DeDRM_tools/FAQs.md

Overview

What's this repository all about?

Providing free open source tools to remove DRM from your ebooks.

What's DRM?

DRM ("Digital Rights Management") is a way of using encryption to tie the books you've bought to a specific device or to a particular piece of software.

Why would I want to remove DRM from my ebooks?

When your ebooks have DRM you are unable to convert the ebook from one format to another (e.g. Kindle KF8 to Kobo ePub), so you are restricted in the range of ebook stores you can use. DRM also allows publishers to restrict what you can do with the ebook you've bought, e.g. preventing the use of text-to-speech software. Longer term, you can never be sure that you'll be able to come back and re-read your ebooks if they have DRM, even if you save back-up copies.

So how can I remove DRM from my ebooks?

Just download and use these tools, that's all! Uh, almost. There are a few, uh, provisos, a couple of quid pro quos.

• The tools don't work on all ebooks. For example, they don't work on any ebooks from Apple's iBooks store.
• You must own the ebook - the tools won't work on library ebooks or rented ebooks or books from a friend.
• You must not use these tools to give your ebooks to a hundred of your closest friends. Or to a million strangers. Authors need to sell books to be able to write more books. Don't be mean to the authors.

Recent Changes to Kindle for PC/Kindle for Mac

Starting with version 1.19, Kindle for PC/Mac uses Amazon's new KFX format which isn't quite as good a source for conversion to ePub as the older KF8 (& MOBI) formats. There are two options to get the older formats. Either stick with version 1.17 or earlier, or modify the executable by changing a file name (PC) or disabling a component of the application (Mac).

Version 1.17 of Kindle is no longer available directly from Amazon, so you will need to search for the proper file name and find it on a third party site. The name is KindleForPC-installer-1.17.44170.exe for PC and KindleForMac-44182.dmg for Mac. (Note that this is a 32-bit application on the Mac, so will not work on Catalina and newer versions of macOS.) Verify the one of the following cryptographic hash values, using software of your choice, before installing the downloaded file in order to avoid viruses. If the hash does not match, delete the downloaded file and try again from another site.

Kindle for PC KindleForPC-installer-1.17.44170.exe:

• MD-5: 53F793B562F4823721AA47D7DE099869
• SHA-1: 73C404D719F0DD8D4AE1C2C96612B095D6C86255
• SHA-256: 14E0F0053F1276C0C7C446892DC170344F707FBFE99B6951762C120144163200

Kindle for Mac KindleForMac-44182.dmg:

• MD-5: E7E36D5369E1F3CF1D28E5D9115DF15F
• SHA-1: 7AB9A86B954CB23D622BD79E3257F8E2182D791C
• SHA-256: 28DC21246A9C7CDEDD2D6F0F4082E6BF7EF9DB9CE9D485548E8A9E1D19EAE2AC

You will need to go to the preferences and uncheck the auto update checkbox. Then download and install 1.17 over the top of the newer installation. You'll also need to delete the KFX folders from your My Kindle Content folder. You may also need to take further action to prevent an auto update. The simplest way is to find the 'updates' folder and replace it with a file. See [this thread] (http://www.mobileread.com/forums/showthread.php?t=283371) at MobileRead for a Script to do this on a PC. On a Mac you can find the folder at ~/Library/Application Support/Kindle/. Make the 'updates' folder read-only, or delete it and save a blank text file called 'updates' in its place.

Another possible solution is to use 1.19 or later, but disable KFX by renaming or disabling a necessary component of the application. This may or may not work on versions after 1.25. In a command window, enter the following commands when Kindle for PC/Mac is not running:

Windows

ren %localappdata%\Amazon\Kindle\application\renderer-test.exe renderer-test.xxx

PC Note: The renderer-test program may be in a different location in some Kindle for PC installations. If the rename command fails look in other folders, such as C:\Program Files\Amazon\Kindle.

