1
0
Files
common/AMWD.Common.AspNetCore/BasicAuthentication/BasicAuthenticationMiddleware.cs

60 lines
2.0 KiB
C#

using System;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
namespace AMWD.Common.AspNetCore.BasicAuthentication
{
/// <summary>
/// Implements a basic authentication.
/// </summary>
public class BasicAuthenticationMiddleware
{
private readonly RequestDelegate next;
private readonly IBasicAuthenticationValidator validator;
/// <summary>
/// Initializes a new instance of the <see cref="BasicAuthenticationMiddleware"/> class.
/// </summary>
/// <param name="next">The following delegate in the process chain.</param>
/// <param name="validator">A basic authentication validator.</param>
public BasicAuthenticationMiddleware(RequestDelegate next, IBasicAuthenticationValidator validator)
{
this.next = next;
this.validator = validator;
}
/// <summary>
/// The delegate invokation.
/// Performs the authentication check.
/// </summary>
/// <param name="httpContext">The corresponding HTTP context.</param>
/// <returns>An awaitable task.</returns>
public async Task InvokeAsync(HttpContext httpContext)
{
if (httpContext.Request.Headers.TryGetValue("Authorization", out var authHeader)
&& ((string)authHeader).StartsWith("Basic "))
{
string encoded = ((string)authHeader).Split(' ', StringSplitOptions.RemoveEmptyEntries).LastOrDefault() ?? "";
string decoded = Encoding.UTF8.GetString(Convert.FromBase64String(encoded));
string[] parts = decoded.Split(':', 2);
var principal = validator.ValidateAsync(parts[0], parts[1], httpContext.GetRemoteIpAddress());
if (principal != null)
{
await next.Invoke(httpContext);
return;
}
}
httpContext.Response.Headers["WWW-Authenticate"] = "Basic";
if (!string.IsNullOrWhiteSpace(validator.Realm))
httpContext.Response.Headers["WWW-Authenticate"] += $" realm=\"{validator.Realm}\"";
httpContext.Response.StatusCode = StatusCodes.Status401Unauthorized;
}
}
}