Basic Authentication in ASP.NET Core

Question

Question

How can I implement Basic Authentication with Custom Membership in an ASP.NET Core web application?

Notes

Answer 1

Super-Simple Basic Authentication in .NET Core:

1. Add this utility method:

static System.Text.Encoding ISO_8859_1_ENCODING = System.Text.Encoding.GetEncoding("ISO-8859-1");
public static (string, string) GetUsernameAndPasswordFromAuthorizeHeader(string authorizeHeader)
{
    string encodedUsernamePassword = authorizeHeader.Substring("Basic ".Length).Trim();
    string usernamePassword = ISO_8859_1_ENCODING.GetString(Convert.FromBase64String(encodedUsernamePassword));

    string username = usernamePassword.Split(':')[0];
    string password = usernamePassword.Split(':')[1];

    return (username, password);
}

2. Update controller action to get username and password from Authorization header:

public async Task Index([FromHeader]string Authorization)
{
    (string username, string password) = GetUsernameAndPasswordFromAuthorizeHeader(Authorization);

    // Now use username and password with whatever authentication process you want 

    return View();
}

---

Example

This example demonstrates using this with ASP.NET Core Identity.

public class HomeController : Controller
{
    private readonly UserManager _userManager;

    public HomeController(UserManager userManager)
    {
        _userManager = userManager;
    }

    [AllowAnonymous]
    public async Task MyApiEndpoint([FromHeader]string Authorization)
    {
        (string username, string password) = GetUsernameAndPasswordFromAuthorizeHeader(Authorization);

        IdentityUser user = await _userManager.FindByNameAsync(username);
        bool successfulAuthentication = await _userManager.CheckPasswordAsync(user, password);

        if (successfulAuthentication)
            return Ok();
        else
            return Unauthorized();
    }
}