Dealing with Kindle ebooks in calibre

[odamizu]

Originally Posted by xyzzy_foo

@odamizu

The OP needs to be updated. K4PC 1.17.1 (44183) can no longer be used. New registration attempts are blocked. 2.3.0 (70673) is still fine, but this is the last version that allows downloading Japanese Kindle books in KF8 (AZW3); for English Kindle books, it switched to KFX in a much earlier version.

For 1.17.1, does it work if you're already registered, or is it totally dead? Can someone who is already registered give it a try?

[quiller1024]

Originally Posted by odamizu

"Legacy Kindle for PC" does not sound good. If I recall correctly, "Legacy" is what they started calling the last version of Kindle for Mac that worked with calibre, before killing it and introducing a hardened K4Mac that is basically dead as a source of calibre-friendly books.



Buying a new Kindle won't work with calibre. At the moment, 10th gen Kindles seem to still work, but we expect that will change soon, so wouldn't recommend spending the money

Thanks for the update. I will probably eventually break down and buy a kindle but know I guess will wait tell after may to see if the10th gen continue as to work with calibre after mine goes dead. It would be worth it to me to have a little more time accessing the kindle with calibre even though I can get a new 16gb for about the same cost as a used 8gb.

[quiller1024]

Oh thought I would add. I downloaded the latest kindle for pc on my desktop and even if you “download” the books you can not access them on your PC. Our at least I have no idea where they are. And yes there is no longer a content file in the kindle user folders

[lkmiller]

Originally Posted by quiller1024

Oh thought I would add. I downloaded the latest kindle for pc on my desktop and even if you “download” the books you can not access them on your PC. Our at least I have no idea where they are. And yes there is no longer a content file in the kindle user folders

Not here? C:\Users\YourUserName\Documents\My Kindle Content

Look in Kindle for PC Tools > Options > Content and see what it says.

[svenlind]

Originally Posted by odamizu

For 1.17.1, does it work if you're already registered, or is it totally dead? Can someone who is already registered give it a try?

V 1.17.1 still works for me.

[Sats]

Originally Posted by Forge

Now if your Kindle is running 5.18.5+, you get a gen 2 kfx, which is once again difficult to DeDRM. They are also either killing off or shutting down or replacing the oldest options to close the last remnants of the azw3 path. Books are also being provided in gen 2 kfx and "legacy" kfx downloads sometimes fail or show unavailable on pre-5.18.5 devices.

There is not really a gen2 KFX. There is, and has always been to my knowledge, 1 KFX.

Some details, though I don't know if this is correct place:
Each KFX has two parts book file(s) and voucher. Some book files are encrypted by book key. Yes, there was always a "per-book key". It is in the voucher and does not change between devices or users. (Does change with the book variant, like high-definition images). Voucher has derivation algorithm ID and encrypted book key (now, from 2.8.2, encrypted two times). Derivation algorithm is a problem here, and the part that changes. It can consume up to 3 inputs (so far): Device serial, Account Secret and Book Salt (that is a new thing),and spits out key to decrypt voucher.

Now, what changed over time: There used to be a set of derivation algos shared between all platforms. Mac, Android, PC, Kindle, all had the same ones. Also, Kindles did not use Account Secrets and their serials were literally written on the cases. Then, after the algos were... exposed, they split per platform. Each release made new derivation algo for Apple, Android, PC and kindles. Also, they started obfuscating executables to the point that algorithms were no longer reasonably extractable. So currently what I use is Kindle executable itself, but I cannot do the same on Mac and Kindles... well, not without jailbreak, anyway.

In about 5.18.5, Kindles started using account secret, which is a string that is sent by Amazon to device when it registers. Since it is hidden in a place user cannot access without jailbreak, even if the derivation algorithm was known, one cannot run it, since it is missing data.
For 5.16.2.1.1, they added new derivation algorithm (before it was using the shared one which was also in K4PC), and used an odd method that injects it at runtime. It is not even in the firmware image, so presumably they can update it at will. I don't have Kindle, but I guess, in theory and qemu it is possible to deal with that, but then Amazon might just add account secret (there is place for it in that firmware) and then we are stuck again.
Likewise, Mac. Account secret is stuck in a place only accessible to apps signed by Amazon and Apple, unless one disables SIP. With SIP off, Kindle memory can be accessed and secret can be pulled, or other approaches can be taken (as epubor does, I assume), but as mentioned, I am not going to publish something that requires one to disable system protection, and then learn how to compile and sign executables. Most people that can do that reliably have their own ways if they feel like it. Also, I don't have Mac to work on that.
And again likewise, Android. I don't even know where they hide dsn/secret, but it is not user-accessible without root, i believe. I did publish an awkward frida script that used to work to get book keys from memory (though it crashed the app quickly, after 1-2 keys), but they fixed it in one of the later versions.

