Factor out authorization from AudioRendererHost.

content/browser/renderer_host/media/media_stream_manager.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 "content/browser/renderer_host/media/media_stream_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1952 matching lines @@
     const url::Origin& security_origin,
     const std::string& device_guid,
     const std::string& raw_unique_id) {
   DCHECK(!raw_unique_id.empty());
   std::string guid_from_raw_device_id =
       GetHMACForMediaDeviceID(salt, security_origin, raw_unique_id);
   return guid_from_raw_device_id == device_guid;
 }
 
 // static
+bool MediaStreamManager::IsValidDeviceId(const std::string& device_id) {

[o1ka, 2016/11/03 10:07:22]

What is the reason for MediaStreaMgr to expose it? Isn't it enough oi have it in
media_device_id?

[Max Morin, 2016/11/10 14:59:52]

I figured I'd put it with the rest of the hashing-related functions, but I've
moved it to media_device_id now.

+  constexpr int hash_size = 64;  // 32 bytes * 2 char/byte hex encoding
+  if (media::AudioDeviceDescription::IsDefaultDevice(device_id) ||
+      device_id == media::AudioDeviceDescription::kCommunicationsDeviceId)
+    return true;
+
+  if (device_id.length() != hash_size)
+    return false;
+
+  return std::all_of(device_id.cbegin(), device_id.cend(), [](const char& c) {
+    return base::IsAsciiLower(c) || base::IsAsciiDigit(c);
+  });
+}
+
+// static
 bool MediaStreamManager::IsOriginAllowed(int render_process_id,
                                          const url::Origin& origin) {
   if (!ChildProcessSecurityPolicyImpl::GetInstance()->CanRequestURL(
           render_process_id, origin.GetURL())) {
     LOG(ERROR) << "MSM: Renderer requested a URL it's not allowed to use.";
     return false;
   }
 
   return true;
 }
@@ skipping 60 matching lines @@
     }
   }
 }
 
 void MediaStreamManager::SetGenerateStreamCallbackForTesting(
     GenerateStreamTestCallback test_callback) {
   generate_stream_test_callback_ = test_callback;
 }
 
 }  // namespace content