Does one need a "Certificate" as well to build and use APO (Audio Processing Objects)?

[karl-police]

I heard that if you want to create a driver e.g. test.sys and use it without restriction, it needs to be signed. I know that one can build driver and run in test mode, but that doesn't speak for me as a non-profit thing at all.

 

But what about APO? These COM things or whatever it is. Do custom APO also have to be signed or not?

Can someone please tell me?

[v-junyli]

@microsoft/windowsaudio can you please take a look

[mvaneerde]

Audio processing objects load in audiodg.exe which runs as a child process of the audiosrv service in session 0, and therefore need to be signed. If you're installing on a test system, test-signing is okay. If you're installing a production system they need to be production-signed; Microsoft will production-sign your driver for you if you submit it to Hardware Dev Center.

Test instructions here: https://github.com/microsoft/Windows-driver-samples/tree/main/audio/sysvad

Submission to Hardware Dev Center instructions here: https://learn.microsoft.com/en-us/windows-hardware/drivers/dashboard/hardware-submission-create

More on signing drivers: https://learn.microsoft.com/en-us/windows-hardware/drivers/develop/signing-a-driver

[karl-police]

Audio processing objects load in audiodg.exe which runs as a child process of the audiosrv service in session 0, and therefore need to be signed. If you're installing on a test system, test-signing is okay. If you're installing a production system they need to be production-signed; Microsoft will production-sign your driver for you if you submit it to Hardware Dev Center.

Test instructions here: https://github.com/microsoft/Windows-driver-samples/tree/main/audio/sysvad

Submission to Hardware Dev Center instructions here: https://learn.microsoft.com/en-us/windows-hardware/drivers/dashboard/hardware-submission-create

More on signing drivers: https://learn.microsoft.com/en-us/windows-hardware/drivers/develop/signing-a-driver

A working APO .DLL from somewhere else, doesn't have any License that contains the word "Microsoft", only SHA1, but it runs. The process to sign a driver... not sure, is it free? There's a lot of steps and apparently it asks for things...

[mvaneerde]

You can use signtool.exe to verify the signature on the working APO. It might be an embedded signature, or the APO may have an entry in a .cat file which is itself signed