http - Set-Cookie on Browser with Ajax Request via CORS

Question

Attempting to implement an ajax login / signup process (no refresh site with authentication). Using cookies for preserving state. I thought I'd have this right by now but for some reason browser doesn't set cookies after it gets them back from the server. Can anyone help? Here are the request and response headers:

Request URL:http://api.site.dev/v1/login
Request Method:POST
Status Code:200 OK

Request Headers

Accept:application/json, text/plain, */*
Accept-Charset:ISO-8859-1,utf-8;q=0.7,*;q=0.3
Accept-Encoding:gzip,deflate,sdch
Accept-Language:en-US,en;q=0.8
Connection:keep-alive
Content-Length:57
Content-Type:application/json;charset=UTF-8
Host:api.site.dev
Origin:http://site.dev
Referer:http://site.dev/
User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.101 Safari/537.11
withCredentials:true
X-Requested-With:XMLHttpRequest
Request Payload
{"email":"[email protected]","password":"foobar"}

Response Headers

Access-Control-Allow-Credentials:true
Access-Control-Allow-Headers:X-Requested-With, Content-Type, withCredentials
Access-Control-Allow-Methods:GET, POST, PUT, DELETE, OPTIONS
Access-Control-Allow-Origin:http://site.dev
Connection:Keep-Alive
Content-Length:19
Content-Type:application/json
Date:Tue, 08 Jan 2013 18:23:14 GMT
Keep-Alive:timeout=5, max=99
Server:Apache/2.2.22 (Unix) DAV/2 PHP/5.4.7 mod_ssl/2.2.22 OpenSSL/0.9.8r
Set-Cookie:site=%2B1THQQ%2BbZkEwTYFvXFVV5fxi00l2K%2B6fvt9SuHACTNsEwUGzDSUckt38ZeDsNbZSsqzHmPMWRLc84eDLZzh8%2Fw%3D%3D; expires=Thu, 10-Jan-2013 18:23:14 GMT; path=/; domain=.site.dev; httponly
X-Powered-By:PHP/5.4.7

I also see the cookie in chrome network tools, as returned from the server:

Response Cookies

Name: site
Value: %2B1THQQ%2BbZkEwTYFvXFVV5fxi00l2K%2B6fvt9SuHACTNsEwUGzDSUckt38ZeDsNbZSsqzHmPMWRLc84eDLZzh8%2Fw%3D%3D
Domain: .site.dev
Path: /
Expires: Session
Size: 196
Http: ?

Answer 1

Your AJAX request must be made with the "withCredentials" settings set to true (only available in XmlHttpRequest2 and fetch):

    var req = new XMLHttpRequest();
    req.open('GET', 'https://api.bobank.com/accounts', true); // force XMLHttpRequest2
    req.setRequestHeader('Content-Type', 'application/json; charset=utf-8');
    req.setRequestHeader('Accept', 'application/json');
    req.withCredentials = true; // pass along cookies
    req.onload = function()  {
        // store token and redirect
        let json;
        try {
            json = JSON.parse(req.responseText);
        } catch (error) {
            return reject(error);
        }
        resolve(json);
    };
    req.onerror = reject;

If you want a detailed explanation on CORS, API security, and cookies, the answer doesn't fit in a StackOverflow comment. Check out this article I wrote on the subject: http://www.redotheweb.com/2015/11/09/api-security.html