lbeder/ssss-js

Shamir's Shared Secred Scheme - JS version of B. Poettering's Linux CLI utility

ssss-js

Fork Notes

Please note that this tool was originally forked from https://github.com/gburca/ssss-js and has been extended to include the following features:

1. Extension/generation of additional shares from an existing threshold of shares.
2. Support for raw entropy export/import. Please note that raw entropy is serialized as-is into the coefficients of the polynomial; therefore, it must be of the exact length. Please be aware that using raw entropy can be risky. It is crucial to ensure that you are using a source of strong and high-quality entropy.

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This project is a JavaScript version of Shamir's Secret Sharing Scheme. It has 2 distinguishing features:

1. It is interoperable and compatible with B. Poettering's Linux ssss utility (ssss-split and ssss-combine) from http://point-at-infinity.org/ssss/ so keys/shares can be created with one and recovered with the other. That project was used as the reference implementation for this project.
2. It consists of a single html file which includes everything needed to split and combine a secret (no network connection needed). As a result it is fully usable from Windows, Mac OSX, Linux, and other operating systems with a modern browser.

There are some other implementations of Shamir's Secret Sharing Scheme (SSSS) floating around, but none seem to be compatible with each other. The Linux utility is great (which is why this project is compatible with it), but chances are the people you want to share the secret with are not running Linux.

The author of the Linux utility maintains a web page where the utility can be demo'd, but the author notes that it's not secure and should not be used for sensitive data.

The ssss.html file generated by this project has no server dependencies (or any other external dependencies) and is as secure as the browser or PC it's being used on. Additionally, it eliminates the need to rely on a 3rd party web site page that may or may not be available in the future.

Usage

• Try it out at https://ebixio.com/ssss.html
• For offline use:
  • Download ssss.html from https://ebixio.com/ssss.html or https://github.com/gburca/ssss-js/releases
  • Open up the downloaded page with a browser and follow the simple instructions.

Build

• A simple Makefile is provided to assist with generating the stand-alone html page.
• npm package is at: https://www.npmjs.com/package/ssss-js

Test

• Since all the tests are in test/*:

    ./node_modules/qunitjs/bin/qunit

OR (during development) if you have entr:

    ls *.js test/*.js | entr -c ./node_modules/qunitjs/bin/qunit