Macintosh

chmod -x /Applications/Kindle.app/Contents/MacOS/renderer-test

Mac Note: If the chmod command fails with a permission error try again using sudo before chmod - sudo chmod [...]. This only works on Kindle for Mac 1.19 thru 1.31, it does NOT work with 1.32 or newer.

After restarting the Kindle program any books previously downloaded in KFX format will no longer open. You will need to remove them from your device and re-download them. All future downloads will use the older Kindle formats instead of KFX although they will continue to be placed in one individual subdirectory per book. Note that books should be downloaded by right-click and 'Download', not by just opening the book. Recent (1.25+) versions of Kindle for Mac/PC may convert KF8 files to a new format that is not supported by these tools when the book is opened for reading.

Decrypting KFX

Thanks to work by several people, the tools can now decrypt KFX format ebooks from Kindle for Mac/PC. In addition to the DeDRM plugin, calibre users will also need to install jhowell's KFX Input plugin which is available through the standard plugin menu in calibre, or directly from his plugin thread on Mobileread.

It's quite possible that Amazon will update their KFX DeDRM to prevent DRM removal from KFX books again. So Remove DRM as soon as possible!

Thanks

Thanks to jhowell for his investigations into KFX format and the KFX Input plugin. Some of these instructions are from his thread on the subject at MobileRead.

Where can I get the latest version of these free DRM removal tools?

Right here at github. Just go to the releases page and download the latest zip archive of the tools, named DeDRM\_tools\_X.X.X.zip, where X.X.X is the version number. You do not need to download the source code archive. This will get you the forked version by noDRM. If you want to download the original version by Apprentice Harper, go to this page instead.

I've downloaded the tools archive. Now what?

First, unzip the archive. You should now have a DeDRM folder containing several files, including a ReadMe_Overview.txt file. Please read the ReadMe_Overview.txt file! That will explain what the files are, and you'll be able to work out which of the tools you need.

That's a big complicated ReadMe file! Isn't there a quick guide?

Install calibre. Install the DeDRM_plugin in calibre. Install the Obok_plugin in calibre. Restart calibre. In the DeDRM_plugin customisation dialog add in any E-Ink Kindle serial numbers. Remember that the plugin only tries to remove DRM when ebooks are imported.

Installing the Tools

The calibre plugin

I am trying to install the calibre plugin, but calibre says "ERROR: Unhandled exception: InvalidPlugin: The plugin in '[path]DeDRM_tools_X.X.X.zip' is invalid. It does not contain a top-level __init__.py file"

You are trying to add the tools archive (e.g. DeDRM_tools_10.0.2.zip) instead of the plugin. The tools archive is not the plugin. It is a collection of DRM removal tools which includes the plugin. You must unzip the archive, and install the calibre plugin DeDRM_plugin.zip from inside the unzipped archive.

I’ve unzipped the tools archive, but I can’t find the calibre plugin when I try to add them to calibre. I use Windows.

You should select the zip file that is in the DeDRM_calibre_plugin folder, not any files inside the plugin’s zip archive. Make sure you are selecting from the folder that you created when you unzipped the tools archive and not selecting a file inside the still-zipped tools archive.

(The problem is that Windows will allow apps to browse inside zip archives without needing to unzip them first. If there are zip archives inside the main zip archives, Windows will show them as unzipped as well. So what happens is people will unzip the DeDRM_tools_X.X.X.zip to a folder, but when using calibre they will actually navigate to the still zipped file by mistake and cannot tell they have done so because they do not have file extensions showing. So to the unwary Windows user, it appears that the zip archive was unzipped and that everything inside it was unzipped as well so there is no way to install the plugins.

We strongly recommend renaming the DeDRM_tools_X.X.X.zip archive (after extracting its contents) to DeDRM_tools_X.X.X_archive.zip. If you do that, you are less likely to navigate to the wrong location from inside calibre.)

Using the Tools

I can’t get the tools to work on my rented or library ebooks.

The tools are not designed to remove DRM from rented or library ebooks.

