Develop Reference

Paypal PDT returns Fail always to my HTTP post request C# MVC

I am facing very weird kind of problem that after successful payment transaction, I am not able to get TransactionId appended with returningUrl. Since Paypal auto redirects me to my ReturnUrl which I have mentioned in PDT settings page, and Paypal appends the trasactionId to this returningUrl named tx and using that trasactionId I make a Post request to this Url
https://www.sandbox.paypal.com/cgi-bin/webscr
But here is the problem that I am not able to get that transactionId? what could be the problem kindly any body help me in this issue. This is my code that I am using to make an HTTP post request.
string authTokenTest = "sMfRi9rJN3AjqsejnMxFfkeIwhwrCmVZz3nplUy9V6a9Yq0_2YdugSvZYNa";
//used this but could not retrieved "tx"
//string txToken = Request.QueryString.Get("tx");
//Then used this but no use
var queryValues = HttpUtility.ParseQueryString(Request.Url.Query);
var txToken = queryValues["tx"];
string query = string.Format("cmd=_notify-synch&tx={0}&at={1}", txToken, authTokenTest);
//// Create the request back
string strSandbox = "https://www.sandbox.paypal.com/cgi-bin/webscr";
string url = strSandbox;
/// to use HTTP 1.1 and TLS 1.2
ServicePointManager.Expect100Continue = true;
ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;
ServicePointManager.DefaultConnectionLimit = 9999;
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
// Set values for the request back
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
req.ContentLength = query.Length;
// Write the request back IPN strings
StreamWriter stOut = new StreamWriter(req.GetRequestStream(), System.Text.Encoding.ASCII);
stOut.Write(query);
stOut.Close();
// Do the request to PayPal and get the response
HttpWebResponse payResp = (HttpWebResponse)req.GetResponse();
StreamReader sr = new StreamReader(payResp.GetResponseStream());
string strResponse = sr.ReadToEnd();
sr.Close();
If I make a direct request to this URL via browser and append a TransactionId and IdentityToken then I get the success response, but in this way I am not getting any way the transactionId and my Response is always Fail. Kindly help my in this problem. What could be the issue in my code or any other problem to resolve this issue. Thanks for your time.

I use MVC and so use model binding to get the tx value from the query string. But I don't think that's your problem.
The Return URL has to be set, as you said you did. Also PDT has to be turned on in the same place the URL is specified. Also, unfortunately, customers will not be returned automatically to your site if they use a credit card instead of a PayPal account.
I'm implementing IPN though because credit card customers may not return to the site.

Getting Error 400: Bad request at authenticate via Twitch.tv api

I am new here and I hope someone can help me. I try to connect to twitch.tv I am trying to get an oauth2 authentication on twitch.tv with a small C# program. I am using the twitch.tv authentication request. Here is my C# code:
var loginURL = "https://api.twitch.tv/kraken/oauth2/authorize?
response_type=code&"+
client_id="+ clientID+"
"&redirect_uri=http://localhost&"+
"state=TWStreamingStateAuthenticated";
this.richTextBox1.Text = loginURL;
string code = get_DownLoadString(loginURL);
this.richTextBox1.Text = code;
This is the part, which does not work. It gives me the Error 400: Bad Request.
WebRequest request = WebRequest.Create("https://api.twitch.tv/kraken/oauth2/token");
request.Method = "POST";
string postData = "client_id=" + clientID +
"&client_secret=" + clientSecret +
"&grant_type=authorization_code" +
"&redirect_uri=http://localhost" +
"&code=" + code +
"&state=TWStreamingStateAuthenticated";
ASCIIEncoding encoding = new ASCIIEncoding();
postData = HttpUtility.UrlEncode(postData);
byte[] byteArray = encoding.GetBytes(postData);
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = byteArray.Length;
Stream datatream = request.GetRequestStream();
datatream.Write(byteArray, 0, byteArray.Length);
datatream.Close();
WebResponse respone = request.GetResponse();
MessageBox.Show(((HttpWebResponse)respone).StatusDescription);
I hope someone can help me.
And here is the Get_DownloadString(string URL) Method.
private static string get_DownLoadString(string URL)
{
try
{
string temp = (new WebClient().DownloadString(URL));
return temp;
}
catch (WebException)
{
return null;
}
}

