cookieSession.js

// Prepare Module
class authSystem {

    // Constructor
    constructor() {

        // Default Values
        this.default = {

            // Check Auth Time
            checkAuthTime: (decodedIdToken) => {

                // Only process if the user just signed in in the last 5 minutes.
                if (new Date().getTime() / 1000 - decodedIdToken.auth_time < 5 * 60) {
                    return true;
                }

                // Nope
                else { return false; }

            },

            // Cookie Time Generator
            cookieTimeGenerator: () => {

                // Set session expiration to 5 days.
                const expiresIn = 60 * 60 * 24 * 5 * 1000;

                // Create the session cookie. This will also verify the ID token in the process.
                // The session cookie will have the same claims as the ID token.
                // To only allow session cookie setting on recent sign-in, auth_time in ID token
                // can be checked to ensure user was recently signed in before creating a session cookie.

                // Complete
                return expiresIn;

            }

        };

        // Set Value
        this.checkAuthTime = this.default.checkAuthTime;
        this.cookieTimeGenerator = this.default.cookieTimeGenerator;

        // Complete
        return this;

    }

    // Check Auth Time
    setCookieTimeGenerator(callback) {
        if (typeof callback === "function") { this.cookieTimeGenerator = callback; }
        return;
    }

    // Check Auth Time
    setCheckAuthTime(callback) {
        if (typeof callback === "function") { this.checkAuthTime = callback; }
        return;
    }

    // Cookie Session Generator
    genCookieSession(auth, token) {
        const tinyThis = this;
        return new Promise(function (resolve, reject) {
            auth.verifyIdToken(token).then(async (decodedIdToken) => {

                // Try
                try {

                    // Check Time
                    const checkedTime = await tinyThis.checkAuthTime(decodedIdToken);
                    if (checkedTime) {

                        // Create Session
                        const expiresIn = await tinyThis.cookieTimeGenerator(decodedIdToken);
                        auth.createSessionCookie(token, { expiresIn }).then((sessionCookie) => {
                            resolve(sessionCookie); return;
                        }).catch(err => { reject(err); return; });

                    }

                    // Nope
                    else {
                        const err = new Error('Invalid Account ID Token Time.');
                        err.code = 401;
                        reject(err);
                    }

                }

                // Fail
                catch (err) { reject(err); }

                // Complete
                return;

            }).catch(err => { reject(err); return; });
            return;
        });
    }

};

// Module
module.exports = authSystem;