horcrux

Horcrux - a helper for preparing backups of data worth protecting

The use case which brought this tool into existence, is that of creating backups of GPG private keys or any other cryptographic key or data of similar value for that matters. Inspired by paperkey, the idea is to transform the data into printable form in such a way that easy recovery into its digital original is possible. Other than paperkey, this tool allow to split the data into fragments, which on its own are worthless and only if brought together, can recreate the secret they were created from.

Install

deb

curl -s https://packagecloud.io/install/repositories/corvus-ch/tools/script.deb.sh | sudo bash
apt install bilocation

rpm

curl -s https://packagecloud.io/install/repositories/corvus-ch/tools/script.rpm.sh | sudo bash
yum install bilocation

Homebrew

brew install corvus-ch/tools/horcrux

If you are not familiar with Homebrew visit https://brew.sh.

Usage

Backup a GPG key:

KEY_ID=… # Declare variable holding the ID of the GPG key you want to backup.
gpg --export "${KEY_ID}" > public.gpg
gpg --export-secret-key "${KEY_ID}" > "${KEY_ID}.gpg"
paperkey --secret-key="${KEY_ID}.gpg" --output-type raw --output="${KEY_ID}.bin"
horcrux create "${KEY_ID}.bin"
ls *.txt.* # Those are the files you can now place at your backup locations.

Restore a GPG key (builds on top of the above example):

horcrux restore -o paperkey.bin *.txt.* # For this example only two of the three files are required.
paperkey --pubring=public.gpg --secrets=paperkey.bin --input-type=raw --output=secret.gpg
diff "${KEY_ID}.gpg" secret.gpg

Known issues

The QR code format provide a limited feature set and can not be used to recover the data. A tool like zbarimg from the zbar libary can be used to scan the qr codes so it can be read by the zbase32 format.

Milestones

• Basic application
• Plain text format for print and easy scan/ocr
• QR Code format for easier scanning
• Template system for custom output

Contributing and license

This library is licenced under MIT. For information about how to contribute to this project, see CONTRIBUTING.md.