Session not getting retrieved in Facebook C# SDK example - c#

I am a newbie at ASP.net programming. This is in reference to the Facebook C# SDK, I have managed to set up all the steps required for authentication on this SDK. However, I keep getting a null from the following code:
(reference: http://csharpsdk.org/docs/web/getting-started#5)
var accessToken = Session["AccessToken"].ToString(); //This line returns null and crashes
var client = new FacebookClient(accessToken);
dynamic result = client.Get("me", new { fields = "name,id" });
string name = result.name;
string id = result.id;
Just like in the example, I had set up a generic handler to set up the session variable to be stored in the HttpContext.Session object.
I even tried to modify the offending line to directly access the HttpContext and retrieve the access token:
var accessToken = HttpContext.Current.Session["AccessToken"].ToString();
but this yielded the same result.
Have I missed out something in the webconfig or is there some other way I can store the access token when shifting from the handler to the log in page?

Make sure in your Facebook developer settings that you do not have query string selected for your app as auth token paramenter!!!
This is the default mode and this wont work unless you do the following:
http://developer.facebook.com
Open your app page.
Then go Settings --> Auth Dialog --> Auth Token Parameter and select URI Fragment.
100% sure this is your problem. It's not included in any literature I found, and it's a damn shame.

If it is returning null then I would assume that the Session value is not being set - have you debugged to make sure the code which sets the session is being hit?
Looking at the linked article - it uses a HttpHandler to do this bit but does not mention anything about registering it in the Web.Config - have you done this? If not see here http://msdn.microsoft.com/en-us/library/46c5ddfy.aspx

Related

Unable to get some user account information in UWP app - In-premise active directory (Not Azure AD)

In a UWP app, I have enabled the User Account Information capability.
I need to get the username and the domain name (each of them separately) of the currently logged on user (The users are logged on with an in-premise Active Directory account - Not Azure AD).
For example, the user would log in to the Active Directory domain domain1 using the username user1. i.e. domain1\user1.
I am using the following code to try to get the required details:
IReadOnlyList<User> users = await User.FindAllAsync();
var user = users.FirstOrDefault();
// get domain
var data1 = await user.GetPropertyAsync(KnownUserProperties.DomainName);
string strDomainName = (string)data1;
// get username
var data2 = await user.GetPropertyAsync(KnownUserProperties.AccountName);
string strUserName = (string)data2;
Issues:
strDomainName returns domain1.com\user1. Why does this include the .com part for all our domains? On c# winforms applications we can easily get domain1\user1 without any issue.
strUserName returns an empty string. i.e. "". Why does this not return any value?
I also checked the following:
KnownUserProperties.FirstName returns an empty string. i.e. ""
KnownUserProperties.LastName returns an empty string. i.e. ""
KnownUserProperties.PrincipalName returns an empty string. i.e. ""
KnownUserProperties.ProviderName returns an empty string. i.e. ""
KnownUserProperties.GuestHost returns an empty string. i.e. ""
Is there anything else I need to enable similar to the User Account Information capability? Or are there any other permissions that need to be granted to the app to get this information?
I understand that I can get the value of strDomainName and perform string functions to get what I need. But I want to know if there is any way to get this information directly. Also curious why KnownUserProperties.AccountName and other properties listed above such as FirstName, LastName etc. just returns an empty string.
I am running the following version of Windows:
I have the following set as the Target version and Min Version:
To verify, I also tested with the UserInfo sample project by Microsoft from GitHub and I got the following output:
The following was automatically enabled in Settings > Privacy > Account Info.
TestApp is the app I tried with and User Info C# Sample is the sample app from GitHub:
Update:
After also enabling the Enterprise Authentication capability, KnownUserProperties.PrincipalName does return the expected value. i.e. user1#domain1.com.
However, other properties listed above such as FirstName, LastName etc. just returns an empty string and I am still unable to find any property that returns domain1\user1 (without the .com part)
The Information you are trying to access are not reliable, as they (as you mentioned) do not have to be set and also they can be restricted access to via privacy settings in general.
I had a similar problem and would advise you to use the UWP OneDrive API
using Microsoft.OneDrive.Sdk;
and then request wl.basic scope. This scope contains at least a reliable username.
public static async Task<bool> GetAuthenticatedClient()
{
string oneDriveConsumerBaseUrl = "https://api.onedrive.com/v1.0";
var scopes = new List<string>
{
"wl.signin",
"wl.basic",
};
Task authTask;
var onlineIdAuthProvider = new OnlineIdAuthenticationProvider(scopes.ToArray());
authTask = onlineIdAuthProvider.RestoreMostRecentFromCacheOrAuthenticateUserAsync();
oneDriveClient = new OneDriveClient(oneDriveConsumerBaseUrl, onlineIdAuthProvider);
AuthProvider = onlineIdAuthProvider;
try
{
await authTask;
if (!AuthProvider.IsAuthenticated)
{
return false;
}
}
catch (ServiceException exception)
{
// Swallow the auth exception but write message for debugging.
//Debug.WriteLine(exception.Error.Message);
return false;
}
return true;
}
As for the domain, I'm not sure, but you could try to access it via Environment.UserDomainName like described on MSDN or with Windows.Networking.Connectivity.NetworkInformation.GetHostNames() like described here.
I found another possible solution to this. If you are still debugging this locally or the app was already installed on the target machine, I could enable the capabality User Account Information but this was not propagated to the actual installed app:
when your search for your app name in the start menu and then right click the entry and select App settings you get something like this:
As soon as I enabled the highlighted option (basically it says 'Account information') it worked.

