chrome/browser/safe_browsing/download_protection_service.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4 //
   5 // Helper class which handles communication with the SafeBrowsing servers for
   6 // improved binary download protection.
   7
   8 #ifndef CHROME_BROWSER_SAFE_BROWSING_DOWNLOAD_PROTECTION_SERVICE_H_
   9 #define CHROME_BROWSER_SAFE_BROWSING_DOWNLOAD_PROTECTION_SERVICE_H_
  10
  11 #include <set>
  12 #include <string>
  13 #include <vector>
  14
  15 #include "base/basictypes.h"
  16 #include "base/callback.h"
  17 #include "base/files/file_path.h"
  18 #include "base/gtest_prod_util.h"
  19 #include "base/memory/ref_counted.h"
  20 #include "chrome/browser/safe_browsing/database_manager.h"
  21 #include "chrome/browser/safe_browsing/ui_manager.h"
  22 #include "url/gurl.h"
  23
  24
  25 namespace content {
  26 class DownloadItem;
  27 class PageNavigator;
  28 }
  29
  30 namespace net {
  31 class URLRequestContextGetter;
  32 class X509Certificate;
  33 }  // namespace net
  34
  35 namespace safe_browsing {
  36 class DownloadFeedbackService;
  37 class BinaryFeatureExtractor;
  38
  39 // This class provides an asynchronous API to check whether a particular
  40 // client download is malicious or not.
  41 class DownloadProtectionService {
  42  public:
  43   enum DownloadCheckResult {
  44     UNKNOWN,
  45     SAFE,
  46     DANGEROUS,
  47     UNCOMMON,
  48     DANGEROUS_HOST,
  49     POTENTIALLY_UNWANTED
  50   };
  51
  52   // Callback type which is invoked once the download request is done.
  53   typedef base::Callback<void(DownloadCheckResult)> CheckDownloadCallback;
  54
  55   // Creates a download service.  The service is initially disabled.  You need
  56   // to call SetEnabled() to start it.  |sb_service| owns this object; we
  57   // keep a reference to |request_context_getter|.
  58   DownloadProtectionService(
  59       SafeBrowsingService* sb_service,
  60       net::URLRequestContextGetter* request_context_getter);
  61
  62   virtual ~DownloadProtectionService();
  63
  64   // Checks whether the given client download is likely to be malicious or not.
  65   // The result is delivered asynchronously via the given callback.  This
  66   // method must be called on the UI thread, and the callback will also be
  67   // invoked on the UI thread.  This method must be called once the download
  68   // is finished and written to disk.
  69   virtual void CheckClientDownload(content::DownloadItem* item,
  70                                    const CheckDownloadCallback& callback);
  71
  72   // Checks whether any of the URLs in the redirect chain of the
  73   // download match the SafeBrowsing bad binary URL list.  The result is
  74   // delivered asynchronously via the given callback.  This method must be
  75   // called on the UI thread, and the callback will also be invoked on the UI
  76   // thread.  Pre-condition: !info.download_url_chain.empty().
  77   virtual void CheckDownloadUrl(const content::DownloadItem& item,
  78                                 const CheckDownloadCallback& callback);
  79
  80   // Returns true iff the download specified by |info| should be scanned by
  81   // CheckClientDownload() for malicious content.
  82   virtual bool IsSupportedDownload(const content::DownloadItem& item,
  83                                    const base::FilePath& target_path) const;
  84
  85   // Display more information to the user regarding the download specified by
  86   // |info|. This method is invoked when the user requests more information
  87   // about a download that was marked as malicious.
  88   void ShowDetailsForDownload(const content::DownloadItem& item,
  89                               content::PageNavigator* navigator);
  90
  91   // Enables or disables the service.  This is usually called by the
  92   // SafeBrowsingService, which tracks whether any profile uses these services
  93   // at all.  Disabling causes any pending and future requests to have their
  94   // callbacks called with "UNKNOWN" results.
  95   void SetEnabled(bool enabled);
  96
  97   bool enabled() const {
  98     return enabled_;
  99   }
 100
 101   // Returns the timeout that is used by CheckClientDownload().
 102   int64 download_request_timeout_ms() const {
 103     return download_request_timeout_ms_;
 104   }
 105
 106   DownloadFeedbackService* feedback_service() {
 107     return feedback_service_.get();
 108   }
 109
 110  protected:
 111   // Enum to keep track why a particular download verdict was chosen.
 112   // This is used to keep some stats around.
