RocketChat/Rocket.Chat

import crypto from 'crypto';

import { serverFetch as fetch } from '@rocket.chat/server-fetch';
import { Match, check } from 'meteor/check';
import { OAuth } from 'meteor/oauth';
import _ from 'underscore';

import { registerAccessTokenService } from './oauth';

const whitelisted = ['id', 'email', 'name', 'first_name', 'last_name', 'link', 'gender', 'locale', 'age_range'];

const FB_API_VERSION = 'v2.9';
const FB_URL = 'https://graph.facebook.com';

const getIdentity = async function (accessToken, fields, secret) {
    const hmac = crypto.createHmac('sha256', OAuth.openSecret(secret));
    hmac.update(accessToken);

    try {
        const request = await fetch(`${FB_URL}/${FB_API_VERSION}/me`, {
            params: {
                access_token: accessToken,
                appsecret_proof: hmac.digest('hex'),
                fields: fields.join(','),
            },
        });

        if (!request.ok) {
            throw new Error(await request.text());
        }

        return request.json();
    } catch (err) {
        throw _.extend(new Error(`Failed to fetch identity from Facebook. ${err.message}`), {
            response: err.message,
        });
    }
};

registerAccessTokenService('facebook', async (options) => {
    check(
        options,
        Match.ObjectIncluding({
            accessToken: String,
            secret: String,
            expiresIn: Match.Integer,
        }),
    );

    const identity = await getIdentity(options.accessToken, whitelisted, options.secret);

    const serviceData = {
        accessToken: options.accessToken,
        expiresAt: +new Date() + 1000 * parseInt(options.expiresIn, 10),
    };

    const fields = _.pick(identity, whitelisted);
    _.extend(serviceData, fields);

    return {
        serviceData,
        options: {
            profile: {
                name: identity.name,
            },
        },
    };
});