Apologies for a long and somewhat offtopic post.

[JSWolf]

I have a PW3 that has firmware 5.16.2.1.1 on it. It's been in airplane mode since sometime between the announcement of D&T going away and D&T going away. If I turn on WiFi and Amazon sends it's parasites to infect my PW3, will I lose any functionality other the not being able to remove the DRM from downloaded eBooks?

[odamizu]

Originally Posted by xyzzy_foo

... The OP needs to be updated. K4PC 1.17.1 (44183) can no longer be used. New registration attempts are blocked. 2.3.0 (70673) is still fine, but this is the last version that allows downloading Japanese Kindle books in KF8 (AZW3); for English Kindle books, it switched to KFX in a much earlier version.

Originally Posted by svenlind

V 1.17.1 still works for me.

Thank you xyzzy_foo and svenlind, I have updated the first post to reflect the fact that 1.17.1 is hit-or-miss nowadays.

Originally Posted by Sats

... Some details, though I don't know if this is correct place ... Apologies for a long and somewhat offtopic post.

Don't apologize! This is great stuff! Very informative and totally on-topic, IMO. Thank you!

Also, does anyone know if Kindle for Android is in any way workable nowadays as a way to obtain calibre-friendly books? Or is it dead and I should update the first post accordingly?

[Sirtel]

Originally Posted by JSWolf

I have a PW3 that has firmware 5.16.2.1.1 on it. It's been in airplane mode since sometime between the announcement of D&T going away and D&T going away. If I turn on WiFi and Amazon sends it's parasites to infect my PW3, will I lose any functionality other the not being able to remove the DRM from downloaded eBooks?

Why would you turn on wifi?

[JSWolf]

Originally Posted by Sirtel

Why would you turn on wifi?

Too see if I can download eBooks and remove the DRM. Basically download one and then turn off the WiFi and hope Amazon has not infected the PW3. I've nothing to lose. I'm already losing my Kindle Touch.

[texasnightowl]

5.16.2.1.1 has been infected for weeks now. DRM was changed and can no longer be removed from books received on devices with that firmware. at least, that is my understanding based on here, github, and reddit.

Now, as to your original question: will I lose any functionality other the not being able to remove the DRM from downloaded eBooks?

Not afaik. Just no ability to remove the drm. You can still download the books from amazon and read them, etc.

But, to be fair, I don't have a device on 5.16.2.1.1.

[Rellwood]

Originally Posted by Sirtel

Why would you turn on wifi?

The way to prevent that from happening is to turn the wifi on - download the book, and then immediately plug it into your computer - hunt down the as of yet to run installer that came with the book - and delete it, remove the book, the Kindle and return to wifi.

AFAIK the Kindle needs to be turned off for it to update, a restart or something.
I know that the older devices like the 5th Gen are so difficult that you have to download from Content & Devices, then wait forever, the restart the Kindle. I believe that the restart is going to be the way they get those ones to sneakily update when they are always on airplane mode and only turned on to download a book.

It isn't intentional, but the fact that the Kindles are so old that it's hard to download the formats, but its going to be a nice side effect that allows those sneak updates.

[Rellwood]

Originally Posted by odamizu

Thank you xyzzy_foo and svenlind, I have updated the first post to reflect the fact that 1.17.1 is hit-or-miss nowadays.



Don't apologize! This is great stuff! Very informative and totally on-topic, IMO. Thank you!

Also, does anyone know if Kindle for Android is in any way workable nowadays as a way to obtain calibre-friendly books? Or is it dead and I should update the first post accordingly?

Im sitting on my KindleForPC-installer-1.17.44170.exe that held up until Feb 2023.

I didn't appreciate how much help having Directory Opus was for a file manager program until I saw all those individual folders mixed in with the bookfiles. Fortunately, flat view without the folders and sorting by extension and shuttling the bookfiles to a single folder took about 10 seconds.

[Rellwood]

Originally Posted by odamizu

For 1.17.1, does it work if you're already registered, or is it totally dead? Can someone who is already registered give it a try?

In 2023 when they enforced the update for me what happened was I started it up and the first thing was the notice to update the program. It wouldn't let it run until I updated.

EDIT - Sorry, I was talking about 1.17.4417 - how anyone was or is still able to go below that I don't know.

[Rellwood]

also, on r/calibre someone has been on a bullhorn blasting step by step instructions to break the NEWEST DRM. I cant even.