Sandboxing built-in flash

This is the last change needed to have an experimental sandboxed flash for windows
- Adds an export so flash can lower the token
- Thightents the policy a bit
- Sets a separate flash data directory.

BUG=50796
TES=see bug


Review URL: http://codereview.chromium.org/3245006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@57899 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 32 insertions, 3 deletions

diff --git a/chrome/plugin/plugin_main.cc b/chrome/plugin/plugin_main.cc
index 8313b68..3267fa0 100644
--- a/chrome/plugin/plugin_main.cc
+++ b/chrome/plugin/plugin_main.cc
@@ -47,6 +47,27 @@ void InitializeChromeApplication();
 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)
@@ -108,9 +129,17 @@ int PluginMain(const MainFunctionParams& parameters) {
     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,