import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; @WebServlet("/servlet") public class SecuredServlet extends HttpServlet { @Override protected void service(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException { resp.getWriter().write("Servlet!"); } }
CDI Realm
This example shows how to secure access to a web resource provided by a servlet. For this, we will use realms.
A realm, in JEE world, is a security policy domain defined for a web or application server. A realm contains a collection of users, who may or may not be assigned to a group.
A realm, basically, specifies a list of users and roles. I’s a "database" of users with associated passwords and possible roles.
The Servlet Specification doesn’t specifies an API for specifying such a list of users and roles for a given application.
For this reason, Tomcat servlet container defines an interface, org.apache.catalina.Realm
. More information can be found here.
In TomEE application server, the mechanism used by Tomcat to define a realm for a servlet is reused and enhanced. More information can be found here.
Example
This example shows a servlet secured using a realm. The secured servlet has a simple functionality, just for illustrating the concepts explained here:
For securing this servlet, we will add the following class:
import javax.enterprise.context.RequestScoped; import java.security.Principal; @RequestScoped // just to show we can be bound to the request but @ApplicationScoped is what makes sense public class AuthBean { public Principal authenticate(final String username, String password) { if (("userA".equals(username) || "userB".equals(username)) && "test".equals(password)) { return new Principal() { @Override public String getName() { return username; } @Override public String toString() { return username; } }; } return null; } public boolean hasRole(final Principal principal, final String role) { return principal != null && ( principal.getName().equals("userA") && (role.equals("admin") || role.equals("user")) || principal.getName().equals("userB") && (role.equals("user")) ); } }
The class defines 2 methods: authenticate
and hasRole
.
Both these methods will be used by a class, LazyRealm
, implemented in TomEE application server.
In the file webapp/META-INF/context.xml
this realm is configured:
<Context preemptiveAuthentication="true"> <Valve className="org.apache.catalina.authenticator.BasicAuthenticator" /> <Realm className="org.apache.tomee.catalina.realm.LazyRealm" cdi="true" realmClass="org.superbiz.AuthBean"/> </Context>
The class AuthBean
defines a "database" with 2 users: userA (having role admin) and userB (having role user), both having the password test.
Class org.apache.tomee.catalina.realm.LazyRealm
will load our AuthBean
class and will use it to check if a user has access to the content provided by our servlet.
Tests
import org.apache.http.HttpHost; import org.apache.http.auth.AuthScope; import org.apache.http.auth.UsernamePasswordCredentials; import org.apache.http.client.AuthCache; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.protocol.HttpClientContext; import org.apache.http.impl.auth.BasicScheme; import org.apache.http.impl.client.BasicAuthCache; import org.apache.http.impl.client.BasicCredentialsProvider; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClients; import org.apache.http.util.EntityUtils; import org.apache.openejb.arquillian.common.IO; import org.jboss.arquillian.container.test.api.Deployment; import org.jboss.arquillian.junit.Arquillian; import org.jboss.arquillian.test.api.ArquillianResource; import org.jboss.shrinkwrap.api.ShrinkWrap; import org.jboss.shrinkwrap.api.asset.EmptyAsset; import org.jboss.shrinkwrap.api.asset.FileAsset; import org.jboss.shrinkwrap.api.spec.WebArchive; import org.junit.Test; import org.junit.runner.RunWith; import java.io.File; import java.io.IOException; import java.net.URL; import static org.hamcrest.CoreMatchers.startsWith; import static org.junit.Assert.assertEquals; import static org.junit.Assert.assertThat; @RunWith(Arquillian.class) public class AuthBeanTest { @Deployment(testable = false) public static WebArchive createDeployment() { return ShrinkWrap.create(WebArchive.class, "low-typed-realm.war") .addClasses(SecuredServlet.class, AuthBean.class) .addAsManifestResource(new FileAsset(new File("src/main/webapp/META-INF/context.xml")), "context.xml") .addAsWebInfResource(EmptyAsset.INSTANCE, "beans.xml"); } @ArquillianResource private URL webapp; @Test public void success() throws IOException { assertEquals("200 Servlet!", get("userA", "test")); } @Test public void failure() throws IOException { assertThat(get("userA", "oops, wrong password"), startsWith("401")); } private String get(final String user, final String password) { final BasicCredentialsProvider basicCredentialsProvider = new BasicCredentialsProvider(); basicCredentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(user, password)); final CloseableHttpClient client = HttpClients.custom() .setDefaultCredentialsProvider(basicCredentialsProvider).build(); final HttpHost httpHost = new HttpHost(webapp.getHost(), webapp.getPort(), webapp.getProtocol()); final AuthCache authCache = new BasicAuthCache(); final BasicScheme basicAuth = new BasicScheme(); authCache.put(httpHost, basicAuth); final HttpClientContext context = HttpClientContext.create(); context.setAuthCache(authCache); final HttpGet get = new HttpGet(webapp.toExternalForm() + "servlet"); CloseableHttpResponse response = null; try { response = client.execute(httpHost, get, context); return response.getStatusLine().getStatusCode() + " " + EntityUtils.toString(response.getEntity()); } catch (final IOException e) { throw new IllegalStateException(e); } finally { try { IO.close(response); } catch (final IOException e) { // no-op } } } }
The test uses Arquillian to start an application server and load the servlet.
There are two tests methods: success
, where our servlet is accessed with the correct username and password, and failure
, where our servlet is accessed with an incorrect password.
Full example can be found here.
It’s a maven project, and the test can be run with mvn clean install
command.