I've unzipped the tools, but what are all the different files, and how do I use them?

Read the ReadMe_Overview.txt file and then the ReadMe files for the tools you're interested in. That's what they're for.

I have installed the calibre plugin, but my books still have DRM. When I try to view or convert my books, calibre says they have DRM.

DRM only gets removed when an ebook is imported into calibre. Also, if the book is already in calibre, by default calibre will discard the newly imported file. You can change this in calibre's Adding books preferences page (Automerge..../Overwrite....), so that newly imported files overwrite existing ebook formats. Then just re-import your books and the DRM-free versions will overwrite the DRMed versions while retaining your books' metadata.

I have installed the calibre plugin, but I don’t know where my ebooks are stored.

Your ebooks are stored on your computer or on your ebook reader. You need to find them to be able to remove the DRM. If they are on your reader, you should be able to locate them easily. On your computer it’s not so obvious. Here are the default locations.

Macintosh

Navigating from your home folder,

Kindle for Mac ebooks are in either Library/Application Support/Kindle/My Kindle Content or Documents/My Kindle Content or Library/Containers/com.amazon.Kindle/Data/Library/Application Support/Kindle/My Kindle Content, depending on your version of Kindle for Mac.

Adobe Digital Editions ebooks are in Documents/Digital Editions

Windows

Navigating from your Documents folder (My Documents folder, pre-Windows 7)

Kindle for PC ebooks are in My Kindle Content

Adobe Digital Editions ebooks are in My Digital Editions

I have installed the calibre plugin, and the book is not already in calibre, but the DRM does not get removed.

You must use the exact file that is used by your ebook reading software or hardware. See the previous question on where to find your ebook files. Do not use an old copy you have that you can no longer read. If you cannot read the ebook on your current device or installed software, the tools will certainly not be able to remove the DRM. Download a fresh copy that does work with your current device or installed software.

I have installed the calibre plugin, and the book is not already in calibre, but the DRM does not get removed. It is a Kindle book.

If you are on Windows 8 and using the Windows 8 AppStore Kindle app, you must download and install the Kindle for PC application directly from the Amazon website. The tools do not work with the Windows 8 AppStore Kindle app.

If this book is from an eInk Kindle (e.g. Paperwhite), you must enter the serial number into the configuration dialog. The serial number is sixteen characters long, and is case-sensitive.

If this book is from Kindle for Mac or Kindle for PC, you must have the Kindle Software installed on the same computer and user account as your copy of calibre.

If the book is from Kindle for PC or Kindle for Mac and you think you are doing everything right, and you are getting this message, it is possible that the files containing the encryption key aren’t quite in the format the tools expect. To try to fix this:

1. Deregister Kindle for PC/Mac from your Amazon account.
2. Uninstall Kindle for PC/Mac
3. Delete the Kindle for PC/Mac preferences
   • PC: Delete the directory [home folder]\AppData\Local\Amazon (it might be hidden) and [home folder]\My Documents\My Kindle Content
   • Mac: Delete the directory [home folder]/Library/Application Support/Kindle/ and/or [home folder]/Library/Containers/com.amazon.Kindle/Data/Library/Application Support/Kindle/ (one or both may be present and should be deleted)
4. Reinstall Kindle for PC/Mac version 1.17 or earlier (see above for download links).
5. Re-register Kindle for PC/Mac with your Amazon account
6. Download the ebook again. Do not use the files you have downloaded previously.

Some of my books had their DRM removed, but some still say that they have DRM and will not convert.

There are several possible reasons why only some books get their DRM removed.

• You still don’t have the DRM removal tools working correctly, but some of your books didn’t have DRM in the first place.

If you are still having problems with particular books, you will need to create a log of the DRM removal attempt for one of the problem books. If you're using NoDRM's fork, open a new issue in the GitHub repo. If you're using Apprentice Harper's version, post that logfile in a new issue at Apprentice Harper's github repository.

My Kindle book has imported and the DRM has been removed, but all the pictures are gone.

