Jetty 9.4 - Review URI encoding in ConcatServlet & WelcomeFilter and improve testing

jetty-server/src/main/java/org/eclipse/jetty/server/ResourceService.java

@@ -240,7 +240,7 @@ public boolean doGet(HttpServletRequest request, HttpServletResponse response)
             // Find the content
             content = _contentFactory.getContent(pathInContext, response.getBufferSize());
             if (LOG.isDebugEnabled())
-                LOG.info("content={}", content);
+                LOG.debug("content={}", content);
 
             // Not found?
             if (content == null || !content.getResource().exists())
@@ -430,7 +430,7 @@ protected void sendWelcome(HttpContent content, String pathInContext, boolean en
                 return;
             }
 
-            RequestDispatcher dispatcher = context.getRequestDispatcher(welcome);
+            RequestDispatcher dispatcher = context.getRequestDispatcher(URIUtil.encodePath(welcome));
             if (dispatcher != null)
             {
                 // Forward to the index

jetty-servlets/src/main/java/org/eclipse/jetty/servlets/ConcatServlet.java

@@ -61,6 +61,7 @@
  * appropriate. This means that when not in development mode, the servlet must be
  * restarted before changed content will be served.</p>
  */
+@Deprecated
 public class ConcatServlet extends HttpServlet
 {
     private boolean _development;
@@ -125,7 +126,8 @@ else if (!type.equals(t))
                 }
             }
 
-            RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(path);
+            // Use the original string and not the decoded path as the Dispatcher will decode again.
+            RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(part);
             if (dispatcher != null)
                 dispatchers.add(dispatcher);
         }

jetty-servlets/src/main/java/org/eclipse/jetty/servlets/WelcomeFilter.java

@@ -27,6 +27,8 @@
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 
+import org.eclipse.jetty.util.URIUtil;
+
 /**
  * Welcome Filter
  * This filter can be used to server an index file for a directory
@@ -41,6 +43,7 @@
  *
  * Requests to "/some/directory" will be redirected to "/some/directory/".
  */
+@Deprecated
 public class WelcomeFilter implements Filter
 {
     private String welcome;
@@ -61,7 +64,10 @@ public void doFilter(ServletRequest request,
     {
         String path = ((HttpServletRequest)request).getServletPath();
         if (welcome != null && path.endsWith("/"))
-            request.getRequestDispatcher(path + welcome).forward(request, response);
+        {
+            String uriInContext = URIUtil.encodePath(URIUtil.addPaths(path, welcome));
+            request.getRequestDispatcher(uriInContext).forward(request, response);
+        }
         else
             chain.doFilter(request, response);
     }

jetty-servlets/src/test/java/org/eclipse/jetty/servlets/ConcatServletTest.java

@@ -26,6 +26,7 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.stream.Stream;
 import javax.servlet.RequestDispatcher;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
@@ -41,7 +42,12 @@
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
 
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.startsWith;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
@@ -112,7 +118,7 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response) t
     }
 
     @Test
-    public void testWEBINFResourceIsNotServed() throws Exception
+    public void testDirectoryNotAccessible() throws Exception
     {
         File directoryFile = MavenTestingUtils.getTargetTestingDir();
         Path directoryPath = directoryFile.toPath();
@@ -134,45 +140,68 @@ public void testWEBINFResourceIsNotServed() throws Exception
         // Verify that I can get the file programmatically, as required by the spec.
         assertNotNull(context.getServletContext().getResource("/WEB-INF/one.js"));
 
-        // Having a path segment and then ".." triggers a special case
-        // that the ConcatServlet must detect and avoid.
-        String uri = contextPath + concatPath + "?/trick/../WEB-INF/one.js";
+        // Make sure ConcatServlet cannot see file system files.
+        String uri = contextPath + concatPath + "?/trick/../../" + directoryFile.getName();
         String request =
             "GET " + uri + " HTTP/1.1\r\n" +
                 "Host: localhost\r\n" +
                 "Connection: close\r\n" +
                 "\r\n";
         String response = connector.getResponse(request);
         assertTrue(response.startsWith("HTTP/1.1 404 "));
+    }
 
