rsa-shamir-secret-sharing

RSA-Shamir-Secret-Sharing

This tool has been written for academic reasons only. I do not recommend to use it in production since it may contain security flaws. It is written with the best of my knowledge and belief, but i am not a cryptographer and can not guarantee anything.

However, if you find any security flaws, please open an issue without disclosing the flaw or contact me via email. I prefer responsible disclosures.

RSA-Shamir-Secret-Sharing is a little tool i wrote for my Bachelor-Thesis. It implements the Shamir-Secret-Sharing-Scheme. It is especially focused on sharing RSA key pairs, but also works perfectly fine with everything else.

Usage

rsasss

> rsasss -h

Implements the shamir secret sharing especially made for rsa private keys

Usage:
  rsasss [flags]
  rsasss [command]

Available Commands:
  gen         Generates a shared RSA KeyPair
  help        Help about any command
  join        Joins shares to reconstruct the secret
  split       Splits a given secret into shares
  version     Print the version number

Flags:
  -h, --help   help for rsasss

Use "rsasss [command] --help" for more information about a command.

rsasss gen

> rsasss gen -h
Generates a public RSA key and n shares for the private key of which k are required for reconstruction

Usage:
  rsasss gen [flags]

Flags:
  -b, --bitsize int      bitsize of the generated key (default 2048)
  -c, --createKeyfile    set to true if you want to save the private key to a file
  -h, --help             help for gen
  -f, --saveShares       set to true if you want to save the shares to a file
  -n, --sharecount int   number of shares to generate (default 5)
  -k, --threshold int    number of required shares to reconstruct the secret (default 3)

rsasss join

> rsasss join -h
Joins multiple shares to reconstruct a secret

Usage:
  rsasss join [flags]

Flags:
  -h, --help   help for join

rsasss split

> rsasss split -h
Splits the given secret into n shares of which k are required to reconstruct the secret

Usage:
  rsasss split [flags]

Flags:
  -h, --help                help for split
  -f, --saveShares          set to true if you want to save the shares to a file
  -s, --secret string       the secret to split
  -p, --secretpath string   filepath to the secret
  -n, --sharecount int      number of shares to generate (default 5)
  -k, --threshold int       number of required shares to reconstruct the secret (default 3)

Contribution

I am not really developing this library and tool actively.
If you have any issues with it, feel free to open an issue or a pull request and i'll look into it.

Structure

In cmd you can find the sources that are required to run the CLI tool
In gf256 you can find an implementation of finite fields (written by @rsc and provided under the BSD-3-License)
in s4 you can find my implementation of the Shamir-Secret-Sharing-Scheme (s4)

Legal

This work is licensed under the MIT License (see LICENSE.md)
The GF256 Package is licensed under the BSD-3-License and belongs to @rsc