This code doesn't look right to me:
string postData = "client_id=" + clientID +
"&client_secret=" + clientSecret +
"&grant_type=authorization_code" +
"&redirect_uri=http://localhost" +
"&code=" + code +
"&state=TWStreamingStateAuthenticated";
ASCIIEncoding encoding = new ASCIIEncoding();
postData = HttpUtility.UrlEncode(postData);
byte[] byteArray = encoding.GetBytes(postData);
// ...
You are URL-encoding the entire post-data string. This has the effect of converting the & and = signs in the post data to %26 and %3d respectively. When the remote server receives this data, it will scan through it looking for the & and = signs in order to separate out the parameter names and values. Of course, it won't find any, so it will assume you have one big parameter name with no value. The server is probably expecting values for each of the six parameters you are attempting to send, but seeing values for none of them, and this may be why you are getting a 400 Bad Request error.
Instead of URL-encoding the whole string, URL-encode parameter values that may contain characters other than letters and numbers. I would try the following instead:
string postData = "client_id=" + HttpUtility.UrlEncode(clientID) +
"&client_secret=" + HttpUtility.UrlEncode(clientSecret) +
"&grant_type=authorization_code" +
"&redirect_uri=" + HttpUtility.UrlEncode("http://localhost") +
"&code=" + HttpUtility.UrlEncode(code) +
"&state=TWStreamingStateAuthenticated";
ASCIIEncoding encoding = new ASCIIEncoding();
byte[] byteArray = encoding.GetBytes(postData);
// ...
This way, the remote server will still see the & and = characters, and so will be able to pull out the parameter names and values. Because we've URL-encoded the client ID, client secret, URL and code, any characters they contain that may have meaning in a URL will not have that meaning and will be received by the remote server as intended.
Also, if you are still getting a 400 Bad Request error response, try reading the contents of the response stream, obtained by calling GetResponseStream() on the response. Often that will contain a message that will help you figure out what's gone wrong.
Having had a closer look at your code, it seems you have a misunderstanding about how OAuth authentication works. Your getDownload_String method will not get the access code you want, it will only get the HTML text of a Twitch login page.
This is how OAuth authentication works:
Your app sends the user to a login URL, to allow the user to log in to Twitch.
In the web browser, the user then enters their login credentials and submits the page to Twitch.
The Twitch API then responds by redirecting the user's web browser to the redirect URL, with a code appended. Your web app then reads this code out of the URL.
If your code is in a web app it will be able to respond to the URL redirected to in step 3. Alternatively, you may be able to use a WebBrowser control (Windows Forms, WPF) to handle the Twitch login, and handle a Navigating event. If the URL being navigated to begins with the redirect URL, grab the code out of the URL, cancel the navigation and hide the login web-browser control.
The presence of what appears to be a RichTextBox control, along with your comment about your code being a 'small C# application', makes me think that your code is a Windows Forms or WPF application. If this is the case, then you will need to either:
use a WebBrowser control as I described above,
replace your WinForms/WPF app with a web app, or
get in contact with Twitch to request the use of the password flow (which appears not to require a redirect), and use that instead.

How can i login to linkedin using HTTP POST Request with C#

I am working on a simple Windows Forms program that take a username and password from a "Textbox" then it show my linked-in name in a "Messagebox".
I want to accomplish the code with the using of "HttpWebRequest" or using any method to send my POST request to Linked-in then i can get the response and find my name to shown it in a "Messagebox".
I am familiar with creating a "GET" Request and also i made some "POST" Requests but in this case i didn't know how can i send my "txt_UserName.Text" and "txt_Password" with the POST Request and how can i receives the Response.
I tried to using Fiddler to capture POST request (=POST) from linkedin when i try to login but it captures more than 4 requests when i see the header of them it seem like a GET Request this is an example of one:
GET /nhome/?trk= HTTP/1.1
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
and all of them have a multiple cookies values.
This is my POST request code:
public void SubmitData()
{
try
{
string postData = "This is a test that posts this string to a Web server.";
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
// Create a request using a URL that can receive a post.
WebRequest request = WebRequest.Create("http://www.linkedin.com");
// Set the Method property of the request to POST.
request.Method = "POST";
// Set the ContentLength property of the WebRequest.
request.ContentLength = byteArray.Length;
//Content Length
request.ContentLength = byteArray.Length;
// Get the request stream.
Stream dataStream = request.GetRequestStream();
// Write the data to the request stream.
dataStream.Write(byteArray, 0, byteArray.Length);
// Close the Stream object.
dataStream.Close();
// Get the response.
WebResponse response = request.GetResponse();
dataStream = response.GetResponseStream();
StreamReader sr = new StreamReader(dataStream);
MessageBox.Show(sr.ReadToEnd());
sr.Close();
dataStream.Close();
}
catch (Exception ex)
{
MessageBox.Show("Error: " + ex.Message);
}
}
Now the only thing i wish to know, how can i send my username and password as a values to login to linked-in?
Edit:
Below is my second try, it's ok, i can now send the User and Password in postData and i can store the Cookies and retrive it. but there are two issues:
1- how can i make sure that the login is accomplished and not failed
2- if the login is accomplished i want to know what is the second step to get my name from profile, is it made another request or what ?
private void button1_Click(object sender, EventArgs e)
{
PostMessage();
}
private void PostMessage()
{
try {
// POST Data and the POST uri
string postData = "isJsEnabled=true&source_app=&session_key=" + textBox1.Text + "&session_password=" + textBox2.Text + "&signin=Sign+In&session_redirect=";
string uri = "https://www.linkedin.com/uas/login-submit";
// Encoding the POST Data
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
// Create the POST Request
HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create(uri);
//POST Parameters (Method and etc.)
WebReq.Method = "POST";
WebReq.ContentType = "application/x-www-form-urlencoded";
WebReq.ContentLength = byteArray.Length;
// Set the POST Request Cookies
var cookieContainer = new CookieContainer();
WebReq.CookieContainer = cookieContainer;
// Get the request stream.
Stream dataStream = WebReq.GetRequestStream();
// Write the data to the request stream.
dataStream.Write(byteArray, 0, byteArray.Length);
// Close the Stream object.
dataStream.Close();
// Get the response.
HttpWebResponse response = (HttpWebResponse)WebReq.GetResponse();
dataStream = response.GetResponseStream();
StreamReader sr = new StreamReader(dataStream);
//MessageBox.Show(sr.ReadToEnd());
sr.Close();
dataStream.Close();
if (response.StatusCode != HttpStatusCode.OK)
{
MessageBox.Show(" Error: " + response.StatusDescription);
response.Close();
}
foreach (Cookie cook in response.Cookies)
{
MessageBox.Show(cook.Name + " " + cook.Value);
}
}
catch (Exception ex)
{
MessageBox.Show("POST Message Error: " + ex.Message);
}
}

