Dealing with Kindle for PC/Mac 1.19 and KFX in calibre

[lkmiller]

Mac store app vs. the app downloaded directly from Amazon? I seem to recall people having problems with that in the past.

At any rate, if you look at the first log in that issue, you can see how the key isn't found. It appears as if they don't have Kindle for Mac installed at all, but they did. I've seen the same thing on Windows when people have version 1.25 of Kindle for PC.

(Yeah, can't see stand-alone DeDRM vs. plugin being the difference either. Same exact scripts, just running on different Python.)

[jhowell]

A change was made in Kindle for PC 1.25. A file named .kinf2011 in "User\name\AppData\Local\Amazon\Kindle\storage " has been replaced with one named .kinf2018 having different content. I presume that is used by the DeDRM tools find the user's key.

I don't have a Mac so I can't say whether or not something similar happened in that platform. Perhaps someone with a Mac can check what files are present there for the new Kindle for Mac stand-alone and store versions.

[odamizu]

I ran more tests with K4Mac and see what's going on now. This is more complicated than I thought and involves more detailed discussion of Alf's tools than I think is allowed here. Suffice to say it is possible to get Alf-friendly KF8 from 1.25.2, including with a clean install, but depending on your Alf set-up, you may need to take extra steps that I don't think I'm allowed to discuss here.

[jhowell]

Originally Posted by odamizu

I ran more tests with K4Mac and see what's going on now. This is more complicated than I thought and involves more detailed discussion of Alf's tools than I think is allowed here.

Perhaps you could open a new issue at Apprentice Harper’s GitHub with more details.

[pdurrant]

Odamizu's method relies on first obtaining the decryption key from an earlier installation of 1.23 or earlier.

No-one's reverse engineered the new key file format yet.

Thanks for being careful about the line between discussion of DRM and detailed help with DRM removal.

[lkmiller]

Thanks for taking another look at it, odamizu. Hopefully things are figured out for both Mac and PC soon.

[odamizu]

Originally Posted by pdurrant

... Thanks for being careful about the line between discussion of DRM and detailed help with DRM removal.

Yes, of course. I figured PM'ing you and jhowell would be more appropriate than discussing on the open forum.

I have updated the instructions to reflect the new findings (without going into detail).

One of the questions swirling around in my head: is the new key a deliberate effort by Amazon to thwart Alf's tools, or is this just a side effect of other changes they're implementing? Thoughts anyone?

[pdurrant]

If I had to guess, I'd say it was a side effect of moving to a 64-bit Mac application.

[jhowell]

Originally Posted by odamizu

One of the questions swirling around in my head: is the new key a deliberate effort by Amazon to thwart Alf's tools, or is this just a side effect of other changes they're implementing? Thoughts anyone?

The replacement of KF8 with KCR in Kindle for Mac is probably due to new requirements from Apple, especially since the same change was not made to Kindle for PC.

The change from .kinf2011 to .kinf2018 and the new DRM for KFX format were both likely done specifically to prevent DRM removal, in my opinion.

----
Added: it does seem odd to me that Amazon still has not done anything to prevent exfiltration of books obtained using the Download & Transfer via USB function of their website for owners of e-ink Kindle devices. It is strange that they continue to leave that open while closing other loopholes.

[ilovejedd]

Originally Posted by jhowell

Added: it does seem odd to me that Amazon still has not done anything to prevent exfiltration of books obtained using the Download & Transfer via USB function of their website for owners of e-ink Kindle devices. It is strange that they continue to leave that open while closing other loopholes.

Maybe it's too expensive to replace the system in terms of development costs? Isn't that the only method available for really old Kindles?

[odamizu]

Originally Posted by jhowell

...The change from .kinf2011 to .kinf2018 and the new DRM for KFX format were both likely done specifically to prevent DRM removal, in my opinion.

----
Added: it does seem odd to me that Amazon still has not done anything to prevent exfiltration of books obtained using the Download & Transfer via USB function of their website for owners of e-ink Kindle devices. It is strange that they continue to leave that open while closing other loopholes.

I was afraid you were going to say that and that :(

[darryl]

Originally Posted by jhowell

The change from .kinf2011 to .kinf2018 and the new DRM for KFX format were both likely done specifically to prevent DRM removal, in my opinion.

----
Added: it does seem odd to me that Amazon still has not done anything to prevent exfiltration of books obtained using the Download & Transfer via USB function of their website for owners of e-ink Kindle devices. It is strange that they continue to leave that open while closing other loopholes.

It is very interesting. I suspect that Amazon benefits from drm removal. It has the best infrastructure including the the best store and prices. I suspect that there are many users of other devices who buy from Amazon. On the other hand, they now have KU. If members read on other devices the author does not get paid. Also, they now have so much exclusive content that the result of restricting or eliminating DRM removal may be the sale of many more of their devices rather than losing customers. And, like it or not, piracy is made significantly easier by the ability to remove DRM. If this becomes impossible it will not eliminate piracy completely, but may well send it back to the days of scanning and OCR. Though I would not have thought piracy was that significant a problem, figures on the impact of piracy are little more than guesses. Perhaps it is more significant than I believe.

The existence of older devices means that if Amazon does start to take DRM more seriously, there will likely be a period where they continue to provide mobi and azw3 downloads with the old drm for older devices. Certainly kfx, which is optimised for each device, is not designed to make reading on non-Amazon devices easier.

[ilovejedd]

Originally Posted by darryl

The existence of older devices means that if Amazon does start to take DRM more seriously, there will likely be a period where they continue to provide mobi and azw3 downloads with the old drm for older devices. Certainly kfx, which is optimised for each device, is not designed to make reading on non-Amazon devices easier.

I'm actually quite concerned that we are already in that transition period.

[darryl]

Originally Posted by ilovejedd

I'm actually quite concerned that we are already in that transition period.

This could quite easily be the case. Amazon's current actions are quite consistent with this, though not conclusive. The last device that Amazon released which has not been updated to use kfx is the Paperwhite 1. As I understand it anything older than the Kindle Keyboard supports only azw (mobi) and not azw3. The next step if Amazon is going down this path is for it to remove the option to download azw (mobi) and azw3 files to your computer for transfer via usb. Even if Amazon does this if you own a device older than the Paperwhite 2 you will still be able to obtain the older formats by downloading them to the device and transferring them via usb to your computer for import into calibre.

To close this loophole is problematic. It is possible that Amazon could update the firmware in older devices to support kfx and new drm, though some of the earlier devices particularly may not have the necessary hardware capabilities. I suspect if they were going to do this they would already have done so. Otherwise Amazon would have to not only end support for these devices but actually exclude them from purchasing ebooks from the Amazon store, or perhaps substantially limit available titles. This is not consistent with Amazon's policy so far. Amazon may choose to wait a long time for the numbers of these older devices in use to decline to insignificant levels.

[Sirtel]

The downloading option is there probably not only for old devices, but also for people who don't have wifi. If Amazon decides to take the option away, what about those people?