setExpressCheckout and SSL/TLS error

Question

I\'m trying to develop a simple application that will enable users to purchase services off a website through the Paypal API. This application is running on ASP.NET with C#.

Answer 1

I've been working with a PayPal (NVP/Signature) Express Checkout integration and have been hit with this SSL/TLS error.

Nothing I did seemed to get around it but then I found the following code to add above my request. For reference, I'm using MVC3/.NET 4 so Tls1.2 isn't available to me by default (like in .NET 4.5 +). This first three lines of this code gets around that. I hope it helps people!

ServicePointManager.Expect100Continue = true;
ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;
ServicePointManager.DefaultConnectionLimit = 9999;

var url = "https://[paypal-api-url]/nvp";
var uri = new Uri(url);
var request = WebRequest.Create(uri);
var encoding = new UTF8Encoding();
var requestData = encoding.GetBytes(data);

request.ContentType = "application/x-www-form-urlencoded";
request.Method = "POST";
request.Timeout = (300 * 1000); 
request.ContentLength = requestData.Length;

using (var stream = request.GetRequestStream())
{
    stream.Write(requestData, 0, requestData.Length);
}

var response = request.GetResponse();
...