-        // Make sure ConcatServlet behaves well if it's case insensitive.
-        uri = contextPath + concatPath + "?/trick/../web-inf/one.js";
-        request =
-            "GET " + uri + " HTTP/1.1\r\n" +
-                "Host: localhost\r\n" +
-                "Connection: close\r\n" +
-                "\r\n";
-        response = connector.getResponse(request);
-        assertTrue(response.startsWith("HTTP/1.1 404 "));
+    public static Stream<Arguments> webInfTestExamples()
+    {
+        return Stream.of(
+            // Cannot access WEB-INF.
+            Arguments.of("?/WEB-INF/", "HTTP/1.1 404 "),
+            Arguments.of("?/WEB-INF/one.js", "HTTP/1.1 404 "),
+
+            // Having a path segment and then ".." triggers a special case that the ConcatServlet must detect and avoid.
+            Arguments.of("?/trick/../WEB-INF/one.js", "HTTP/1.1 404 "),
+
+            // Make sure ConcatServlet behaves well if it's case insensitive.
+            Arguments.of("?/trick/../web-inf/one.js", "HTTP/1.1 404 "),
+
+            // Make sure ConcatServlet behaves well if encoded.
+            Arguments.of("?/trick/..%2FWEB-INF%2Fone.js", "HTTP/1.1 404 "),
+            Arguments.of("?/%2557EB-INF/one.js", "HTTP/1.1 500 "),
+            Arguments.of("?/js/%252e%252e/WEB-INF/one.js", "HTTP/1.1 500 ")
+        );
+    }
 
-        // Make sure ConcatServlet behaves well if encoded.
-        uri = contextPath + concatPath + "?/trick/..%2FWEB-INF%2Fone.js";
-        request =
-            "GET " + uri + " HTTP/1.1\r\n" +
-                "Host: localhost\r\n" +
-                "Connection: close\r\n" +
-                "\r\n";
-        response = connector.getResponse(request);
-        assertTrue(response.startsWith("HTTP/1.1 404 "));
+    @ParameterizedTest
+    @MethodSource("webInfTestExamples")
+    public void testWEBINFResourceIsNotServed(String querystring, String expectedStatus) throws Exception
+    {
+        File directoryFile = MavenTestingUtils.getTargetTestingDir();
+        Path directoryPath = directoryFile.toPath();
+        Path hiddenDirectory = directoryPath.resolve("WEB-INF");
+        Files.createDirectories(hiddenDirectory);
+        Path hiddenResource = hiddenDirectory.resolve("one.js");
+        try (OutputStream output = Files.newOutputStream(hiddenResource))
+        {
+            output.write("function() {}".getBytes(StandardCharsets.UTF_8));
+        }
 
-        // Make sure ConcatServlet cannot see file system files.
-        uri = contextPath + concatPath + "?/trick/../../" + directoryFile.getName();
-        request =
+        String contextPath = "";
+        WebAppContext context = new WebAppContext(server, directoryPath.toString(), contextPath);
+        server.setHandler(context);
+        String concatPath = "/concat";
+        context.addServlet(ConcatServlet.class, concatPath);
+        server.start();
+
+        // Verify that I can get the file programmatically, as required by the spec.
+        assertNotNull(context.getServletContext().getResource("/WEB-INF/one.js"));
+
+        String uri = contextPath + concatPath + querystring;
+        String request =
             "GET " + uri + " HTTP/1.1\r\n" +
                 "Host: localhost\r\n" +
                 "Connection: close\r\n" +
                 "\r\n";
-        response = connector.getResponse(request);
-        assertTrue(response.startsWith("HTTP/1.1 404 "));
+        String response = connector.getResponse(request);
+        assertThat(response, startsWith(expectedStatus));
     }
 }

