| // Copyright 2013 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 "content/public/browser/media_device_id.h" |
| |
| #include "base/logging.h" |
| #include "base/strings/string_number_conversions.h" |
| #include "base/strings/string_util.h" |
| #include "content/public/browser/resource_context.h" |
| #include "crypto/hmac.h" |
| |
| namespace content { |
| |
| std::string GetHMACForMediaDeviceID(ResourceContext* rc, |
| const GURL& security_origin, |
| const std::string& raw_unique_id) { |
| DCHECK(security_origin.is_valid()); |
| DCHECK(!raw_unique_id.empty()); |
| crypto::HMAC hmac(crypto::HMAC::SHA256); |
| const size_t digest_length = hmac.DigestLength(); |
| std::vector<uint8> digest(digest_length); |
| std::string salt = rc->GetMediaDeviceIDSalt(); |
| bool result = hmac.Init(security_origin.spec()) && |
| hmac.Sign(raw_unique_id + salt, &digest[0], digest.size()); |
| DCHECK(result); |
| return StringToLowerASCII(base::HexEncode(&digest[0], digest.size())); |
| } |
| |
| bool DoesMediaDeviceIDMatchHMAC(ResourceContext* rc, |
| const GURL& security_origin, |
| const std::string& device_guid, |
| const std::string& raw_unique_id) { |
| DCHECK(security_origin.is_valid()); |
| DCHECK(!raw_unique_id.empty()); |
| std::string guid_from_raw_device_id = |
| GetHMACForMediaDeviceID(rc, security_origin, raw_unique_id); |
| return guid_from_raw_device_id == device_guid; |
| } |
| |
| } // namespace content |