Adventures in discovering the K4PC PID.

[MerLock]

I wonder with this exposure, if Amazon will be pressured to quickly release an update to prevent the decryption on the Kindle for PC application.

[kennyc]

Originally Posted by MerLock

I wonder with this exposure, if Amazon will be pressured to quickly release an update to prevent the decryption on the Kindle for PC application.

Well, they didn't do that for the straight-up Kindle (azm) files..

[animedude01]

They have to be careful to make sure an update doesn't cause problems for users. It would be really bad publicity for them to put out an update that negatively affects all users to block a small subset of users from doing something Amazon doesn't like.

Most likely the costs outweigh the benefits. If Amazon's bottom line isn't greatly affected, it will likely be a low priority for them. So as long as the cracked books don't start showing up on the darknet in large numbers, and they don't start losing sales because of that, I don't see them spending lots of time on a fix.

In fact, I wouldn't be surprised of they saw a slight uptick in sales due to non-Kindle owners buying Kindle books to read on other devices.

[kennyc]

Originally Posted by animedude01

They have to be careful to make sure an update doesn't cause problems for users. It would be really bad publicity for them to put out an update that negatively affects all users to block a small subset of users from doing something Amazon doesn't like.

Most likely the costs outweigh the benefits. If Amazon's bottom line isn't greatly affected, it will likely be a low priority for them. So as long as the cracked books don't start showing up on the darknet in large numbers, and they don't start losing sales because of that, I don't see them spending lots of time on a fix.

In fact, I wouldn't be surprised of they saw a slight uptick in sales due to non-Kindle owners buying Kindle books to read on other devices.

Exactly which would be the case as well with NO DRM.

[=X=]

Originally Posted by kennyc

Not true. In Windows that doesn't make much sense because it's the extension that drives what application opens the file.
as long as it's unique that's fine, but if it's .epub there could be any number of apps that might handle it.
That is likely WHY amazon chose to make them unique.

I'm not following you what is unique? The point of my comment was that Amazon chose to keep one extension for all their different formats. Download a Topaz book on the Kindle for PC and you will see it has the PRC extension.

The point I'm making is the software has to handle the different format it supports. The format identity is kept within the file, sure it can use the extension but that is not reliable since anybody can change a name.

So there is no need to expose the different formats by displaying different extensions.
I don't know where your example of ePub came in since we are talking about mobi and topaz formats

[kennyc]

Originally Posted by =X=

I'm not following you what is unique? The point of my comment was that Amazon chose to keep one extension for all their different formats. Download a Topaz book on the Kindle for PC and you will see it has the PRC extension.

The point I'm making is the software has to handle the different format it supports. The format identity is kept within the file, sure it can use the extension but that is not reliable since anybody can change a name.

So there is no need to expose the different formats by displaying different extensions.
I don't know where your example of ePub came in since we are talking about mobi and topaz formats

But that's not correct for the PC world. It only works if you associate the Amazon reader with that file type. By using the same file extension for different types of files the PC has no idea that they are different.

a *.doc file is opened my MS-Word (even if it's a Wordperfect file) and it results in an error. If I try to open an amazon PRC file by clicking on it, it trys to open it with mobiReader and gets an error because it not really a .mobi file or it DRM'd etc.

What I'm saying is that for programs in general to work properly in the PC world then the file extension should be associated with a unique file type/format otherwise errors can result.

[Obi]

Hi, I've read through this and other forums about getting the PID for my Kindle 2. I downloaded Python and tried versions 2.6 and 2.3 and I'm still getting an invalid syntax error. Can you Help? I'm not a programmer so I'm somewhat challenged at this stuff.
Thanks, Obi

[animedude01]

Obi, it's against forum rules to give step by step instructions. If you give us an error message, though, we may be able to point to towards more help. You can also search for i(heart)cabbages blog. I don't think the same restrictions apply there

[=X=]

Originally Posted by kennyc

But that's not correct for the PC world. It only works if you associate the Amazon reader with that file type. By using the same file extension for different types of files the PC has no idea that they are different.
a *.doc file is opened my MS-Word (even if it's a Wordperfect file) and it results in an error. If I try to open an amazon PRC file by clicking on it, it trys to open it with mobiReader and gets an error because it not really a .mobi file or it DRM'd etc.
What I'm saying is that for programs in general to work properly in the PC world then the file extension should be associated with a unique file type/format otherwise errors can result.

