Sandboxing built-in flash...

chrome/plugin/plugin_main.cc

 // Copyright (c) 2006-2008 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 "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <objbase.h>
 #include <windows.h>
 #endif
@@ skipping 29 matching lines @@
 // doesn't carry into any processes that plugins might start.
 void TrimInterposeEnvironment();
 
 // Initializes the global Cocoa application object.
 void InitializeChromeApplication();
 #elif defined(OS_LINUX)
 // Work around an unimplemented instruction in 64-bit Flash.
 void WorkaroundFlashLAHF();
 #endif
 
+#if defined(OS_WIN)
+// This function is provided so that the built-in flash can lock down the
+// sandbox by calling DelayedLowerToken(0).
+extern "C" DWORD __declspec(dllexport) __stdcall DelayedLowerToken(void* ts) {
+  // s_ts is only set the first time the function is called, which happens
+  // in PluginMain.
+  static sandbox::TargetServices* s_ts =
+      reinterpret_cast<sandbox::TargetServices*>(ts);
+  if (ts)
+    return 0;
+  s_ts->LowerToken();
+  return 1;
+};
+
+// Returns true if the plugin to be loaded is the internal flash.
+bool IsPluginBuiltInFlash(const CommandLine& cmd_line) {
+  FilePath path =  cmd_line.GetSwitchValuePath(switches::kPluginPath);
+  return (path.BaseName() == FilePath(L"gcswf32.dll"));
+}
+#endif
+
 // main() routine for running as the plugin process.
 int PluginMain(const MainFunctionParams& parameters) {
 #if defined(USE_LINUX_BREAKPAD)
   // Needs to be called after we have chrome::DIR_USER_DATA.
   InitCrashReporter();
 #endif
 
   // The main thread of the plugin services UI.
 #if defined(OS_MACOSX)
 #if !defined(__LP64__)
@@ skipping 41 matching lines @@
   }
 #endif
   if (parsed_command_line.HasSwitch(switches::kPluginStartupDialog)) {
     ChildProcess::WaitForDebugger(L"Plugin");
   }
 
   {
     ChildProcess plugin_process;
     plugin_process.set_main_thread(new PluginThread());
 #if defined(OS_WIN)
-    if (!no_sandbox && target_services)
-      target_services->LowerToken();
-
+    if (!no_sandbox && target_services) {
+      // We are sandboxing the plugin. If it is a generic plug-in, we lock down
+      // the sandbox right away, but if it is the built-in flash we let flash
+      // start elevated and it will call DelayedLowerToken(0) when it's ready.
+      if (IsPluginBuiltInFlash(parsed_command_line)) {
+        DLOG(INFO) << "Sandboxing flash";
+        DelayedLowerToken(target_services);
+      } else {
+        target_services->LowerToken();
+      }
+    }
     if (sandbox_test_module) {
       RunRendererTests run_security_tests =
           reinterpret_cast<RunPluginTests>(GetProcAddress(sandbox_test_module,
                                                           kPluginTestCall));
       DCHECK(run_security_tests);
       if (run_security_tests) {
         int test_count = 0;
         DLOG(INFO) << "Running plugin security tests";
         BOOL result = run_security_tests(&test_count);
         DCHECK(result) << "Test number " << test_count << " has failed.";
@@ skipping 11 matching lines @@
 
     MessageLoop::current()->Run();
   }
 
 #if defined(OS_WIN)
   CoUninitialize();
 #endif
 
   return 0;
 }