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Trying to extract Widewine key: A journey to failure

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Re: Trying to extract Widewine key: A journey to failure

#31
post #27

Earlier quoted context omitted.

For now, at least. It is possible they fix all issues.

Not really, since that would entail breaking playback on current devices/firmwares. They can only try again next time (for 8K?).

Broken TZ does not mean the algorithms are broken, only that exploits exist to bypass TZ. Fixing the exploits doesn't break anything about the algorithms for decode / decrypt.

Re: Trying to extract Widewine key: A journey to failure

#32

Earlier quoted context omitted.

Not really, since that would entail breaking playback on current devices/firmwares. They can only try again next time (for 8K?).

Broken TZ does not mean the algorithms are broken, only that exploits exist to bypass TZ. Fixing the exploits doesn't break anything about the algorithms for decode / decrypt.

I'm not sure what in my comment you were disagreeing to. Fixing the exploits would entail requiring a software update/breaking unupdatable devices.

Re: Trying to extract Widewine key: A journey to failure

#33

From the repo: >It is my honest opinion that DRM is a malignant tumor growing upon various forms of media, and that people that either implement or enforce implementation are morally repugnant and do no good to society. With that in mind, I was sad to learn in May 2021 that the original extension would soon be rendered obsolete. I really can't agree more. I don't use, and never have, services that require DRM. I buy…

> This might seem like a hard rant, but all of these binary blobs can be broken with varying degree of difficulty -- as this person's work shows -- because DRM is fundamentally pointless . I think that this ease of circumventing DRM is actually an indirect, but major, reason why movie theaters will never really go away. Online streaming new movie releases is great for direct-to-consumer business, but it comes with th…

DRM is not about piracy. Content producers know that all their content ends up on PirateBay anyway, and know DRM causes them support costs and lost customers.

For content distributors DRM is still worth in because of the power it gives them in dictating how the content can be viewed. They can demand hardware manufacturers to give them prominent placement, or be blocked. They can sell the same content over and over again for every screen type and platform individually, with rules and prices at maximum each will bear. They can set their own rules, instead of relying on general provisions of the copyright law.

Re: Trying to extract Widewine key: A journey to failure

#34
post #27

Earlier quoted context omitted.

I don't know why you're being downvoted, you're right. There are plenty of TrustZone exploits that allow extraction of L1 keys.

For now, at least. It is possible they fix all issues.

Except that people who exploit L1 just never reveal how they do it, good luck with that.

That's the beauty of the asymmetry against DRM, only a single decoded file (which will always happen) is enough for seeding to everybody.

Re: Trying to extract Widewine key: A journey to failure

#36
post #33

Earlier quoted context omitted.

> This might seem like a hard rant, but all of these binary blobs can be broken with varying degree of difficulty -- as this person's work shows -- because DRM is fundamentally pointless . I think that this ease of circumventing DRM is actually an indirect, but major, reason why movie theaters will never really go away. Online streaming new movie releases is great for direct-to-consumer business, but it comes with th…

DRM is not about piracy. Content producers know that all their content ends up on PirateBay anyway, and know DRM causes them support costs and lost customers. For content distributors DRM is still worth in because of the power it gives them in dictating how the content can be viewed. They can demand hardware manufacturers to give them prominent placement, or be blocked. They can sell the same content over and over ag…

But the point is that DRM doesn't give content producers power over how content can be viewed. I could, if I wanted, go on The Pirate Bay and torrent Black Widow for free, and watch it however, wherever, whenever I want, regardless of whatever DRM Disney+ has on their streaming. It doesn't matter whether hardware manufacturers are restricted from displaying DRM content, because they can be bypassed entirely.

Re: Trying to extract Widewine key: A journey to failure

#37

Hmmm... Would love if this allows me watch netflix using a fully FLOSSed arm sbc.

I've never really looked long into these things, but now that most GPUs do the actual video decoding, how come it's still not possible to use Linux or any random OS? Isn't the GPU supposed to somehow guarantee that it only sends the decrypted stream to a compliant screen? Isn't this the point of HDCP? When this was done in software, I understand that open source decoders could have been modified to pipe the clear str…

Linux is not the issue here but ARM processor as OP said. First DRM library for ARM came only earlier this year so finally I am able to play DRM content on Raspberry Pi 4 in Chromium but I am not going to because chromium is painfully slow and plugin maintainers have figured out how to play Netflix in Kodi.

edit: DRM library still doesn't get to "fully FLOSSed"

Re: Trying to extract Widewine key: A journey to failure

#38

Earlier quoted context omitted.

Broken TZ does not mean the algorithms are broken, only that exploits exist to bypass TZ. Fixing the exploits doesn't break anything about the algorithms for decode / decrypt.

I'm not sure what in my comment you were disagreeing to. Fixing the exploits would entail requiring a software update/breaking unupdatable devices.

Yep. I remember when Blu-ray "required" Windows Vista because it had better DRM APIs then a few months later the studios gave in and allowed playback on XP... which was immediately cracked. Ultimately you have to meet customers where they are which is old devices.

Re: Trying to extract Widewine key: A journey to failure

#39

Hmmm... Would love if this allows me watch netflix using a fully FLOSSed arm sbc.

I've never really looked long into these things, but now that most GPUs do the actual video decoding, how come it's still not possible to use Linux or any random OS? Isn't the GPU supposed to somehow guarantee that it only sends the decrypted stream to a compliant screen? Isn't this the point of HDCP? When this was done in software, I understand that open source decoders could have been modified to pipe the clear str…

Between the video decoder and the screen is the display server (e.g. Xorg or GNOME Shell) which is untrusted.

Re: Trying to extract Widewine key: A journey to failure

#40
post #5

Hmmm... Would love if this allows me watch netflix using a fully FLOSSed arm sbc.

The point of semi-unusable DRMed crap when L1 released keep getting WEB-DLed? Very likely it's not the Shield now which leaks L1, but an actual key recovery because they get the stream even before it gets watermarked in the secure domain. My guess, it's Qualcomm's debugging TZ applets. They cannot really revoke keys because they will take down a giant amount of Snapdragon based handsets for which manufacturers don't…

Lately Google has mostly stopped revoking whole devices. Instead, when someone extracts a key from a device and it leaks publicly, they just revoke that one specific device's key. That improves the experience for legitimate users, but also means the person who extracted the key can just go buy another device of the same model and use the same exploit to extract a new working key.
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