Asp.net - Using SSL to prevent cookie replay attack - asp.net

I'm looking to put SSL into place to prevent cookie replay attacks on our site.
The site is using .NET forms authentication. Do I just need to enable SSL for the login page or would it be every page behind the forms authentication that needs to be secure?
THanks

You would need to enable SSL for every page where the browser is instructed to send the authentication ticket cookie. By default, that would mean every page on your website, although when writing the cookie to the browser you can instruct it to only send it over HTTPS or to limit it to certain paths.
But in general it would mean SSL protecting every page on your site, not just your sign in page.

.Net websites transfer non only the viewstate but any cookies back to the server on postback. This impacts your security in that someone using firesheep (or a similar tool) could easily pick up an authentication cookie, not on login, but when a user postsback via a button press, or ajax event several pages into the application.
If you have access to IIS you can not only enable SSL use, but force it.

Related

Do I need to maintain the HTTPS (SSL) state after user logged even the data are not sensitive?

I have a website where users can post ads and view them. I am using ASP.net build it. So normally site is free for to view ads. But if anybody wants to post an ad he or she needs to be a registered user. So if an user try to Post an ad without logging then he will be redirect to login page. So I want to enable SSL for login page to securely transfer information over the internet.
Here few things you should know.
I just only need to secure the user name and passwords.
Ads post by users are not sensitive data. So it is OK if it transfer through non secure path.
I dont want to enable SSL for every page. Because it will slow down page loading and it is a CPU intense task.
So how to achieve this? Do I need to maintain the HTTPS state after user logged under SSL connection until he post articles and until he log out?
Cant I just secure the login page for authenticate the user and then go with normal pages? Keep in mind that I need to keep the logged information because I saw in an another blog that saying When you go from HTTPS to HTTP all the states are being lost. Is that true?
So Help me here.
Thank you very much.
You should maintain SSL for every page once a user is logged in so that you can use secure cookies for the authentication cookie. This can be set using the requireSSL="true" in the web.config (MSDN doc). You definitely should use secure cookies for authentication, and you'll only be able to utilize that cookie over HTTPS.
Or as Scott Hanselman put it in this seriously old blog post:
In order to prevent Session Hijacking, when you've got a secure site,
it's a good idea to mark your cookies as "secure," meaning that they
can't be accessed over HTTP. This prevents folks from being issued
cookies over HTTPS then switching to HTTP in order to access the
cookie with sniffers or other evil.
This question has also been covered at Information Security Stack Exchange and Programmers Stack Exchange.
More Reading: OWASP Top 10 for .NET developers part 9: Insufficient Transport Layer Protection

Forms Authentication Cookie value vulnerability in asp.net

In asp.net, I am able to login using forms authentication as usual, copy our auth cookie value, log out, add the cookie artificially to the client using the 'Edit This Cookie' addon for Chrome, refresh the (anonymous) landing page and hey presto i'm logged in again. This seems to be a vulnerability - is there any way of fixing it using the the standard forms auth or will I have to do something like use a custom Authorize attribute which overrides the existing one in asp.net mvc?
I don't think this is a bug per se. The following happens during forms authentication
You provide a username/password to the server
Server validates username/password
If valid, the server then sends an encrypted authentication ticket (cookie) to the client with the expiration time (set in the web.config forms authentication section) and username (all encrypted)
On each request that requires authorization, the cookie is decrypted on the server, expiration time is checked and username is used to see if authorized (or getting that role for the requested resource).
When you logout, the expiration time on the cookie is set in the past, therefore, it is not longer a valid cookie
Now, as to why you are seeing what you are seeing... You are copying the cookie before you logout. Thus your copied cookie never registers the logout (moved expiration time). When you reattach, you still have a valid auth cookie. Now, if your forms authentication timeout is set to...let's say 20 minutes...this method would fail if you copy the cookie and wait 21 minutes as by that time, it has expired.
Cookies are always vulerable and we can't do much about that. What we can do is prevent someone from stealing the cookies.
Regarding ASP.NET MVC it does a good job to avoid stealing cookies. Some of the main things it does by default as part of security are:
Encode the strings that are rendered to the view (if you are using Razor don't know about others) to prevent from XSS attacks.
Request validation (stop potentially dangerous data ever reaching the
application).
Preventing GET access for JSON data.
Preventing CSRF Using the Antiforgery Helpers
Regarding cookies Microsoft provides HttpOnly feature and this helps to hide the cookies from javascript. The Forms authentication that you are talking about is a HttpOnly cookie means someone can't steal that through JavaScript and it's more safe.
You can do that with any cookie/s. You can inspect/copy all the cookies from any given domain, and spoof if you want. You can do that to yourself (only) because its your PC (or user logged in to PC). Obviously if you're on a shared PC, that is a problem (across all your info).
The act of "copying your cookie" is in fact one way malware attempts to steal/hijack your identity (or current session on some web site). That said, unless you have some malware, you can't just "copy cookies" of someone else.
Assuming logout is done, you can ask users to close their browsers so the expired cookie is removed from the (file) system.

