DeOneBook --------- This program is designed to decrypt the contents of eOneBook SD cards. It is able to extract the encryption keys from SD cards to make this automatic with the proper hardware. Without hardware support, decryption is a two-step process, extracting a key using the eOneBook itself, and decryption using that key. Building -------- If you have a system with a directly attached SD card reader (i.e. a device that appears as `/dev/mmcblk0` or similar, *not* as `/dev/sdb`), you can build a native version of the program with: make If you do not (this includes all USB readers and some internal devices that are attached through an internal USB adapter), you'll need to cross-compile the tool to run directly on the eOneBook. First install a cross compiler. On Debian and Ubuntu systems, you can do this with: sudo apt install crossbuild-essential-armhf Then build with the cross compiler: make CC=arm-linux-gnueabihf-gcc Automatic Decryption -------------------- If your system has a directly connected SD card reader, you can decrypt files with: deonebook [-d devicename] The default device is `mmcblk0`. If your SD card reader is something else (n.b. it *must* be an `mmcblk` device), specify that via the `-d` option. Replace with the path to an encrypted file (e.g. `/media/sd/001/100E`) and with the path to place the newly decrypted file. DeOneBook will determine the encryption key by reading information directly from the SD card. On-device Key Extraction ------------------------ If your system does not have a directly connected SD card reader, you can use your eOneBook device to extract the encryption key. You'll need to prep the SD card to execute the program and save its output. First, make sure the SD card is not write-protected by moving the write-protect slider to the end of its slot nearest the pins of the card. Mount the SD card somewhere you can write to it, `cd` to that mount point, and run the following commands, replacing `$DEONEBOOKDIR` with the path to the compiled DeOneBook. ***Be very careful with these commands, as if you lose or overwrite the original `.A001` file, you will not be able to use that SD card in your eOneBook anymore. You are strongly advised to back up the entire SD card before attempting this.*** mv .A001 eonebook # rename the official firmware cp $DEONEBOOKDIR/deonebook . # copy over the key extractor cp $DEONEBOOKDIR/extract.sh .A001 # copy over the extraction script chmod +x deonebook .A001 # ensure deonebook files are executable Put the SD card in your eOneBook and open it up. When the official interface comes up, the key extraction is complete. Close the eOneBook and there will be a file called `eonebook.key` containing the encryption key for that card. Manual Decryption ----------------- Once you have extraced the key using your eOneBook, you can use that key to manually decrypt that SD card's files. Run: deonebook -k $KEY Replace `$KEY` with the contents of `eonebook.key` from the previous step (you could also simply replace it with `$(cat eonebook.key)`). Replace with the path to an encrypted file, and with the path for the newly decrypted file.