Set cookies for cross origin requests

Question

How to share cookies cross origin? More specifically, how to use the Set-Cookie header in combination with the header Access-Control-Allow-Origin?

Here's an explanation of my situation:

I am attempting to set a cookie for an API that is running on localhost:4000 in a web app that is hosted on localhost:3000.

It seems I'm receiving the right response headers in the browser, but unfortunately they have no effect. These are the response headers:

HTTP/1.1 200 OK
Access-Control-Allow-Origin: http://localhost:3000
Vary: Origin, Accept-Encoding
Set-Cookie: token=0d522ba17e130d6d19eb9c25b7ac58387b798639f81ffe75bd449afbc3cc715d6b038e426adeac3316f0511dc7fae3f7; Max-Age=86400; Domain=localhost:4000; Path=/; Expires=Tue, 19 Sep 2017 21:11:36 GMT; HttpOnly
Content-Type: application/json; charset=utf-8
Content-Length: 180
ETag: W/"b4-VNrmF4xNeHGeLrGehNZTQNwAaUQ"
Date: Mon, 18 Sep 2017 21:11:36 GMT
Connection: keep-alive

Furthermore, I can see the cookie under Response Cookies when I inspect the traffic using the Network tab of Chrome's developer tools. Yet, I can't see a cookie being set in in the Application tab under Storage/Cookies. I don't see any CORS errors, so I assume I'm missing something else.

Any suggestions?

Update I:

I'm using the request module in a React-Redux app to issue a request to a /signin endpoint on the server. For the server I use express.

Express server:

res.cookie('token', 'xxx-xxx-xxx', { maxAge: 86400000, httpOnly: true, domain: 'localhost:3000' })

Request in browser:

request.post({ uri: '/signin', json: { userName: 'userOne', password: '123456'}}, (err, response, body) => {
    // doing stuff
})

Update II:

I am setting request and response headers now like crazy now, making sure that they are present in both the request and the response. Below is a screenshot. Notice the headers Access-Control-Allow-Credentials, Access-Control-Allow-Headers, Access-Control-Allow-Methods and Access-Control-Allow-Origin. Looking at the issue I found at Axios's github, I'm under the impression that all required headers are now set. Yet, there's still no luck...

Answer 1

Backend code :

app.use(
  cors({
    credentials: true,
    origin: [
      "http://localhost:3000",
      "http://localhost:8080",
      "http://localhost:4200",
    ],
  })
);
router.post("/", (req, res) => {
  res
    .cookie("access_token", "token", { httpOnly: true })
    .status(200)
    .json({ message: "Cookie set!" });
});

Frontend code:

const fetchData = async () => {
  const response = await fetch("http://localhost:4000/", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
    },
    credentials: "include",
    body: JSON.stringify({
      name: "sreesha",
    }),
  });
  const json = await response.json();
  console.log(json);
};

Dont forget to set credentials:include in frontend . Even if you set cookie in response, without credentials include ,cookie will not be set in browser

Answer 2

In addition to awesome answers above I'd like to offer alternatives. Generally cross-origin cookies is hard especially if you use it for authentication. So my suggestion would be to use proxy. Basically just a proxy to make your backend and frontend lookslike coming from the same host. You can use reverse proxy from loadbalancer that you're using e.g. Nginx, httpd, etc.

Bonus: If you're using Netlify you can use their rewrites and proxy feature to make it work.

For example, as hobbyist I want to develop things cheaply so I use the free version of Fly.io and Netlify for backend and frontend respectively. So to make everything appears coming from the same host, in the Netlify (frontend) I setup the following to avoid cross origin cookies.

# netlify.toml
[[redirects]]
from = "/api/*"
to = "https://yourbackend.fly.dev/:splat"
status = 200
force = true
headers = {Origin = "https://yourfrontend.netlify.app"}


[[redirects]]
from = "/*"
to = "/index.html"
status = 20

Hope it useful for you 🙂

Answer 3

Seems it is not possible to set cookies in cross origin requests as from app.example.com to api.example.com for all users.

Note that cookies set in CORS responses are subject to normal third-party cookie policies. In the example above, the page is loaded from foo.example but the cookie on line 19 is sent by bar.other, and would thus not be saved if the user's browser is configured to reject all third-party cookies.

Cookie in the request (line 10) may also be suppressed in normal third-party cookie policies. The enforced cookie policy may therefore nullify the capability described in this chapter, effectively preventing you from making credentialed requests whatsoever.

