@bogeychan/elysia-oauth2

A plugin for Elysia.js for server-side OAuth 2.0 Authorization Code Flow

Migration guide

Installation

bun add @bogeychan/elysia-oauth2

Usage

import { Elysia } from 'elysia'
import oauth2, { github } from '@bogeychan/elysia-oauth2'

import { randomBytes } from 'crypto'

const globalState = randomBytes(8).toString('hex')
let globalToken = null

const app = new Elysia()

const auth = oauth2({
	profiles: {
		// define multiple OAuth 2.0 profiles
		github: {
			provider: github(),
			scope: ['user']
		}
	},
	state: {
		// custom state verification between requests
		check(ctx, name, state) {
			return state === globalState
		},
		generate(ctx, name) {
			return globalState
		}
	},
	storage: {
		// storage of users' access tokens is up to you
		get(ctx, name) {
			return globalToken
		},
		set(ctx, name, token) {
			globalToken = token
		},
		delete(ctx, name) {
			globalToken = null
		}
	}
})

function userPage(user: {}, logout: string) {
	const html = `<!DOCTYPE html>
    <html lang="en">
    <body>
      User:
      <pre>${JSON.stringify(user, null, '\t')}</pre>
      <a href="${logout}">Logout</a>
    </body>
    </html>`

	return new Response(html, { headers: { 'Content-Type': 'text/html' } })
}

app
	.use(auth)
	.get('/', async (ctx) => {
		// get login, callback, logout urls for one or more OAuth 2.0 profiles
		const profiles = ctx.profiles('github')

		// check if one or more OAuth 2.0 profiles are authorized
		if (await ctx.authorized('github')) {
			const user = await fetch('https://api.github.com/user', {
				// ... and use the Authorization header afterwards
				headers: await ctx.tokenHeaders('github')
			})

			return userPage(await user.json(), profiles.github.logout)
		}

		// Render login page
		const html = `<!DOCTYPE html>
    <html lang="en">
    <body>
      <h2>Login with <a href="${profiles.github.login}">Github</a></h2>
    </body>
    </html>`

		return new Response(html, { headers: { 'Content-Type': 'text/html' } })
	})
	.listen(3000)

console.log('Listening on http://localhost:3000')

Where are the client credentials?

Generate a client id and client secret for an OAuth app on Github
Use http://localhost:3000/login/github/authorized as your Authorization callback URL

Create an .env file based on the previously generated client credentials:

GITHUB_OAUTH_CLIENT_ID=client id
GITHUB_OAUTH_CLIENT_SECRET=client secret

Bun automatically loads environment variables from .env files

If you are unsure which URL should be used as Authorization callback URL call ctx.profiles() without an argument to get all URLs of all registered OAuth 2.0 Profiles:

app
	.use(auth)
	.get('/', (ctx) => {
		return ctx.profiles()
	})
	.listen(3000)

Use custom plugins in `Storage` and `State`

import oauth2, {
	github,
	type InferContext,
	type TOAuth2AccessToken
} from '@bogeychan/elysia-oauth2'

const mySessionPLugin = new Elysia().derive((ctx) => ({
	session: {
		getOAuthToken(name: string): TOAuth2AccessToken {
			const sessionId = ctx.cookie['session-id'].value
			return // TODO
		},
		setOAuthToken(name: string, token: TOAuth2AccessToken) {
			// TODO
		},
		deleteOAuthToken(name: string) {
			// TODO
		}
	}
}))

const app = new Elysia().use(mySessionPLugin)

const auth = oauth2({
	profiles: {
		github: {
			provider: github(),
			scope: ['user']
		}
	},
	state: {
		check(ctx, name, state) {
			return state === globalState
		},
		generate(ctx, name) {
			return globalState
		}
	},
	storage: {
		get(ctx: InferContext<typeof app>, name) {
			return ctx.session.getOAuthToken(name)
		},
		set(ctx: InferContext<typeof app>, name, token) {
			ctx.session.setOAuthToken(name, token)
		},
		delete(ctx: InferContext<typeof app>, name) {
			ctx.session.deleteOAuthToken(name)
		}
	}
})

Use predefined OAuth 2.0 providers

import { azure, discord, github, ... } from '@bogeychan/elysia-oauth2';

All available providers are listed inside the providers folder.
Checkout the examples folder on github for further use cases such as the Bun's sqlite module.

Define your own OAuth 2.0 provider

import oauth2, { TOAuth2Provider } from '@bogeychan/elysia-oauth2'

function myGithub(): TOAuth2Provider {
	return {
		clientId: 'YOUR_CLIENT_ID',
		clientSecret: 'YOUR_CLIENT_SECRET',

		auth: {
			url: 'https://github.com/login/oauth/authorize',
			params: {
				allow_signup: true
			}
		},

		token: {
			url: 'https://github.com/login/oauth/access_token',
			params: {}
		}
	}
}

const auth = oauth2({
	profiles: {
		github: {
			provider: myGithub(),
			scope: ['user']
		}
	}
	// ...
})

License

MIT