client connections and server to server connections, the Directory Server supports a variety of secure connection types:

•Secure Sockets Layer (SSL) and Transport Layer Security (TLS)

To provide secure communications over the network, the Directory Server can use LDAP over the Secure Sockets Layer (SSL) or Transport Layer Security (TLS).

SSL/TLS can be used in conjunction with the RC2 and RC4 encryption algorithms from RSA. The encryption method selected for a particular connection is the result of a negotiation between the client application and Directory Server.

•Start TLS

Directory Server also supports Start TLS, a method of initiating a Transport Layer Security (TLS) connection over a regular port.

•Simple Authentication and Security Layer (SASL)

SASL is a security framework, meaning that it sets up a system that allows different mechanisms to authenticate a user to the server, depending on what mechanism is enabled in both client and server applications. It can also establish an encrypted session between the client and a server. In Directory Server, SASL is used with GSS-API to enable Kerberos logins and can be used for almost all server to server connections, including replication, chaining, and pass-through authentication. (SASL cannot be used with Windows Sync.)

NOTE:

SASL encryption is not supported for client connections that use SSL/TLS.

Secure connections are recommended for any operations which handle sensitive information, like replication, and are required for some operations, like Windows password synchronization. Directory Server can support SSL/TLS connections and non-SSL connections simultaneously.

For more information about using SSL/TLS, Start TLS, and SASL, check out the Administrator's Guide.

8.10 Other security resources

For more information about designing a secure directory, refer to the following:

•Understanding and Deploying LDAP Directory Services. T. Howes, M. Smith, G. Good, Macmillan Technical Publishing, 1999.

•SecurityFocus.com http://www.securityfocus.com

•Computer Emergency Response Team (CERT) Coordination Center http://www.cert.org

•CERT Security Improvement Modules http://www.cert.org/security-improvement/

124 Designing a secure directory