Access cookie before View loaded in MVC5?

Let's say I have a cookie with value "OLD", then I update the cookie with following code :
var lang = new HttpCookie("lang");
lang.Value = "NEW";
lang.Expires = DateTime.UtcNow.AddDays(2);
HttpContext.Current.Response.SetCookie(lang); //set updated cookie value
var x = HttpContext.Current.Request.Cookies("lang");
x will still have "OLD" as value because it's not being sent to the client. Is it possible to get the updated value without it being sent to client first?
The Problem
you are setting the cookie in HttpContext.Current.Response and trying to find it in HttpContext.Current.Request even before the next request has come to server.
It is not going to work.
My Advice
For this case, use of cookie is incorrect. You have other options better fit for purpose, like -
ViewData
ViewBag
TempData
Session
ViewModel
The Answer
But if you still want to use cookie this way, search the cookie in HttpContext.Current.Response. I am sure you will get it.
Like this:
var cookieValue = HttpContext.Current.Response.Cookies["OLD"].Value
If you don't want to send value to client side and only want to use for reference you can use TempData for your purpose. Which might help.
I think, you should look for it in Response, not in Request, because request - it's that came from client.

C# MVC4 windows username and cookie issues

First, I'm sad to say I'm not sure whether this code should be in the _Layout.cshtml or somewhere in the controller. It needs to run on all pages, so I've put it in the _Layout.cshtml page.
This is for an intranet web app. What I'm attempting to do is this: if a cookie (holding the user's userid) is not found, get the windows username, run it through a class that will go into the database and get the corresponding user's username, and - if we get a user id back - make a cookie containing it. Doesn't sound too hard, but one line in particular, and various incarnations of it, is refusing to be supportive. Here's the code as a whole.
if(!Context.Response.Cookies.AllKeys.Contains("userid")){
var winuser = System.Web.HttpContext.Current.User.Identity.Name;
var winuserid = myprojectname.Models.MyIntranetDataContext.getUserId(winuser).UserID();
if (winuserid == null) {
Response.Redirect("/someotherpage");
} else {
HttpCookie cookieuser = new HttpCookie("userid");
DateTime now = DateTime.Now;
cookieuser.Value = winuserid;
cookieuser.Expires = now.AddMonths(1);
Response.Cookies.Add(cookieuser);
}
}
Line 2 - var winuser... - appears to be the problem. In this current incarnation, I'm getting a build error: An object reference is required for the non-static field, method, or property 'myprojectname.Models.MyIntranetDataContext.getUserId(string)'
It doesn't like it when I add a .ToString to it either.
I've tried making winuser this as well:
Page.User.Identity.Name;
That gave no build errors. When I attempt to Start Debugging, she blows up with this beauty of an error: 'Cannot perform runtime binding on a null reference'
Once I get the windows username, all will be well.
Really, this isn't about cookies, or even mvc to much of an extent (except maybe guidance on where to put this code - the _Layout.cshtml?). Really it's about getting the windows username, which I seem unable to do. Thanks in advance for any assistance you are able to provide.
Note, the above names aren't actual - just for example only.
If they are on the domain, couldn't you use something like the following to retrieve that information?
AppDomain.CurrentDomain.SetPrincipalPolicy(PrincipalPolicy.WindowsPrincipal);
WindowsPrincipal principal = (WindowsPrincipal)Thread.CurrentPrincipal;
WindowsIdentity identity = (WindowsIdentity)principal.Identity;
String userName= principal.Identity.Name;

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);

Simple C# Evernote API OAuth example or guide?

