Is a user able to edit localstorage (and sessionstorage) items? Specifically, would a malicious user be able to edit it like cookies can be edited?
I am researching session info for a web application I am writing, and I had the idea of using localstorage for some items. Yes, I have looked into session variables, and I am probably going to use them, but I was just wondering this and could not find it anywhere. My project is built with jQuery and PHP. The interface is completely driven by jQuery, and I am using localstorage for some other info--that is why I thought of it.
Thanks!
Yes he can, actually you should always assume that anything that is done on client side
can be altered, of course JavaScript as well.
If you want to make sure that something is not altered you can use some kind of cryptographic
signature on data and validate it on server side.
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How would I go about deploying a web app intended for only a single user (myself)? I feel like making a login that only accepts 1 user is the wrong method and also easy to hack? Would it be a good idea to make it only accessible from a certain IP? Please advise! Thank you. Backend will be using nodejs.
If I were you, I would program the back-end the proper way. This involves generalizing the entire implementation so that any hypothetical user with the correct password could use your login system. You could still authorize and authenticate the application so that when anybody else tries to log in, you automatically decline their request. If you are concerned about security, ensure that you are using SSL, basic encryption, hash passwords and, most importantly, do not use your own authorization library. It is far more secure if you use OAuth instead of using an IP, for example. Last, but definitely not least, make it as hard as you can for hackers to steal your data in the client side. This way, you also learn a lot of things that might come in handy in the near future.
Overview: I am trying to understand the interactions between OAuth security in my server and in my chrome extension. I think I have 90% of the answer working, but I'm missing a bit. I'd like to find the cleanest way to finish my implementation using existing tools, rather than reinventing any wheels.
Background: I have a node.js app that uses passport, passport-google-auth, and express-session to authenticate users. I save per-user information, keyed by the user's Google identity. This works fine. My web pages can exchange data with the app, and the Google login screen pops up correctly in exactly the cases I'd expect.
I also have a chrome extension, which includes a browser_action popup that needs to write data to my node.js app and a content_script that needs to read data from my app.
My extension already uses chrome.identity.getAuthToken to get the user identity.
For testing, if I ignore security, I can pass this id to my node.js app, and access the info I need.
But, this is no good, of course. I want my node.js API to be locked down, only letting in clients that have the cookie generated for me by passport.
Side note: I imagine, instead, that I could do some song-and-dance wheel reinvention and pass the id securely to my server via https. But this seems completely wrong, right?
Question: I assume that my chrome extension really should be doing the OAuth2 dance directly with my node.js app. But, I don't know what piece I should be using, or how to cleanly play with chrome.identity. I suspect that I'm just missing a small bit of wisdom, but I don't know what it is.
Side comment: Because cookies are shared between browser tabs, I can (clumsily) achieve what I want by simply connecting to my node.js app from another tab in the browser. So, I guess I just need to get the same behavior from my extension background page.
It looks like the easiest answer for me was to use the Stormpath APIs for this. It took some effort, but was reasonably straightforward.
I am building a website with a Parse backend. So I'm building register/login right now, and am thinking that users can take the AppId and Javascript key and write their own javascript to register users on their own.
How can I prevent this from happening, is there a way to restrict the IPs where javascript Parse can run?
I'm guessing you mean because the user can look at your javascript and get the variables from there. If thats the case look here for a thread looking at javascript security. How to prevent your JavaScript code from being stolen, copied, and viewed?
The jist of it seemed to be that it is hard to do.
wkhtmltopdf allows to make a screenshot of a browser view with a webkit browser.
I have a Symfony 1.4 application that requires login, which I would like to use wkhtmltopdf to create a "print this page" function.
How can I securely facilitate this. I'm thinking of creating a one-off token on each screen for the print button that allows wkhtmltopdf to login without using the password of the user.
Any suggestions for how to structure this?
We'vbe come to the conclusion to use the built in "keep me logged in" functionality for this problem.
Would you consider a different printing framework ?
What about jquery plugin (e.g. https://github.com/ianoxley/jqueryprintpage#readme) ?
That way you won't have to allow access to the restricted area from outside the session.
If you still want to use wkhtmltopdf, you can easily create an action that receives a url and a user_id and creates a unique token, I might save this token in your DB or in a Key-Value cache (depends what is your system architecture). I wouldn't create the unique token in advance, I think its better creating it on demand (When your user is asking a print).
You have couple of options in order to enable printing in secured actions,
1) Create a custom security filter. In the filter, in addition to authenticated request, you have to allow requests that contain "token" parameter with right combination of url and user
2) Change the action to unsecured. If you don't want the change the security filter, you would have to change each action to "unsecured" and create a function that verifies if either the request is authenticated or it has a proper token parameter.
It would be smart to remove each token after you used it once to make it even harder to guess a token.
In addition you might want to create a periodic worker that clears old tokens that were never in use.
Even though you already decided on an approach, I would still like to add one more alternate option that might help others viewing this issue.
Another alternate route might be to grab the current source of the page being viewed and post that into your printer backend using something like
$.post("/printer", document.documentElement.outerHTML);
This way you can also preprocess the HTML in an easy way. Your backed could first store the HTML and then parse it to for example convert images or perhaps remove some parts of the page that will not be used when printing.
Will this idea work? It seems pretty stupid, because my app is simply checking that the browser sent two copies of the same information (ie the session key).
Also, remembering to make this check sounds very tedious. Do web frameworks such as Rails and CakePHP have things that make it easier to write XSRF-proof web apps?
Assuming that the session key is not leaked (which could happen if your PHP is poorly configured and uses session.use_trans_sid) and you are not vulnerable to session fixation attacks, yes, this is secure. This is because a request forger cannot read your cookies, and thus does not know what the correct value is.
You may be interested in CSRF Magic, which claims to allow you to protect your application by including a single file.