content/public/browser/media_device_id.cc

   1 // Copyright 2013 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 #include "content/public/browser/media_device_id.h"
   5
   6 #include "base/logging.h"
   7 #include "base/strings/string_number_conversions.h"
   8 #include "base/strings/string_util.h"
   9 #include "content/browser/browser_main_loop.h"
  10 #include "content/browser/renderer_host/media/media_stream_manager.h"
  11 #include "crypto/hmac.h"
  12
  13 namespace content {
  14
  15 std::string GetHMACForMediaDeviceID(const ResourceContext::SaltCallback& sc,
  16                                     const GURL& security_origin,
  17                                     const std::string& raw_unique_id) {
  18   DCHECK(security_origin.is_valid());
  19   DCHECK(!raw_unique_id.empty());
  20   crypto::HMAC hmac(crypto::HMAC::SHA256);
  21   const size_t digest_length = hmac.DigestLength();
  22   std::vector<uint8> digest(digest_length);
  23   std::string salt = sc.Run();
  24   bool result = hmac.Init(security_origin.spec()) &&
  25       hmac.Sign(raw_unique_id + salt, &digest[0], digest.size());
  26   DCHECK(result);
  27   return base::StringToLowerASCII(base::HexEncode(&digest[0], digest.size()));
  28 }
  29
  30 bool DoesMediaDeviceIDMatchHMAC(const ResourceContext::SaltCallback& sc,
  31                                 const GURL& security_origin,
  32                                 const std::string& device_guid,
  33                                 const std::string& raw_unique_id) {
  34   DCHECK(security_origin.is_valid());
  35   DCHECK(!raw_unique_id.empty());
  36   std::string guid_from_raw_device_id =
  37       GetHMACForMediaDeviceID(sc, security_origin, raw_unique_id);
  38   return guid_from_raw_device_id == device_guid;
  39 }
  40
  41 bool GetMediaDeviceIDForHMAC(MediaStreamType stream_type,
  42                              const ResourceContext::SaltCallback& rc,
  43                              const GURL& security_origin,
  44                              const std::string& source_id,
  45                              std::string* device_id) {
  46   content::MediaStreamManager* manager =
  47       content::BrowserMainLoop::GetInstance()->media_stream_manager();
  48
  49   return manager->TranslateSourceIdToDeviceId(
  50       content::MEDIA_DEVICE_VIDEO_CAPTURE,
  51       rc,
  52       security_origin,
  53       source_id,
  54       device_id);
  55 }
  56
  57 }  // namespace content