# The Java EE 7 Tutorial

# 50.7 Configuring Security Using Deployment Descriptors

The recommended way to configure security in the Java EE 7 platform is with annotations. If you wish to override the security settings at deployment time, you can use security elements in the `web.xml` deployment descriptor to do so. This section describes how to use the deployment descriptor to specify basic authentication and to override default principal-to-role mapping.

## 50.7.1 Specifying Security for Basic Authentication in the Deployment Descriptor

The elements of the deployment descriptor that add basic authentication to an example tell the server or browser to perform the following tasks.

- Send a standard login dialog box to collect user name and password data.

- Verify that the user is authorized to access the application.

- If authorized, display the servlet to the user.

The following sample code shows the security elements for a deployment descriptor that could be used in the example of basic authentication found in the tut-install`/examples/security/hello2_basicauth/` directory:

        <security-constraint>
            <display-name>SecurityConstraint</display-name>
            <web-resource-collection>
                 <web-resource-name>WRCollection</web-resource-name>
                <url-pattern>/greeting</url-pattern>
            </web-resource-collection>
            <auth-constraint>
                <role-name>TutorialUser</role-name>
            </auth-constraint>
            <user-data-constraint>
                 <transport-guarantee>CONFIDENTIAL</transport-guarantee>
            </user-data-constraint>
        </security-constraint>
        <login-config>
            <auth-method>BASIC</auth-method>
            <realm-name>file</realm-name>
        </login-config>
        <security-role>
            <role-name>TutorialUser</role-name>
        </security-role>

This deployment descriptor specifies that the request URI `/greeting` can be accessed only by users who have entered their user names and passwords and have been authorized to access this URL because they have been verified to be in the role `TutorialUser`. The user name and password data will be sent over a protected transport in order to keep it from being read in transit.

## 50.7.2 Specifying Non-Default Principal-to-Role Mapping in the Deployment Descriptor

To map a role name permitted by the application or module to principals (users) and groups defined on the server, use the `security-role-mapping` element in the runtime deployment descriptor file (`glassfish-application.xml`, `glassfish-web.xml`, or `glassfish-ejb-jar.xml`). The entry needs to declare a mapping between a security role used in the application and one or more groups or principals defined for the applicable realm of GlassFish Server. An example for the `glassfish-web.xml` file is shown below:

    <glassfish-web-app>
        <security-role-mapping>
            <role-name>DIRECTOR</role-name>
            <principal-name>schwartz</principal-name>
        </security-role-mapping>
        <security-role-mapping>
            <role-name>DEPT-ADMIN</role-name>
            <group-name>dept-admins</group-name>
        </security-role-mapping>
    </glassfish-web-app>

The role name can be mapped to either a specific principal (user), a group, or both. The principal or group names referenced must be valid principals or groups in the current default realm of GlassFish Server. The `role-name` in this example must exactly match the `role-name` in the `security-role` element of the corresponding `web.xml` file or the role name defined in the `@DeclareRoles` and/or `@RolesAllowed` annotations.