how do we retreave the AAC keys

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Akria
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Joined: Wed Dec 30, 2020 1:24 am

how do we retreave the AAC keys

Post by Akria » Wed Dec 30, 2020 1:27 am

so I'm trying to find out how we get the AAC keys manualy because I have so many movies that I can't find the key for so I want to know how we can get them ourselfs


(I'm doing this because of the blu rays for Demon Slayer)

Woodstock
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Joined: Sun Jul 24, 2011 11:21 pm

Re: how do we retreave the AAC keys

Post by Woodstock » Wed Dec 30, 2020 3:11 am

If you're working with disks, the key information is extracted automatically by MakeMKV. There's no reason to have to download keys.
MakeMKV Frequently Asked Questions
How to aid in finding the answer to your problem: Activating Debug Logging

Akria
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Joined: Wed Dec 30, 2020 1:24 am

Re: how do we retreave the AAC keys

Post by Akria » Wed Dec 30, 2020 3:31 am

no I'm asking how to use the program to extract them and put them in a separate file

MartyMcNuts
Posts: 1192
Joined: Wed Nov 22, 2017 11:45 pm

Re: how do we retreave the AAC keys

Post by MartyMcNuts » Wed Dec 30, 2020 7:15 am

Akria wrote:
Wed Dec 30, 2020 3:31 am
no I'm asking how to use the program to extract them and put them in a separate file
Nope. Can't be done. MakeMKV does the actual AACS key decryption process behind the scenes just like a standard blu-ray player would.
Cheers :D
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preserve
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Location: Canada

Re: how do we retreave the AAC keys

Post by preserve » Wed Dec 30, 2020 4:12 pm

If you're interested in non-MakeMKV usage of keys (since MakeMKV handles all that stuff internally so that you don't have to), then the utility that you want is FindVUK:

http://fvonline-db.bplaced.net/
Using: ASUS BW-16D1HT 3.00

thetoad
Posts: 136
Joined: Thu Jul 28, 2016 4:18 am

Re: how do we retreave the AAC keys

Post by thetoad » Mon Jan 04, 2021 7:53 am

MartyMcNuts wrote:
Wed Dec 30, 2020 7:15 am
Akria wrote:
Wed Dec 30, 2020 3:31 am
no I'm asking how to use the program to extract them and put them in a separate file
Nope. Can't be done. MakeMKV does the actual AACS key decryption process behind the scenes just like a standard blu-ray player would.
that's not true. If you make a protected backup, I'm pretty sure it stores the VUK in the .dat file it adds to the backup). How its stored, I don't know (pretty sure I had a quetions about this once, was told the format was in the OSS part of makemkv, and my head hurt when I looked at the c++ side of it)

MartyMcNuts
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Re: how do we retreave the AAC keys

Post by MartyMcNuts » Mon Jan 04, 2021 8:40 am

thetoad wrote:
Mon Jan 04, 2021 7:53 am
MartyMcNuts wrote:
Wed Dec 30, 2020 7:15 am
Akria wrote:
Wed Dec 30, 2020 3:31 am
no I'm asking how to use the program to extract them and put them in a separate file
Nope. Can't be done. MakeMKV does the actual AACS key decryption process behind the scenes just like a standard blu-ray player would.
that's not true. If you make a protected backup, I'm pretty sure it stores the VUK in the .dat file it adds to the backup). How its stored, I don't know (pretty sure I had a quetions about this once, was told the format was in the OSS part of makemkv, and my head hurt when I looked at the c++ side of it)
No it doesn’t. The VUK is calculated only when decrypting. The VolumeID is stored in the discatt.dat file.
Cheers :D
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thetoad
Posts: 136
Joined: Thu Jul 28, 2016 4:18 am

Re: how do we retreave the AAC keys

Post by thetoad » Fri Jan 08, 2021 9:31 am

considering you can decrypt a protected bluray backup without the original disc, how does it do that, if it doesn't calculate the vuk in advance?