How to preserve authentication for ASP.NET Forms authentication cookie, Http to Https (different domains) and back?

We have a non-SSL ASP.NET web app that allows a user to login (ASP forms authentication, inproc).
Once authenticated, we redirect their browser to an external, SSL secured page on another web site / domain altogether that we do not control.
The client is redirected back to a pre-configured url on our original http web app when done.
However, the customer is then asked to "re-login" again on our side which is undesired...
It seems the forms authentication cookie is destroyed when transitioning between HTTP and HTTPS and back again.
How can I keep the forms authentication cookie alive so that the customer does not have to re-authenticate on the round trip?
It's not being destroyed; you're not authenticating on your domain, so the cookie's not being set on your domain, and thus requests on your domain will not contain said authentication cookie.
This is GOOD. If this didn't happen, then every cookie from every domain you ever visited would get sent with every request. Which is obviously 1) crazy and 2) a security hole. Setting a cookie on mydomain.com should never be visible to pages on myotherdomain.com.
If you're using a 3rd party authentication system, like google, facebook, etc, they'll all have some sort of callback token that you'll have to process and set your own cookies.
Consider to set cookie's domain property for your cookies with more specified can be found here or try this code:
Response.Cookies["your_cookie_name"].Domain = "yourdomain.com";
You're looking for a Single Sign On solution.
It might be a little overkill for your problem, for which you might just want to get the same domainname. But if that isn't an option you might want to take a look at:
Windows Identity Foundation

IIS6 SSL Config - Have to log in twice (once for :80, once for :443)

I have a virtual folder containing an administration application, like
https://www.mysite.com/alpha
which requires SSL. In the IIS manager properties for the folder, under "Authentication and access control", Anonymous Access is disabled and "Authenticated Access" is set to "Integrated Windows authentication."
When I connect to the site in Chrome, I receive two login boxes. The first is from mysite.com/alpha:443, and the second is from mysite.com/alpha:80. Firefox appears to re-send my credentials for the second box so it is never shown.
Any ideas why I'd be required to log in twice?
If you require SSL for authenticated users on your website (for any reason), then the best solution is to always have your "Login" page on https://. That way when they log in, they are instantly secure. The reason for this is because of the native design of SSL. It separates/secures it's self from the non secure version by not passing authentication states between http and https.
you will also have to write some logic to redirect returning authenticated visitors to the secure page (IE: visitors who can return authenticated from a cookie).
EDIT:
Since your using windows authentication, it's probably easiest to simply redirect ALL incoming http traffic to https. This means your entire site will be over SSL and will be inaccessible via http (other than to redirect to https)
I wrote a Blog Post on forcing a website to use WWW in the web address, but it can also be ported to forcing https.
Yep,
The one uses SSL, the other not.
therefore, you are not allowed to share the credential cache from a Secure session, with the one of the unsecure session.
if you require SSL, then directly redirect the users to the SSL website.

ASP.NET Login via SSL doesn't persist when switching to non-SSL

I have an application I would like to force SSL on the login page and on the page that the CC is entered on. I would prefer to keep the rest of the application free of SSL.
I have the code working to force SSL on certain pages, and remove SSL on others. The problem I have is that if I log in with SSL enabled the user is only authenticated on the pages that are SSL. The reverse holds true as well, if the user logs in without SSL they are only authenticated on pages without SSL.
What can I do to have this persist between the two. Is this using cookies or the session?
Thanks!
Classically, one would use the session for this.
You can use cookies as well.
In either case, you need to keep in mind that they can be spoofed, so you want to only keep a "logged in" token that you can verify on them.

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