I used Fiddler while I was logging in and found a request to https://www.linkedin.com/uas/login-submit containing the username and password. Found it? Now, if you want to look at it completely from an HTTP Request perspective, you will have to figure out how to generate the other data in the post data/cookie header using the other requests and responses that your browser sent and received to and from the site before this particular request (the information should be there). I think this will lead you to what you need to do, but there's some work to be done!

You're going to need more than you think to log in there is good documentation on how to do this just here, you are going to need an auth token etc, This is because like other services, for example google, they are using oauth2 to secure applications etc.
oauth works by issuing tokens and refreshing tokens and there's a bit of a learning curve but its not especially difficult.
Essentially the following happens
You register your application with linked in and they give you a
client secret.
You pass this code to linked in in your application
and they will generate an auth screen saying that the application is
requesting permission.
you then approve this and it will give you an access token
You then log in with the access token (access tokens on linkedin are valid for 60 days, you must refresh them by this time).
On the plus side the linked in api is pretty straight forward and once authorised you will be able to get stuff pretty easily. All of this is detailed in the link provided in nice step by step stages.
By the way there is also a nuget package that gives you access to profile information.
Try Install-Package LinkedIn
I should point out that the nuget package above gives you a login provider to help authenticate if you don't want to roll your own.
Added after your comments below.
If all you want to do is know how to send a post request here's a generic bit of code that does just that:
string url = "www.foo.bar.com";
using (var webClient= new WebClient())
{
var data = new NameValueCollection();
data["username"] = "<yourusername>";
data["password"] = "<yourPassword>";
var response = webClient.UploadValues(url, "POST", data);
}
note: because its a web uri you should use POST in the method argument here.

The problem you up against is that Linkedin uses a redirect within the login session and is differcult to catch.
So somehow within the login session you need to code that it redirects to the https://www.linkedin.com/nhome/?trk= this provides the user page access.
I am also testing with this, however did not manage to figure this part out, normally
httpWebRequest.AllowAutoRedirect = true;
should do the trick but not in this case it does not work.
So if you find the solution let me know, if I find will post it also.

Server for GCM push notification to android in C#

I am working on an android application which uses push notification service by GCM. Currently I am stuck at creating a server. The guides provided by the GCM documentation is in java which I have no idea how to implement. After researching for awhile, I found GCMSharp on github which uses C#
PushSharp - https://github.com/Redth/PushSharp
But as of now, I am new to creating a server and have no idea how to get started. Is the server actually a web service that keeps listening to request and upon getting a request directs it to the GCM which pushes notification to the client phone?
And if yes, do I implement it in a webservice such as WCF?

You could follow this tutorial.
Is the server actually a web service that keeps listening to request
and upon getting a request directs it to the GCM which pushes
notification to the client phone?
You don't need to listen to requests. GCM Push directly pushes any message to the device without any request. For more details, Read this documentation.

