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ASP .Net, Redirect to an external page while POSTING data

Hi I have a requirement to deal with an external API in MY ASP.Net Application.
There in a button click in my application, I have to redirect the user to an external URL at the same time POSTING some user credentials(username, password) to allow access to there (The external 3rd party page).
If I try to access to that external page without posting credentials(Just a redirect) I will not be able to view the required page and istead an error message saying invalid credentials(From the 3rd party page).
Suppose following are the information
1. URL need to access : https://externalurl.com/external-page.asp
2. username : myusername
3. password : mypassword
If I do a simple HTML form submission it works brilliantly as follows.
No Idea of how to do this in C# code in ASP .Net.
I can post the data using WebRequest APIs but no way to redirect in the same session. If someone can guide on doing this would be great. Thanks in advance...!!!
Edits...
In my case I can't use javascript or any client side scripting to do this.
Basically I don't have to read any response for my POST data. I need to redirect to that page(External location while posting information)

You can do it with an HttpWebRequest, but you need to cache your credentials so that they get passed with each request, not just the first; like this:
// Set queryUrl to your URL, either hard-coded or passed in
HttpWebRequest req = WebRequest.Create(queryUrl) as HttpWebRequest;
// Set your credentials
NetworkCredential cred = new NetworkCredential(username, pwd, domain);
// Setup cache to store your credentials for future requests
var cache = new CredentialCache {{queryUrl, "Ntlm", cred}};
req.Credentials = cache;
HttpWebResponse response = req.GetResponse() as HttpWebResponse;

Do like this to your button
<asp:Button ID="Button1" PostBackUrl="https://externalurl.com/external-page.asp" runat="server" Text="Submit" />
Hope this is clear
http://msdn.microsoft.com/en-us/library/ms178140%28v=vs.100%29.ASPX

You can either set the form method and action exactly like you have it now. Or use a postbackURL on the button.
The problem is going to be setting the name on the elements to be able to submit them. You have to use javascript to set the hidden fields. Because .net changes the "name" property of the rendered elements on server-side controls.
So, on the client side click event of the button, you can set the values of the hidden fields (just like the ones in your question) to whatever values you need. And, when the form submits, they will be posted with the proper names.

Cookie persistence and best practice

In our application there are two types of user, let's call them Alpha and Beta users. Each of these users sees a different type of toolbar / menu.
We have decided to track this using cookies. The majority of our pages are either Alpha pages or Beta pages and then there are some common pages that Alpha and Beta users share. So in each view of our application where we know the user type (Alpha or Beta) we have the following code:
HttpCookie isAlphaCookie = new HttpCookie("IsAlpha", "false"); // or true
HttpCookie isBetaCookie = new HttpCookie("IsBeta", "true"); // or false
isAlphaCookie.Expires = DateTime.MaxValue;
isBetaCookie.Expires = DateTime.MaxValue;
Response.Cookies.Add(isAlphaCookie);
Response.Cookies.Add(isBetaCookie);
The idea is then, in common pages, we don't set any cookie and rely on the previously set cookie to determine which toolbar to load. So, these two cookies are set to true or false as above in our known pages before we read them in the controller method which loads our toolbar like so:
HeaderViewModel header = new HeaderViewModel
{
FirstName = UserProfile.CurrentUser.FirstName,
LastName = UserProfile.CurrentUser.LastName,
ImageUrl = null,
OrganisationName = UserProfile.CurrentUser.OrganisationName,
OrganisationUrl = UserProfile.CurrentUser.OrganisationUrl,
ShowAlphaToolbar = bool.Parse(Request.Cookies["IsAlpha"].Value),
ShowBetaToolbar = bool.Parse(Request.Cookies["IsBeta"].Value),
ShowPublicToolbar = false
};
return PartialView("Common/_Header", header);
From reading up on how to read / write cookies this seems to be the right approach; writing the cookie to the Response object and reading the cookie from the Request object.
The problem I'm having is that when i get to the controller method that loads the toolbar the values of the IsAlpha and IsBeta cookies are both empty strings and this breaks the application.
I have confirmed that the cookies are set in the Response before they are read in the Request.
I'm wondering whether I'm missing something fundamental here.

