The Java EE 7 Tutorial

48.4 Examples: Securing Web Applications

Some basic setup is required before any of the example applications will run correctly. The examples use annotations, programmatic security, and/or declarative security to demonstrate adding security to existing web applications.

Here are some other locations where you will find examples of securing various types of applications:

48.4.1 To Set Up Your System for Running the Security Examples

To set up your system for running the security examples, you need to configure a user database that the application can use for authenticating users. Before continuing, follow these steps.

Make sure that GlassFish Server has been started (see Starting and Stopping GlassFish Server).
Add an authorized user to GlassFish Server. For the examples in this chapter and in Chapter 49, "Getting Started Securing Enterprise Applications", add a user to the file realm of GlassFish Server, and assign the user to the group TutorialUser.
1. From the Administration Console, expand the Configurations node, then expand the server-config node.
2. Expand the Security node.
3. Expand the Realms node.
4. Select the File node.
5. On the Edit Realm page, click Manage Users.
6. On the File Users page, click New.
7. In the User ID field, enter a user ID.
8. In the Group List field, enter TutorialUser.
9. In the New Password and Confirm New Password fields, enter a password.
10. Click OK.
Be sure to write down the user name and password for the user you create so that you can use it for testing the example applications. Authentication is case sensitive for both the user name and password, so write down the user name and password exactly. This topic is discussed more in Managing Users and Groups in GlassFish Server.
Set up Default Principal to Role Mapping in GlassFish Server.
1. From the Administration Console, expand the Configurations node, then expand the server-config node.
2. Select the Security node.
3. Select the Default Principal to Role Mapping Enabled check box.
4. Click Save.

48.4.2 The hello2-basicauth Example: Basic Authentication with a Servlet

This example explains how to use basic authentication with a servlet. With basic authentication of a servlet, the web browser presents a standard login dialog box that is not customizable. When a user submits his or her name and password, the server determines whether the user name and password are those of an authorized user and sends the requested web resource if the user is authorized to view it.

In general, the following steps are necessary for adding basic authentication to an unsecured servlet, such as the ones described in Chapter 6, "Getting Started with Web Applications". In the example application included with this tutorial, many of these steps have been completed for you and are listed here simply to show what needs to be done should you wish to create a similar application. This application can be found in the tut-install/examples/security/hello2-basicauth/ directory.

Follow the steps in To Set Up Your System for Running the Security Examples.
Create a web module for the servlet example, hello2, as described in Chapter 6, "Getting Started with Web Applications".
Add the appropriate security annotations to the servlet. The security annotations are described in Specifying Security for Basic Authentication Using Annotations.
Build, package, and deploy the web application by following the steps in To Build, Package, and Deploy the hello2-basicauth Example Using NetBeans IDE or To Build, Package, and Deploy the hello2-basicauth Example Using Maven.
Run the web application by following the steps described in To Run the hello2-basicauth Example.

48.4.2.1 Specifying Security for Basic Authentication Using Annotations

The default authentication mechanism used by GlassFish Server is basic authentication. With basic authentication, GlassFish Server spawns a standard login dialog box to collect user name and password data for a protected resource. Once the user is authenticated, access to the protected resource is permitted.

To specify security for a servlet, use the @ServletSecurity annotation. This annotation allows you to specify both specific constraints on HTTP methods and more general constraints that apply to all HTTP methods for which no specific constraint is specified. Within the @ServletSecurity annotation, you can specify the following annotations:

The @HttpMethodConstraint annotation, which applies to a specific HTTP method
The more general @HttpConstraint annotation, which applies to all HTTP methods for which there is no corresponding @HttpMethodConstraint annotation

Both the @HttpMethodConstraint and @HttpConstraint annotations within the @ServletSecurity annotation can specify the following:

A transportGuarantee element that specifies the data protection requirements (that is, whether or not SSL/TLS is required) that must be satisfied by the connections on which requests arrive. Valid values for this element are NONE and CONFIDENTIAL.
A rolesAllowed element that specifies the names of the authorized roles.

