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# @root/keypairs
Lightweight JavaScript RSA and ECDSA utils that work on Windows, Mac, and Linux
using modern node.js APIs (no need for C compiler).
A thin wrapper around [Eckles.js (ECDSA)](
and [Rasha.js (RSA)](
# Features
- [x] Generate keypairs
- [x] RSA
- [x] ECDSA (P-256, P-384)
- [x] PEM-to-JWK (and SSH-to-JWK)
- [x] JWK-to-PEM (and JWK-to-SSH)
- [x] Create JWTs (and sign JWS)
- [x] SHA256 JWK Thumbprints
- [ ] JWK fetching. See [Keyfetch.js](
- [ ] OIDC
- [ ] Auth0
- [ ] CLI
- See [keypairs-cli](
- [x] Node
- [x] Browsers (Webpack >=5)
* [ ] generate CSR (DER as PEM or base64url)
# Progress
This is fully functional, but the re-usable code from ACME.js hasn't been fully teased out for the v2.0 release.
(SSH conversions have not yet made it to 2.0)
# Usage
A brief introduction to the APIs:
// generate a new keypair as jwk
// (defaults to EC P-256 when no options are specified)
Keypairs.generate().then(function (pair) {
// JWK to PEM
// (supports various 'format' and 'encoding' options)
return Keypairs.export({ jwk: pair.private, format: 'pkcs8' }).then(function (
) {
// PEM to JWK
return Keypairs.import({ pem: pem }).then(function (jwk) {
// Thumbprint a JWK (SHA256)
return Keypairs.thumbprint({ jwk: jwk }).then(function (thumb) {
// Sign a JWT (aka compact JWS)
return Keypairs.signJwt({
jwk: pair.private
, iss: ''
, exp: '1h'
// optional claims
, claims: {
, sub: ''
By default ECDSA keys will be used since they've had native support in node
_much_ longer than RSA has, and they're smaller, and faster to generate.
## Webpack 5+ (for Browsers)
This package includes native browser versions of all special functions.
Since Webpack 5 now fully supports vanilla JavaScript and exclusive browser builds out-of-the-box,
it's pretty easy to create a minimal config to use Keypairs in your browser projects:
'use strict';
var path = require('path');
module.exports = {
entry: './main.js',
mode: 'development',
devServer: {
contentBase: path.join(__dirname, 'dist'),
port: 3001
output: {
publicPath: 'http://localhost:3001/'
module: {
rules: [{}]
plugins: []
'use strict';
var Keypairs = require('./keypairs.js');
Keypairs.generate().then(function (pair) {
<!DOCTYPE html>
<script src="./dist/main.js"></script>
npm install --save-dev webpack@5
npx webpack
ls dist/
## API Overview
- generate (JWK)
- parse (PEM)
- parseOrGenerate (PEM to JWK)
- import (PEM-to-JWK)
- export (JWK-to-PEM, private or public)
- publish (Private JWK to Public JWK)
- thumbprint (JWK SHA256)
- signJwt
- signJws
#### Keypairs.generate(options)
Generates a public/private pair of JWKs as `{ private, public }`
Option examples:
- RSA `{ kty: 'RSA', modulusLength: 2048 }`
- ECDSA `{ kty: 'ECDSA', namedCurve: 'P-256' }`
When no options are supplied EC P-256 (also known as `prime256v1` and `secp256r1`) is used by default.
#### Keypairs.parse(options)
Parses either a JWK (encoded as JSON) or an x509 (encdode as PEM) and gives
back the JWK representation.
Option Examples:
- JWK { key: '{ "kty":"EC", ... }' }
- PEM { key: '-----BEGIN PRIVATE KEY-----\n...' }
- Public Key Only { key: '-----BEGIN PRIVATE KEY-----\n...', public: true }
- Must Have Private Key { key: '-----BEGIN PUBLIC KEY-----\n...', private: true }
Keypairs.parse({ key: '...' }).catch(function (e) {
// could not be parsed or was a public key
return Keypairs.generate();
#### Keypairs.parseOrGenerate({ key, throw, [generate opts]... })
Parses the key. Logs a warning on failure, marches on.
