1  # node-jwa [![Build Status](https://travis-ci.org/brianloveswords/node-jwa.svg?branch=master)](https://travis-ci.org/brianloveswords/node-jwa)
  2  
  3  A
  4  [JSON Web Algorithms](http://tools.ietf.org/id/draft-ietf-jose-json-web-algorithms-08.html)
  5  implementation focusing (exclusively, at this point) on the algorithms necessary for
  6  [JSON Web Signatures](http://self-issued.info/docs/draft-ietf-jose-json-web-signature.html).
  7  
  8  This library supports all of the required, recommended and optional cryptographic algorithms for JWS:
  9  
 10  alg Parameter Value | Digital Signature or MAC Algorithm
 11  ----------------|----------------------------
 12  HS256 | HMAC using SHA-256 hash algorithm
 13  HS384 | HMAC using SHA-384 hash algorithm
 14  HS512 | HMAC using SHA-512 hash algorithm
 15  RS256 | RSASSA using SHA-256 hash algorithm
 16  RS384 | RSASSA using SHA-384 hash algorithm
 17  RS512 | RSASSA using SHA-512 hash algorithm
 18  PS256 | RSASSA-PSS using SHA-256 hash algorithm
 19  PS384 | RSASSA-PSS using SHA-384 hash algorithm
 20  PS512 | RSASSA-PSS using SHA-512 hash algorithm
 21  ES256 | ECDSA using P-256 curve and SHA-256 hash algorithm
 22  ES384 | ECDSA using P-384 curve and SHA-384 hash algorithm
 23  ES512 | ECDSA using P-521 curve and SHA-512 hash algorithm
 24  none | No digital signature or MAC value included
 25  
 26  Please note that PS* only works on Node 6.12+ (excluding 7.x).
 27  
 28  # Requirements
 29  
 30  In order to run the tests, a recent version of OpenSSL is
 31  required. **The version that comes with OS X (OpenSSL 0.9.8r 8 Feb
 32  2011) is not recent enough**, as it does not fully support ECDSA
 33  keys. You'll need to use a version > 1.0.0; I tested with OpenSSL 1.0.1c 10 May 2012.
 34  
 35  # Testing
 36  
 37  To run the tests, do
 38  
 39  ```bash
 40  $ npm test
 41  ```
 42  
 43  This will generate a bunch of keypairs to use in testing. If you want to
 44  generate new keypairs, do `make clean` before running `npm test` again.
 45  
 46  ## Methodology
 47  
 48  I spawn `openssl dgst -sign` to test OpenSSL sign → JS verify and
 49  `openssl dgst -verify` to test JS sign → OpenSSL verify for each of the
 50  RSA and ECDSA algorithms.
 51  
 52  # Usage
 53  
 54  ## jwa(algorithm)
 55  
 56  Creates a new `jwa` object with `sign` and `verify` methods for the
 57  algorithm. Valid values for algorithm can be found in the table above
 58  (`'HS256'`, `'HS384'`, etc) and are case-insensitive. Passing an invalid
 59  algorithm value will throw a `TypeError`.
 60  
 61  
 62  ## jwa#sign(input, secretOrPrivateKey)
 63  
 64  Sign some input with either a secret for HMAC algorithms, or a private
 65  key for RSA and ECDSA algorithms.
 66  
 67  If input is not already a string or buffer, `JSON.stringify` will be
 68  called on it to attempt to coerce it.
 69  
 70  For the HMAC algorithm, `secretOrPrivateKey` should be a string or a
 71  buffer. For ECDSA and RSA, the value should be a string representing a
 72  PEM encoded **private** key.
 73  
 74  Output [base64url](http://en.wikipedia.org/wiki/Base64#URL_applications)
 75  formatted. This is for convenience as JWS expects the signature in this
 76  format. If your application needs the output in a different format,
 77  [please open an issue](https://github.com/brianloveswords/node-jwa/issues). In
 78  the meantime, you can use
 79  [brianloveswords/base64url](https://github.com/brianloveswords/base64url)
 80  to decode the signature.
 81  
 82  As of nodejs *v0.11.8*, SPKAC support was introduce. If your nodeJs
 83  version satisfies, then you can pass an object `{ key: '..', passphrase: '...' }`
 84  
 85  
 86  ## jwa#verify(input, signature, secretOrPublicKey)
 87  
 88  Verify a signature. Returns `true` or `false`.
 89  
 90  `signature` should be a base64url encoded string.
 91  
 92  For the HMAC algorithm, `secretOrPublicKey` should be a string or a
 93  buffer. For ECDSA and RSA, the value should be a string represented a
 94  PEM encoded **public** key.
 95  
 96  
 97  # Example
 98  
 99  HMAC
100  ```js
101  const jwa = require('jwa');
102  
103  const hmac = jwa('HS256');
104  const input = 'super important stuff';
105  const secret = 'shhhhhh';
106  
107  const signature = hmac.sign(input, secret);
108  hmac.verify(input, signature, secret) // === true
109  hmac.verify(input, signature, 'trickery!') // === false
110  ```
111  
112  With keys
113  ```js
114  const fs = require('fs');
115  const jwa = require('jwa');
116  const privateKey = fs.readFileSync(__dirname + '/ecdsa-p521-private.pem');
117  const publicKey = fs.readFileSync(__dirname + '/ecdsa-p521-public.pem');
118  
119  const ecdsa = jwa('ES512');
120  const input = 'very important stuff';
121  
122  const signature = ecdsa.sign(input, privateKey);
123  ecdsa.verify(input, signature, publicKey) // === true
124  ```
125  ## License
126  
127  MIT
128  
129  ```
130  Copyright (c) 2013 Brian J. Brennan
131  
132  Permission is hereby granted, free of charge, to any person obtaining a
133  copy of this software and associated documentation files (the
134  "Software"), to deal in the Software without restriction, including
135  without limitation the rights to use, copy, modify, merge, publish,
136  distribute, sublicense, and/or sell copies of the Software, and to
137  permit persons to whom the Software is furnished to do so, subject to
138  the following conditions:
139  
140  The above copyright notice and this permission notice shall be included
141  in all copies or substantial portions of the Software.
142  
143  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
144  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
145  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
146  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
147  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
148  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
149  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
150  ```