See https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#third-party_cookies

Additionally, Google is currently set to phase out third-party cookies in Chrome by 2024. (see google)

Alternativ ideas are

1. Proxy calls to api.example.com through app.example.com/api/.
2. Add an iframe to app.example.com that loads a page from api.example.com. The iFrame page can set cookies and send requests to api.example.com. Pages on app.example.com can send messages to the iFrame via postMessage.
3. Use an iFrame to set a cookie on the parent as example.com. Though I do not see an advantage to 2 as it is also needed to pass data (user credentials in case of a auth cookie) to the iFrame.
4. Instead of using an iFrame the client browser can be redirected to api.example.com to set a cookie.
5. Use an alternative to cookies to pass data. For example if an auth cookie is needed, set it on app.example.com and when calling api.example.com, pass the cookie data in a header. Though this is a bit less secure as you will need access to the cookie on the client and thus cannot use HttpOnly.

Answer 4

Cross site approach

To allow receiving & sending cookies by a CORS request successfully, do the following.

Back-end (server) HTTP header settings:

• Set the HTTP header Access-Control-Allow-Credentials value to true.

• Make sure the HTTP headers Access-Control-Allow-Origin and Access-Control-Allow-Headers are set. Don't use a wildcard *. When you set the allowed origin make sure to use the entire origin including the scheme, i.e. http is not same as https in CORS.

For more info on setting CORS in express js read the docs here.

Cookie settings: Cookie settings per Chrome and Firefox update in 2021:

• SameSite=None
• Secure

When doing SameSite=None, setting Secure is a requirement. See docs on SameSite and on requirement of Secure. Also note that Chrome devtools now have improved filtering and highlighting of problems with cookies in the Network tab and Application tab.

Front-end (client): Set the XMLHttpRequest.withCredentials flag to true, this can be achieved in different ways depending on the request-response library used:

• ES6 fetch() This is the preferred method for HTTP. Use credentials: 'include'.

• jQuery 1.5.1 Mentioned for legacy purposes. Use xhrFields: { withCredentials: true }.

• axios As an example of a popular NPM library. Use withCredentials: true.

Proxy approach

Avoid having to do cross site (CORS) stuff altogether. You can achieve this with a proxy. Simply send all traffic to the same top level domain name and route using DNS (subdomain) and/or load balancing. With Nginx this is relatively little effort.

This approach is a perfect marriage with JAMStack. JAMStack dictates API and Webapp code to be completely decoupled by design. More and more users block 3rd party cookies. If API and Webapp can easily be served on the same host, the 3rd party problem (cross site / CORS) dissolves. Read about JAMStack here or here.

Sidenote

It turned out that Chrome won't set the cookie if the domain contains a port. Setting it for localhost (without port) is not a problem. Many thanks to Erwin for this tip!

Answer 5

This code worked for me

In the backend

Set credentials to true in your corsOptions:

const corsOptions = {
 credentials: true,
  };

Set cookies before sending requests:

res.cookie('token', 'xxx-xxx-xxx', { 
maxAge: 24*60*60*1000, httpOnly: true, 
SameSite:"None" })

In the frontend

Request in browser (using axios):

axios.post('uri/signin', 
JSON.stringify({ username: 'userOne', 
password: '123456'}),. 
{withCredentials:true})
.the(result 
=>console.log(result?.data))
.catch(err => console.log(err))

Answer 6

This is an answer to "Lode Michels" from above regarding CORS cookie with the Heroku server, (and for other cloud providers, like AWS)

The reason your CORS cookie can't be set is because Heroku strip down SSL certificate at Load Balancer, so when you try to set the "secure" cookie at the server, it fails since it's no longer from the secure connection.

You can explicitally specify if the connection is secure, rather than the cookie module examining request. https://github.com/pillarjs/cookies

with koa, add this:

ctx.cookies.secure = true;

---

edit: I can't comment on that answer directly due to lower than 50 reputation

Answer 7

Hope this would help for me regarding the sameSite property, after enabling CORS I also add "CookieSameSite = SameSiteMode.None" to the CookieAuthenticationOptions in the Startup file

app.UseCookieAuthentication(new CookieAuthenticationOptions {
..... CookieSameSite = SameSiteMode.None, ..... }

Answer 8

Pim's Answer is very helpful, But here is an edge case I had gone through,

In my case even though I had set the Access-Control-Allow-Origin to specific origins in BE , In FE I received it as * ; which was not allowed

The problem was, some other person handled the webserver setup, in that, there was a config to set the Access-Control-* headers which was overriding my headers set from BE application

phew.. took a while to figure it out .

