haste-server/node_modules/connect/lib/middleware/csrf.js

105 lines
2.7 KiB
JavaScript

/*!
* Connect - csrf
* Copyright(c) 2011 Sencha Inc.
* MIT Licensed
*/
/**
* Module dependencies.
*/
var utils = require('../utils')
, crypto = require('crypto');
/**
* CRSF protection middleware.
*
* By default this middleware generates a token named "_csrf"
* which should be added to requests which mutate
* state, within a hidden form field, query-string etc. This
* token is validated against the visitor's `req.session._csrf`
* property which is re-generated per request.
*
* The default `value` function checks `req.body` generated
* by the `bodyParser()` middleware, `req.query` generated
* by `query()`, and the "X-CSRF-Token" header field.
*
* This middleware requires session support, thus should be added
* somewhere _below_ `session()` and `cookieParser()`.
*
* Examples:
*
* var form = '\n\
* <form action="/" method="post">\n\
* <input type="hidden" name="_csrf" value="{token}" />\n\
* <input type="text" name="user[name]" value="{user}" />\n\
* <input type="password" name="user[pass]" />\n\
* <input type="submit" value="Login" />\n\
* </form>\n\
* ';
*
* connect(
* connect.cookieParser()
* , connect.session({ secret: 'keyboard cat' })
* , connect.bodyParser()
* , connect.csrf()
*
* , function(req, res, next){
* if ('POST' != req.method) return next();
* req.session.user = req.body.user;
* next();
* }
*
* , function(req, res){
* res.setHeader('Content-Type', 'text/html');
* var body = form
* .replace('{token}', req.session._csrf)
* .replace('{user}', req.session.user && req.session.user.name || '');
* res.end(body);
* }
* ).listen(3000);
*
* Options:
*
* - `value` a function accepting the request, returning the token
*
* @param {Object} options
* @api public
*/
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();
}
};
/**
* Default value function, checking the `req.body`
* and `req.query` for the CSRF token.
*
* @param {IncomingMessage} req
* @return {String}
* @api private
*/
function defaultValue(req) {
return (req.body && req.body._csrf)
|| (req.query && req.query._csrf)
|| (req.headers['x-csrf-token']);
}