I have answered to this on another thread and here i am repeating. Code looks bit longer but it works. I just sent a push notification to my phone after struggling 2 days by implementing the following code in C# project. I referred a link regarding this implementation, But couldn't find it to post here. So will share my code with you. If you want to test the Notification online you may visit to this link.
note : I have hardcorded apiKey, deviceId and postData, please pass
the apiKey,deviceId and postData in your request and remove them from
the method body. If you want pass message string also
public string SendGCMNotification(string apiKey, string deviceId, string postData)
{
string postDataContentType = "application/json";
apiKey = "AIzaSyC13...PhtPvBj1Blihv_J4"; // hardcorded
deviceId = "da5azdfZ0hc:APA91bGM...t8uH"; // hardcorded
string message = "Your text";
string tickerText = "example test GCM";
string contentTitle = "content title GCM";
postData =
"{ \"registration_ids\": [ \"" + deviceId + "\" ], " +
"\"data\": {\"tickerText\":\"" + tickerText + "\", " +
"\"contentTitle\":\"" + contentTitle + "\", " +
"\"message\": \"" + message + "\"}}";
ServicePointManager.ServerCertificateValidationCallback += new RemoteCertificateValidationCallback(ValidateServerCertificate);
//
// MESSAGE CONTENT
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
//
// CREATE REQUEST
HttpWebRequest Request = (HttpWebRequest)WebRequest.Create("https://android.googleapis.com/gcm/send");
Request.Method = "POST";
Request.KeepAlive = false;
Request.ContentType = postDataContentType;
Request.Headers.Add(string.Format("Authorization: key={0}", apiKey));
Request.ContentLength = byteArray.Length;
Stream dataStream = Request.GetRequestStream();
dataStream.Write(byteArray, 0, byteArray.Length);
dataStream.Close();
//
// SEND MESSAGE
try
{
WebResponse Response = Request.GetResponse();
HttpStatusCode ResponseCode = ((HttpWebResponse)Response).StatusCode;
if (ResponseCode.Equals(HttpStatusCode.Unauthorized) || ResponseCode.Equals(HttpStatusCode.Forbidden))
{
var text = "Unauthorized - need new token";
}
else if (!ResponseCode.Equals(HttpStatusCode.OK))
{
var text = "Response from web service isn't OK";
}
StreamReader Reader = new StreamReader(Response.GetResponseStream());
string responseLine = Reader.ReadToEnd();
Reader.Close();
return responseLine;
}
catch (Exception e)
{
}
return "error";
}
public static bool ValidateServerCertificate(
object sender,
X509Certificate certificate,
X509Chain chain,
SslPolicyErrors sslPolicyErrors)
{
return true;
}
You may not familiar with words like apiKey, deviceId. Dont worry i will explain what are they and how to create those.
apiKey What & why :This a key that will be used when sending requests to GCM server. How to create : Refer this post
deviceId What & why : This id also known as RegistrationId. This is a unique id to identify the device. When you want to send a
notification to a specific device you need this id. How to
create: This depends on how you implement the application. For cordova
i used a simple pushNotification Plugin You can simply create a
deviceId/RegistrationId using this plugin. To do that you need to have
a senderId. Google how to create a senderId it is really simple =)
If anyone needs some help leave a comment.
Happy Coding.
-Charitha-

How do I connect to the Asana Rest API using c#?

Does anyone have a snippet of code for connecting to the Asana API using c#?
There is a Hello World application on their site but unfortunately it is written in ruby.
https://asana.com/developers/documentation/examples-tutorials/hello-world
I'm doing this as a quick side project and can only dedicate a small amount of time to it. Any help would be greatly appreciated.
Thanks in advance!
Follow up:
I've tried multiple ways of accessing/authentication and I keep getting a 401 Not Authorized error.
My latest code looks like this:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://app.asana.com/api/1.0/users/me");
request.Method = "GET";
request.Headers.Add("Authorization: Basic " + "*MyUniqueAPIKey*");
request.ContentType = "application/x-www-form-urlencoded";
request.Accept = "application/json";
WebResponse ws = request.GetResponse();

Try this code. I was able to get a list of users with it:
const string apiKey = "whateverYourApiKeyIs";
public string GetUsers()
{
var req = WebRequest.Create("https://app.asana.com/api/1.0/users");
SetBasicAuthentication(req);
return new StreamReader(req.GetResponse().GetResponseStream()).ReadToEnd();
}
void SetBasicAuthentication(WebRequest req)
{
var authInfo = apiKey + ":";
var encodedAuthInfo = Convert.ToBase64String(
Encoding.Default.GetBytes(authInfo));
req.Headers.Add("Authorization", "Basic " + encodedAuthInfo);
}
This just returns the data as a string. Parsing the JSON is left as an exercise for the reader. ;)
I borrowed the SetBasicAuthentication method from here:
Forcing basic http authentication for HttpWebRequest (in .NET/C#)

You could try using my library, AsanaNet :)
https://github.com/acron0/AsanaNet

You need to do HTTP requests, there are so many tutorials like this one
http://msdn.microsoft.com/en-us/library/debx8sh9(v=vs.80).aspx