Adding a DownloadRestrictions group policy.

chrome/browser/download/chrome_download_manager_delegate.cc

 // Copyright (c) 2012 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/download/chrome_download_manager_delegate.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 137 matching lines @@
 // |callback| is invoked with a danger type determined as follows:
 //
 // Danger type is (in order of preference):
 //   * DANGEROUS_URL, if the URL is a known malware site.
 //   * MAYBE_DANGEROUS_CONTENT, if the content will be scanned for
 //         malware. I.e. |is_content_check_supported| is true.
 //   * NOT_DANGEROUS.
 void CheckDownloadUrlDone(
     const DownloadTargetDeterminerDelegate::CheckDownloadUrlCallback& callback,
     bool is_content_check_supported,
+    DownloadItem* restricted_download_item,
     DownloadProtectionService::DownloadCheckResult result) {
+  // The restricted_download_item is a weak pointer that's only safe to acces on
+  // the UI thread.
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
   content::DownloadDangerType danger_type;
   if (result == DownloadProtectionService::SAFE ||
       result == DownloadProtectionService::UNKNOWN) {
     // If this type of files is handled by the enhanced SafeBrowsing download
     // protection, mark it as potentially dangerous content until we are done
     // with scanning it.
     if (is_content_check_supported)
       danger_type = content::DOWNLOAD_DANGER_TYPE_MAYBE_DANGEROUS_CONTENT;
     else
       danger_type = content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS;
   } else {
     // If the URL is malicious, we'll use that as the danger type. The results
     // of the content check, if one is performed, will be ignored.
     danger_type = content::DOWNLOAD_DANGER_TYPE_DANGEROUS_URL;
   }
   callback.Run(danger_type);
+  // TODO(mad): Find a way to interrupt the download here when
+  // restricted_download_item is not null and danger_type is set to URL.
 }
 
 #endif  // FULL_SAFE_BROWSING
 
 // Called asynchronously to determine the MIME type for |path|.
 std::string GetMimeType(const base::FilePath& path) {
   std::string mime_type;
   net::GetMimeTypeFromFile(path, &mime_type);
   return mime_type;
 }
@@ skipping 155 matching lines @@
     // In case the service was disabled between the download starting and now,
     // we need to restore the danger state.
     content::DownloadDangerType danger_type = item->GetDangerType();
     if (DownloadItemModel(item).GetDangerLevel() !=
             DownloadFileType::NOT_DANGEROUS &&
         (danger_type == content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS ||
          danger_type ==
              content::DOWNLOAD_DANGER_TYPE_MAYBE_DANGEROUS_CONTENT)) {
       DVLOG(2) << __func__
                << "() SB service disabled. Marking download as DANGEROUS FILE";
-      item->OnContentCheckCompleted(
-          content::DOWNLOAD_DANGER_TYPE_DANGEROUS_FILE);
+      if (ShouldBlockFile(content::DOWNLOAD_DANGER_TYPE_DANGEROUS_FILE)) {
+        item->OnContentCheckCompleted(
+            content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS, true /*block_file*/);
+      } else {
+        item->OnContentCheckCompleted(danger_type, false);
+      }
       UMA_HISTOGRAM_ENUMERATION("Download.DangerousFile.Reason",
                                 SB_NOT_AVAILABLE, DANGEROUS_FILE_REASON_MAX);
       content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
                                        internal_complete_callback);
       return false;
     }
   } else if (!state->is_complete()) {
     // Don't complete the download until we have an answer.
     state->set_callback(internal_complete_callback);
     return false;
@@ skipping 182 matching lines @@
       FROM_HERE,
       base::Bind(&base::PathExists, download->GetTargetFilePath()),
       callback);
 }
 
 std::string
 ChromeDownloadManagerDelegate::ApplicationClientIdForFileScanning() const {
   return std::string(chrome::kApplicationClientIDStringForAVScanning);
 }
 