I only expect your assumption " in common pages, we don't set any cookie and rely on the previously set cookie to determine which toolbar to load" to work if you are calling these partial actions, which you referring to as "common pages" I guess, through Ajax Calls. If you are using
#Html.RenderAction('nameOfaAtion')
then I don't think what you have in place will work.
Reason is Both your main action and partial actions are executed within the same Http Request Cycle so the cookies you are trying to access from the Request Object in your common pages have not yet came as part of Request.
Edit
As I can see you are hard coding the cookies on each page so Guess you can also do something like below. Not originally the way you are trying to do but I think it will do the same thing you are trying.
In your pages change the partial view call to like this.
#Html.Action("LoadHeader", "Profile", new{IsAlpha=False, IsBeta=true});
Then Change the signature of the LoadHeader action to receive these two extra parameters
public ViewAction LoadHeader(bool IsAlpha, Bool IsBeta)
Then with the viewModel Initialization change two lines as below.
ShowAlphaToolbar = IsAlpha,
ShowBetaToolbar = IsBeta,

Create cookie with cross domain

I am working on cookies. I am able to create cookies very easily. To create a cookie I am using this code:
HttpCookie aCookie = new HttpCookie("Cookie name");
aCookie.Value = "Value";
Response.Cookies.Add(aCookie);
This code is fine for me and it gives me localhost as Host. But the problem comes here when I try to add a domain name here like:
HttpCookie aCookie = new HttpCookie("Cookie name");
aCookie.Value = "Value";
aCookie.Domain = "192.168.0.11";
Response.Cookies.Add(aCookie);
Now the cookie is not generated. Any suggestions?

You can only set the domain to yourself (the current site) and sub-domains of yourself, for security reasons. You can't set cookies for arbitrary sites.

As Marc has said - you can't do this; unless the domain is a subdomain of the one returning the response.
The same limitation applies to javascript code on the client adding cookies as well - the same origin policy will apply.
A simple way to achieve this is generally to include on the page returned from abc.com somewhere a reference to a resource on the domain xyz.com - typically a javascript file or something like that.
You have to watch out there, though, because that's a third-party cookie and some users will have those disabled (because it's how ad-tracking works).

Assuming you have a known set of cookies you want to track across domains and that you own all the domains you are sharing cookies with, you can build this functionality yourself. Here is poor man's cross-domain cookie tracking:
You can add "?favoriteColor=red" to all links on abc.com that point to xyz.com.
XYZ Contact
Then do the same thing for all links on xyz.com that point to abc.com.
ABC Contact
Now on every page of abc.com and xyz.com need to check the http request path for ?favoriteColor=red and if it exists, set the favoriteColor cookie on that domain to red.
// Pseudocode
if(queryString["favoriteColor"] != null) {
setCookie("favoriteColor", queryString["favoriteColor"]);
}
Tip 1: Do some validation to ensure that the value you get is valid because users can enter anything.
Tip 2: You should be using https if you're going to do this.
Tip 3: Be sure to url escape your cookie name and value in the url.

How do I use the cookie container with RestSharp and ASP.NET sessions?

I'd like to be able to call an authentication action on a controller and if it succeeds, store the authenticated user details in the session.
However, I'm not sure how to keep the requests inside the session as I'm using RestSharp as a detached client. I need to somehow get a key back from the server on successful authorisation and then for each future call, check the key with that stored in the session.
How do I ensure the RestClient in RestSharp sends all future requests with the cookie set correctly so inside service calls, the session variable can be retrieved correctly?
I've been looking at the cookie container with HttpFactory but there doesn't seem to be any documentation on this anywhere.