Most likely, this is a book downloaded from Amazon directly to an eInk Kindle (e.g. Paperwhite). Unfortunately, the pictures are probably in a .azw6 file that the tools don't understand. You must download the book manually from Amazon's web site "For transfer via USB" to your Kindle. When you download the eBook in this manner, Amazon will package the pictures in the with text in a single file that the tools will be able to import successfully.

My Kindle book has imported, but it's showing up as an AZW4 format. Conversions take a long time and/or are very poor.

You have found a Print Replica Kindle ebook. This is a PDF in a Kindle wrapper. Now the DRM has been removed, you can extract the PDF from the wrapper using the KindleUnpack plugin. Conversion of PDFs rarely gives good results.

Do the tools work on books from Kobo?

If you use the Kobo desktop application for Mac or PC, install the Obok plugin. This will import and remove the DRM from your Kobo books, and is the easiest method for Kobo ebooks.

I cannot solve my problem with the DeDRM plugin, and now I need to ‘post a log’. How do I do that?

Remove the DRMed book from calibre. Click the Preferences drop-down menu and choose 'Restart in debug mode'. Once calibre has re-started, import the problem ebook. Now close calibre. A log will appear that you can copy and paste into a new issue in NoDRM’s GitHub repo. If you're using Apprentice Harper’s version, post that logfile in a new issue at Apprentice Harper's GitHub repository.

Is there a way to use the DeDRM plugin for Calibre from the command line?

See the Calibre command line interface (CLI) instructions.

The plugin displays a "MemoryError" in its log file during DRM removal.

A "MemoryError" usually occurs when you're using the 32-bit version of Calibre (which is limited in the amount of useable RAM). If you have a 64-bit installation of your operating system (on Windows, press Windows+Break, then make sure it says "64-bit Operating System" under "System type"), try downloading the 64-bit version of Calibre instead of the 32-bit version.

If the error still occurs, even with the 64-bit version, please open a bug report.

General Questions

Once the DRM has been removed, is there any trace of my personal identity left in the ebook?

That question cannot be answered for sure. While it is easy to check if a book has DRM or not, it is very difficult to verify if all (traces of) personal information have been removed from a book. The tools attempt to remove watermarks when they are detected (optionally, there's an option in the plugin settings to enable that), but that will not be the case for all watermarks.

Why do some of my Kindle ebooks import as HTMLZ format in calibre?

Most Amazon Kindle ebooks are Mobipocket format ebooks, or the new KF8 format. However, some are in a format known as Topaz. The Topaz format is only used by Amazon. A Topaz ebook is a collections of glyphs and their positions on each page tagged with some additional information from that page including OCRed text (Optical Character Recognition generated Text) to allow searching, and some additional layout information. Each page of a Topaz ebook is effectively a description of an image of that page. To convert a Topaz ebook to another format is not easy as there is not a one-to-one mapping between glyphs and characters/fonts. To account for this, two different formats are generated by the DRM removal software. The first is an html description built from the OCRtext and images stored in the Topaz file (HTMLZ). This format is easily reflowed but may suffer from typical OCRtext errors including typos, garbled text, missing italics, missing bolds, etc. The second format uses the glyph and position information to create an accurate scalable vector graphics (SVG) image of each page of the book that can be viewed in web browsers that support svg images (Safari, Firefox 4 or later, etc). Additional conversion software can be used to convert these SVG images to an image only PDF file. The DeDRM calibre plugin only imports the HTMLZ versions of the Topaz ebook. The html version can be manually cleaned up and spell checked and then converted using Sigil/calibre to epubs, mobi ebooks, and etc.

Are the tools open source? How can I be sure they are safe and not a trojan horse?

All the DRM removal tools hosted here are almost entirely written in Python. So they are inherently open source, and open to inspection by everyone who downloads them.

