Use volume serial number as device id

Author: zcbenz

chromium_src/chrome/browser/renderer_host/pepper/pepper_flash_drm_host.cc

@@ -4,6 +4,8 @@
 
 #include "chrome/browser/renderer_host/pepper/pepper_flash_drm_host.h"
 
+#include <cmath>
+
 #if defined(OS_WIN)
 #include <Windows.h>
 #endif
@@ -12,12 +14,14 @@
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
+#include "base/strings/string_number_conversions.h"
 #include "build/build_config.h"
 #include "content/public/browser/browser_ppapi_host.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/child_process_security_policy.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/common/pepper_plugin_info.h"
+#include "net/base/net_util.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/host/dispatch_host_message.h"
 #include "ppapi/host/host_message_context.h"
@@ -38,7 +42,30 @@ using content::BrowserPpapiHost;
 namespace chrome {
 
 namespace {
+
 const char kVoucherFilename[] = "plugin.vch";
+
+#if defined(OS_WIN)
+bool GetSystemVolumeSerialNumber(std::string* number) {
+  // Find the system root path (e.g: C:\).
+  wchar_t system_path[MAX_PATH + 1];
+  if (!GetSystemDirectoryW(system_path, MAX_PATH))
+    return false;
+
+  wchar_t* first_slash = wcspbrk(system_path, L"\\/");
+  if (first_slash != NULL)
+    *(first_slash + 1) = 0;
+
+  DWORD number_local = 0;
+  if (!GetVolumeInformationW(system_path, NULL, 0, &number_local, NULL, NULL,
+                             NULL, 0))
+    return false;
+
+  *number = base::IntToString(std::abs(static_cast<int>(number_local)));
+  return true;
+}
+#endif
+
 }
 
 #if defined(OS_WIN)
@@ -149,7 +176,15 @@ int32_t PepperFlashDRMHost::OnResourceMessageReceived(
 
 int32_t PepperFlashDRMHost::OnHostMsgGetDeviceID(
     ppapi::host::HostMessageContext* context) {
-  context->reply_msg = PpapiPluginMsg_FlashDRM_GetDeviceIDReply("");
+  static std::string id;
+#if defined(OS_WIN)
+  if (id.empty() && !GetSystemVolumeSerialNumber(&id))
+    id = net::GetHostName();
+#else
+  if (id.empty())
+    id = net::GetHostName();
+#endif
+  context->reply_msg = PpapiPluginMsg_FlashDRM_GetDeviceIDReply(id);
   return PP_OK;
 }