iframe security - asp.net

I ve a task in which I insert on a page iframe only when user enters valid code. User enters a code I check whether its valid and if it is I insert iframe element on my site. It works great but I wonder if its possible to hide src of the iframe cause when one knows the source of the iframe can get onto this site whenever one want without valid code any more.
is it common problem ? what can I do about this ?

You can not hide the source. Find another way to do it.

You can't hide the src of an iframe. Even if you could hide it from the user, it's easy enough to find, after all, your browser has to make an HTTP request. It seems the easiest solution to your problem is just have something like:
if (code == whateverTheCodeIsSupposedToBe){
Session["CorrectCode"] = true;
}
Then in your iframe page do:
if (Session["CorrectCode"] != true){
Response.Redirect("SorryYouDontHaveTheRightCode.aspx");
}

As the others have said, the browser NEEDS the iframe source to draw it, so there really isn't a way to tell the browser the src and at the same time NOT tell it.
I'll try to add some value here with respect to your underlying problem. Why not pass the validation code that the user enters to the page inside the frame and have that page verify it is correct?
Then it doesn't matter if the user knows the src of the frame, without the validation code it won't do them any good.

Related

disable a direct access to a specific web page in ASP.NET

Is there a trusted way to disable the direct access to an special web page? I mean I want to open it only by clicking on a Button for example. I know I can access to the webpage by using this code but It can not prevent accessing to the web page directly (Pasting the url or typing it):
Response.Redirect("~/Code.aspx")
Thanks
This is a long shot because I don't have the time to test this now (I can see some downvotes coming already!), but...
In the "Code.aspx" page, check for Session["allowed"]. If the value is not there, end the response.
Next, make another page (from where Code.aspx can be accessed). In this page, set Session["allowed"] and then do a Server.Transfer() to Code.aspx, which will then run OK.
Finally, at the end of processing Code.aspx., remember to clear the Session["allowed"] variable again.
Hope this makes even vague sense :)
You may be able to write a piece of code on page load that checks the contents of HttpContext.Current.Request.ServerVariables("HTTP_REFERER") - if it's blank, a user has navigated to the page directly and you can handle it that way.
On the source page create a token into a hiddenfield. To your button add PostBackUrl property and let it point to your destination page.
On the destination page you can validate that the request was made from your allowed source page. And you dont need to use session and all its drawback.
Check this Link for detailed information about how to use the mentioned property.

Possible to only update part of page and change query string parameters at same time in asp.net?

Is there a way to only update part of the page and update the query string parameters at the same time without completely refreshing the whole page in ASP.NET?
I only need to update the "main" section of my page and not the whole page. I understand I can do a partial page postback (or use asp ajax) to do the partial page update, but then how do I update the query string parameters in the URL at the same time? Is that even possible?
Or is it not possible and I'll have to just do a Response.Redirect in the code behind of the partial page postback redirecting to the same page with new query params and just let the whole page refresh?
Use pushState.
This new feature offers you a way to change the URL displayed in the browser* through javascript without reloading the page. It will also create a back-button event and you even have a state object you can interact with.
window.history.pushState(“object or string”, “Title”, “/new-url”);
Described here
You have absolutely zero programmatic access to the address bar. The only way to change it is to redirect.
You could, however, do it like some sites do and provide a "send a link to this page to your friends" area. Youtube comes to mind - see how it provides a URL, querystring parameters included, for you to copy, should you wish to send someone a link to a video starting from some specific point.
Also check the handy "Share" link right under your question. You could provide a link like that, with the target URL, so for the user it's just a matter of right-clicking and copying from the context menu. A link well structured into your site is more user friendly than having the user copy directly from the bar, or from a text box. Specially for mobile browsers, where the sequence is usually press-and-hold, then copy. Copying from the address bar, on the other hand, may involve selecting the address bar text, which in some Android devices is a pain in the ass.

Need parent name of Iframe

I've been searching for a couple hours and haven't found a solution. Hopefully you can help.
I want to get the name & path of the parent page within an Iframe. The reason for this is to prevent the page within the Iframe to be displayed outside it's intended location. If I can get the session variables of the parent page, that would be even better as I could verify the user.
The Iframe will be written in ASP.NET, while the parent page is PHP.
I have found Javascript code that might work, but I'm very unfamiliar with javascript and how to pass the return value to the code behind in ASP.NET. If your solution involves javascript, I will need the whole thing from calling it in the form load to getting back the value.
I have tried these functions, but they don't show what I need.
Request.Url.AbsoluteUri.ToString
Request.ApplicationPath.ToString
Request.UrlReferrer.AbsolutePath.ToString
Thanks
I understand that you looking for a code behind solution and redirect, but the code behind can not recognize if the page is calling from some other.
You may try the Request.ServerVariables["HTTP_REFERER"] but this can make mistake, and can even been disable by some users, or changed.
One simple working solution with javascript is to check on the iframe it self if its inside your master page or not. So this code go to the page that lives inside the iframe, and if see that is alone is redirect the user back to the master page.
<script type="text/javascript" language="javascript">
// this line is check if its inside an iframe.
// if top==self then is not in iframe
if(top == self)
{
alert("This page can not be viewed alone, please press ok to load the master page");
top.location.replace("MasterPage.aspx");
}
</script>

How do I remove a page from the browser history?