There are some optional shared libraries (*.dll, *.dylib, and *.so) included for performance. The source for any compiled pieces are provided within alfcrypto_src.zip. If this is a concern either delete the binary files (there's fallback code in the plugin that allows it to work without these, it will just be slower) or manually rebuild them from source.

What ebooks do these tools work on?

The Calibre plugin removes DRM from PDF, ePub, kePub (Kobo), eReader, Kindle (Mobipocket, KF8, Print Replica and Topaz) format ebooks using Adobe Adept, Barnes & Noble, Amazon, Kobo and eReader DRM schemes. It used to remove Readium LCP DRM from ePub or PDF files in the past, but that functionality had to be removed due to a DMCA takedown request.

Note these tools do NOT ‘crack’ the DRM. They simply allow the book’s owner to use the encryption key information already stored someplace on their computer or device to decrypt the ebook in the same manner the official ebook reading software uses.

Why don’t the tools work with Kindle Fire ebooks?

Because no-one's found out how to remove the DRM from ebooks from Kindle Fire devices yet. The workaround is to install Kindle for PC or Kindle for Mac and use books from there instead.

Why don't the tools work with Kindle for iOS ebooks?

Amazon changed the way the key was generated for Kindle for iOS books, and the tools can no longer find the key. The workaround is to install Kindle for PC or Kindle for Mac and use books from there instead.

Why don't the tools work with Kindle for Android ebooks?

Amazon turned off backup for Kindle for Android, so the tools can no longer find the key. The workaround is to install Kindle for PC or Kindle for Mac and use books from there instead.

Why don't the tools work on books from the Apple iBooks Store?

Apple regularly change the details of their DRM and so the tools in the main tools archive will not work with these ebooks. Apple’s Fairplay DRM scheme can be removed using Requiem if the appropriate version of iTunes can still be installed and used. See the post Apple and ebooks: iBookstore DRM and how to remove it at Apprentice Alf's blog for more details.

Why don't the tools work with LCP-encrypted ebooks? / Error message about a "DMCA takedown"

Support for LCP DRM removal was included in the past, but Readium (the company who developed that particular DRM) has decided to open a DMCA takedown request in January 2022. This means that for legal reasons, this GitHub repository no longer contains the code needed to remove DRM from LCP-encrypted books. For more information please read this bug report.

I’ve got the tools archive and I’ve read all the FAQs but I still can’t install the tools and/or the DRM removal doesn’t work

• Read the ReadMe_Overview.txt file in the top level of the tools archive
• Read the ReadMe file for the tool you want to use.
• If you still can’t remove the DRM, create a new GitHub issue. If you are using Apprentice Harper's original version and not this fork, you can also create a new issue at Apprentice Harper's github repository. If you do report an issue in any of the GitHub repositories, please report the error as precisely as you can. Include what platform you use, what tool you have tried, what errors you get, and what versions you are using. If the problem happens when running one of the tools, post a log (see previous questions on how to do this).

Who wrote these scripts?

The authors tend to identify themselves only by pseudonyms:

• The Adobe Adept and Barnes & Noble scripts were created by i♥cabbages
• The Adobe Adept support for ADE3.0+ DRM was added by a980e066a01
• ~The Readium LCP support for this plugin was created by NoDRM~ (removed due to a DMCA takedown, see #18 )
• The Amazon Mobipocket and eReader scripts were created by The Dark Reverser
• The Amazon K4PC DRM/format was further decoded by Bart Simpson aka Skindle
• The Amazon K4 Mobi tool was created by by some_updates, mdlnx and others
• The Amazon Topaz DRM removal script was created by CMBDTC
• The Amazon Topaz format conversion was created by some_updates, clarknova, and Bart Simpson
• The DeDRM all-in-one calibre plugin was created by Apprentice Alf
• The support for .kinf2018 key files and KFX 2&3 was by Apprentice Sakuya
• The Scuolabooks tool was created by Hex
• The Microsoft code was created by drs
• The Apple DRM removal tool was created by Brahms

Since the original versions of the scripts and programs were released, various people have helped to maintain and improve them.