media: Verify CDM Host files

content/ppapi_plugin/ppapi_thread.cc

Index: content/ppapi_plugin/ppapi_thread.cc
diff --git a/content/ppapi_plugin/ppapi_thread.cc b/content/ppapi_plugin/ppapi_thread.cc
index 85b2c6cb1995e66e9669e38a5b6e769f717a3f9c..1a2781258e0a0da88861463c8adc1a9292e1dc7f 100644
--- a/content/ppapi_plugin/ppapi_thread.cc
+++ b/content/ppapi_plugin/ppapi_thread.cc
@@ -29,6 +29,7 @@
 #include "content/child/browser_font_resource_trusted.h"
 #include "content/child/child_process.h"
 #include "content/common/child_process_messages.h"
+#include "content/common/media/cdm_host_files.h"
 #include "content/ppapi_plugin/broker_process_dispatcher.h"
 #include "content/ppapi_plugin/plugin_process_dispatcher.h"
 #include "content/ppapi_plugin/ppapi_blink_platform_impl.h"
@@ -354,6 +355,17 @@ void PpapiThread::OnLoadPlugin(const base::FilePath& path,
     }
   }
 
+  std::unique_ptr<CdmHostFiles> cdm_host_files;

[xhwang, 2016/12/16 01:23:03]

Use a local instance such that if we return early for any error, all files will
be closed automatically.

+// Open CDM host files before the process is sandboxed.
+#if defined(OS_WIN) || defined(OS_MACOSX)
+  if (!is_broker_ && IsCdm(path))
+    cdm_host_files = OpenCdmHostFiles(path);

[Greg K, 2016/12/16 22:10:41]

Am I missing something? Where is this defined?

[xhwang, 2016/12/16 22:30:15]

oops, this is some old code that I didn't update. This should be

cdm_host_files = CdmHostFiles::Create(path);

[Greg K, 2016/12/16 22:34:41]

Thanks, I'll take a look now.

[xhwang, 2017/01/18 06:03:59]

Done.

+#elif defined(OS_LINUX)
+  cdm_host_files = CdmHostFiles::TakeGlobalInstance();
+  if (is_broker_ || !IsCdm(path))
+    cdm_host_files.reset();  // Close all opened files.
+#endif
+
 #if defined(OS_WIN)
   // If code subsequently tries to exit using abort(), force a crash (since
   // otherwise these would be silent terminations and fly under the radar).
@@ -440,6 +452,11 @@ void PpapiThread::OnLoadPlugin(const base::FilePath& path,
       ReportLoadResult(path, INIT_FAILED);
       return;
     }
+    // Now the process is sandboxed. Verify CDM host.
+    if (cdm_host_files) {
+      DCHECK(IsCdm(path));
+      cdm_host_files->VerifyFiles(library.get(), path);

[xhwang, 2016/12/16 01:08:27]

tinskip / hmchen: This will be called right after INITIALIZE_CDM_MODULE() and
before CreateCdmInstance().

[Haoming Chen, 2017/01/04 22:23:39]

Acknowledged.

[Haoming Chen, 2017/01/04 22:23:39]

The interface name on the design doc
(https://docs.google.com/document/d/1XXZzRqudB0fQC9q-ZKLUW7NksMMFV-CVzuwXjMhQb...)
is "InitVmp", not "VerifyFiles".

Which name should we use?

[xhwang, 2017/01/12 20:15:02]

Nobody would be able to understand what VMP is. So I'd like a simpler name to
describe what we do here.

+    }
   }
 
   // Initialization succeeded, so keep the plugin DLL loaded.