(a shortcut for the above, with `private: true`)
Option Examples:
- parse key if exist, otherwise generate `{ key: process.env["PRIVATE_KEY"] }`
- generated key curve `{ key: null, namedCurve: 'P-256' }`
- generated key modulus `{ key: null, modulusLength: 2048 }`
Keypairs.parseOrGenerate({ key: process.env['PRIVATE_KEY'] }).then(function (
) {
Great for when you have a set of shared keys for development and randomly
generated keys in
#### Keypairs.import({ pem: '...' }
Takes a PEM in pretty much any format (PKCS1, SEC1, PKCS8, SPKI) and returns a JWK.
#### Keypairs.export(options)
Exports a JWK as a PEM.
Exports PEM in PKCS8 (private) or SPKI (public) by default.
{ jwk: jwk
, public: true
, encoding: 'pem' // or 'der'
, format: 'pkcs8' // or 'ssh', 'pkcs1', 'sec1', 'spki'
#### Keypairs.publish({ jwk: jwk, exp: '3d', use: 'sig' })
Promises a public key that adheres to the OIDC and Auth0 spec (plus expiry), suitable to be published to a JWKs URL:
{ "kty": "EC"
, "crv": "P-256"
, "x": "..."
, "y": "..."
, "kid": "..."
, "use": "sig"
, "exp": 1552074208
In particular this adds "use" and "exp".
#### Keypairs.thumbprint({ jwk: jwk })
Promises a JWK-spec thumbprint: URL Base64-encoded sha256
#### Keypairs.signJwt({ jwk, header, claims })
Returns a JWT (otherwise known as a protected JWS in "compressed" format).
{ jwk: jwk
// required claims
, iss: ''
, exp: '15m'
// all optional claims
, claims: {
Exp may be human readable duration (i.e. 1h, 15m, 30s) or a datetime in seconds.
Header defaults:
{ kid: thumbprint
, alg: 'xS256'
, typ: 'JWT'
Payload notes:
- `iat: now` is added by default (set `false` to disable)
- `exp` must be set (set `false` to disable)
- `iss` should be the base URL for JWK lookup (i.e. via OIDC, Auth0)
`header` is actually the JWS `protected` value, as all JWTs use protected headers (yay!)
and `claims` are really the JWS `payload`.
#### Keypairs.signJws({ jwk, header, protected, payload })
This is provided for APIs like ACME (Let's Encrypt) that use uncompressed JWS (instead of JWT, which is compressed).
- `header` not what you think. Leave undefined unless you need this for the spec you're following.
- `protected` is the typical JWT-style header
- `kid` and `alg` will be added by default (these are almost always required), set `false` explicitly to disable
- `payload` can be JSON, a string, or even a buffer (which gets URL Base64 encoded)
- you must set this to something, even if it's an empty string, object, or Buffer
# Additional Documentation
Keypairs.js provides a 1-to-1 mapping to the Rasha.js and Eckles.js APIs for the following:
- generate(options)
- import({ pem: '---BEGIN...' })
- export({ jwk: { kty: 'EC', ... })
- thumbprint({ jwk: jwk })
If you want to know the algorithm-specific options that are available for those
you'll want to take a look at the corresponding documentation:
- See ECDSA documentation at [Eckles.js](
- See RSA documentation at [Rasha.js](
# Contributions
Did this project save you some time? Maybe make your day? Even save the day?
Please say "thanks" via Paypal or Patreon:
- Paypal: [\$5]( | [\$10]( | Any amount: <>
- Patreon: <>
Where does your contribution go?
[Root]( is a collection of experts
who trust each other and enjoy working together on deep-tech,
Indie Web projects.
Our goal is to operate as a sustainable community.
Your contributions - both in code and _especially_ monetarily -
help to not just this project, but also our broader work
of [projects]( that fuel the **Indie Web**.
Also, we chat on [Keybase](
in [#rootprojects](
# Commercial Support
Do you need...
- more features?
- bugfixes, on _your_ timeline?
- custom code, built by experts?
- commercial support and licensing?
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Contact <> for support options.
# Legal
Copyright [AJ ONeal](,
[Root]( 2018-2019
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