horcrux

README

horcrux v1.0.0

Split file into encrypted horcrux-files, reconstitutable without key

• Repo: https://github.com/pepa65/horcrux
• After https://github.com/jesseduffield/horcrux
• The technique used is Hashicorp's Shamir's secret sharing, based on 256 bit AES encryption with CTR.
• Versions of horcrux before 1.0.0 used OFB and are not compatible with version 1 horcrux-files!

Function

The program horcrux can split a file into a predefined number of encrypted horcrux-files, or reconstruct a (predefinable) sufficient number of constituent horcrux-files in a directory back into the original file.

Split

To split up a file into horcrux-files, call horcrux with the filename and optionally flags -n/--num with the number of desired horcrux-files and/or -m/--min followed by the minimum number of horcrux-files needed to reconstruct the original file. Example:

horcrux -n 5 -m 3 secret.txt

The resulting horcrux-files can be renamed, dispersed (given to different people or stored at different locations) and later be used to reconstruct the original file if the minimum number of needed horcrux-files is met (in this case: 3 out of the 5 are needed).

Reconstruct

To merge horcrux-files back into the original file, call horcrux in the directory containing the horcruxes, or pass that directory as an argument: horcrux directory/with/horcruxes

Only files ending in .horcrux will be taken into account, other files will be ignored. (There should not be any horcrux-files in that directory that were produced at a different time or from a different file!)

Query

To display information about a horcrux-file, call horcrux with the -q/--query flag followed by the filename of the horcrux-file, like:

horcrux -q file.horcrux

Installation

Download

Download any of horcrux horcrux_pi horcrux_bsd horcrux_osx horcrux.exe through:

wget -O BINARY https://gitlab.com/pepa65/horcrux/-/jobs/artifacts/master/raw/BINARY?job=building

(replace BINARY with the desired binary name, e.g. `horcrux is for Linux amd64).

Then put it into a location on your PATH, or use it by specifying its path, like: ./horcrux

Go install

Or do go install github.com/pepa65/horcrux@latest (needs Golang fully installed).

Git clone and go install

Or, clone this repo by: git clone https://github.com/pepa65/horcrux and do cd horcrux followed by go install (needs both Git and Golang).

Better binaries

CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go install -ldflags="-s -w"
CGO_ENABLED=0 GOOS=linux GOARCH=arm go install -ldflags="-s -w" -o horcrux_pi
CGO_ENABLED=0 GOOS=freebsd GOARCH=amd64 go install -ldflags="-s -w" -o horcrux_freebsd
CGO_ENABLED=0 GOOS=darwin GOARCH=amd64 go install -ldflags="-s -w" -o horcrux_osx
CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go install -ldflags="-s -w" -o horcrux.exe

More extreme shrinking

upx --best --lzma horcrux

(Needs upx installed.)

Usage

horcrux v1.0.0 - Split file into 'horcrux-files', reconstructable without key
Usage:
  - Split & encrypt:  horcrux [-n|--number N] [-m|--minimum M] FILE
        N:     Number of horcrux-files to produce [2..255, default: 2]
        M:     Min.number of horcrux-files to reconstruct [2..N, default: N]
        FILE:  Original file to split up and encrypt
  - Reconstruct file:  horcrux [DIR]
       DIR:  Directory with horcrux-files to reconstruct [default: current]
  - Query horcrux-file:  horcrux -q|--query FILE.horcrux
       FILE.horcrux:  The horcrux-file to query for information
  - Get help or version:  horcrux -h|--help | -V|--version