index.js

#!/usr/bin/env node
/**
 * Routes File
 */

'use strict'

/* MODULE IMPORTS */
const express = require('express')
const handlebars = require('express-handlebars').create({defaultLayout: 'main'})
const bodyParser = require('body-parser')
const app = express()
app.use(express.static('public'))
const fs = require('fs-extra')

//Necessary for file upload
const multer = require('multer')
//multerConfig: to store files in temporary server storage
const multerConfig = {
	//Configure destination for the user's file
	storage: multer.diskStorage({
		destination: function(req, file, next){
			next(null, './uploads');
		},

	//Give the file a unique name
    filename: function(req, file, next){
		const ext = file.mimetype.split('/')[1];
		next(null, file.fieldname + '-' + Date.now() + '.'+ext);
	  }
	})
}


//IMPORT CUSTOM MODULES 
var fileRoute = require('./routes/file-upload');

//Set up body parsing middleware
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json())

//Initialize authentication packages required for passport
var passport = require('passport')
var LocalStrategy = require('passport-local').Strategy;
var flash=require("connect-flash");

//Run functions related to passport
app.use(flash());
app.use(require('serve-static')(__dirname + '/../../public'));
app.use(require('express-session')({
	secret: 'keyboard cat',
	resave: true,
	saveUninitialized: true
  }));

app.use(passport.initialize());
app.use(passport.session());
passport.serializeUser(function(user, done) {
	done(null, user);
});
passport.deserializeUser(function(user, done) {
	done(null, user);
});

//Set up handlebars 
app.engine('handlebars', handlebars.engine)
app.set('view engine', 'handlebars')

app.get('/', (req, res) => {
	//Render with appropriate message
	res.render('login', {message: req.flash('message')});
})

app.post('/', passport.authenticate
	//login success: render upload page
	//login failure: stay at menu
	('local', {
	successRedirect: '/upload',
	failureRedirect: '/'
})); 

const port = 8080

app.get('/upload', (req, res) => {
	res.render('upload')
})
	
app.post('/uploaded', multer(multerConfig).single('file'), function(req, res) {
	//Stop the user from uploading without importing a file
	var username = req.body.username
	if (req.file == undefined){
		var message = 'Please choose a file to upload.'
		message = {message: message}
		res.render('upload', message)
	}else{
		/*If uploader input username, check if it exists in
		the database, if not return the appropriate message*/
			const sqlite3 = require('sqlite3').verbose();

			let usersdb = new sqlite3.Database('./users.db', (err) => {
				if (err){done(err)}
			})

			usersdb.get('SELECT user FROM Users WHERE user = ?', [username],
			function(err, results, done){
				if (err) {done(err)}
				if (results === undefined && username.length > 0){
					//username doesn't exist
					var message = 'username does not exist in the database, please input a valid one'
					message = {message: message}
					res.render('upload', message)
				}

	if (results !== undefined || username.length === 0){
	//username exists or user didn't input an username

	//Use request http client to store uploaded file to aws s3 server
	var fs = require('fs');
	var request = require('request');
	const path = require('path')

	//Use callback function to read all files stored under uploads directory
	const dir = './uploads'; 
	var filename;

	function getFiles(path, callback) {
		fs.readdir(path, function (err, files) {
			if (err) return callback(err)
			callback(null, files)
		})
	}
	
	getFiles(dir, function (err, files){
		//Obtain file path and use it to upload the file to aws s3 server through postman api
		filename = ((files[files.length - 1]));
		const filepath = path.join(dir, filename)

		var options = { method: 'POST',
		url: 'http://localhost:8080/file-upload',
		headers: 
		{ 'postman-token': '1b098a37-a9a1-a072-65f2-557aa1dd7fef',
			'cache-control': 'no-cache',
			'content-type': 'multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW' },
		formData: 
		{ file: 
			{ value: fs.createReadStream(filepath),
				options: { filename: filename, contentType: null } } } };

		request(options, function (error) { 
			if (error) throw new Error(error);
		});
	})
	res.render('uploaded')
	}
	})
	usersdb.close()
	}
})

app.get('/download', (req, res) => {
	const path = require("path")
	const dir = './uploads'; 

	function getFiles(path, callback) {
		fs.readdir(path, function (err, files) {
			if (err) return callback(err)
			callback(null, files)
		})
	}

	getFiles(dir, function (err, files) {
		/*Extract updated file from the uploads folder and use it for 
		generating and sending the hash-included download link*/
		var filename = ((files[files.length - 1]));
		var AWS = require('aws-sdk');
		AWS.config.update(
			{
				secretAccessKey: "086X4701/yjK6DgnBC52PfZqFOv6JIHuvQMBUR83",
				accessKeyId: "AKIAIXXAXHIU44MFASTQ",
				region: 'eu-west-2'
			}
		);

		//Create an aws s3 object
		const s3 = new AWS.S3()
		const myBucket = '340ct-project-file-server'
		const myKey = filename
		const signedUrlExpireSeconds = 60 * 5 //Expiry time in seconds

		var url = s3.getSignedUrl('getObject', {
		Bucket: myBucket,
		Key: myKey,
		Expires: signedUrlExpireSeconds
		})

		//Read contents of uploads directory and clear it
		fs.readdir(dir, (err, files) => {
			if (err) throw err;
		  
			for (const file of files) {
			  fs.unlink(path.join(dir, file), err => {
				if (err) throw err;
			  });
			}
		  });