If someone is having a similar problem, please note that the above is not quite required for a simple "store my cookies after each request" problem.
Jaffas approach above works, but you can simply attach a CookieStore to your RestClient and have the cookies be stored automatically.
I know this is not a solution for everyone, since you might want to store dedicated cookies only. On the other hand it makes your life easier for testing a REST client!
(I used Jaffas variables for ease):
CookieContainer _cookieJar = new CookieContainer();
var client = new RestClient("http://<test-server>/letteron"); //test URL
client.CookieContainer = _cookieJar;

I worked this out in the end.
Basically create a cookie container, then add the session cookie from the response into the cookie container. All future requests will then contain this cookie.
var sessionCookie = response.Cookies.SingleOrDefault(x => x.Name == "ASP.NET_SessionId");
if (sessionCookie != null)
{
_cookieJar.Add(new Cookie(sessionCookie.Name, sessionCookie.Value, sessionCookie.Path, sessionCookie.Domain));
}

Grabbing Cookies in Web Browser Control - WP7

In order to log into a certain part of a website the users of my application require their cookie. To do this I need to grab it and pass it to url.
Does anyone know how to grab a certain websites cookie from the browser control?
I saw this method but wasn't quite clear.
Thanks, TP.

As of WP 7.1 Mango "release", if one may call it, please see the WebBrowser Control Overview for Windows Phone. It has been recently updated a little bit, and it turns out that they actually have added some support for cookie-retrieval from the WebBrowser. On the bottom of the page you will find a tiny link GetCookies(WebBrowser) pointing to description of a new class: WebBrowserExtensions with this very handy method. Yes, this class has only that one single member. It's an extension method, I suppose no explanations needed on that.
I have not played with this method much, but it seems that this will allow you to access the very same thing as the JS trick: the cookieset for the current URL. It probably will not allow to set anything, nor to peek cookies for other URLs. Maybe if you play hard with the CookieContainer you will receive, but I doubt.
On the 7.0 release, I've been struggling quite hard to achieve "cookie transparency" for my App. Long story short, my app was doing some background HTTP requests, and also had a WebBrowser to show some online content -- and "it would be great" if both sources of connections would emit the same cookies to the server.. And guess what, my application had to make the first request, then let the browser navigate. With such requirements, there was virtually is no way to achieve consistency of the cookies - bah, even with the current new and glorious GetCookie method, I suppose it would be damn hard. So, to the point - it was possible, but needed to use some hidden API, that is present publicitly on the Phone, but is hidden in the SDK. The API is available the (public) class System.Net.Browser.WebRequestCreator, freely available. The quirk is: in the SDK this class has a single public static property "IWebRequestCreate ClientHttp" with a method "Create" that you can use to "factory" your "raw http" connections - in case you dont want to use the WebClient for some reason. On the phone, and on the emulator, there is a second public static property called "IWebRequestCreate BrowserHttp", easily returned by Reflection:
PropertyInfo brwhttp = typeof(System.Net.Browser.WebRequestCreator)
.GetProperty("BrowserHttp")
with this property, you will be able to obtain a "special" internal instance of IWebRequestCreate that is used internally by the WebBrowser. By opening your background HTTP requests with this class, you will get your cookies automatically set as if they were created/sent by the WebBrowser control, but in turn - you will NOT be able to modify http headers, userprovide http user authentication and neither do a few lowlevel things - because all that settings will be synced with the WebBrowser's data stored for current 'system user instance', if I'm allowed to call it as such on the single-user Phone device heh. The interoperation between connections and the WebBrowser works both ways - if your HTTP connection (created with use of the 'hidden property') receives any settings/cookies/etc -- then the WebBrowser will instantly notice them and update its own cache. No cookie/session loss on neither of the sides!
If you need to passively get cookies for your subsequent connections after some first WebBrowser navigation - please use the GetCookie or the JS way.
But if you need your code to be first, and then pass authz to the WebBrowser -- you will probably have to dig deeper and use the above.. It's been hidden, so please resort to the other means first!
..and don't ask me how did I found it or how much time it took :P
have a nice fun with it
//edit: I've just found out, that the BrowserHttp property is a normal Silverlight's way to access the Browser's connection factory, please see BrowserHttp. It seems that it is only has been hidden in the 'miniSilverlight' written for the WP7 platform!

