svelte/site/src/backend/auth.js

151 lines
4.4 KiB

import polka from 'polka';
import devalue from 'devalue';
import send from '@polka/send';
import { get, post } from 'httpie';
import { parse, stringify } from 'querystring';
import { decode, sign, verify } from './token';
import { find, query } from '../utils/db';
const {
BASEURL,
GITHUB_CLIENT_ID,
GITHUB_CLIENT_SECRET,
} = process.env;
const OAuth = 'https://github.com/login/oauth';
function exit(res, code, msg='') {
const error = msg.charAt(0).toUpperCase() + msg.substring(1);
send(res, code, { error });
}
function onError(err, req, res) {
const error = err.message || err;
const code = err.code || err.status || 500;
res.headersSent || send(res, code, { error });
}
/**
* Middleware to determine User validity
*/
export async function isUser(req, res) {
const abort = exit.bind(null, res, 401);
const auth = req.headers.authorization;
if (!auth) return abort('Missing Authorization header');
const [scheme, token] = auth.split(' ');
if (scheme !== 'Bearer' || !token) return abort('Invalid Authorization format');
let data;
const decoded = decode(token, { complete:true });
if (!decoded || !decoded.header) return abort('Invalid token');
try {
data = await verify(token);
} catch (err) {
return abort(err.message);
}
const { uid, username } = data;
if (!uid || !username) return abort('Invalid token payload');
try {
const row = await find(`select * from users where uid = $1 and username = $2 limit 1`, [uid, username]);
return row || abort('Invalid token');
} catch (err) {
console.error('Auth.isUser', err);
return send(res, 500, 'Unknown error occurred');
}
}
export function toUser(obj={}) {
const { uid, username, name, avatar } = obj;
const token = sign({ uid, username });
return { uid, username, name, avatar, token };
}
export function API() {
const app = polka({ onError });
if (GITHUB_CLIENT_ID) {
app.get('/auth/login', (req, res) => {
try {
const Location = `${OAuth}/authorize?` + stringify({
scope: 'read:user',
client_id: GITHUB_CLIENT_ID,
redirect_uri: `${BASEURL}/auth/callback`,
});
send(res, 302, Location, { Location });
} catch (err) {
console.error('GET /auth/login', err);
send(res, 500);
}
});
app.get('/auth/callback', async (req, res) => {
try {
// Trade "code" for "access_token"
const r1 = await post(`${OAuth}/access_token?` + stringify({
code: req.query.code,
client_id: GITHUB_CLIENT_ID,
client_secret: GITHUB_CLIENT_SECRET,
}));
// Now fetch User details
const { access_token } = parse(r1.data);
const r2 = await get('https://api.github.com/user', {
headers: {
'User-Agent': 'svelte.dev',
Authorization: `token ${access_token}`
}
});
const { id, name, avatar_url, login } = r2.data;
// Upsert `users` table
const [user] = await query(`
insert into users(uid, name, username, avatar, github_token)
values ($1, $2, $3, $4, $5) on conflict (uid) do update
set (name, username, avatar, github_token, updated_at) = ($2, $3, $4, $5, now())
returning *
`, [id, name, login, avatar_url, access_token]);
send(res, 200, `
<script>
window.opener.postMessage({
user: ${devalue(toUser(user))}
}, window.location.origin);
</script>
`, {
'Content-Type': 'text/html; charset=utf-8'
});
} catch (err) {
console.error('GET /auth/callback', err);
send(res, 500, err.data, {
'Content-Type': err.headers['content-type'],
'Content-Length': err.headers['content-length']
});
}
});
} else {
// Print "Misconfigured" error
app.get('/auth/login', (req, res) => {
send(res, 500, `
<body style="font-family: sans-serif; background: rgb(255,215,215); border: 2px solid red; margin: 0; padding: 1em;">
<h1>Missing .env file</h1>
<p>In order to use GitHub authentication, you will need to <a target="_blank" href="https://github.com/settings/developers">register an OAuth application</a> and create a local .env file:</p>
<pre>GITHUB_CLIENT_ID=[YOUR_APP_ID]\nGITHUB_CLIENT_SECRET=[YOUR_APP_SECRET]\nBASEURL=http://localhost:3000</pre>
<p>The <code>BASEURL</code> variable should match the callback URL specified for your app.</p>
<p>See also <a target="_blank" href="https://github.com/sveltejs/svelte/tree/master/site#repl-github-integration">here</a></p>
</body>
`, {
'Content-Type': 'text/html; charset=utf-8'
});
});
}
return app;
}