You often need to protect resources to ensure that only authorized users have access. Authorization provides controlled access to protected resources. Authorization is based on identification and authentication. Identification is a process that enables recognition of an entity by a system, and authentication is a process that verifies the identity of a user, device, or other entity in a computer system, usually as a prerequisite to allowing access to resources in a system. These concepts are discussed in more detail in Characteristics of Application Security (page 904).
This section discusses setting up users so that they can be correctly identified and either given access to protected resources, or denied access if the user is not authorized to access the protected resources. To authenticate a user, you need to follow these basic steps:
What Are Realms, Users, Groups, and Roles?
A realm is defined on a web or application server. It contains a collection of users, which may or may not be assigned to a group, that are controlled by the same authentication policy. Managing users on the Application Server is discussed in Managing Users and Groups on the Application Server (page 918).
An application will often prompt a user for their user name and password before allowing access to a protected resource. After the user has entered their user name and password, that information is passed to the server, which either authenticates the user and sends the protected resource, or does not authenticate the user, in which case access to the protected resource is denied. This type of user authentication is discussed in Specifying an Authentication Mechanism (page 1010).
In some applications, authorized users are assigned to roles. In this situation, the role assigned to the user in the application must be mapped to a group defined on the application server. Figure 286 shows this. More information on mapping roles to users and groups can be found in Setting Up Security Roles (page 920).
Figure 286. Mapping Roles to Users and Groups
The following sections provide more information on realms, users, groups, and roles.
What Is a Realm?
For a web application, a realm is a complete database of users and groups that identify valid users of a web application (or a set of web applications) and are controlled by the same authentication policy.
The Java EE server authentication service can govern users in multiple realms. In this release of the Application Server, the file, admin-realm, and certificate realms come preconfigured for the Application Server.
In the file realm, the server stores user credentials locally in a file named keyfile. You can use the Admin Console to manage users in the file realm.
When using the file realm, the server authentication service verifies user identity by checking the file realm. This realm is used for the authentication of all clients except for web browser clients that use the HTTPS protocol and certificates.
In the certificate realm, the server stores user credentials in a certificate database. When using the certificate realm, the server uses certificates with the HTTPS protocol to authenticate web clients. To verify the identity of a user in the certificate realm, the authentication service verifies an X.509 certificate. For step-by-step instructions for creating this type of certificate, see Working with Digital Certificates (page 926). The common name field of the X.509 certificate is used as the principal name.
The admin-realm is also a FileRealm and stores administrator user credentials locally in a file named admin-keyfile. You can use the Admin Console to manage users in this realm in the same way you manage users in the file realm. For more information, see Managing Users and Groups on the Application Server (page 918).
What Is a User?
A user is an individual (or application program) identity that has been defined in the Application Server. In a web application, a user can have a set of roles associated with that identity, which entitles them to access all resources protected by those roles. Users can be associated with a group.
A Java EE user is similar to an operating system user. Typically, both types of users represent people. However, these two types of users are not the same. The Java EE server authentication service has no knowledge of the user name and password you provide when you log on to the operating system. The Java EE server authentication service is not connected to the security mechanism of the operating system. The two security services manage users that belong to different realms.
What Is a Group?
A group is a set of authenticated users, classified by common traits, defined in the Application Server.
A Java EE user of the file realm can belong to an Application Server group. (A user in the certificate realm cannot.) An Application Server group is a category of users classified by common traits, such as job title or customer profile. For example, most customers of an e-commerce application might belong to the CUSTOMER group, but the big spenders would belong to the PREFERRED group. Categorizing users into groups makes it easier to control the access of large numbers of users.
An Application Server group has a different scope from a role. An Application Server group is designated for the entire Application Server, whereas a role is associated only with a specific application in the Application Server.
What Is a Role?
A role is an abstract name for the permission to access a particular set of resources in an application. A role can be compared to a key that can open a lock. Many people might have a copy of the key. The lock doesn't care who you are, only that you have the right key.
