jwa

JWA implementation (supports all JWS algorithms)

node-jwa

A JSON Web Algorithms implementation focusing (exclusively, at this point) on the algorithms necessary for JSON Web Signatures.

This library supports all of the required, recommended and optional cryptographic algorithms for JWS:

Requirements

In order to run the tests, a recent version of OpenSSL is required. **The version that comes with OS X (OpenSSL 0.9.8r 8 Feb

1. is not recent enough**, as it does not fully support ECDSA keys. You'll need to use a version > 1.0.0; I tested with OpenSSL 1.0.1c 10 May 2012.

Testing

To run the tests, do

$ npm test

This will generate a bunch of keypairs to use in testing. If you want to generate new keypairs, do make clean before running npm test again.

Methodology

I spawn openssl dgst -sign to test OpenSSL sign → JS verify and openssl dgst -verify to test JS sign → OpenSSL verify for each of the RSA and ECDSA algorithms.

Usage

jwa(algorithm)

Creates a new jwa object with sign and verify methods for the algorithm. Valid values for algorithm can be found in the table above ('HS256', 'HS384', etc) and are case-insensitive. Passing an invalid algorithm value will throw a TypeError.

jwa#sign(input, secretOrPrivateKey)

Sign some input with either a secret for HMAC algorithms, or a private key for RSA and ECDSA algorithms.

If input is not already a string or buffer, JSON.stringify will be called on it to attempt to coerce it.

For the HMAC algorithm, secretOrPrivateKey should be a string or a buffer. For ECDSA and RSA, the value should be a string represented a PEM encoded private key.

Output base64url formatted. This is for convenience as JWS expects the signature in this format. If your application needs the output in a different format, please open an issue. In the meantime, you can use brianloveswords/base64url to decode the signature.

jwa#verify(input, signature, secretOrPublicKey)

Verify a signature. Returns true or false.

signature should be a base64url encoded string.

For the HMAC algorithm, secretOrPublicKey should be a string or a buffer. For ECDSA and RSA, the value should be a string represented a PEM encoded public key.

Example

HMAC

const jwa = require('jwa');
 
const hmac = jwa('HS256');
const input = 'super important stuff';
const secret = 'shhhhhh';
 
const signature = hmac.sign(input, secret);
hmac.verify(input, signature, secret) // === true 
hmac.verify(input, signature, 'trickery!') // === false 

With keys

const fs = require('fs');
const jwa = require('jwa');
const privateKey = fs.readFileSync(__dirname + '/ecdsa-p521-private.pem');
const publicKey = fs.readFileSync(__dirname + '/ecdsa-p521-public.pem');
 
const ecdsa = jwa('ES512');
const input = 'very important stuff';
 
const signature = ecdsa.sign(input, privateKey);
ecdsa.verify(input, signature, publicKey) // === true 

License

MIT

Copyright (c) 2013 Brian J. Brennan
 
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