CODEWITHSUNDEEP
c#asp.nethttpwebrequesthttp-post
HuwD
HuwD

Reputation: 1800

Http post error: An existing connection was forcibly closed by the remote host

I realise there have been a number of similar posts to this but I haven't found a solution yet. Am trying to post some xml to an MPI gateway but keep getting the following error:

Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.

Below is the code I'm currently using but have tried just about every different approach I can think of and they all return the same error:

        string result = "";

        string xml = "<TNSAuthRequest><CardNumber>0123456789</CardNumber><ExpiryDate>1801</ExpiryDate><PurchaseAmt>750</PurchaseAmt><CurrencyCode>826</CurrencyCode><CurrencyExponent>2</CurrencyExponent><CountryCode>826</CountryCode><MerchantName>Mayflower</MerchantName><MerchantId>0123456789</MerchantId><MerchantData>abcdefghijklmnopqrstuvwxyz0123456789</MerchantData><MerchantUrl>example.com</MerchantUrl><NotificationURL>example.com/basket</NotificationURL></TNSAuthRequest>";

        var url = "https://mpi.securecxl.com";
        byte[] bytes = System.Text.Encoding.ASCII.GetBytes("xmldata=" + xml.ToString());

        ServicePointManager.ServerCertificateValidationCallback += new System.Net.Security.RemoteCertificateValidationCallback(ValidateRemoteCertificate);

        var req = (HttpWebRequest)WebRequest.Create(url);
        req.AllowWriteStreamBuffering = true;
        req.ContentType = "text/xml";
        req.Method = "POST";
        //req.ContentLength = bytes.Length;
        req.KeepAlive = false;
        req.ProtocolVersion = HttpVersion.Version10;
        req.ServicePoint.ConnectionLimit = 1;
        //req.Timeout = -1;

        try
        {
            using (var writer = new StreamWriter(req.GetRequestStream(), Encoding.ASCII))
            {
                writer.WriteLine(bytes);
            }
            using (WebResponse resp = req.GetResponse())
            {
                using (StreamReader sr = new StreamReader(resp.GetResponseStream()))
                {
                    result = sr.ReadToEnd().Trim();
                }
            }
        }
        catch (Exception ex)
        {
            result = ex.Message + "<br />" + ex.InnerException.Message + "<br /><br />" + xml.Replace("<", "&lt;");
        }

        ViewBag.result = result;

Am basically wandering if anyone can see anything that might be wrong with the code that could be causing this error or if it's most likely I problem on the their end? Have tried running on my localhost, our live server and my own private server (with a completely different IP) and still get same result.

Any ideas?

Upvotes: 13

Views: 18334

Answers (3)

Gilbert
Gilbert

Reputation: 3324

@AlisettarHuseynli is right, this sometimes has to do with https. Most likely occurs when the infrastructure gets updates which may mean TLS gets updated for example from TLS1.0 to TLS1.2 Usually happens with some APIs, etcetera.

If the service you are trying to access can be accessed over http, do that. Change the scheme from https to http. Worked in my case. Otherwise you'll have to add code to support higher versions of TLS. Popular software usually have an opt-in option to use TLS1.2 instead of the old TLS1.0.

Upvotes: 0

sapbucket
sapbucket

Reputation: 7195

Slightly better perhaps: 

System.Net.ServicePointManager.SecurityProtocol = System.Net.ServicePointManager.SecurityProtocol | System.Net.SecurityProtocolType.Tls12;

Upvotes: 2

Alisettar Huseynli
Alisettar Huseynli

Reputation: 994

I think its because you are connecting to "https" url. In this case you have to add following line to your code.

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

It will accept "ssl" protocol for your request. "ServicePointManager.ServerCertificateValidationCallback" handler just controls certificate validity.

Upvotes: 33

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