For the hello2-basicauth application, the GreetingServlet has the following annotations:

@WebServlet(name = "GreetingServlet", urlPatterns = {"/greeting"})
@ServletSecurity(
@HttpConstraint(transportGuarantee = TransportGuarantee.CONFIDENTIAL,
    rolesAllowed = {"TutorialUser"}))

These annotations specify that the request URI /greeting can be accessed only by users who have been authorized to access this URL because they have been verified to be in the role TutorialUser. The data will be sent over a protected transport in order to keep the user name and password data from being read in transit.

If you use the @ServletSecurity annotation, you do not need to specify security settings in the deployment descriptor. Use the deployment descriptor to specify settings for nondefault authentication mechanisms, for which you cannot use the @ServletSecurity annotation.

48.4.2.2 To Build, Package, and Deploy the hello2-basicauth Example Using NetBeans IDE

Follow the steps in To Set Up Your System for Running the Security Examples.
From the File menu, choose Open Project.
In the Open Project dialog box, navigate to:
```
tut-install/examples/security
```
Select the hello2-basicauth folder.
Click Open Project.
In the Projects tab, right-click the hello2-basicauth project and select Build.

This command builds and deploys the example application to your GlassFish Server instance.

48.4.2.3 To Build, Package, and Deploy the hello2-basicauth Example Using Maven

Follow the steps in To Set Up Your System for Running the Security Examples.

In a terminal window, go to:

tut-install/examples/security/hello2-basicauth/

Enter the following command:
```
mvn install
```
This command builds and packages the application into a WAR file, hello2-basicauth.war, that is located in the target directory, then deploys the WAR file.

48.4.2.4 To Run the hello2-basicauth Example

In a web browser, enter the following URL:
```
https://localhost:8181/hello2-basicauth/greeting
```
You may be prompted to accept the security certificate for the server. If so, accept the security certificate. If the browser warns that the certificate is invalid because it is self-signed, add a security exception for the application.

An Authentication Required dialog box appears. Its appearance varies, depending on the browser you use.
Enter a user name and password combination that corresponds to a user who has already been created in the file realm of GlassFish Server and has been assigned to the group TutorialUser; then click OK.

Basic authentication is case sensitive for both the user name and password, so enter the user name and password exactly as defined for GlassFish Server.

The server returns the requested resource if all the following conditions are met.
- A user with the user name you entered is defined for GlassFish Server.
- The user with the user name you entered has the password you entered.
- The user name and password combination you entered is assigned to the group TutorialUser in GlassFish Server.
- The role of TutorialUser, as defined for the application, is mapped to the group TutorialUser, as defined for GlassFish Server.
Enter a name in the field and click Submit.

Because you have already been authorized, the name you enter in this step does not have any limitations. You have unlimited access to the application now.

The application responds by saying "Hello" to the name you entered.

48.4.3 The hello1-formauth Example: Form-Based Authentication with a JavaServer Faces Application

This example explains how to use form-based authentication with a JavaServer Faces application. With form-based authentication, you can customize the login screen and error pages that are presented to the web client for authentication of the user name and password. When a user submits his or her name and password, the server determines whether the user name and password are those of an authorized user and, if authorized, sends the requested web resource.

This example, hello1-formauth, adds security to the basic JavaServer Faces application shown in A Web Module That Uses JavaServer Faces Technology: The hello1 Example.

In general, the steps necessary for adding form-based authentication to an unsecured JavaServer Faces application are similar to those described in The hello2-basicauth Example: Basic Authentication with a Servlet. The major difference is that you must use a deployment descriptor to specify the use of form-based authentication, as described in Specifying Security for the Form-Based Authentication Example. In addition, you must create a login form page and a login error page, as described in Creating the Login Form and the Error Page.

This application can be found in the tut-install/examples/security/hello1-formauth/ directory.

