##CSRF-User CSRF-User is a quick and easy CSRF protection middleware for Express that protects all but GET requests. CSRF tokens are tied to an individual user, so only that user can use the token they created, and CSRF tokens will also expire after a configurable timeout.

####Installation npm install csrf-user

####Usage ######1. Enable cookies and sessions in express app.use(cookieParser()); //requires cookie-parser package in Express 4.x+ app.use(session({secret: 'Your Session Secret'}));

######2. Call the middleware app.use(csrf('Your CSRF Secret', 'username')); There are five arguments that can be passed, to csrf(), but only first two are required.

  csrf(secret, username, [disableCSRF], [sessionVar], [timeout]);

• secret: A unique secret key to use for hashing the CSRF token.
• usernameVar: The session variable (req.session.usernameVar) where the current user's username is stored.
• disableCSRF: (default = []) Array of paths to disable CSRF protection on. For example ['/public', '/help'].
• sessionVar: (default='signed') The session variable (req.session.sessionVar) to save the CSRF token in. Use this to inject the token into your app.
• timeout: (default = 60) Number of minutes after which CSRF token should be invalidated.

######3. Inject the token into your app Inject the token into your HTML such that you can set it as a header in your POST, PUT, and DELETE requests.

For example:

<input type="hidden" id="token" value="<% signed %>" />

Where <% signed %> gets replaced by your CSRF token (stored in your session as whatever you set sessionVar to).

######4. Set the X-CSRF-Token header Ensure that any POST, PUT, or DELETE requests have the X-CSRF-Token header set to the token value. Example using jQuery:

$(document).bind("ajaxSend", function(elm, xhr, s){
    if(s.type == "POST" || s.type == "PUT" || s.type == "DELETE"){
	    xhr.setRequestHeader('X-CSRF-Token', $('#token').val());
	}
});

---

That's it! Your application is now protected against CSRF. If a POST, PUT, or DELETE comes through with any of the following:

• No CSRF token
• A valid CSRF token generated by another User
• An expired CSRF token

The server will throw an 403 response.

csrf-user is written by Jonah Hirsch