README

cosette

Typescript implementation of COSE, RFC8152

This is a fork of cose-js with the objective of providing a well-typed implementation of cose that works in NodeJS and the browser.

It depends on isomorphic-webcrypto, so on the browser, it uses the fast and secure WebCrypto cryptographic API.

Current state

Working with isomorphic-webcrypto :

Create and verify ECDSA signatures
Create and verify MAC and AES-CCM signatures

Still not ported to isomorphic-webcrypto :

Encryption and Decryption

Sign

const cose = require('cosette');
const crypto = cose.sign.webcrypto;

async function sign() {
  const plaintext = 'Important message!';
  const headers = {
    'p': {'alg': 'ES256'},
    'u': {'kid': '11'}
  };
  const signer = {
    // See https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/importKey
    'key': await crypto.subtle.importKey("jwk", {
                  "kty":"EC",
                  "crv":"P-256",
                  "x":"usWxHK2PmfnHKwXPS54m0kTcGJ90UiglWiGahtagnv8",
                  "y":"IBOL-C3BttVivg-lSreASjpkttcsz-1rb7btKLv8EX4",
                  "d":"V8kgd2ZBRuh2dgyVINBUqpPDr7BOMGcF22CQMIUHtNM"
               }, { name: "ECDSA", namedCurve: "P-256" }, true, [usage]);
  };

  const buf = await cose.sign.create(headers, plaintext, signer);
  console.log('Signed message: ' + buf.toString('hex'));
}

sign()

Verify Signature

const cose = require('cose-js');

const verifier = {
  'key': {
    'x': Buffer.from('143329cce7868e416927599cf65a34f3ce2ffda55a7eca69ed8919a394d42f0f', 'hex'),
    'y': Buffer.from('60f7f1a780d8a783bfb7a2dd6b2796e8128dbbcef9d3d168db9529971a36e7b9', 'hex')
  }
};
const COSEMessage = Buffer.from('d28443a10126a10442313172496d706f7274616e74206d6573736167652158404c2b6b66dfedc4cfef0f221cf7ac7f95087a4c4245fef0063a0fd4014b670f642d31e26d38345bb4efcdc7ded3083ab4fe71b62a23f766d83785f044b20534f9', 'hex');

cose.sign.verify(
  COSEMessage,
  verifier)
.then((buf) => {
  console.log('Verified message: ' + buf.toString('utf8'));
}).catch((error) => {
  console.log(error);
});

MAC

const cose = require('cose-js');

const plaintext = 'Important message!';
const headers = {
  'p': {'alg': 'SHA-256_64'},
  'u': {'kid': 'our-secret'}
};
const recipent = {
  'key': Buffer.from('231f4c4d4d3051fdc2ec0a3851d5b383', 'hex')
};

cose.mac.create(
  headers,
  plaintext,
  recipent)
.then((buf) => {
  console.log('MACed message: ' + buf.toString('hex'));
}).catch((error) => {
  console.log(error);
});

Verify MAC

const cose = require('cose-js');

const key = Buffer.from('231f4c4d4d3051fdc2ec0a3851d5b383', 'hex');
const COSEMessage = Buffer.from('d18443a10104a1044a6f75722d73656372657472496d706f7274616e74206d65737361676521488894981d4aa5d614', 'hex');
cose.mac.read(
  COSEMessage,
  key)
.then((buf) => {
  console.log('Verified message: ' + buf.toString('utf8'));
}).catch((error) => {
  console.log(error);
});

Encrypt

const cose = require('cose-js');

const plaintext = 'Secret message!';
const headers = {
  'p': {'alg': 'A128GCM'},
  'u': {'kid': 'our-secret'}
};
const recipient = {
  'key': Buffer.from('231f4c4d4d3051fdc2ec0a3851d5b383', 'hex')
};

cose.encrypt.create(
  headers,
  plaintext,
  recipient
).then((buf) => {
  console.log('Encrypted message: ' + buf.toString('hex'));
}).catch((error) => {
  console.log(error);
});

Decrypt

const cose = require('cose-js');

const key = Buffer.from('231f4c4d4d3051fdc2ec0a3851d5b383', 'hex');
const COSEMessage = Buffer.from('d8608443a10101a2044a6f75722d736563726574054c291a40271067ff57b1623c30581f23b663aaf9dfb91c5a39a175118ad7d72d416385b1b610e28b3b3fd824a397818340a040', 'hex');

cose.encrypt.read(
  COSEMessage,
  key)
.then((buf) => {
  console.log('Protected message: ' + buf.toString('utf8'));
}).catch((error) => {
  console.log(error);
});

Install

npm install cose-js --save

Test

npm test

Usage no npm install needed!