Anybody know where I can find a simple example C# code example? Apparently really tough to find.
I'm just starting out, got my Developer key.
Initial (really noob question/presumption) - -Can (should/must) my solution be a web service client? No new libraries I need to install in .Net right?
Basically, as a test, I want to be able to securely present a single note from a private notebook in html similar to what the Everfort export in html looks like on a outside WebSite.
Many Thanks in Advance!
You should start by downloading our API ZIP from http://www.evernote.com/about/developer/api/. You'll find C# client sample code in /sample/csharp. This sample code demonstrates using the Evernote API from a desktop application that authenticates using username and password.
I am not sure if you ever got this working, but I was playing around with Evernote, OpenAuth and C# this morning and managed to get it all working. I have put together a blog post / library explaining the experience and outlining how to do it with MVC here - http://www.shaunmccarthy.com/evernote-oauth-csharp/ - it uses the AsyncOAuth library: https://github.com/neuecc/AsyncOAuth
I wrote a wrapper around AsyncOAuth that you might find useful here: https://github.com/shaunmccarthy/AsyncOAuth.Evernote.Simple
One prickly thing to be aware of - the Evernote Endpoints (/oauth and /OAuth.action) are case sensitive
// Download the library from https://github.com/shaunmccarthy/AsyncOAuth.Evernote.Simple
// Configure the Authorizer with the URL of the Evernote service,
// your key, and your secret.
var EvernoteAuthorizer = new EvernoteAuthorizer(
"https://sandbox.evernote.com",
"slyrp-1234", // Not my real id / secret :)
"7acafe123456badb123");
// First of all, get a request token from Evernote - this causes a
// webrequest from your server to Evernote.
// The callBackUrl is the URL you want the user to return to once
// they validate the app
var requestToken = EvernoteAuthorizer.GetRequestToken(callBackUrl);
// Persist this token, as we are going to redirect the user to
// Evernote to Authorize this app
Session["RequestToken"] = requestToken;
// Generate the Evernote URL that we will redirect the user to in
// order to
var callForwardUrl = EvernoteAuthorizer.BuildAuthorizeUrl(requestToken);
// Redirect the user (e.g. MVC)
return Redirect(callForwardUrl);
// ... Once the user authroizes the app, they get redirected to callBackUrl
// where we parse the request parameter oauth_validator and finally get
// our credentials
// null = they didn't authorize us
var credentials = EvernoteAuthorizer.ParseAccessToken(
Request.QueryString["oauth_verifier"],
Session["RequestToken"] as RequestToken);
// Example of how to use the credential with Evernote SDK
var noteStoreUrl = EvernoteCredentials.NotebookUrl;
var noteStoreTransport = new THttpClient(new Uri(noteStoreUrl));
var noteStoreProtocol = new TBinaryProtocol(noteStoreTransport);
var noteStore = new NoteStore.Client(noteStoreProtocol);
List<Notebook> notebooks = client.listNotebooks(EvernoteCredentials.AuthToken);
http://weblogs.asp.net/psteele/archive/2010/08/06/edamlibrary-evernote-library-for-c.aspx might help. As the author states it just bundles some and fixes some. Haven't tried it myself but thought I'd mention for a possibly easier way to get started. Possibly.
This might help too...found it using the Way Back Machine since the original blog site was offline.
https://www.evernote.com/pub/bluecockatoo/Evernote_API#b=bb2451c9-b5ff-49bb-9686-2144d984c6ba&n=c30bc4eb-cca4-4a36-ad44-1e255eeb26dd
The original blog post: http://web.archive.org/web/20090203134615/http://macrolinz.com/macrolinz/index.php/2008/12/
Scroll down and find the post from December 26 - "Get it while it's hot..."

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