If you have upgraded from an earlier version of the plugin, any existing Barnes and Noble keys will have been automatically imported, so you might not need to do any more configuration. Continue reading for key generation and management instructions.
In mid-2014, Barnes & Noble changed the way they generated encryption keys. Instead of deriving the key from the user's name and credit card number, they started generating a random key themselves, sending that key through to devices when they connected to the Barnes & Noble servers. This means that some users will find that no combination of their name and CC# will work in decrypting their ebooks.
There is a work-around. Barnes & Noble’s desktop app NOOK Study generates a log file that contains the encryption key. You can download NOOK Study from https://yuzu.com/nsdownload.
Once downloaded, install the application, register with your Barnes & Noble or nook account, and download at least one DRMed ebook through NOOK Study. It will be saved somewhere in a folder called "My Barnes & Noble eBooks" in your Documents folder.
Now import that book into calibre. The log file and the key in the log should be automatically found by the plugin and used to decrypt the book.
If the automatic process doesn't work for you, you can still find extract it manually and save it as a .b64 file for import into the plugin's preferences as follows:
On the right-hand side of the plugin’s customization dialog, you will see a button with an icon that looks like a green plus sign (+). Clicking this button will open a new dialog for entering the necessary data to generate a new key.
Click the OK button to create and store the generated key. Or Cancel if you don’t want to create a key.
New keys are checked against the current list of keys before being added, and duplicates are discarded.
On the right-hand side of the plugin’s customization dialog, you will see a button with an icon that looks like a red "X". Clicking this button will delete the highlighted key in the list. You will be prompted once to be sure that’s what you truly mean to do. Once gone, it’s permanently gone.
On the right-hand side of the plugin’s customization dialog, you will see a button with an icon that looks like a sheet of paper. Clicking this button will promt you to enter a new name for the highlighted key in the list. Enter the new name for the encryption key and click the OK button to use the new name, or Cancel to revert to the old name..
On the right-hand side of the plugin’s customization dialog, you will see a button with an icon that looks like a computer’s hard-drive. Use this button to export the highlighted key to a file (with a ‘.b64’ file name extension). Used for backup purposes or to migrate key data to other computers/calibre installations. The dialog will prompt you for a place to save the file.
At the bottom-left of the plugin’s customization dialog, you will see a button labeled "Import Existing Keyfiles". Use this button to import existing ‘.b64’ key files. Key files might come from being exported from this or older plugins, or may have been generated using the original i♥cabbages script, or you may have made it by following the instructions above.
Once done creating/deleting/renaming/importing decryption keys, click Close to exit the customization dialogue. Your changes wil only be saved permanently when you click OK in the main configuration dialog.