jetty-servlets/src/test/java/org/eclipse/jetty/servlets/WelcomeFilterTest.java

@@ -0,0 +1,143 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.servlets;
+
+import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.EnumSet;
+import java.util.stream.Stream;
+import javax.servlet.DispatcherType;
+
+import org.eclipse.jetty.server.LocalConnector;
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.servlet.FilterHolder;
+import org.eclipse.jetty.toolchain.test.MavenTestingUtils;
+import org.eclipse.jetty.webapp.WebAppContext;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.containsString;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+public class WelcomeFilterTest
+{
+    private Server server;
+    private LocalConnector connector;
+
+    @BeforeEach
+    public void prepareServer() throws Exception
+    {
+        server = new Server();
+        connector = new LocalConnector(server);
+        server.addConnector(connector);
+
+        Path directoryPath = MavenTestingUtils.getTargetTestingDir().toPath();
+        Files.createDirectories(directoryPath);
+        Path welcomeResource = directoryPath.resolve("welcome.html");
+        try (OutputStream output = Files.newOutputStream(welcomeResource))
+        {
+            output.write("<h1>welcome page</h1>".getBytes(StandardCharsets.UTF_8));
+        }
+
+        Path otherResource = directoryPath.resolve("other.html");
+        try (OutputStream output = Files.newOutputStream(otherResource))
+        {
+            output.write("<h1>other resource</h1>".getBytes(StandardCharsets.UTF_8));
+        }
+
+        Path hiddenDirectory = directoryPath.resolve("WEB-INF");
+        Files.createDirectories(hiddenDirectory);
+        Path hiddenResource = hiddenDirectory.resolve("one.js");
+        try (OutputStream output = Files.newOutputStream(hiddenResource))
+        {
+            output.write("CONFIDENTIAL".getBytes(StandardCharsets.UTF_8));
+        }
+
+        Path hiddenWelcome = hiddenDirectory.resolve("index.html");
+        try (OutputStream output = Files.newOutputStream(hiddenWelcome))
+        {
+            output.write("CONFIDENTIAL".getBytes(StandardCharsets.UTF_8));
+        }
+
+        WebAppContext context = new WebAppContext(server, directoryPath.toString(), "/");
+        server.setHandler(context);
+        String concatPath = "/*";
+
+        FilterHolder filterHolder = new FilterHolder(new WelcomeFilter());
+        filterHolder.setInitParameter("welcome", "welcome.html");
+        context.addFilter(filterHolder, concatPath, EnumSet.of(DispatcherType.REQUEST));
+        server.start();
+
+        // Verify that I can get the file programmatically, as required by the spec.
+        assertNotNull(context.getServletContext().getResource("/WEB-INF/one.js"));
+    }
+
+    @AfterEach
+    public void destroy() throws Exception
+    {
+        if (server != null)
+            server.stop();
+    }
+
+    public static Stream<Arguments> argumentsStream()
+    {
+        return Stream.of(
+            // Normal requests for the directory are redirected to the welcome page.
+            Arguments.of("/", new String[]{"HTTP/1.1 200 ", "<h1>welcome page</h1>"}),
+
+            // Try a normal resource (will bypass the filter).
+            Arguments.of("/other.html", new String[]{"HTTP/1.1 200 ", "<h1>other resource</h1>"}),
+
+            // Cannot access files in WEB-INF.
+            Arguments.of("/WEB-INF/one.js", new String[]{"HTTP/1.1 404 "}),
+
+            // Cannot serve welcome from WEB-INF.
+            Arguments.of("/WEB-INF/", new String[]{"HTTP/1.1 404 "}),
+
+            // Try to trick the filter into serving a protected resource.
+            Arguments.of("/WEB-INF/one.js#/", new String[]{"HTTP/1.1 404 "}),
+            Arguments.of("/js/../WEB-INF/one.js#/", new String[]{"HTTP/1.1 404 "}),
+
+            // Test the URI is not double decoded in the dispatcher.
+            Arguments.of("/%2557EB-INF/one.js%23/", new String[]{"HTTP/1.1 404 "})
+        );
+    }
+
+    @ParameterizedTest
+    @MethodSource("argumentsStream")
+    public void testWelcomeFilter(String uri, String[] contains) throws Exception
+    {
+        String request =
+            "GET " + uri + " HTTP/1.1\r\n" +
+                "Host: localhost\r\n" +
+                "Connection: close\r\n" +
+                "\r\n";
+        String response = connector.getResponse(request);
+        for (String s : contains)
+        {
+            assertThat(response, containsString(s));
+        }
+    }
+}