// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/ssl/certificate_error_reporter.h"

#include <stddef.h>

#include <set>
#include <utility>

#include <memory>

#include "base/logging.h"
#include "base/strings/string_piece.h"
#include "chrome/browser/net/chrome_report_sender.h"
#include "components/encrypted_messages/encrypted_message.pb.h"
#include "components/encrypted_messages/message_encrypter.h"
#include "net/traffic_annotation/network_traffic_annotation.h"
#include "net/url_request/report_sender.h"
#include "services/network/public/cpp/shared_url_loader_factory.h"

namespace {

// Constants used for crypto. The corresponding private key is used by
// the SafeBrowsing client-side detection server to decrypt reports.
static const uint8_t kServerPublicKey[] = {
    0x51, 0xcc, 0x52, 0x67, 0x42, 0x47, 0x3b, 0x10, 0xe8, 0x63, 0x18,
    0x3c, 0x61, 0xa7, 0x96, 0x76, 0x86, 0x91, 0x40, 0x71, 0x39, 0x5f,
    0x31, 0x1a, 0x39, 0x5b, 0x76, 0xb1, 0x6b, 0x3d, 0x6a, 0x2b};

static const uint32_t kServerPublicKeyVersion = 1;

static const char kHkdfLabel[] = "certificate report";

constexpr net::NetworkTrafficAnnotationTag
    kSafeBrowsingCertificateErrorReportingTrafficAnnotation =
        net::DefineNetworkTrafficAnnotation(
            "safe_browsing_certificate_error_reporting",
            R"(
        semantics {
          sender: "Safe Browsing Extended Reporting"
          description:
            "When a user has opted in to Safe Browsing Extended Reporting, "
            "Chrome will send information about HTTPS certificate errors that "
            "the user encounters to Google. This information includes the "
            "certificate chain and the type of error encountered. The "
            "information is used to understand and mitigate common causes of "
            "spurious certificate errors."
          trigger:
            "When the user encounters an HTTPS certificate error and has opted "
            "in to Safe Browsing Extended Reporting."
          data:
            "The hostname that was requested, the certificate chain, the time "
            "of the request, information about the type of certificate error "
            "that was encountered, and whether the user was opted in to a "
            "limited set of field trials that affect certificate validation."
          destination: GOOGLE_OWNED_SERVICE
        }
        policy {
          cookies_allowed: NO
          setting:
            "Users can control this feature via the 'Automatically report "
            "details of possible security incidents to Google' setting under "
            "'Privacy'. The feature is disabled by default."
          chrome_policy {
            SafeBrowsingExtendedReportingOptInAllowed {
              policy_options {mode: MANDATORY}
              SafeBrowsingExtendedReportingOptInAllowed: false
            }
          }
        })");

}  // namespace

CertificateErrorReporter::CertificateErrorReporter(
    scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory,
    const GURL& upload_url)
    : CertificateErrorReporter(url_loader_factory,
                               upload_url,
                               kServerPublicKey,
                               kServerPublicKeyVersion) {}

CertificateErrorReporter::CertificateErrorReporter(
    scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory,
    const GURL& upload_url,
    const uint8_t server_public_key[/* 32 */],
    const uint32_t server_public_key_version)
    : url_loader_factory_(url_loader_factory),
      upload_url_(upload_url),
      server_public_key_(server_public_key),
      server_public_key_version_(server_public_key_version) {
  DCHECK(!upload_url.is_empty());
}

CertificateErrorReporter::~CertificateErrorReporter() {}

void CertificateErrorReporter::SendExtendedReportingReport(
    const std::string& serialized_report,
    base::OnceCallback<void()> success_callback,
    base::OnceCallback<void(int, int)> error_callback) {
  std::string serialized_encrypted_report;
  const std::string* string_to_send = &serialized_report;
  if (!upload_url_.SchemeIsCryptographic()) {
    encrypted_messages::EncryptedMessage encrypted_report;
    // By mistake, the HKDF label here ends up with an extra null byte on
    // the end, due to using sizeof(kHkdfLabel) in the StringPiece
    // constructor instead of strlen(kHkdfLabel). This has since been changed
    // to strlen() + 1, but will need to be fixed in future to just be strlen.
    // TODO(estark): fix this...
    //  https://crbug.com/517746
    if (!encrypted_messages::EncryptSerializedMessage(
            server_public_key_, server_public_key_version_,
            base::StringPiece(kHkdfLabel, strlen(kHkdfLabel) + 1),
            serialized_report, &encrypted_report)) {
      LOG(ERROR) << "Failed to encrypt serialized report.";
      return;
    }

    encrypted_report.SerializeToString(&serialized_encrypted_report);
    string_to_send = &serialized_encrypted_report;
  }

  SendReport(url_loader_factory_,
             kSafeBrowsingCertificateErrorReportingTrafficAnnotation,
             upload_url_, "application/octet-stream", *string_to_send,
             std::move(success_callback), std::move(error_callback));
}