I have an have an ASP.Net page which contains a button. This Page contains a ServerSide Paypal button.
When pushed my server does various clever things on the back end and then rewrites the response as a form and some javascript which posts this form to paypal..
This all works great.
However, if the user then elects to click back, they will arrive at my generated self-posting form and that will forward them again to Paypal.
I thought if I could find a way to have my generated form page not exist in the history, then this will solve my problem. but I have no idea how to correct this.
How can I remove my page from the history or just have it never appear?
Update: Thanks to all... Those are some great answers. Upvoted all good ones but went with splattne on account of clever use of hidden field rather than cookies for basis of decision.
window.location.replace(URL);
window.location:
replace(url)
Replace the current document with the
one at the provided URL. The
difference from the assign() method is
that after using replace() the current
page will not be saved in session
history, meaning the user won't be
able to use the Back button to
navigate to it.
I'm not sure if that can be done. But here is an idea how you could prevent that resubmit of the form.
You could insert a hidden input in your form which at the beginning would be empty. On submit you'll write a value in that field and make sure you check on every submit attempt if this field is empty.
If it is not empty on submit you know that the form was previously sent and you could warn the user.
As a web application, you'll never have full control of the user's browser. Even if there was a way to instruct the browser to not store the page in history, which I doubt, you can't be sure it'll work. For example, a clever user could tweak an open-source browser to store every page in history, no matter what.
I think you should try to approach the problem from another angle. You could, for example, detect that it's the same form which is being forwarded and not send it to paypal the second time. The important thing is to do it server-side.
Perhaps you could set a cookie before submitting the form.
When the page is loaded, check for the existence of that cookie (meaning the form was already submitted). If found, instead of automatically submitting the form, automatically go back (window.history.back()) again.
I'm not sure if you can do this easily with PayPal integration, but the
"Post / Redirect / Get" pattern can be used to address this problem
A useful Hint for some might be this...
window.history.go(-2);
particularly in the advent of a load failure warning popup.
You could simply programme your page not to submit, or to do something / navigate somewhere else, if window.referer is the Paypal page you are trying to avoid invoking a second time.
protected void Page_Load(object sender, EventArgs e)
{
Page.RegisterClientScriptBlock("", "<script>if(history.length>0)history.go(+1);</script>");
}

How to disable browser postback warning dialog

I have an asp.net application that runs exclusively on IE7 (internal web site).
When a user needs to enter data, I pop up a child window with a form. When the form closes, it calls javascript:window.opener.location.reload(true) so that the new data will display on the main page.
The problem is that the browser complains that it must repost the page. Is there any way to turn this feature off?
No, but there is a solution. Its generally considered good design to use a 302 redirect immediately after someone posts data to a page. This prevents that popup from ever occuring. Allow me to elaborate.
1) The user fills in a form and submits data via POST.
2) The backend receives the data and acts upon it.
3) Instead of returning the content to the user, the backend issues a 302 redirect as soon as its done processing the page (possibly redirecting the user back to the exact same url, if need be)
4) The page that the user will see is the page you told their browser to redirect to. They will load up the redirected page with a standard GET request. If they try to refresh the page, it will not repost the data. Problem solved.
This is a problem with the usual "postback" way of ASP.NET. If you need to reload a page without this warning, this page must come from a GET, not a POST. You could do a Response.Redirect("...") yourself. But this will destroy the use of viewstate.
asp.net mvc fixes this issue, not an ie7 only problem but a security feature of most browsers. No fix that I know of except you could just update the content in the main form with js rather than reloading the whole page
It's because the page in window.opener comes from a POST Request
Maybe you can use
javascript:window.opener.location = window.opener.location; to do just a GET request if the data can be fetched without a POST.
I do not believe that there is a way to do that. Instead, why not direct the parent window to a page without a reload.
javascript:window.opener.location='your url'
AFAIK, not via your scripts.
You might try:
window.opener.location = '#';
It should circumvent the browser reposting. And, you can adjust the hash name as needed.
If you move from page1 to page2, and want to disable the browser from going back to page 1,then add the following at the top of page1.
<script>
if(window.history.forward(1) != null)
window.history.forward(1);
</script>

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