// ========================================================================
// Copyright 2009 Webtide LLC
// ------------------------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ========================================================================
package com.acme;
import junit.framework.TestCase;
import org.mortbay.jetty.servlet.DefaultServlet;
import org.mortbay.jetty.servlet.ServletHolder;
import org.mortbay.jetty.testing.ServletTester;
/**
* Simple tests against DispatchServlet.
*/
public class DispatchServletTest extends TestCase
{
/**
* As filed in JETTY-978.
*
* Security problems in demo dispatch servlet.
*
* <blockquote>
* <p>
* The dispatcher servlet (com.acme.DispatchServlet) is prone to a Denial of
* Service vulnerability.
* </p>
* <p>
* This example servlet is meant to be used as a resources dispatcher,
* however a malicious aggressor may abuse this functionality in order to
* cause a recursive inclusion. In details, it is possible to abuse the
* method com.acme.DispatchServlet.doGet(DispatchServlet.java:203) forcing
* the application to recursively include the "Dispatch" servlet.
* </p>
* <p>
* Dispatch com.acme.DispatchServlet 1 Dispatch /dispatch/* As a result, it
* is possible to trigger a "java.lang.StackOverflowError" and consequently
* an internal server error (500).
* </p>
* <p>
* Multiple requests may easily affect the availability of the servlet
* container. Since this attack can cause the server to consume resources in
* a non-linear relationship to the size of inputs, it should be considered
* as a server flaw.
* </p>
* <p>
* The vulnerability seems confined to the example servlet and it does not
* afflict the Jetty's core."
* </p>
* </blockquote>
*
* @throws Exception
*/
public void testSelfRefForwardDenialOfService() throws Exception
{
ServletTester tester = new ServletTester();
tester.setContextPath("/tests");
ServletHolder dispatch = tester.addServlet(DispatchServlet.class,"/dispatch/*");
tester.addServlet(DefaultServlet.class,"/");
tester.start();
StringBuffer req1 = new StringBuffer();
req1.append("GET /tests/dispatch/includeN/"+dispatch.getName()+" HTTP/1.1\n");
req1.append("Host: tester\n");
req1.append("Connection: close\n");
req1.append("\n");
String response = tester.getResponses(req1.toString());
String msg = "Response code on SelfRefDoS";
assertFalse(msg + " should not be code 500.",response.startsWith("HTTP/1.1 500 "));
assertTrue(msg + " should return error code 403 (Forbidden)", response.startsWith("HTTP/1.1 403 "));
}
public void testSelfRefDeep() throws Exception
{
ServletTester tester = new ServletTester();
tester.setContextPath("/tests");
tester.addServlet(DispatchServlet.class,"/dispatch/*");
tester.addServlet(DefaultServlet.class,"/");
tester.start();
String selfRefs[] =
{ "/dispatch/forward", "/dispatch/includeS", "/dispatch/includeW", "/dispatch/includeN", };
/*
* Number of nested dispatch requests. 220 is a good value, as it won't
* trigger an Error 413 response (Entity too large). Anything larger
* than 220 will trigger a 413 response.
*/
int nestedDepth = 220;
for (int sri = 0; sri < selfRefs.length; sri++)
{
String selfRef = selfRefs[sri];
StringBuffer req1 = new StringBuffer();
req1.append("GET /tests");
for (int i = 0; i < nestedDepth; i++)
{
req1.append(selfRef);
}
req1.append("/ HTTP/1.1\n");
req1.append("Host: tester\n");
req1.append("Connection: close\n");
req1.append("\n");
String response = tester.getResponses(req1.toString());
StringBuffer msg = new StringBuffer();
msg.append("Response code on nested \"").append(selfRef).append("\"");
msg.append(" (depth:").append(nestedDepth).append(")");
assertFalse(msg + " should not be code 413 (Request Entity Too Large)," +
"the nestedDepth in the TestCase is too large (reduce it)",
response.startsWith("HTTP/1.1 413 "));
assertFalse(msg + " should not be code 500.",response.startsWith("HTTP/1.1 500 "));
assertTrue(msg + " should return error code 403 (Forbidden)", response.startsWith("HTTP/1.1 403 "));
}
}
}