You obviously have some knowledge on files and there extension but is not entirely correct. The extensions have little to do with the programs ability to read them. They are important only for the association.
Before you respond to this post try this test, using your example above.
1. Copy your word file and rename it with a BMP extension then double click on the file and see what happens. According to your argument the file should open just fine.
My point is that it will not work
2. The second test open the same word file with OpenOffice. Your argument is that this file will not open my argument is that it will.
But don't only take my word. Reread this thread and you will see there are many people stating that the Kindle4PC downloads two different formats topaz and mobi, but stores them with one file extension.
The only way a user can distinguish the two is by opening the file in a text editor and looking for the word topaz or MOBI within the file.
hope I've helped clarify your confusion ... Computer can be tricky.
Regards,
=X=

[skindle]

In an effort to contribute to the state of knowledge on KindleForPC, I just posted an all in one tool I am calling skindle to rapidshare:

download removed

This tool reads your kindle.info file and an input Mobi DRM'ed file to produce a dedrm'ed file. Thre is no dependency on mobidedrm and no use of the windows debugging api. This tool does not need to run KindleForPC in order to work. This tool derives the book specific PID in the same manner that K4PC does, then uses that PID in the same way that mobidedrm does to produce an output file.

C source and a compiled cygwin binary are included. I have not had the chance to get a version working that runs free of cygwin. Maybe someone here can figure it out.

EDIT: New version fixes a bug and removes cygwin dependency for the executable:

download removed

[mikeage]

Originally Posted by skindle

C source and a compiled cygwin binary are included. I have not had the chance to get a version working that runs free of cygwin. Maybe someone here can figure it out.

You code compiled perfectly for Win32 using MinGW [gcc for Windows, without cygwin]. I've put it at download removed; feel free to include this version of the executable.

I have not tested it, as I don't have access to my VM that I use for random software that I haven't reviewed the code (and no time for a proper review yet), but it's there if you want to distribute it (it's a free account, so it will be deleted after 10 downloads).

[skindle]

mikeage, thanks for the attempt, but I had the same problem with your exe as I did when I tried using the -mno-cygwin option. The code compiled fine, but inexplicably quits with no error message halfway through. I have tried looking into the problem but ran out of ideas which is why I posted the cygwin version. It may boil down to a wide character vs ascii issue somewhere.

[mikeage]

Ok, fixed (although I'm not sure exactly why/how; I haven't taken the time to see whether the lengths mentioned below are actually correct... <g>).

in skindle.c, on line 842, you allocate DataOut.cbData + 2 * MD5_DIGEST_LENGTH + 1 bytes. You then copy to that pointer:

memcpy(devId, DataOut.pbData, DataOut.cbData);
strcpy(devId + DataOut.cbData, vsn);
strcat(devId + DataOut.cbData, username)

However, vsn and username both are 32 bytes long (and MD5_DIGEST_LENGTH is only 16).

When I added another 32 bytes, I was able to de-drm a book (I only have one kindle 4 pc content; it was a free book that I once "bought". However, the original is DRMed, at least enough that calibre refuses to show it)!

EDIT: Try this with cygwin; if you want, I'll send you the mingw32-gcc build as well, if you don't have an environment.

EDIT2: For some reason, after this is done, Calibre no longer sees metadata in these files. Mobipocket reader crashes each time I try to import one of these files [although the copy with DRM does show up (with a warning)]

[skindle]

Ah, great catch. I fixed that length a few lines below, but failed to make the change that you note. New version with cygwin dependency removed is available here:

download link removed

Thanks!

[mikeage]

Do you see the issue with the metadata?