Added user sign up and login.

src/auth.js

@@ -0,0 +1,80 @@
+'use strict';
+
+const util = require('util');
+const crypto = require('crypto');
+
+const knex = require('./knex');
+const { curateUser } = require('./users');
+const { HttpError } = require('./errors');
+
+const scrypt = util.promisify(crypto.scrypt);
+
+async function verifyPassword(password, storedPassword) {
+	const [salt, hash] = storedPassword.split('/');
+	const hashedPassword = (await scrypt(password, salt, 64)).toString('hex');
+
+	if (hashedPassword === hash) {
+		return true;
+	}
+
+	throw new HttpError('Username or password incorrect', 401);
+}
+
+async function login(credentials) {
+	const user = await knex('users')
+		.select('users.*', 'users_roles.abilities as role_abilities')
+		.where('username', credentials.username)
+		.orWhere('email', credentials.username)
+		.leftJoin('users_roles', 'users_roles.role', 'users.role')
+		.first();
+
+	if (!user) {
+		throw new HttpError('Username or password incorrect', 401);
+	}
+
+	await verifyPassword(credentials.password, user.password);
+
+	return curateUser(user);
+}
+
+async function signup(credentials) {
+	if (!credentials.username) {
+		throw new HttpError('Username required', 400);
+	}
+
+	if (!credentials.email) {
+		throw new HttpError('E-mail required', 400);
+	}
+
+	if (credentials.password?.length < 3) {
+		throw new HttpError('Password must be 3 characters or longer', 400);
+	}
+
+	const existingUser = await knex('users')
+		.where('username', credentials.username)
+		.orWhere('email', credentials.email)
+		.first();
+
+	if (existingUser) {
+		throw new HttpError('Username or e-mail already in use', 409);
+	}
+
+	const salt = crypto.randomBytes(16).toString('hex');
+	const hashedPassword = (await scrypt(credentials.password, salt, 64)).toString('hex');
+	const storedPassword = `${salt}/${hashedPassword}`;
+
+	const [user] = await knex('users')
+		.insert({
+			username: credentials.username,
+			email: credentials.email,
+			password: storedPassword,
+		})
+		.returning('*');
+
+	return curateUser(user);
+}
+
+module.exports = {
+	login,
+	signup,
+};