System.Net.Security.NetworkCredential Class

Overview

The System.Net.Security.NetworkCredential class represents a user's credentials, typically a username and password, for network authentication. This class is fundamental for scenarios where your application needs to authenticate with network resources such as web servers, FTP servers, or other services that require credentials.

It provides a secure way to store and transmit authentication information. You can create instances of this class to specify the credentials needed to access protected network resources.

Syntax

public class NetworkCredential : System.Net.ICredentials

Namespace: System.Net

Assembly: System (in System.dll)

Members

Constructors

Properties

Methods

Remarks

When using the NetworkCredential class, be mindful of security. Passwords should be handled with care and ideally encrypted or stored securely. The framework may handle some encryption internally, but it's good practice to be aware of the security implications of transmitting credentials over a network.

The Domain property is particularly relevant for Windows authentication environments, where it specifies the security domain to which the user belongs. For other authentication schemes, it might be unused or have a different meaning.

Examples

Creating and Using Network Credentials

The following example demonstrates how to create a NetworkCredential object and use it with an HttpClient for basic authentication.

using System;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;

public class Example
{
    public static void Main(string[] args)
    {
        // Define credentials
        string userName = "myuser";
        string password = "mypassword";
        string domain = "MYDOMAIN"; // Optional, can be null or empty

        // Create NetworkCredential object
        NetworkCredential credentials = new NetworkCredential(userName, password, domain);

        // Example with HttpClient (conceptual - actual request may vary)
        using (HttpClient client = new HttpClient())
        {
            // Construct the Basic Authentication header
            string authHeader = "Basic " + Convert.ToBase64String(Encoding.ASCII.GetBytes($"{userName}:{password}"));
            client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(Encoding.ASCII.GetBytes($"{credentials.UserName}:{credentials.Password}")));

            Console.WriteLine($"Attempting to connect with credentials: User='{credentials.UserName}', Domain='{credentials.Domain}'");

            // Replace with your actual URL
            // try
            // {
            //     HttpResponseMessage response = await client.GetAsync("http://example.com/protected/resource");
            //     response.EnsureSuccessStatusCode();
            //     string responseBody = await response.Content.ReadAsStringAsync();
            //     Console.WriteLine("Request successful.");
            //     // Process responseBody
            // }
            // catch (HttpRequestException e)
            // {
            //     Console.WriteLine($"Request exception: {e.Message}");
            // }
        }

        // Example demonstrating constructor overloads
        NetworkCredential credentialsSimple = new NetworkCredential("simpleUser", "simplePass");
        Console.WriteLine($"Simple Credentials: User='{credentialsSimple.UserName}'");

        NetworkCredential credentialsBytes = new NetworkCredential("byteUser", new byte[] { 0x61, 0x62, 0x63 }); // 'abc'
        Console.WriteLine($"Byte Password Credentials: User='{credentialsBytes.UserName}'");
    }
}
            

This example shows how to create NetworkCredential instances and then uses them conceptually within an HttpClient. In a real-world application, you would replace the placeholder URL and handle the actual HTTP response.

Using with WebRequest (Legacy Example)

using System;
using System.Net;

public class LegacyExample
{
    public static void Main(string[] args)
    {
        try
        {
            // Create a WebRequest
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://example.com/api/data");

            // Set credentials
            request.Credentials = new NetworkCredential("apiUser", "apiKey123", "RESOURCEHOST");

            // Send the request and get the response (simplified)
            using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
            {
                Console.WriteLine($"Status Code: {response.StatusCode}");
                // Process response...
            }
        }
        catch (WebException e)
        {
            Console.WriteLine($"Error: {e.Message}");
            if (e.Response != null)
            {
                using (var errorResponse = (HttpWebResponse)e.Response)
                {
                    Console.WriteLine($"Status Code: {errorResponse.StatusCode}");
                    // Read error stream if necessary
                }
            }
        }
    }
}