Some Other Terminology
The following terminology is also used to describe the security requirements of the Java EE platform:
Managing Users and Groups on the Application Server
Managing users on the Application Server is discussed in more detail in the Application Server's Administration Guide. For a link to this guide, see Further Information (page 934).
This tutorial provides steps for managing users that will need to be completed to work through the tutorial examples.
Adding Users to the Application Server
To add users to the Application Server, follow these steps:
Adding Users to the Certificate Realm
In the certificate realm, user identity is set up in the Application Server security context and populated with user data obtained from cryptographically-verified client certificates. For step-by-step instructions for creating this type of certificate, see Working with Digital Certificates (page 926).
Setting Up Security Roles
When you design an enterprise bean or web component, you should always think about the kinds of users who will access the component. For example, a web application for a human resources department might have a different request URL for someone who has been assigned the role of DEPT_ADMIN than for someone who has been assigned the role of DIRECTOR. The DEPT_ADMIN role may let you view employee data, but the DIRECTOR role enables you to modify employee data, including salary data. Each of these security roles is an abstract logical grouping of users that is defined by the person who assembles the application. When an application is deployed, the deployer will map the roles to security identities in the operational environment, as shown in Figure 286.
For applications, you define security roles in the Java EE deployment descriptor file application.xml, and the corresponding role mappings in the Application Server deployment descriptor file sun-application.xml. For individually deployed web or EJB modules, you define roles in the Java EE deployment descriptor files web.xml or ejb-jar.xml and the corresponding role mappings in the Application Server deployment descriptor files sun-web.xml or sun-ejb-jar.xml.
The following is an example of a security constraint from a web.xml application deployment descriptor file where the role of DEPT-ADMIN is authorized for methods that review employee data and the role of DIRECTOR is authorized for methods that change employee data.
<security-constraint> <web-resource-collection> <web-resource-name>view dept data</web-resource-name> <url-pattern>/hr/employee/*</url-pattern> <http-method>GET</http-method> <http-method>POST</http-method> </web-resource-collection> <auth-constraint> <role-name>DEPT_ADMIN</role-name> </auth-constraint> <user-data-constraint> <transport-guarantee>CONFIDENTIAL</transport-guarantee> </user-data-constraint> </security-constraint> <security-constraint> <web-resource-collection> <web-resource-name>change dept data</web-resource-name> <url-pattern>/hr/employee/*</url-pattern> <http-method>GET</http-method> <http-method>PUT</http-method> </web-resource-collection> <auth-constraint> <role-name>DIRECTOR</role-name> </auth-constraint> <user-data-constraint> <transport-guarantee>CONFIDENTIAL</transport-guarantee> </user-data-constraint> </security-constraint>
The web.xml application deployment descriptor is described in more detail in Declaring Security Requirements in a Deployment Descriptor (page 1002).
After users have provided their login information, and the application has declared what roles are authorized to access protected parts of an application, the next step is to map the security role to the name of a user, or principal. This step is discussed in the following section.
Mapping Roles to Users and Groups
When you are developing a Java EE application, you don't need to know what categories of users have been defined for the realm in which the application will be run. In the Java EE platform, the security architecture provides a mechanism for mapping the roles defined in the application to the users or groups defined in the runtime realm. 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 (sun-application.xml, sun-web.xml, or sun-ejb-jar.xml) file. 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 the Application Server. An example for the sun-web.xml file is shown below:
<sun-web-app> <security-role-mapping> <role-name>DIRECTOR</role-name> <principal-name>mcneely</principal-name> </security-role-mapping> <security-role-mapping> <role-name>MANAGER</role-name> <group-name>manager</group-name> </security-role-mapping> </sun-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 the Application 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 or @RolesAllowed annotations.
Sometimes the role names used in the application are the same as the group names defined on the Application Server. Under these circumstances, you can enable a default principal-to-role mapping on the Application Server using the Admin Console. From the Admin Console, select Configuration, then Security, then check the enable box beside Default Principal to Role Mapping. If you need more information about using the Admin Console, see Adding Users to the Application Server (page 918).