code-boxx/0-NODE-CSRF.MD

## 0-NODE-CSRF.MD

      
    Raw
  

              0-NODE-CSRF.MD
            
          
    NODEJS EXPRESS CSRF EXAMPLE

https://code-boxx.com/simple-nodejs-express-csrf/
NOTES


Run unpack.bat (Windows) unpack.sh (Linux/Mac). This will automatically:

Create public folder, move x-dummy.css inside.
Create views folder, move 1-form inside.
Install required modules - npm i express express-session ejs cookie-parser body-parser
Start the server - node 2-server.js


Access http://localhost in your browser and submit the dummy form.

LICENSE

Copyright by Code Boxx
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

  
## 1-form.ejs
<!DOCTYPE html>
<html>
  <head>
    <title>Dummy Form</title>
    <link rel="stylesheet" href="public/x-dummy.css">
  </head>
  <body>
    <form method="post" action="go" target="_blank">
      <!-- (A) HIDDEN HTML TOKEN -->
      <div>* This token should be hidden in your actual project</div>
      <input type="text" name="token" value="<%= token %>">

      <!-- (B) FIELDS AS USUAL -->
      <input type="email" required name="email" value="jon@doe.com">
      <input type="submit" value="GO">
    </form>
  </body>
</html>

## 2-server.js
// (A) LOAD REQUIRED MODULES
const express = require("express"),
path = require("path"),
bodyParser = require("body-parser"),
cookieParser = require("cookie-parser"),
session = require("express-session");

// (B) INIT EXPRESS SERVER
const app = express();
app.set("view engine", "ejs");
app.use(cookieParser());
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({ extended: false }))
app.use(session({
  secret: "YOUR-SECRET-KEY", // CHANGE TO YOUR OWN!
  resave: false,
  saveUninitialized: true
}));

// (C) HTML PAGES
// (C1) PUBLIC FOLDER
app.use("/public", express.static(path.join(__dirname, "public")))

// (C2) HTML FORM
app.get("/", (req, res) => {
  req.session.token = (Math.random() + 1).toString(36).substring(4);
  res.render("1-form.ejs" , { token: req.session.token })
});

// (C3) SUBMIT HTML FORM
app.post("/go", (req, res) => {
  // (C3-1) CHECK TOKEN
  if (req.session.token == null) { res.send("Invalid token"); }
  if (req.session.token != req.body.token) { res.send("Invalid token"); }

  // (C3-2) PROCEED ONLY IF TOKEN MATCH
  console.log(req.session.token);
  console.log(req.body);

  // (C3-3) REMOVE TOKEN & RESPOND
  req.session.token = null;
  res.send("OK");
});

// (D) START SERVER
app.listen(80, () => console.log(`Server running at port 80`));

## unpack.bat
md public
md views
move x-dummy.css public
move 1-form.ejs views
call npm i express express-session ejs cookie-parser body-parser
node 2-server.js

## unpack.sh
mkdir -m 777 public
mkdir -m 777 views
mv ./x-dummy.css ./public
mv ./1-form.ejs ./views
source "npm i express express-session ejs cookie-parser body-parser"
node 2-server.js

## x-dummy.css
* {
  font-family: Arial, Helvetica, sans-serif;
  box-sizing: border-box;
}
form {
  max-width: 500px;
  margin: 0 auto;
  padding: 20px;
  background: #fafafa;
  border: 1px solid #ebebeb;
}
input {
  width: 100%;
  padding: 10px;
}
input[type=text], input[type=email] {
  margin-top: 10px;
  border: 1px solid #d7d7d7;
}
input[type=submit] {
  font-weight: 700;
  border: 0;
  margin-top: 10px;
  color: #fff;
  background: #bb1b1b;
  cursor: pointer;
}
	<!DOCTYPE html>
	<html>
	<head>
	<title>Dummy Form</title>
	<link rel="stylesheet" href="public/x-dummy.css">
	</head>
	<body>
	<form method="post" action="go" target="_blank">
	<!-- (A) HIDDEN HTML TOKEN -->
	<div>* This token should be hidden in your actual project</div>
	<input type="text" name="token" value="<%= token %>">

	<!-- (B) FIELDS AS USUAL -->
	<input type="email" required name="email" value="jon@doe.com">
	<input type="submit" value="GO">
	</form>
	</body>
	</html>
	// (A) LOAD REQUIRED MODULES
	const express = require("express"),
	path = require("path"),
	bodyParser = require("body-parser"),
	cookieParser = require("cookie-parser"),
	session = require("express-session");

	// (B) INIT EXPRESS SERVER
	const app = express();
	app.set("view engine", "ejs");
	app.use(cookieParser());
	app.use(bodyParser.json())
	app.use(bodyParser.urlencoded({ extended: false }))
	app.use(session({
	secret: "YOUR-SECRET-KEY", // CHANGE TO YOUR OWN!
	resave: false,
	saveUninitialized: true
	}));

	// (C) HTML PAGES
	// (C1) PUBLIC FOLDER
	app.use("/public", express.static(path.join(__dirname, "public")))

	// (C2) HTML FORM
	app.get("/", (req, res) => {
	req.session.token = (Math.random() + 1).toString(36).substring(4);
	res.render("1-form.ejs" , { token: req.session.token })
	});

	// (C3) SUBMIT HTML FORM
	app.post("/go", (req, res) => {
	// (C3-1) CHECK TOKEN
	if (req.session.token == null) { res.send("Invalid token"); }
	if (req.session.token != req.body.token) { res.send("Invalid token"); }

	// (C3-2) PROCEED ONLY IF TOKEN MATCH
	console.log(req.session.token);
	console.log(req.body);

	// (C3-3) REMOVE TOKEN & RESPOND
	req.session.token = null;
	res.send("OK");
	});

	// (D) START SERVER
	app.listen(80, () => console.log(`Server running at port 80`));
	md public
	md views
	move x-dummy.css public
	move 1-form.ejs views
	call npm i express express-session ejs cookie-parser body-parser
	node 2-server.js
	mkdir -m 777 public
	mkdir -m 777 views
	mv ./x-dummy.css ./public
	mv ./1-form.ejs ./views
	source "npm i express express-session ejs cookie-parser body-parser"
	node 2-server.js
	* {
	font-family: Arial, Helvetica, sans-serif;
	box-sizing: border-box;
	}
	form {
	max-width: 500px;
	margin: 0 auto;
	padding: 20px;
	background: #fafafa;
	border: 1px solid #ebebeb;
	}
	input {
	width: 100%;
	padding: 10px;
	}
	input[type=text], input[type=email] {
	margin-top: 10px;
	border: 1px solid #d7d7d7;
	}
	input[type=submit] {
	font-weight: 700;
	border: 0;
	margin-top: 10px;
	color: #fff;
	background: #bb1b1b;
	cursor: pointer;
	}