/*
 * Copyright (C) 2013 Google, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "core/html/parser/XSSAuditorDelegate.h"

#include "core/dom/Document.h"
#include "core/frame/LocalFrame.h"
#include "core/inspector/ConsoleMessage.h"
#include "core/loader/DocumentLoader.h"
#include "core/loader/FrameLoader.h"
#include "core/loader/FrameLoaderClient.h"
#include "core/loader/NavigationScheduler.h"
#include "core/loader/PingLoader.h"
#include "platform/json/JSONValues.h"
#include "platform/network/EncodedFormData.h"
#include "platform/network/ResourceError.h"
#include "platform/weborigin/SecurityOrigin.h"
#include "wtf/text/StringBuilder.h"

namespace blink {

String XSSInfo::buildConsoleError() const {
  StringBuilder message;
  message.append("The XSS Auditor ");
  message.append(m_didBlockEntirePage ? "blocked access to"
                                      : "refused to execute a script in");
  message.append(" '");
  message.append(m_originalURL);
  message.append("' because ");
  message.append(m_didBlockEntirePage ? "the source code of a script"
                                      : "its source code");
  message.append(" was found within the request.");

  if (m_didSendXSSProtectionHeader)
    message.append(
        " The server sent an 'X-XSS-Protection' header requesting this "
        "behavior.");
  else
    message.append(
        " The auditor was enabled as the server did not send an "
        "'X-XSS-Protection' header.");

  return message.toString();
}

bool XSSInfo::isSafeToSendToAnotherThread() const {
  return m_originalURL.isSafeToSendToAnotherThread();
}

XSSAuditorDelegate::XSSAuditorDelegate(Document* document)
    : m_document(document), m_didSendNotifications(false) {
  ASSERT(isMainThread());
  ASSERT(m_document);
}

DEFINE_TRACE(XSSAuditorDelegate) {
  visitor->trace(m_document);
}

PassRefPtr<EncodedFormData> XSSAuditorDelegate::generateViolationReport(
    const XSSInfo& xssInfo) {
  ASSERT(isMainThread());

  FrameLoader& frameLoader = m_document->frame()->loader();
  String httpBody;
  if (frameLoader.documentLoader()) {
    if (EncodedFormData* formData =
            frameLoader.documentLoader()->originalRequest().httpBody())
      httpBody = formData->flattenToString();
  }

  std::unique_ptr<JSONObject> reportDetails = JSONObject::create();
  reportDetails->setString("request-url", xssInfo.m_originalURL);
  reportDetails->setString("request-body", httpBody);

  std::unique_ptr<JSONObject> reportObject = JSONObject::create();
  reportObject->setObject("xss-report", std::move(reportDetails));

  return EncodedFormData::create(reportObject->toJSONString().utf8().data());
}

void XSSAuditorDelegate::didBlockScript(const XSSInfo& xssInfo) {
  ASSERT(isMainThread());

  UseCounter::count(m_document, xssInfo.m_didBlockEntirePage
                                    ? UseCounter::XSSAuditorBlockedEntirePage
                                    : UseCounter::XSSAuditorBlockedScript);

  m_document->addConsoleMessage(ConsoleMessage::create(
      JSMessageSource, ErrorMessageLevel, xssInfo.buildConsoleError()));

  FrameLoader& frameLoader = m_document->frame()->loader();
  if (xssInfo.m_didBlockEntirePage)
    frameLoader.stopAllLoaders();

  if (!m_didSendNotifications) {
    m_didSendNotifications = true;

    frameLoader.client()->didDetectXSS(m_document->url(),
                                       xssInfo.m_didBlockEntirePage);

    if (!m_reportURL.isEmpty())
      PingLoader::sendViolationReport(m_document->frame(), m_reportURL,
                                      generateViolationReport(xssInfo),
                                      PingLoader::XSSAuditorViolationReport);
  }

  if (xssInfo.m_didBlockEntirePage) {
    m_document->frame()->navigationScheduler().schedulePageBlock(
        m_document, ResourceError::BLOCKED_BY_XSS_AUDITOR);
  }
}

}  // namespace blink