So, if there is mismatches in what you set and what you received, Check your web server configs also.

Answer 9

After more then a day of trying all your suggestions and many more, I surrender. Chrome just does not accept my cross domain cookies on localhost. No errors, just silently ignored. I want to have http only cookies to safer store a token. So for localhost a proxy sounds like the best way around this. I haven't really tried that.

What I ended up doing, maybe it helps someone.

Backend (node/express/typescript)

set cookie as you normally would

res.status(200).cookie("token", token, cookieOptions)

make a work around for localhost

// if origin localhost
response.setHeader("X-Set-Cookie", response.getHeader("set-cookie") ?? "");

Allow x-set-cookie header in cors

app.use(cors({
    //...
    exposedHeaders: [
        "X-Set-Cookie",
        //... 
    ]
}));

Frontend (Axios)

On the Axios response remove the domain= so it's defaulted. split multiple cookies and store them locally.

// Localhost cookie work around
const xcookies = response.headers?.["x-set-cookie"];
if(xcookies !== undefined){
    xcookies
        .replace(/\s+Domain=[^=\s;]+;/g, "")
        .split(/,\s+(?=[^=\s]+=[^=\s]+)/)
        .forEach((cookie:string) => {
            document.cookie = cookie.trim();
    });
}

Not ideal, but I can move on with my life again.

In general this is just been made to complicated I think :-(

Update my use case maybe we can resolve it?

It's a heroku server with a custom domain. According to this article that should be okay https://devcenter.heroku.com/articles/cookies-and-herokuapp-com

I made an isolated test case but still no joy. I'm pretty sure I've seen it work in FireFox before but currently nothing seems to work, besides my nasty work around.

Server Side

app.set("trust proxy", 1);

app.get("/cors-cookie", (request: Request, response: Response) => {

    // http://localhost:3000
    console.log("origin", request.headers?.["origin"]);

    const headers = response.getHeaders();
    Object.keys(headers).forEach(x => {
        response.removeHeader(x);
        
        console.log("remove header ", x, headers[x]);
    });
    console.log("headers", response.getHeaders());

    const expiryOffset = 1*24*60*60*1000; // +1 day

    const cookieOptions:CookieOptions = {
        path: "/",
        httpOnly: true,
        sameSite: "none",
        secure: true,
        domain: "api.xxxx.nl",
        expires: new Date(Date.now() + expiryOffset)
    }

    return response
        .status(200)
        .header("Access-Control-Allow-Credentials", "true")
        .header("Access-Control-Allow-Origin", "http://localhost:3000")
        .header("Access-Control-Allow-Methods", "GET,HEAD,OPTIONS,POST,PUT")
        .header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept")
        .cookie("test-1", "_1_", cookieOptions)
        .cookie("test-2", "_2_", {...cookieOptions, ...{ httpOnly: false }})
        .cookie("test-3", "_3_", {...cookieOptions, ...{ domain: undefined }})
        .cookie("test-4", "_4_", {...cookieOptions, ...{ domain: undefined, httpOnly: false }})
        .cookie("test-5", "_5_", {...cookieOptions, ...{ domain: undefined, sameSite: "lax" }})
        .cookie("test-6", "_6_", {...cookieOptions, ...{ domain: undefined, httpOnly: false, sameSite: "lax" }})
        .cookie("test-7", "_7_", {...cookieOptions, ...{ domain: "localhost"}}) // Invalid domain
        .cookie("test-8", "_8_", {...cookieOptions, ...{ domain: ".localhost"}}) // Invalid domain
        .cookie("test-9", "_9_", {...cookieOptions, ...{ domain: "http://localhost:3000"}}) // Invalid domain
        .json({
            message: "cookie"
        });
});

Client side

const response = await axios("https://api.xxxx.nl/cors-cookie", {
    method: "get",
    withCredentials: true,
    headers: {
        "Accept": "application/json",
        "Content-Type": "application/json",                
    }
});

Which yields the following reponse

I see the cookies in the Network > request > cookies Tab.

But no cookies under Application > Storage > Cookies nor in document.cookie.