 113   enum DownloadCheckResultReason {
 114     REASON_INVALID_URL,
 115     REASON_SB_DISABLED,
 116     REASON_WHITELISTED_URL,
 117     REASON_WHITELISTED_REFERRER,
 118     REASON_INVALID_REQUEST_PROTO,
 119     REASON_SERVER_PING_FAILED,
 120     REASON_INVALID_RESPONSE_PROTO,
 121     REASON_NOT_BINARY_FILE,
 122     REASON_REQUEST_CANCELED,
 123     REASON_DOWNLOAD_DANGEROUS,
 124     REASON_DOWNLOAD_SAFE,
 125     REASON_EMPTY_URL_CHAIN,
 126     DEPRECATED_REASON_HTTPS_URL,
 127     REASON_PING_DISABLED,
 128     REASON_TRUSTED_EXECUTABLE,
 129     REASON_OS_NOT_SUPPORTED,
 130     REASON_DOWNLOAD_UNCOMMON,
 131     REASON_DOWNLOAD_NOT_SUPPORTED,
 132     REASON_INVALID_RESPONSE_VERDICT,
 133     REASON_ARCHIVE_WITHOUT_BINARIES,
 134     REASON_DOWNLOAD_DANGEROUS_HOST,
 135     REASON_DOWNLOAD_POTENTIALLY_UNWANTED,
 136     REASON_MAX  // Always add new values before this one.
 137   };
 138
 139  private:
 140   class CheckClientDownloadRequest;  // Per-request state
 141   friend class DownloadProtectionServiceTest;
 142   FRIEND_TEST_ALL_PREFIXES(DownloadProtectionServiceTest,
 143                            CheckClientDownloadWhitelistedUrl);
 144   FRIEND_TEST_ALL_PREFIXES(DownloadProtectionServiceTest,
 145                            CheckClientDownloadValidateRequest);
 146   FRIEND_TEST_ALL_PREFIXES(DownloadProtectionServiceTest,
 147                            CheckClientDownloadSuccess);
 148   FRIEND_TEST_ALL_PREFIXES(DownloadProtectionServiceTest,
 149                            CheckClientDownloadHTTPS);
 150   FRIEND_TEST_ALL_PREFIXES(DownloadProtectionServiceTest,
 151                            CheckClientDownloadZip);
 152   FRIEND_TEST_ALL_PREFIXES(DownloadProtectionServiceTest,
 153                            CheckClientDownloadFetchFailed);
 154   FRIEND_TEST_ALL_PREFIXES(DownloadProtectionServiceTest,
 155                            TestDownloadRequestTimeout);
 156   FRIEND_TEST_ALL_PREFIXES(DownloadProtectionServiceTest,
 157                            CheckClientCrxDownloadSuccess);
 158   static const char kDownloadRequestUrl[];
 159
 160   // Cancels all requests in |download_requests_|, and empties it, releasing
 161   // the references to the requests.
 162   void CancelPendingRequests();
 163
 164   // Called by a CheckClientDownloadRequest instance when it finishes, to
 165   // remove it from |download_requests_|.
 166   void RequestFinished(CheckClientDownloadRequest* request);
 167
 168   // Given a certificate and its immediate issuer certificate, generates the
 169   // list of strings that need to be checked against the download whitelist to
 170   // determine whether the certificate is whitelisted.
 171   static void GetCertificateWhitelistStrings(
 172       const net::X509Certificate& certificate,
 173       const net::X509Certificate& issuer,
 174       std::vector<std::string>* whitelist_strings);
 175
 176   // Returns the URL that will be used for download requests.
 177   static GURL GetDownloadRequestUrl();
 178
 179   // These pointers may be NULL if SafeBrowsing is disabled.
 180   scoped_refptr<SafeBrowsingUIManager> ui_manager_;
 181   scoped_refptr<SafeBrowsingDatabaseManager> database_manager_;
 182
 183   // The context we use to issue network requests.
 184   scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
 185
 186   // Map of client download request to the corresponding callback that
 187   // has to be invoked when the request is done.  This map contains all
 188   // pending server requests.
 189   std::set<scoped_refptr<CheckClientDownloadRequest> > download_requests_;
 190
 191   // Keeps track of the state of the service.
 192   bool enabled_;
 193
 194   // BinaryFeatureExtractor object, may be overridden for testing.
 195   scoped_refptr<BinaryFeatureExtractor> binary_feature_extractor_;
 196
 197   int64 download_request_timeout_ms_;
 198
 199   scoped_ptr<DownloadFeedbackService> feedback_service_;
 200
 201   DISALLOW_COPY_AND_ASSIGN(DownloadProtectionService);
 202 };
 203 }  // namespace safe_browsing
 204
 205 #endif  // CHROME_BROWSER_SAFE_BROWSING_DOWNLOAD_PROTECTION_SERVICE_H_