Asp.net core使用Authentication使用jwt简单登录认证

研究了两天，简单使用就这些，如果需要token续期或者刷新或者自定义校验处理需要重写比较麻烦。

在controller中单独获取请求头可使用 

HttpContext.Request.Headers["Authorization"]

使用流程是：先认证登录 -> 再校验权限

Authentication -> Authorization

 

1. 安装依赖，.net8版本为例

1. Microsoft.AspNetCore.Authentication.JwtBearer
2. Newtonsoft.Json

2. 配置jwt所需配置，再appsettings.json文件

"Jwt": {
  "SecretKey": "U2FsdGVkX1/52fw3vL3OY4F1H7BV12pjPPb1mUhZyEPVRk72S5X2z/A8V9lTvK6T",
  "Issuer": "WebAppIssuer",
  "Audience": "WebAppAudience",
  "Expire": 30000
}

3. jwt生成或解析帮助类 JwtHelper

using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Text;
using Microsoft.IdentityModel.Tokens;

namespace jwt_api.Helper;

public class JwtHelper
{

    private readonly IConfiguration _configuration;
    
    public JwtHelper(IConfiguration configuration)
    {
        _configuration = configuration;
    }

    public string CreateToken(string Name, int id)
    {
        // 1. 定义需要使用到的Claims
        var claims = new[]
        {
            new Claim(ClaimTypes.Name, "u_admin"), //HttpContext.User.Identity.Name       
            new Claim("Id", id.ToString()),
            new Claim("Name", Name)
        };

        // 2. 从 appsettings.json 中读取SecretKey
        var secretKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_configuration["Jwt:SecretKey"]));

        // 3. 选择加密算法
        var algorithm = SecurityAlgorithms.HmacSha256Signature;

        // 4. 生成Credentials   
        var signingCredentials = new SigningCredentials(secretKey, algorithm);

        // 5. 根据以上，生成token
        var jwtSecurityToken = new JwtSecurityToken(
            _configuration["Jwt:Issuer"],     //Issuer
            _configuration["Jwt:Audience"],   //Audience
            claims,                          //Claims,
            DateTime.Now,                    //notBefore
            DateTime.Now.AddSeconds(Convert.ToInt32(_configuration["Jwt:Expire"])),    //expires
            signingCredentials               //Credentials
        );

        // 6. 将token变为string
        var token = new JwtSecurityTokenHandler().WriteToken(jwtSecurityToken);

        return token;
    }

}

4. 主程序编写 Program.cs

using System.Text;
using jwt_api.Helper;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using Newtonsoft.Json;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddControllers();

#region 配置登录认证

var configuration = builder.Configuration;
// 配置登录认证
builder.Services.AddAuthentication(options =>
                                   {
                                       options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme; 
                                   }).AddJwtBearer(options =>
                {
                    options.TokenValidationParameters = new TokenValidationParameters()
                    {
                        ValidateIssuer = true, //是否验证Issuer
                        ValidIssuer = configuration["Jwt:Issuer"], //发行人Issuer
                        ValidateAudience = true, //是否验证Audience
                        ValidAudience = configuration["Jwt:Audience"], //订阅人Audience
                        ValidateIssuerSigningKey = true, //是否验证SecurityKey
                        IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(configuration["Jwt:SecretKey"])), //SecurityKey
                        ValidateLifetime = true, //是否验证失效时间
                        ClockSkew = TimeSpan.FromSeconds(30), //过期时间容错值，解决服务器端时间不同步问题（秒）
                        RequireExpirationTime = true,
                    };
                    // 当token验证通过后（执行完 JwtBearerEvents.TokenValidated 后），
                    // 是否将token存储在 Microsoft.AspNetCore.Authentication.AuthenticationProperties 中
                    // 默认 true
                    options.SaveToken = true;
                    options.Events = new JwtBearerEvents
                    {
                        //此处为权限验证失败后触发的事件
                        OnChallenge = context =>
                        {
                            //此处代码为终止.Net Core默认的返回类型和数据结果，这个很重要哦，必须
                            context.HandleResponse();

                            //自定义自己想要返回的数据结果，我这里要返回的是Json对象，通过引用Newtonsoft.Json库进行转换
                            var payload = JsonConvert.SerializeObject(new { Code = "401", Message = "很抱歉，您无权访问该接口；请登录！" });
                            //自定义返回的数据类型
                            context.Response.ContentType = "application/json";
                            //自定义返回状态码，默认为401 我这里改成 200
                            context.Response.StatusCode = StatusCodes.Status200OK;
                            //输出Json数据结果
                            context.Response.WriteAsync(payload);
                            return Task.FromResult(0);
                        }
                    };
                });
// 添加一个生成jwt和解析帮助类
builder.Services.AddSingleton<JwtHelper>();

#endregion

builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

#region 启用认证

app.UseAuthentication();
app.UseAuthorization();

#endregion

app.MapControllers();

/*app.MapGet("/secret", (ClaimsPrincipal user) => $"Hello {user.Identity?.Name}. My secret")
    .RequireAuthorization();*/

app.Run();

5. 编写测试请求

6. 测试结果

1. 使用1接口获取token，再测试2接口成功结果

2. 失败结果如下