Kuznechik JS SDK

Vanilla JavaScript implementation of the Kuznechik (GOST R 34.12-2015) symmetric block cipher.

Features

• Full support for 256-bit keys and 128-bit blocks.
• Optimized for performance with precomputed inverse S-box and round constants.
• Verified against standard GOST R 34.12-2015 test vectors.
• No dependencies.

Installation

Just copy kuznechik.js to your project or use require:

const { Kuznechik } = require("./kuznechik");

Usage

const key = new Uint8Array([
  /* 32 bytes */
]);
const cipher = new Kuznechik(key);

const plaintext = new Uint8Array([
  /* 16 bytes */
]);
const ciphertext = cipher.encrypt(plaintext);
const decrypted = cipher.decrypt(ciphertext);

Testing

Run the included test suite:

npm test

License

MIT