Derby provides support for user authentication. User authentication means that Derby authenticates the name and password for a user before allowing that user access to the system.

When user authentication is enabled (which it is not by default), the user requesting a connection must provide a valid name and password, which Derby verifies against the repository of users defined for the system. After Derby authenticates the user, it grants the user access to the Derby system but not necessarily access to the database made in the connection request. In the Derby system, access to a database is determined by user authorization.

For user authentication, Derby allows you to provide a repository of users in a number of different ways. For example, you can hook Derby up to an external directory service elsewhere in your enterprise, create your own directory service, or use Derby's simple mechanism for creating a built-in repository of users.

You can define a repository of users for a particular database or for an entire system, depending on whether you use system-wide or database-wide properties.

When Derby user authentication is enabled and Derby uses an external directory service, the architecture looks something like that shown in the figure below.

Figure 1. Derby user authentication using an external service. The application can be a single-user application with an embedded Derby engine or a multi-user application server.

Derby always runs embedded in another Java application, whether that application is a single-user application or a multiple-user application server or connectivity framework.

A database can be accessed by only one JVM at a time, so it is possible to deploy a system in which the application in which Derby is embedded, not Derby, handles the user authentication by connecting to an external directory service.

Figure 2. The application provides the user authentication using an external service. The application can be a single-user application with an embedded Derby engine or a multi-user application server.

• Enabling user authentication
  To enable user authentication, set the derby.connection.requireAuthentication property to true. Otherwise, Derby does not require a user name and password. You can set this property as a system-wide property or as a database-wide property.
• Defining users
  Derby provides several ways to define the repository of users and passwords. To specify which of these services to use with your Derby system, set the property derby.authentication.provider to the appropriate value as discussed here.
• External directory service
  A directory service stores names and attributes of those names. A typical use for a directory service is to store user names and passwords for a computer system. Derby uses the Java naming and directory interface (JNDI) to interact with external directory services that can provide authentication of users' names and passwords.
• Built-in Derby users
  Derby provides a simple, built-in repository of user names and passwords.
• List of user authentication properties
  This table summarizes the various properties related to user authentication.
• Programming applications for Derby user authentication
  This section discusses programming user authentication into applications for use with Derby.