Answer 10

In the latest chrome standard, if CORS requests to bring cookies, it must turn on samesite = none and secure, and the back-end domain name must turn on HTTPS,

Answer 11

1. frontend

   `await axios.post(`your api`, data,{
       withCredentials:true,
   })
   await axios.get(`your api`,{
           withCredentials:true,
       });`
   

2. backend

   var  corsOptions  = {
    origin: 'http://localhost:3000', //frontend url
    credentials: true}
   
   
   app.use(cors(corsOptions));
   const token=jwt.sign({_id:user_id},process.env.JWT_SECRET,{expiresIn:"7d"});
   res.cookie("token",token,{httpOnly:true});
   
   
   
   hope it will work.
   

Answer 12

In order for the client to be able to read cookies from cross-origin requests, you need to have:

1. All responses from the server need to have the following in their header:

   Access-Control-Allow-Credentials: true

2. The client needs to send all requests with withCredentials: true option

In my implementation with Angular 7 and Spring Boot, I achieved that with the following:

---

Server-side:

@CrossOrigin(origins = "http://my-cross-origin-url.com", allowCredentials = "true")
@Controller
@RequestMapping(path = "/something")
public class SomethingController {
  ...
}

The origins = "http://my-cross-origin-url.com" part will add Access-Control-Allow-Origin: http://my-cross-origin-url.com to every server's response header

The allowCredentials = "true" part will add Access-Control-Allow-Credentials: true to every server's response header, which is what we need in order for the client to read the cookies

---

Client-side:

import { HttpInterceptor, HttpXsrfTokenExtractor, HttpRequest, HttpHandler, HttpEvent } from "@angular/common/http";
import { Injectable } from "@angular/core";
import { Observable } from 'rxjs';

@Injectable()
export class CustomHttpInterceptor implements HttpInterceptor {

    constructor(private tokenExtractor: HttpXsrfTokenExtractor) {
    }

    intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        // send request with credential options in order to be able to read cross-origin cookies
        req = req.clone({ withCredentials: true });

        // return XSRF-TOKEN in each request's header (anti-CSRF security)
        const headerName = 'X-XSRF-TOKEN';
        let token = this.tokenExtractor.getToken() as string;
        if (token !== null && !req.headers.has(headerName)) {
            req = req.clone({ headers: req.headers.set(headerName, token) });
        }
        return next.handle(req);
    }
}

With this class you actually inject additional stuff to all your request.

The first part req = req.clone({ withCredentials: true });, is what you need in order to send each request with withCredentials: true option. This practically means that an OPTION request will be send first, so that you get your cookies and the authorization token among them, before sending the actual POST/PUT/DELETE requests, which need this token attached to them (in the header), in order for the server to verify and execute the request.

The second part is the one that specifically handles an anti-CSRF token for all requests. Reads it from the cookie when needed and writes it in the header of every request.

The desired result is something like this:

Answer 13

For express, upgrade your express library to 4.17.1 which is the latest stable version. Then;

In CorsOption: Set origin to your localhost url or your frontend production url and credentials to true e.g

  const corsOptions = {
    origin: config.get("origin"),
    credentials: true,
  };

I set my origin dynamically using config npm module.

Then , in res.cookie:

For localhost: you do not need to set sameSite and secure option at all, you can set httpOnly to true for http cookie to prevent XSS attack and other useful options depending on your use case.

For production environment, you need to set sameSite to none for cross-origin request and secure to true. Remember sameSite works with express latest version only as at now and latest chrome version only set cookie over https, thus the need for secure option.

Here is how I made mine dynamic

 res
    .cookie("access_token", token, {
      httpOnly: true,
      sameSite: app.get("env") === "development" ? true : "none",
      secure: app.get("env") === "development" ? false : true,
    })

Answer 14

Note for Chrome Browser released in 2020.

A future release of Chrome will only deliver cookies with cross-site requests if they are set with SameSite=None and Secure.

So if your backend server does not set SameSite=None, Chrome will use SameSite=Lax by default and will not use this cookie with { withCredentials: true } requests.

More info https://www.chromium.org/updates/same-site.

Firefox and Edge developers also want to release this feature in the future.

Spec found here: https://datatracker.ietf.org/doc/html/draft-west-cookie-incrementalism-01#page-8

Answer 15

Pim's answer is very helpful. In my case, I have to use

Expires / Max-Age: "Session"

If it is a dateTime, even it is not expired, it still won't send the cookie to the backend:

Expires / Max-Age: "Thu, 21 May 2020 09:00:34 GMT"

Hope it is helpful for future people who may meet same issue.