universal-github-app-jwt

What is universal-github-app-jwt?

The universal-github-app-jwt npm package is designed to help developers generate JSON Web Tokens (JWT) for GitHub Apps. This is particularly useful for authenticating GitHub Apps and making API requests on behalf of the app.

What are universal-github-app-jwt's main functionalities?

Generate JWT

This feature allows you to generate a JWT for your GitHub App using the app's ID, private key, and installation ID. The generated token can then be used to authenticate API requests.

const { createAppAuth } = require('universal-github-app-jwt');

const auth = createAppAuth({
  appId: process.env.GITHUB_APP_ID,
  privateKey: process.env.GITHUB_PRIVATE_KEY,
  installationId: process.env.GITHUB_INSTALLATION_ID
});

async function getToken() {
  const { token } = await auth({ type: 'app' });
  console.log(token);
}

getToken();

Other packages similar to universal-github-app-jwt

github-app

The github-app package is another alternative for generating JWTs for GitHub Apps. It provides a straightforward API for creating tokens and can be a simpler choice for developers who do not need the full suite of features provided by Octokit.

README

universal-github-app-jwt

Calculate GitHub App bearer tokens for Node & modern browsers

⚠ The private keys provide by GitHub are in PKCS#1 format, but the WebCrypto API only supports PKCS#8. You can see the difference in the first line, PKCS#1 format starts with -----BEGIN RSA PRIVATE KEY----- while PKCS#8 starts with -----BEGIN PRIVATE KEY-----. You can convert one format to the other using oppenssl:

openssl pkcs8 -topk8 -inform PEM -outform PEM -nocrypt -in private-key.pem -out private-key-pkcs8.key

It's also possible to convert the formats with JavaScript, e.g. using node-rsa, but it turns a 4kb to a 200kb+ built. I'm looking for help to create a minimal PKCS#1 to PKCS#8 convert library that I can recommend people to use before passing the private key to githubAppJwt. Please create an issue if you'd like to help.

The way it works with node-rsa is this

const PRIVATE_KEY = `-----BEGIN RSA PRIVATE KEY-----
...
-----END RSA PRIVATE KEY-----`;

const key = new NodeRSA(PRIVATE_KEY);
const privateKeyPkcs8 = key.exportKey("pkcs8-private-pem");

// privateKeyPkcs8 is now
// -----BEGIN PRIVATE KEY-----
// ...
// -----END PRIVATE KEY-----

When using a node, a conversion is not necessary, the implementation is agnostic to either format.

Usage

Browsers	Load universal-github-app-jwt directly from esm.sh <script type="module"> import githubAppJwt from "https://esm.sh/universal-github-app-jwt"; </script>
Node	Install with npm install universal-github-app-jwt import githubAppJwt from "universal-github-app-jwt";
Deno	Load universal-github-app-jwt directly from esm.sh, including types. import githubAppJwt from "https://esm.sh/universal-github-app-jwt";

const { token, appId, expiration } = await githubAppJwt({
  id: APP_ID,
  privateKey: PRIVATE_KEY,
});

The retrieved token can now be used in Authorization request header, e.g. with @octokit/request:

request("GET /app", {
  headers: {
    authorization: `bearer ${token}`,
  },
});

For a complete implementation of GitHub App authentication strategies, see @octokit/auth-app.js.

githubAppJwt(options)

name	type	description
options.id	number	Required. Find App ID on the app’s about page in settings.
options.privateKey	string	Required. Content of the *.pem file you downloaded from the app’s about page. You can generate a new private key if needed. Make sure to preserve the line breaks.
options.now	number	An optional override for the current time in seconds since the UNIX epoch. Defaults to Math.floor(Date.now() / 1000)). This value can be overridden to account for a time skew between the local machine and the authentication server.

githubAppJwt(options) resolves with an object with the following keys

name	type	description
token	string	The JSON Web Token (JWT) to authenticate as the app.
appId	number	The GitHub App database ID passed in options.id.
expiration	number	Timestamp as UNIX epoch, e.g. 1530922170. A Date object can be created using new Date(authentication.expiration).

License

MIT