48.4.3.1 Creating the Login Form and the Error Page

When using form-based login mechanisms, you must specify a page that contains the form you want to use to obtain the user name and password, as well as a page to display if login authentication fails. This section discusses the login form and the error page used in this example. Specifying Security for the Form-Based Authentication Example shows how you specify these pages in the deployment descriptor.

The login page can be an HTML page or a servlet, and it must return an HTML page containing a form that conforms to specific naming conventions (see the Java Servlet 3.1 specification for more information on these requirements). To do this, include the elements that accept user name and password information between <form></form> tags in your login page. The content of an HTML page or servlet for a login page should be coded as follows:

<form method="post" action="j_security_check">
    <input type="text" name="j_username">
    <input type="password" name= "j_password">
</form>

The full code for the login page used in this example can be found at tut-install/examples/security/hello1-formauth/src/main/webapp/login.html. Here is the code for this page:

<html lang="en">
    <head>
        <title>Login Form</title>
    </head>
    <body>
        <h2>Hello, please log in:</h2>
        <form method="post" action="j_security_check">
            <table role="presentation">
                <tr>
                    <td>Please type your user name: </td> 
                    <td><input type="text" name="j_username" 
                               size="20"/></td> 
                </tr>
                <tr>
                    <td>Please type your password: </td>
                    <td><input type="password" name="j_password"
                               size="20"/></td> 
                </tr>
            </table>
            <p></p>
            <input type="submit" value="Submit"/>
            &nbsp;
            <input type="reset" value="Reset"/>
        </form>
    </body>
</html>

The login error page is displayed if the user enters a user name and password combination that is not authorized to access the protected URI. For this example, the login error page can be found at tut-install/examples/security/hello1-formauth/src/main/webapp/error.html. For this example, the login error page explains the reason for receiving the error page and provides a link that will allow the user to try again. Here is the code for this page:

<html lang="en">
    <head>
        <title>Login Error</title>
    </head>
    <body>
        <h2>Invalid user name or password.</h2>

        <p>Please enter a user name or password that is authorized to access 
           this application. For this application, this means a user that 
           has been created in the <code>file</code> realm and has been 
           assigned to the <em>group</em> of <code>TutorialUser</code>.</p>
        <p><a href="login.html">Return to login page</a></p>
    </body>
</html>

48.4.3.2 Specifying Security for the Form-Based Authentication Example

This example takes a very simple servlet-based web application and adds form-based security. To specify form-based instead of basic authentication for a JavaServer Faces example, you must use the deployment descriptor.

The following sample code shows the security elements added to the deployment descriptor for this example, which can be found in tut-install/examples/security/hello1-formauth/src/main/webapp/WEB-INF/web.xml:

    <security-constraint>
        <display-name>Constraint1</display-name>
        <web-resource-collection>
            <web-resource-name>wrcoll</web-resource-name>
            <description/>
            <url-pattern>/*</url-pattern>
        </web-resource-collection>
        <auth-constraint>
            <description/>
            <role-name>TutorialUser</role-name>
        </auth-constraint>
    </security-constraint>

    <login-config>
        <auth-method>FORM</auth-method>
        <realm-name>file</realm-name>
        <form-login-config>
            <form-login-page>/login.xhtml</form-login-page>
            <form-error-page>/error.xhtml</form-error-page>
        </form-login-config>
    </login-config>

    <security-role>
        <description/>
        <role-name>TutorialUser</role-name>
    </security-role>

48.4.3.3 To Build, Package, and Deploy the hello1-formauth Example Using NetBeans IDE

Follow the steps in To Set Up Your System for Running the Security Examples.
From the File menu, choose Open Project.
In the Open Project dialog box, navigate to:
```
tut-install/examples/security
```
Select the hello1-formauth folder.
Click Open Project.
In the Projects tab, right-click the hello1-formauth project and select Run.

This command builds and deploys the example application to your GlassFish Server instance, then opens it in a browser.

48.4.3.4 To Build, Package, and Deploy the hello1-formauth Example Using Maven and the asadmin Command

Follow the steps in To Set Up Your System for Running the Security Examples.