MartyMcNuts
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Joined: Wed Nov 22, 2017 11:45 pm

Re: how do we retreave the AAC keys

Post by MartyMcNuts » Fri Jan 08, 2021 10:12 am

thetoad wrote:
Fri Jan 08, 2021 9:31 am
considering you can decrypt a protected bluray backup without the original disc, how does it do that, if it doesn't calculate the vuk in advance?
No, the VUK is not calculated in advance!! As I said before, the discatt.dat file created in a protected backup contains the VolumeID. If the VolumeID was not obtained in the discatt.dat file, the decryption process could not be done and the VUK would never be obtained.

I'm not sure how MakeMKV starts the process but it probably has a Device Key, which is used to obtain the Processing Key, which is used to decrypt the MKB to obtain the Media Key, which is used with the VolumeID to obtain the VUK.
Cheers :D
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thetoad
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Re: how do we retreave the AAC keys

Post by thetoad » Sat Jan 09, 2021 6:19 am

so in other words, there's enough information in the file to calculate the vuk?

is that effectively different that what I said? if all the information needed to calculate the vuk is in the file, I'd argue tht the the vuk is effectively in the file.

MartyMcNuts
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Re: how do we retreave the AAC keys

Post by MartyMcNuts » Sat Jan 09, 2021 8:29 am

thetoad wrote:
Sat Jan 09, 2021 6:19 am
so in other words, there's enough information in the file to calculate the vuk?

is that effectively different that what I said? if all the information needed to calculate the vuk is in the file, I'd argue tht the the vuk is effectively in the file.
It is extremely different to what you said. You can argue as much as you like but you are wrong!

The VolumeID is but one of several, let's just say 'keys' required to decrypt and obtain the VUK. If any of these are missing, VUK cannot be obtained. The discatt.dat file only contains the VolumeID. Therefore, there is nowhere near enough information in that file to obtain the VUK.

For example: A new release Bluray disc has a new AACS version that MakeMKV does not yet have a device key or processing key for. Even though the discatt.dat file contains the VolumeID, the VUK cannot be obtained as the AACS decryption process cannot be completed.
Cheers :D
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thetoad
Posts: 136
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Re: how do we retreave the AAC keys

Post by thetoad » Fri Jan 15, 2021 10:02 am

so how does makemkv decrypt a protected backup (regular bluray, not UHD) without the physical disc being inside the drive?

I should note, that when I asked this ages ago

https://www.makemkv.com/forum/viewtopic ... 581#p75581

mike didn't say my guess was wrong and that it was open source how to read the file (with that said, he didn't confirm my guess either).

Krawk
Posts: 237
Joined: Thu Jul 02, 2015 12:10 am

Re: how do we retreave the AAC keys

Post by Krawk » Fri Jan 15, 2021 8:58 pm

How does an actual set top player with 8 year old firmware cope with new discs?

MartyMcNuts
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Re: how do we retreave the AAC keys

Post by MartyMcNuts » Sat Jan 16, 2021 12:19 am

thetoad wrote:
Fri Jan 15, 2021 10:02 am
so how does makemkv decrypt a protected backup (regular bluray, not UHD) without the physical disc being inside the drive?
When creating a protected backup (both BD & UHD), MakeMKV creates the discatt.dat file (which contains the VolumeID for that disc). Without the discatt.dat file, the protected folder cannot be decrypted.

This is why a protected backup created using other software cannot be decrypted with MakeMKV.
Cheers :D
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MartyMcNuts
Posts: 1192
Joined: Wed Nov 22, 2017 11:45 pm

Re: how do we retreave the AAC keys

Post by MartyMcNuts » Sat Jan 16, 2021 12:24 am

Krawk wrote:
Fri Jan 15, 2021 8:58 pm
How does an actual set top player with 8 year old firmware cope with new discs?
Set top players are built with a full set of device keys. I can't remember how many off the top of my head but I think it's something like 256 keys. Anyway, these machines just decrypt and play the disc, so the age of the firmware is not really relevant in that regard.
Cheers :D
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