media_device_id.cc revision 5c02ac1a9c1b504631c0a3d2b6e737b5d738bae1 
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
13namespace content {
14
15std::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 StringToLowerASCII(base::HexEncode(&digest[0], digest.size()));
28}
29
30bool 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
41bool 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
58