Cookies suck. The interface is beyond terrible, they were never scoped properly, and they don't have to be used.
Browser storage (sessionStorage, localStorage) is perfectly valid for storing an authentication token.
Browser storage (sessionStorage, localStorage) is perfectly valid for storing an authentication token.
Tokens stored in those storages you mention can be read by any javascript code, even third party.
That doesn't happen with http-only cookies.
Be careful with what you recommend publicly, as others might end up assuming this is fine, when it is clearly not.
If you're sending your password in plain text without HTTPs, then saying "ok, nevermind, we already have that problem so let's just not use any CSRF protection" you're just making things worse.
Authentication tokens that allow anyone reading them to impersonate you are bad, no discussion about it. Go and google for this if you don't believe me. Ask any security expert (which I'm not).
Cookies have the exact same problem. Except if you set the http-only flag in them, which is what I'm advocating for here.
You can still use localStorage, just not for security tokens.
1. If you are using Http-only cookies, these are clearly unrelated. 2. If you are sharing an authentication token with the browser, cookie or not, it can be read by any scripts on the same origin.
So...what exactly are you trying to say?
No, it can't. Read about http-only cookies.
We've dealt with plenty of security issues and exactly zero of them centered around XSS. I've seen more issues surrounding bad dependencies that could end up running right inside your API server. Browser extensions can do so many other things, like reading all the forms and middling your API requests. So, I can't take responsibility for that.
I would recommend http-only cookies over localStorage, but if you protect yourself in other ways then putting auth tokens in localStorage is not the end of the world. It hasn't ever affected us, so I'll leave the pearl-clutching over this up to the experts.
But, we haven't had any issues with using localStorage. Probably mainly because we are not a huge target. Nobody is going to write a chrome extension to try to hack one of our tiny little sites.
Slack [0] has entered the chat.
Jira [1] has entered that chat.
I could go on but I don't need to. Many web applications that people use store an unnecessarily obnoxious amount of data locally. I can only imagine how much of that is used just once or possibly even never (like images in settings windows that were never accessed).
[0]: On one instance of Firefox on one computer, app.slack.com has stored 1.9GB. On another instance of Firefox on another computer, app.slack.com has stored about 633KB. On a third instance of Firefox on yet another computer, app.slack.com has stored about 600MB.
[1]: Jira doesn't load _at all_ if you've got any secure settings enabled (like... no CORS and no cross-domain cookies and no cross-domain XHRs and ... the list goes on). So Jira loads in an incognito window in a VM. But suffice to say that its local storage is even more _fucking obnoxious_.
> Tokens stored in those storages you mention can be read by any javascript code, even third party.
I don't doubt you. But I am not a javascript developer. I'd like it if you could link to some demonstrations of how that can be abused.
I'm saying you should not use for SECURITY tokens which, if leaked, can allow others to impersonate your user. So it doesn't matter it uses 40Gb of cached data. Security is not black or white, it is a full spectrum and despite it would be bad for a hacker to obtain a full chat historory or your list of jira card titles it is still less worrysome that somebody able to impersonate you in those services. Security is an arms race....you need to raise the barrier more and more as attacks get more and more sophisticated. So the "then just don't run extensions" or "just don't use untrusted third party scripts", despite it is something we should do, it is not a justification for lowering the bar of all the other stuff we should be doing.
Regarding the references you ask for, what can I say. localStorage can be accessed by any JavaScript running in the page, even from browser extensions or XSS attacks. I'm pretty sure you will find people more knowledgeable than me here [1] and overal just googling for it you will find a lot of resources about why storing authentication tokens in localStorage is a bad idea
[1] https://security.stackexchange.com/search?q=localstorage+sec...
https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies#re...
Like some here, I don't understand the hate around keeping tokens in localstorage. People immediately say "but js can read it!" but so what? If someone can put malicious js in my site, it is GAME OVER, secure http-only cookie or not. When that is the case, the saner option is doing away with an old and misused invention called cookies. The upside with ditching cookies is that you are an order of magnitude safer against CSRF since your browser does not send anything automatically. You don't need to keep CSRF token state in your server(s) either (helps with scale, one less state to worry about), it is a win.
http-only secure cookies do not give you any additional security. Ditching cookies does.
Store a security token in localStorage and additionally store a secure signature for it in a secure, HTTP-only cookie. On your backend, verify validity of both the token and its additional signature contained in the cookie.
My actual point stands, the Web Storage API doesn’t offer the same protections as cookies. Don’t store sensitive data in localStorage, that is emphatically not it’s intended use.
And what would those be that are relevant to this discussion? The way we (ab)use cookies is arguably not their intended use either.
I can't think of a scenario in this context where an attacker says "damn he is using http-only cookies, I won't be able to do what I want to do"
The only pragmatic difference between both is js accessibility. That only matters when someone can inject scripts into your site. My point is, when that happens, cookies are also bust.