LibreDrive and revocation list update protection

Discussion of LibreDrive mode, compatible drives and firmwares
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VA1DER
Posts: 11
Joined: Sat Apr 19, 2025 4:35 pm

LibreDrive and revocation list update protection

Post by VA1DER »

As I understand it, LibreDrive mode, when it is engaged on a drive, prevents a drive from updating its revocation list when it encounters a later MKB version on a loaded disc.

I have seen mention a couple times, though, that LibreDrive mode is only soft-loaded microcode that gets stored on the drive temporarily. That patched firmwares don't have it turned on all the time, they merely make the drive amenable to uploading the LibreDrive mode microcode.

So then, as I understand it, my drive is only protected from updating its revocation list from a newer MKB when MakeMKV is running and has enabled LibreDrive on the drive. Is this correct?
SamuriHL
Posts: 2519
Joined: Mon Jun 14, 2010 5:32 pm

Re: LibreDrive and revocation list update protection

Post by SamuriHL »

VA1DER wrote:
Fri May 09, 2025 2:48 am
As I understand it, LibreDrive mode, when it is engaged on a drive, prevents a drive from updating its revocation list when it encounters a later MKB version on a loaded disc.
No. It does not prevent that from happening...see below. It only ignores it when it's in LibreDrive mode.
VA1DER wrote:
Fri May 09, 2025 2:48 am
I have seen mention a couple times, though, that LibreDrive mode is only soft-loaded microcode that gets stored on the drive temporarily. That patched firmwares don't have it turned on all the time, they merely make the drive amenable to uploading the LibreDrive mode microcode.
Correct.
VA1DER wrote:
Fri May 09, 2025 2:48 am
So then, as I understand it, my drive is only protected from updating its revocation list from a newer MKB when MakeMKV is running and has enabled LibreDrive on the drive. Is this correct?
Yes. And in order to put the drive in LibreDrive mode, you have to insert the disc which then automatically updates the MKB revocation list on the drive. You can't prevent it. You can, however, with LibreDrive, ignore it.
VA1DER
Posts: 11
Joined: Sat Apr 19, 2025 4:35 pm

Re: LibreDrive and revocation list update protection

Post by VA1DER »

SamuriHL wrote:
Fri May 09, 2025 2:54 am
Yes. And in order to put the drive in LibreDrive mode, you have to insert the disc which then automatically updates the MKB revocation list on the drive.
Hmmm. I thought the drive was in LibreDrive mode the moment you ran MakeMKV and selected the drive - hence the "Status: Enabled" message. So the drive still updates its revocation list and that can't be prevented. That changes my drive plans. I have an LG WH16NS60 which is UHD native. I wanted to be able to rip MKBv82 discs with it without having it update its revocation list.

I may not use it for ripping then. I just ripped my first UHD - The Abyss 4k (which from all accounts has posed problems for a lot of drives) with an old little Pioneer UD03 (cross-patched to UD04). Maybe I'll use this for my ripping and keep my UHD LG clean.

[EDIT] I just re-read mike admin's post on the subject to see where I misunderstood the process:
mike admin wrote: The moment you insert the disc into your drive, the drive checks if the list is newer than the one it knows about, and if it is, the drive re-flashes itself (updates firmware). With LibreDrive mode your drive just became immune to this nonsense.
So while he doesn't quite say the drive won't update itself, I think this wording strongly implies it. I would recommend changing this to read the drive is immune to the changed revocation list, not that it is immune to reflashing itself.
SamuriHL
Posts: 2519
Joined: Mon Jun 14, 2010 5:32 pm

Re: LibreDrive and revocation list update protection

Post by SamuriHL »

The firmware for libredrive is loaded only after a disc is inserted and you then scan that disc with makemkv... Either by opening the disc in makemkv or activating libredrive from a commandline. Once the disc is inserted the mkb is updated.

As for mkb v82 that's not really a big deal. There's a publicly posted device key for it. If you use my keydb helper tool, as found in the uhd FAQ in the uhd section of the forum and follow the instructions I link to in that post for updating your keydb file with the device key then you can decrypt all your Blu-rays including mkb v82.

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