asp.net core jwt demo

下面是一个简单的ASP.NET Core JWT鉴权授权的demo，可以作为参考：

Startup.cs文件：

using System.Text;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.IdentityModel.Tokens;

namespace JwtDemo
{
    public class Startup
    {
        public IConfiguration Configuration { get; }
        
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();

            services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
                .AddJwtBearer(options =>
                {
                    options.TokenValidationParameters = new TokenValidationParameters
                    {
                        ValidateIssuer = true,
                        ValidateAudience = true,
                        ValidateLifetime = true,
                        ValidateIssuerSigningKey = true,
                        ValidIssuer = Configuration["Jwt:Issuer"],
                        ValidAudience = Configuration["Jwt:Audience"],
                        IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Configuration["Jwt:SecretKey"]))
                    };
                });
        }

        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Error");
            }

            app.UseStaticFiles();

            app.UseAuthentication();

            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=Home}/{action=Index}/{id?}");
            });
        }
    }
}

HomeController.cs文件：

using System;
using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Text;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.IdentityModel.Tokens;

namespace JwtDemo.Controllers
{
    public class HomeController : Controller
    {
        private readonly IConfiguration _configuration;

        public HomeController(IConfiguration configuration)
        {
            _configuration = configuration;
        }

        public IActionResult Index()
        {
            return View();
        }

        [HttpPost]
        public IActionResult Login(string username, string password)
        {
            if (username == "admin" && password == "password")
            {
                var claims = new[]
                {
                    new Claim(JwtRegisteredClaimNames.Sub, username),
                    new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),
                    new Claim(JwtRegisteredClaimNames.Iat, DateTimeOffset.UtcNow.ToUnixTimeSeconds().ToString(), ClaimValueTypes.Integer64),
                    new Claim(ClaimTypes.Role, "Admin")
                };

                var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_configuration["Jwt:SecretKey"]));
                var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);

                var token = new JwtSecurityToken(
                    issuer: _configuration["Jwt:Issuer"],
                    audience: _configuration["Jwt:Audience"],
                    claims: claims,
                    expires: DateTime.UtcNow.AddMinutes(30),
                    signingCredentials: creds);

                var response = new
                {
                    token = new JwtSecurityTokenHandler().WriteToken(token)
                };

                return Ok(response);
            }

            return BadRequest();
        }

        [Authorize(Roles = "Admin")]
        public IActionResult Secret()
        {
            return Ok("You have access to this action because you are an Admin!");
        }
    }
}

appsettings.json文件：

{
  "Jwt": {
    "Issuer": "https://localhost:44363",
    "Audience": "https://localhost:44363",
    "SecretKey": "your secret key"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  }
}

在以上示例中，我们定义了一个Login方法用于生成JWT，并将其作为响应返回给客户端。我们还定义了一个Secret方法，并添加了Authorize特性，指定需要验证的角色为Admin。当客户端请求该方法时，ASP.NET Core会自动进行JWT验证，并根据角色信息进行授权。

示例中的SecretKey为示例密钥，实际应用中应使用更加安全的密钥。