Asp.net Vnext 中间件实现基本验证

概述

---

 本文已经同步到《Asp.net Vnext 系列教程 》中]

vnext 没有 web.config 可以配置基本验证，本文使用中间件实现基本验证

实现

---

通过Startup(启动类)Configure 方法加入中间件

  public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerfactory)
        {


            app.UseMyMiddleware();

 //通过扩展注册中间件
    public static class BasicAuthenticationExtensions
        {
        public static IApplicationBuilder UseMyMiddleware(this IApplicationBuilder app)
            {
            return app.UseMiddleware<BasicAuthentication>();
            }
        }

  //中间件类
    public class BasicAuthentication
        {
        private readonly RequestDelegate next;

        public BasicAuthentication(RequestDelegate next)
            {
            this.next = next;
            }

        public async Task Invoke(HttpContext context,
                                 IAuthenticationService authenticationService)
            {
            try
                {
                var parser = new BasicAuthenticationParser(context);
                var username = parser.GetUsername();
                var password = parser.GetPassword();

                await authenticationService.AuthenticateAsync(username, password);
                await next(context);
                }
            catch (Exception e)
                {
                context.Response.StatusCode = 401;
                context.Response.Headers.Add("WWW-Authenticate",
                    new[] { "Basic" });
                }
            }
        }

 //解析上下文获取 密码 用户名
    internal class BasicAuthenticationParser
        {
        private readonly string credentials;

        public BasicAuthenticationParser(HttpContext context)
            {
            credentials = GetCredentials(context);
            }

        public string GetUsername()
            {
            return GetValue(credentials, 0);
            }

        public string GetPassword()
            {
            return GetValue(credentials, 1);
            }

        private static string GetValue(string credentials, int index)
            {
            if (string.IsNullOrWhiteSpace(credentials))
                return null;

            var parts = credentials.Split(':');
            return parts.Length == 2 ? parts[index] : null;
            }

        private static string GetCredentials(HttpContext context)
            {
            try
                {
                string[] authHeader;
                if (context.Request.Headers.TryGetValue("Authorization", out authHeader) &&
                    authHeader.Any() &&
                    authHeader[0].StartsWith("Basic "))
                    {
                    var value = Convert.FromBase64String(authHeader[0].Split(' ')[1]);
                    return Encoding.UTF8.GetString(value);
                    }

                return null;
                }
            catch
                {
                return null;
                }
            }
        }

 //认证服务接口

    public interface IAuthenticationService
        {
        Task AuthenticateAsync(string username, string password);
        }
    public class SimpleAuthenticationService : IAuthenticationService
        {
        public Task AuthenticateAsync(string username, string password)
            {
            //判读密码
            if ("123".Equals(username, StringComparison.OrdinalIgnoreCase) &&
                "123".Equals(password))
                {
                return Task.FromResult(0);
                }

            throw new Exception();
            }
        }

运行效果