Thanks very much for this, it would have taken us a lot longer without a known good working implementation to reference against and knowledge of what crypto algorithms they were using.
In return: in the mdns from the Apple TV, there is an “sf” field, which normally has values like “0x24c”. I think this is some sort of bit flag, and the 2 in the higher order byte means “authentication required”. The lower order byte seems to indicate password/pincode authentication, but in practice both of those are the same from our point of view. There’s also a bunch of bits that appear to be unused, no idea what they do.
Yes, the “sf” (flags) might reflect this (pretty sure).
On my ATVv3 the value does change in case the user toggles password-authentication, but does not change in case the user toggles “device authentication”.
Also with “device authentication” disabled, iTunes does the pin-pair.
My users are frequently using AirPlay-emulators which always claim to be an AppleTV 3 (am=appletv3,2) but do not support the device authentication (causing iTunes to fail to pair).
So for now I’m enabling the pairing for AppleTV 4+ (am contains “appletv” but not “appletv3” and not "appletv2).
Feel free to open-source your pairing-implementation, in case you like to
One thing to note is the need to enable the network device (Apple TV) within Roon setting each time and re-enter the airplay passcode… this is intentional or is there another way to set up to bypass these steps?
If that’s the case, it sounds like a bug in Roon. Once the client is paired and the credentials/auth-tokens do not change, he could do the “pair-verify” without the need to re-pair. Re-Pairing is only required if the auth-tokens are lost/changed, or if the authentication has been toggled on/off inside the AppleTV (still possible on ATVv3).
Under Networked you should see your Apple TV listed
Click on the gears next to your Apple TV and choose Disable
After it’s disabled, you can click on Enable again and it will prompt for the passcode
Hope that helps! Those steps should really be documented somewhere, or better yet Roon should detect that it needs the passcode and prompt, but for now I’m just super that I have ATV streaming again.
Hi @Joe_Spivey ---- Thank you for your patience here and apologies for the wait.
Moving forward, our team believes that we’ve identified the issue and a fix (that we feel will improve this experience) has been set into place, pending our next build release. For the time being, we would recommend switching to “password mode”.
that I have ATV streaming again.