Is SAR still not workable with chromium audio sandbox :?

[neKmaI]

I know we can turn audio sanbox off, but as I know, turn that off mean put you in a vulnerable position ( the vulnerability called CVE-2019-13720 ) :((((

[amurzeau]

I didn't reproduced the problem, but I've retested it, I still cannot reproduce that issue with chrome 92.
Maybe you can debug the problem so I can implement the required fix to help others ?

I use this:

• Latest build (https://github.com/eiz/SynchronousAudioRouter/releases/tag/v0.13.2)
• Secure boot disabled
• Test signing enabled
• SAR is allowed for all users (check this in the installer, be sure to select Allow any user to access SAR. More user friendly, but somewhat less secure.)
• SAR is started at boot and never stopped until shutdown (I use jackd which I never stop)

I you play something else using a different player and while it is playing, try to:

• Start chrome
• Play something in chrome
  Does it work fine ? or only the first player audio is there but not chrome's audio ?

[neKmaI]

I didn't reproduced the problem, but I've retested it, I still cannot reproduce that issue with chrome 92.
Maybe you can debug the problem so I can implement the required fix to help others ?

I use this:

• Latest build (https://github.com/eiz/SynchronousAudioRouter/releases/tag/v0.13.2)
• Secure boot disabled
• Test signing enabled
• SAR is allowed for all users (check this in the installer, be sure to select Allow any user to access SAR. More user friendly, but somewhat less secure.)
• SAR is started at boot and never stopped until shutdown (I use jackd which I never stop)

I you play something else using a different player and while it is playing, try to:

• Start chrome
• Play something in chrome
  Does it work fine ? or only the first player audio is there but not chrome's audio ?

• I use the same setting as you, SAR 0.13.2; Chrome 92; Test mode on; Secure boot unsupported in my PC; Allow all user when install. I cant use Jack due to some issue. I have try AISO Link, but as soon as SAR turn on with DAW, chromium audio output will disappear until computer restart.

• Any other audio player work great, expect chromium browser like (Edge, Chrome).

• It only work for me when I put this flag {--disable-features=AudioServiceSandbox}. Sometime I have to re-put this flag to browser shortcut in order for audio to work.

I don't know how to debug the problem for you, can you show me how :? Thanks you <3

[eiz]

The way SAR is designed is largely obsolete. I can talk about this now: if you want to solve this problem, look in the 10.0.22000 Windows SDK headers um\audioclientactivationparams.h for VIRTUAL_AUDIO_DEVICE_PROCESS_LOOPBACK and knock yourself out =)

The likely proximate cause here is that the Chrome audio sandbox uses SetProcessMitigationPolicy to prevent arbitrary DLL loads in its process, which will break the SAR mmdevice wrapper functionality that overrides default audio endpoints.

[amurzeau]

The likely proximate cause here is that the Chrome audio sandbox uses SetProcessMitigationPolicy to prevent arbitrary DLL loads in its process, which will break the SAR mmdevice wrapper functionality that overrides default audio endpoints.

In that case, maybe this can help:

• In the registry, go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Audio key
• If not existing already, create a new DWORD named DisableProtectedAudioDG
• Set DisableProtectedAudioDG to 1

This disables the signature check for APOs, so that unsigned APOs will be loaded. This also means that applications requiring a secure audio path may change their behaviour or refuse to output audio altogether.

(source: https://sourceforge.net/p/equalizerapo/wiki/Developer%20documentation/)

[amurzeau]

Let's keep this issue focused; I've created a new issue about Windows 10.0.22000 and VIRTUAL_AUDIO_DEVICE_PROCESS_LOOPBACK here #122.