+bool ChromeDownloadManagerDelegate::ShouldBlockAllDownloads() const {
+  return download_prefs_->download_restriction() ==
+         DownloadPrefs::DOWNLOAD_RESTRICTION_ALL_FILES;
+}
+
 DownloadProtectionService*
     ChromeDownloadManagerDelegate::GetDownloadProtectionService() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 #if defined(FULL_SAFE_BROWSING)
   safe_browsing::SafeBrowsingService* sb_service =
       g_browser_process->safe_browsing_service();
   if (sb_service && sb_service->download_protection_service() &&
       profile_->GetPrefs()->GetBoolean(prefs::kSafeBrowsingEnabled)) {
     return sb_service->download_protection_service();
   }
@@ skipping 91 matching lines @@
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
 #if defined(FULL_SAFE_BROWSING)
   safe_browsing::DownloadProtectionService* service =
       GetDownloadProtectionService();
   if (service) {
     bool is_content_check_supported =
         service->IsSupportedDownload(*download, suggested_path);
     DVLOG(2) << __func__ << "() Start SB URL check for download = "
              << download->DebugString(false);
-    service->CheckDownloadUrl(download,
-                              base::Bind(&CheckDownloadUrlDone,
-                                         callback,
-                                         is_content_check_supported));
+    DownloadItem* restricted_download_item = nullptr;
+    if (download_prefs_->download_restriction() ==
+        DownloadPrefs::DOWNLOAD_RESTRICTION_POTENTIALLY_DANGEROUS_FILES) {
+      restricted_download_item = download;
+    }
+    service->CheckDownloadUrl(
+        download,
+        base::Bind(&CheckDownloadUrlDone, callback, is_content_check_supported,
+                   restricted_download_item));
     return;
   }
 #endif
   callback.Run(content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS);
 }
 
 void ChromeDownloadManagerDelegate::GetFileMimeType(
     const base::FilePath& path,
     const GetFileMimeTypeCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
@@ skipping 50 matching lines @@
       case DownloadProtectionService::DANGEROUS_HOST:
         danger_type = content::DOWNLOAD_DANGER_TYPE_DANGEROUS_HOST;
         break;
       case DownloadProtectionService::POTENTIALLY_UNWANTED:
         danger_type = content::DOWNLOAD_DANGER_TYPE_POTENTIALLY_UNWANTED;
         break;
     }
     DCHECK_NE(danger_type,
               content::DOWNLOAD_DANGER_TYPE_MAYBE_DANGEROUS_CONTENT);
 
-    if (danger_type != content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS)
-      item->OnContentCheckCompleted(danger_type);
+    if (danger_type != content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS) {
+      if (ShouldBlockFile(danger_type)) {
+        item->OnContentCheckCompleted(
+            // Specifying a dangerous type here would take precendence over the
+            // blocking of the file.
+            content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS, true /*block_file*/);
+      } else {
+        item->OnContentCheckCompleted(danger_type, false /*block_file*/);
+      }
+    }
   }
 
   SafeBrowsingState* state = static_cast<SafeBrowsingState*>(
       item->GetUserData(&kSafeBrowsingUserDataKey));
   state->CompleteDownload();
 }
 #endif  // FULL_SAFE_BROWSING
 
 // content::NotificationObserver implementation.
 void ChromeDownloadManagerDelegate::Observe(
@@ skipping 61 matching lines @@
       path.MatchesExtension(FILE_PATH_LITERAL(".xht")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xhtm")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xhtml")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xsl")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xslt"))) {
     return true;
   }
 #endif
   return false;
 }
+
+bool ChromeDownloadManagerDelegate::ShouldBlockFile(
+    content::DownloadDangerType danger_type) const {
+  if (danger_type == content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS)
+    return false;
+
+  DownloadPrefs::DOWNLOAD_RESTRICTION download_restriction =
+      download_prefs_->download_restriction();
+  return (download_restriction ==
+              DownloadPrefs::DOWNLOAD_RESTRICTION_DANGEROUS_FILES &&
+          danger_type == content::DOWNLOAD_DANGER_TYPE_DANGEROUS_CONTENT) ||
+         (download_restriction ==
+          DownloadPrefs::DOWNLOAD_RESTRICTION_POTENTIALLY_DANGEROUS_FILES);
+}