// Copyright (C) 2008 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.rpc;
import com.google.common.collect.ListMultimap;
import com.google.common.collect.MultimapBuilder;
import com.google.gerrit.audit.AuditService;
import com.google.gerrit.audit.RpcAuditEvent;
import com.google.gerrit.common.TimeUtil;
import com.google.gerrit.common.audit.Audit;
import com.google.gerrit.common.auth.SignInRequired;
import com.google.gerrit.common.errors.NotSignedInException;
import com.google.gerrit.extensions.registration.DynamicItem;
import com.google.gerrit.httpd.WebSession;
import com.google.gerrit.server.AccessPath;
import com.google.gerrit.server.CurrentUser;
import com.google.gson.GsonBuilder;
import com.google.gwtjsonrpc.common.RemoteJsonService;
import com.google.gwtjsonrpc.server.ActiveCall;
import com.google.gwtjsonrpc.server.JsonServlet;
import com.google.gwtjsonrpc.server.MethodHandle;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Inject;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** Base JSON servlet to ensure the current user is not forged. */
@SuppressWarnings("serial")
final class GerritJsonServlet extends JsonServlet<GerritJsonServlet.GerritCall> {
private static final Logger log = LoggerFactory.getLogger(GerritJsonServlet.class);
private static final ThreadLocal<GerritCall> currentCall = new ThreadLocal<>();
private static final ThreadLocal<MethodHandle> currentMethod = new ThreadLocal<>();
private final DynamicItem<WebSession> session;
private final RemoteJsonService service;
private final AuditService audit;
@Inject
GerritJsonServlet(
final DynamicItem<WebSession> w, final RemoteJsonService s, final AuditService a) {
session = w;
service = s;
audit = a;
}
@Override
protected GerritCall createActiveCall(
final HttpServletRequest req, final HttpServletResponse rsp) {
final GerritCall call = new GerritCall(session.get(), req, new AuditedHttpServletResponse(rsp));
currentCall.set(call);
return call;
}
@Override
protected GsonBuilder createGsonBuilder() {
return gerritDefaultGsonBuilder();
}
private static GsonBuilder gerritDefaultGsonBuilder() {
final GsonBuilder g = defaultGsonBuilder();
g.registerTypeAdapter(
org.eclipse.jgit.diff.Edit.class, new org.eclipse.jgit.diff.EditDeserializer());
return g;
}
@Override
protected void preInvoke(final GerritCall call) {
super.preInvoke(call);
if (call.isComplete()) {
return;
}
if (call.getMethod().getAnnotation(SignInRequired.class) != null) {
// If SignInRequired is set on this method we must have both a
// valid XSRF token *and* have the user signed in. Doing these
// checks also validates that they agree on the user identity.
//
if (!call.requireXsrfValid() || !session.get().isSignedIn()) {
call.onFailure(new NotSignedInException());
}
}
}
@Override
protected Object createServiceHandle() {
return service;
}
@Override
protected void service(final HttpServletRequest req, final HttpServletResponse resp)
throws IOException {
try {
super.service(req, resp);
} finally {
audit();
currentCall.set(null);
}
}
private void audit() {
try {
GerritCall call = currentCall.get();
MethodHandle method = call.getMethod();
if (method == null) {
return;
}
Audit note = method.getAnnotation(Audit.class);
if (note != null) {
String sid = call.getWebSession().getSessionId();
CurrentUser username = call.getWebSession().getUser();
ListMultimap<String, ?> args = extractParams(note, call);
String what = extractWhat(note, call);
Object result = call.getResult();
audit.dispatch(
new RpcAuditEvent(
sid,
username,
what,
call.getWhen(),
args,
call.getHttpServletRequest().getMethod(),
call.getHttpServletRequest().getMethod(),
((AuditedHttpServletResponse) (call.getHttpServletResponse())).getStatus(),
result));
}
} catch (Throwable all) {
log.error("Unable to log the call", all);
}
}
private ListMultimap<String, ?> extractParams(Audit note, GerritCall call) {
ListMultimap<String, Object> args = MultimapBuilder.hashKeys().arrayListValues().build();
Object[] params = call.getParams();
for (int i = 0; i < params.length; i++) {
args.put("$" + i, params[i]);
}
for (int idx : note.obfuscate()) {
args.removeAll("$" + idx);
args.put("$" + idx, "*****");
}
return args;
}
private String extractWhat(final Audit note, final GerritCall call) {
Class<?> methodClass = call.getMethodClass();
String methodClassName = methodClass != null ? methodClass.getName() : "<UNKNOWN_CLASS>";
methodClassName = methodClassName.substring(methodClassName.lastIndexOf(".") + 1);
String what = note.action();
if (what.length() == 0) {
what = call.getMethod().getName();
}
return methodClassName + "." + what;
}
static class GerritCall extends ActiveCall {
private final WebSession session;
private final long when;
private static final Field resultField;
private static final Field methodField;
// Needed to allow access to non-public result field in GWT/JSON-RPC
static {
resultField = getPrivateField(ActiveCall.class, "result");
methodField = getPrivateField(MethodHandle.class, "method");
}
private static Field getPrivateField(Class<?> clazz, String fieldName) {
Field declaredField = null;
try {
declaredField = clazz.getDeclaredField(fieldName);
declaredField.setAccessible(true);
} catch (Exception e) {
log.error("Unable to expose RPS/JSON result field");
}
return declaredField;
}
// Surrogate of the missing getMethodClass() in GWT/JSON-RPC
public Class<?> getMethodClass() {
if (methodField == null) {
return null;
}
try {
Method method = (Method) methodField.get(this.getMethod());
return method.getDeclaringClass();
} catch (IllegalArgumentException e) {
log.error("Cannot access result field");
} catch (IllegalAccessException e) {
log.error("No permissions to access result field");
}
return null;
}
// Surrogate of the missing getResult() in GWT/JSON-RPC
public Object getResult() {
if (resultField == null) {
return null;
}
try {
return resultField.get(this);
} catch (IllegalArgumentException e) {
log.error("Cannot access result field");
} catch (IllegalAccessException e) {
log.error("No permissions to access result field");
}
return null;
}
GerritCall(final WebSession session, final HttpServletRequest i, final HttpServletResponse o) {
super(i, o);
this.session = session;
this.when = TimeUtil.nowMs();
}
@Override
public MethodHandle getMethod() {
if (currentMethod.get() == null) {
return super.getMethod();
}
return currentMethod.get();
}
@Override
public void onFailure(final Throwable error) {
if (error instanceof IllegalArgumentException || error instanceof IllegalStateException) {
super.onFailure(error);
} else if (error instanceof OrmException || error instanceof RuntimeException) {
onInternalFailure(error);
} else {
super.onFailure(error);
}
}
@Override
public boolean xsrfValidate() {
final String keyIn = getXsrfKeyIn();
if (keyIn == null || "".equals(keyIn)) {
// Anonymous requests don't need XSRF protection, they shouldn't
// be able to cause critical state changes.
//
return !session.isSignedIn();
} else if (session.isSignedIn() && session.isValidXGerritAuth(keyIn)) {
// The session must exist, and must be using this token.
//
session.getUser().setAccessPath(AccessPath.JSON_RPC);
return true;
}
return false;
}
public WebSession getWebSession() {
return session;
}
public long getWhen() {
return when;
}
public long getElapsed() {
return TimeUtil.nowMs() - when;
}
}
}