The approach being described in the post you linked is to use the WebBrowser control's InvokeScript method to run some javascript. However the post appears to use a "cookies" collection which doesn't actually exist.
string cookie = myWebBrowser.InvokeScript("document.cookie") as string;
Now for the hard part the string you get contains all pertinent cookie name/value pairs for the page with the values still being Url encoded. You will need to parse the returned string for the value you need.
See document.cookie property documentation.
Edit:
Looking at it fresh instead of relying on the post, InvokeScript invokes named function on the window of the host browser. Hence the page being displayed in the WebBrowser would itself need to include a function like:-
function getCookie() { return document.cookie; }
Then the InvokeScript would look like:-
string cookie = myWebBrowser.InvokeScript("getCookie");

As #quetzalcoatl already suggested, you can use internal instance of WebRequestCreator to share cookies between browser instances and instances of WebRequest. You don't get to access the cookies directly though, I think that's just a security measure by Microsoft.
This code below creates a WebReqeust object, connected to CookieContainer of WebBrowser instance. It then posts to a url to log in the user and store cookies in the container.
After it's done, all browser instances within the app instance will have required set of cookies.
var browser = new WebBrowser();
var brwhttp = typeof (WebRequestCreator).GetProperty("BrowserHttp");
var requestFactory = brwhttp.GetValue(browser, null) as IWebRequestCreate;
var uri = new Uri("https://www.login.com/login-handler");
var req = requestFactory.Create(uri);
req.Method = "POST";
var postParams = new Dictionary<string, string> {
{"username", "turtlepower"},
{"password": "ZoMgPaSSw0Rd1"}
};
req.BeginGetRequestStream(aReq => {
var webRequest = (HttpWebRequest)aReq.AsyncState;
using (var postStream = webRequest.EndGetRequestStream(aReq)) {
// Build your POST request here
var postDataBuilder = new StringBuilder();
foreach (var pair in paramsDict) {
if (postDataBuilder.Length != 0) {
postDataBuilder.Append("&");
}
postDataBuilder.AppendFormat("{0}={1}", pair.Key, HttpUtility.UrlEncode(pair.Value));
}
var bytes = Encoding.UTF8.GetBytes(postDataBuilder.ToString());
postStream.Write(bytes, 0, bytes.Length);
}
// Receive response
webRequest.BeginGetResponse(aResp => {
var webRequest2 = (HttpWebRequest) aResp.AsyncState;
webRequest = (HttpWebRequest)aResp.AsyncState;
string resp;
using (var response = (HttpWebResponse)webRequest2.EndGetResponse(aResp)) {
using (var streamResponse = response.GetResponseStream()) {
using (var streamReader = new System.IO.StreamReader(streamResponse)) {
resp = streamReader.ReadToEnd();
}
}
}
}, webRequest);
}, req);
One of the issues I couldn't solve though was exceptions thrown when server returns 302 - it seems to throw WebException error with "Not found" description.

// Ensure this is set to true BEFORE navigating to the page
webBrowser1.IsScriptEnabled = true;
// Once the page has loaded, you can read the cookie string
string cookieString = webBrowser1.InvokeScript("eval", new string[] { "document.cookie;" }) as string;
The cookieString variable will contain the full cookie for the document. You can then parse the string.

There is an WebBrowser Extension class which is exactly developed for this:
CookieCollection tempCookies = Microsoft.Phone.Controls.WebBrowserExtensions.GetCookies(this.BrowserControl);