How do I generate CSRF tokens in Express?

Question

newbie. I'm using ExpressJS/Node. Here's my config stuff:

var express = require('express'),
app = express.createServer(),
jade=require('jade');
// Configuration
app.configure(function(){
app.set('views', __dirname + '/views');
app.use(express.logger());
app.use(express.cookieParser());
app.use(express.session({ secret: "secretive secret" }));
app.set('view engine', 'jade');
app.use(express.bodyParser());
app.use(express.methodOverride());
app.use(require('stylus').middleware({ src: __dirname + '/public' }));
app.use(app.router);
app.use(express.static(__dirname + '/public'));
app.use(express.csrf());

I found csrf.js in Express directories, and see that it should be generated and assigned to req.body._csrf, but I'm not sure how to access it.

Here's the csrf.js code

module.exports = function csrf(options) {
var options = options || {}
, value = options.value || defaultValue;

return function(req, res, next){
// generate CSRF token
var token = req.session._csrf || (req.session._csrf = utils.uid(24));

// ignore GET (for now)
if ('GET' == req.method) return next();

// determine value
var val = value(req);

// check
if (val != token) return utils.forbidden(res);

next();
}
}; 

Help? Thanks!

Answer 1

Dynamic helpers has been removed from Express since 3.x.

The new usage would be app.use(express.csrf());, which comes from Connect.

Answer 2

Add the token to dynamic helpers.

app.dynamicHelpers({
  token: function(req, res) {
    return req.session._csrf;
  }
});

Reference it in your jade template.

input(type='hidden', value=token)

Source: http://senchalabs.github.com/connect/middleware-csrf.html