Use a filter to enforce all HTTP requests through SSL

Rather than checking only the host page, enforce SSL on every
request, including our JavaScript, icons, and RPCs.

Change-Id: I902e958fd53afa8e16fbc9c599852ee9faaec474
Signed-off-by: Shawn O. Pearce <sop@google.com>

gerrit-httpd/src/main/java/com/google/gerrit/httpd/RequireSslFilter.java

@@ -0,0 +1,97 @@
+// Copyright (C) 2009 The Android Open Source Project
+//
+// 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.google.gerrit.httpd;
+
+import com.google.gerrit.server.config.CanonicalWebUrl;
+import com.google.gerrit.server.config.Nullable;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
+import com.google.inject.servlet.ServletModule;
+
+import java.io.IOException;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+/** Requires the connection to use SSL, redirects if not. */
+@Singleton
+class RequireSslFilter implements Filter {
+  static class Module extends ServletModule {
+    @Override
+    protected void configureServlets() {
+      filter("/*").through(RequireSslFilter.class);
+    }
+  }
+
+  private final Provider<String> urlProvider;
+
+  @Inject
+  RequireSslFilter(@CanonicalWebUrl @Nullable final Provider<String> urlProvider) {
+    this.urlProvider = urlProvider;
+  }
+
+  @Override
+  public void init(FilterConfig filterConfig) {
+  }
+
+  @Override
+  public void destroy() {
+  }
+
+  @Override
+  public void doFilter(final ServletRequest request,
+      final ServletResponse response, final FilterChain chain)
+      throws IOException, ServletException {
+    final HttpServletRequest req = (HttpServletRequest) request;
+    final HttpServletResponse rsp = (HttpServletResponse) response;
+
+    if (isSecure(req)) {
+      chain.doFilter(request, response);
+
+    } else {
+      // If we wanted SSL, but the user didn't come to us over it,
+      // force SSL by issuing a protocol redirect. Try to keep the
+      // name "localhost" in case this is an SSH port tunnel.
+      //
+      final String url;
+      if (isLocalHost(req)) {
+        final StringBuffer b = req.getRequestURL();
+        b.replace(0, b.indexOf(":"), "https");
+        url = b.toString();
+
+      } else {
+        url = urlProvider.get();
+      }
+      rsp.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY);
+      rsp.setHeader("Location", url);
+    }
+  }
+
+  private static boolean isSecure(final HttpServletRequest req) {
+    return "https".equals(req.getScheme()) || req.isSecure();
+  }
+
+  private static boolean isLocalHost(final HttpServletRequest req) {
+    return "localhost".equals(req.getServerName())
+        || "127.0.0.1".equals(req.getServerName());
+  }
+}

gerrit-httpd/src/main/java/com/google/gerrit/httpd/WebModule.java

@@ -29,8 +29,10 @@ import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.RemotePeer;
 import com.google.gerrit.server.account.AccountManager;
 import com.google.gerrit.server.config.AuthConfig;
+import com.google.gerrit.server.config.CanonicalWebUrl;
 import com.google.gerrit.server.config.FactoryModule;
 import com.google.gerrit.server.config.GerritRequestModule;
+import com.google.gerrit.server.config.Nullable;
 import com.google.gerrit.server.contact.ContactStore;
 import com.google.gerrit.server.contact.ContactStoreProvider;
 import com.google.gerrit.server.ssh.SshInfo;
@@ -49,15 +51,19 @@ public class WebModule extends FactoryModule {
   private final Provider<SshInfo> sshInfoProvider;
   private final Provider<SshKeyCache> sshKeyCacheProvider;
   private final AuthType authType;
+  private final boolean wantSSL;
   private final GitWebConfig gitWebConfig;
 
   @Inject
   WebModule(final Provider<SshInfo> sshInfoProvider,
       final Provider<SshKeyCache> sshKeyCacheProvider,
-      final AuthConfig authConfig, final Injector creatingInjector) {
+      final AuthConfig authConfig,
+      @CanonicalWebUrl @Nullable final String canonicalUrl,
+      final Injector creatingInjector) {
     this.sshInfoProvider = sshInfoProvider;
     this.sshKeyCacheProvider = sshKeyCacheProvider;
     this.authType = authConfig.getAuthType();
+    this.wantSSL = canonicalUrl != null && canonicalUrl.startsWith("https:");
 
     this.gitWebConfig =
         creatingInjector.createChildInjector(new AbstractModule() {
@@ -77,6 +83,10 @@ public class WebModule extends FactoryModule {
       }
     });
 
+    if (wantSSL) {
+      install(new RequireSslFilter.Module());
+    }
+
     switch (authType) {
       case OPENID:
         install(new OpenIdModule());

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/HostPageServlet.java

@@ -19,8 +19,7 @@ import com.google.gerrit.common.data.HostPageData;
 import com.google.gerrit.httpd.HtmlDomUtil;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
-import com.google.gerrit.server.config.CanonicalWebUrl;
-import com.google.gerrit.server.config.Nullable;
+import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.config.SitePath;
 import com.google.gwt.user.server.rpc.RPCServletUtils;
 import com.google.gwtjsonrpc.server.JsonServlet;
@@ -28,6 +27,7 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 
+import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.w3c.dom.Document;
@@ -52,20 +52,15 @@ import javax.servlet.http.HttpServletResponse;
 public class HostPageServlet extends HttpServlet {
   private final Provider<CurrentUser> currentUser;
   private final GerritConfig config;
-  private final Provider<String> urlProvider;
-  private final boolean wantSSL;
   private final Document hostDoc;
 
   @Inject
   HostPageServlet(final Provider<CurrentUser> cu,
       @SitePath final File sitePath, final GerritConfig gc,
-      @CanonicalWebUrl @Nullable final Provider<String> up,
-      @CanonicalWebUrl @Nullable final String configuredUrl,
-      final ServletContext servletContext) throws IOException {
+      @GerritServerConfig final Config cfg, final ServletContext servletContext)
+      throws IOException {
     currentUser = cu;
-    urlProvider = up;
     config = gc;
-    wantSSL = configuredUrl != null && configuredUrl.startsWith("https:");
 
     final String pageName = "HostPage.html";
     hostDoc = HtmlDomUtil.parseFile(getClass(), pageName);
@@ -187,23 +182,6 @@ public class HostPageServlet extends HttpServlet {
   @Override
   protected void doGet(final HttpServletRequest req,
       final HttpServletResponse rsp) throws IOException {
-    // If we wanted SSL, but the user didn't come to us over an SSL channel,
-    // force it to be SSL by issuing a protocol redirect. Try to keep the
-    // name "localhost" in case this is an SSH port tunnel.
-    //
-    if (wantSSL && !isSecure(req)) {
-      final StringBuffer reqUrl = req.getRequestURL();
-      if (isLocalHost(req)) {
-        reqUrl.replace(0, reqUrl.indexOf(":"), "https");
-      } else {
-        reqUrl.setLength(0);
-        reqUrl.append(urlProvider.get());
-      }
-      rsp.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY);
-      rsp.setHeader("Location", reqUrl.toString());
-      return;
-    }
-
     final HostPageData pageData = new HostPageData();
     pageData.config = config;
 
@@ -237,13 +215,4 @@ public class HostPageServlet extends HttpServlet {
       out.close();
     }
   }
-
-  private static boolean isSecure(final HttpServletRequest req) {
-    return "https".equals(req.getScheme()) || req.isSecure();
-  }
-
-  private static boolean isLocalHost(final HttpServletRequest req) {
-    return "localhost".equals(req.getServerName())
-        || "127.0.0.1".equals(req.getServerName());
-  }
 }