		/*Use md5 to create hash string from everything after hostname/
		in url for e.g. if url = 'http://www.google.com/filename?X-Am...', build hash from
		filename?X-Am...'*/
		var crypto = require('crypto')
		var fileData = url.substring(url.lastIndexOf('/')+1);
		console.log("filedata: "+fileData)
		var hash = crypto.createHash('md5').update(fileData).digest('hex')
		console.log("filedata hash: "+hash)

		/*Access Denied error returned from clicking url link generated from 
		commented code, had to append hash to URL object instead

		//Remove everything in url after hostname and replace with '/'+hash
		----------------------------------
		var newUrl = url.lastIndexOf('/')
		url = url.substring(0, newUrl)
		console.log("url: "+url+'/'+hash)
		---------------------------------
		*/

		//Create URL object and include hash
		const fileUrl = new URL(url)
		fileUrl.hash = hash
		console.log("fileUrl: "+fileUrl)

		//Send fileUrl to the user's email through nodemailer
		var nodemailer = require('nodemailer')
		var smtpTransport = require('nodemailer-smtp-transport')

		//Setup nodemailer transport (gain authentication for gmail)
		var smtpTrans = nodemailer.createTransport(smtpTransport({
			service: 'gmail',
			//  host:'smtp.gmail.com',
			//  port:465,
			//  secure:true,
			auth: {
					user: "s3fileshare@gmail.com",
					pass: "datastore749"
			},
			tls: { rejectUnauthorized: false }
		}));

		//Retrieve user's email address
		var userEmail = app.get('email')
		
		//Configure mailing options
		var mailOptions = {
        from: "s3fileshare@gmail.com", // sender address
        to: userEmail,
		subject: "FileShare: Download Link For "+myKey,
        html: "URL: "+fileUrl+"</br></br>"+"Use the above url to share your file!"// html body
		};
		
		//message to be displayed to the user
		var message;
		//sendMail function called to send the email 
		smtpTrans.sendMail(mailOptions, function(error){
			if(error){
					console.log(error);
					message = "Error: Unable to send email containing the url for your file!";
			}else{
					console.log("Message successfully sent!");
					message = "An email containing the url for your file has been sent to you!";
			}
			message = {message: message}
			//Close transport
			smtpTrans.close();
			res.render('uploaded', message)
		})		
	})
})

/**
 * The secure home page.
 *
 * @name Home Page
 * @authentication This route requires cookie-based authentication.
 */
app.get('/', (req, res) => {
		res.render('login')
})

/**
 * The user registration page.
 *
 * @name Register Page
 */

app.get('/register', (req, res) => {
	res.render('register')
})

/**
 * The script to process new user registrations.
 *
 * @name Register Script
 */
app.post('/register', (req, res) => {
	//Used to Initialize the database
	const sqlite3 = require('sqlite3').verbose(); 

	//Get data from the form
	const formData = JSON.stringify(req.body, null, 2)
	const jsonObj = JSON.parse(formData)
	
	//Initialize the database
	let usersdb = new sqlite3.Database('./users.db', (err) => {
	if (err){
		return console.error(err.message); 
	}
		console.log('Connected to Users database.');
	})
	
	//Insert users registration data into Users table
	usersdb.run('INSERT INTO Users(fname, lname, user, pass, email) VALUES(?, ?, ?, ?, ?)', 
	[jsonObj.fname, jsonObj.lname, jsonObj.user, jsonObj.pass, jsonObj.email], (err) => {
		if(err) {
			return console.log(err.message); 
		}
		console.log('The Users table has been updated.');
	})
	
	//Store the users details in the form of objects
	const users_details = {
		fname: jsonObj.fname,
		lname: jsonObj.lname,
		user: jsonObj.user,
		pass: jsonObj.pass,
		email: jsonObj.email
	}
	
	res.render('userdetails', users_details)
})

app.get('/about', (req, res) => {
	res.render('about')
})

//Passport api used for validating login information
passport.use(new LocalStrategy({passReqToCallback : true},
	function(req, username, password, done) {
		const sqlite3 = require('sqlite3').verbose(); 
		const usersdb = new sqlite3.Database('./users.db'); 

		//Retrieve the user's password and email if username exists in the database
		usersdb.get('SELECT pass, email FROM Users WHERE user = ?', [username],
			function(err, results){
				if (err) {done(err)}; 
				
				if (results != undefined){
					//Length of returned object is 0 therefore return to menu page
					if (results.length === 0){
						done(null, false)
					}
					/*Username exists in the database, so compare password input by the user
					to password stored in the database that corresponds to the username, if
					they match log the user in.*/
					if (results.pass === password){
						//log the user in and store the email
						app.set('email', results.email)
						return done(null, {username}); 
					}else{
						//Incorrect password therefore return to menu page
						return done(null, false, req.flash('message', 'Invalid Password!'));
					}
				//Username doesn't exist in the database therefore return to menu page
				}else{
					  done(null, false, req.flash('message', 'Invalid Username!'))
				}
		})
	}
)); 

//Use file-upload.js
app.use(fileRoute)
module.exports = app.listen(port, 'localhost', async() => {
	//Make sure we have a database with the correct schema
	const sqlite3 = require('sqlite3').verbose(); 

	let usersdb = new sqlite3.Database('./users.db', (err) => {
		if (err){
			return console.error(err.message); 
		}
			console.log('Connected to Users database.');
		})

	usersdb.run('CREATE TABLE IF NOT EXISTS Users (fname TEXT, lname TEXT, user TEXT, pass TEXT, email TEXT);')
	//Close database
	usersdb.close()
	console.log(`listening on port ${port}`)
})