System.Net.SecurityProtocolType

Syntax

public enum SecurityProtocolType

Members

Remarks

The SecurityProtocolType enumeration provides a set of constants that you can use to specify the protocol that the System.Net.Security.SslStream class uses to secure a stream. You can use the bitwise OR operator (|) to combine multiple protocol types if the application supports them.

In .NET Framework 4.5 and later, the Default value is recommended as it allows the system to choose the best available protocol. For applications targeting older versions of .NET Framework or for specific security requirements, you might need to explicitly set the protocol.

When using ServicePointManager.SecurityProtocol, you can set it to a single protocol type or a combination of protocol types. For example, to allow both TLS 1.2 and TLS 1.3:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls13;

Examples

The following example demonstrates how to set the default security protocol to TLS 1.2 for all HttpClient requests.

using System;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;

public class Example
{
    public static async Task MakeSecureRequestAsync()
    {
        // Set the default security protocol to TLS 1.2
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

        using (HttpClient client = new HttpClient())
        {
            try
            {
                string url = "https://www.example.com";
                HttpResponseMessage response = await client.GetAsync(url);
                response.EnsureSuccessStatusCode();
                string responseBody = await response.Content.ReadAsStringAsync();
                Console.WriteLine($"Response from {url}:");
                Console.WriteLine(responseBody.Substring(0, Math.Min(responseBody.Length, 200)) + "...");
            }
            catch (HttpRequestException e)
            {
                Console.WriteLine($"Request error: {e.Message}");
            }
        }
    }

    public static void Main(string[] args)
    {
        MakeSecureRequestAsync().Wait();
    }
}

Requirements