netcore使用JwtBearer生成token并进行验证

• 先安装jwt包
  
  

Microsoft.AspNetCore.Authentication.JwtBearer;

• 配置类JwtConfig
  

 public class JwtConfig
    {
        public string Key { get; set; } //key
        public int expres { get; set; } //过期时间（单位秒）
        public string Issuer { get; set; }
        public string Audience { get; set; }
    }
//注入配置类
builder.Services.Configure<JwtConfig>(builder.Configuration.GetSection("JWT"));
//配置文件appsettings.json
{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*",
  "JWT": {
    "Key": "sasdjfakljdssfjanjkdsjiio3*98sdkjndfkandsf111",
    "expres": "3"
  }
}

创建token

 //依赖注入
   private readonly IOptionsSnapshot<JwtConfig> jwtconfig;

        public Demo3Controller(IOptionsSnapshot<JwtConfig> jwtconfig)
        {
            this.jwtconfig = jwtconfig;
        }
 
 public string CreateToken()
        {
            List<Claim> claims = new List<Claim>();
            claims.Add(new Claim(ClaimTypes.Name, "admin"));
            claims.Add(new Claim(ClaimTypes.NameIdentifier, "1080"));
            DateTime expres = DateTime.Now.AddSeconds(jwtconfig.Value.expres);
            Console.WriteLine($"过期时间{expres}");
            byte[] secbyse = Encoding.UTF8.GetBytes(jwtconfig.Value.Key);
            var secKey = new SymmetricSecurityKey(secbyse);
            var credetials = new SigningCredentials(secKey, SecurityAlgorithms.HmacSha256);
            var tokenDescriptor = new JwtSecurityToken(claims: claims, expires: expres, signingCredentials: credetials);
            string jwt = new JwtSecurityTokenHandler().WriteToken(tokenDescriptor);
            return jwt;
        }

Program.cs验证token

//配置Jwt密钥
builder.Services.Configure<JwtConfig>(builder.Configuration.GetSection("JWT"));
builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme).AddJwtBearer(opt =>
{
    var JwtOtp = builder.Configuration.GetSection("JWT").Get<JwtConfig>();

    byte[] keybase = Encoding.UTF8.GetBytes(JwtOtp.Key);

    var seckey = new SymmetricSecurityKey(keybase);

    opt.TokenValidationParameters = new()
    {
        ValidateIssuer = false,
        ValidateAudience = false,
        ValidateLifetime = true,
        ValidateIssuerSigningKey = true,
        IssuerSigningKey = seckey,

    };
    opt.Events = new JwtBearerEvents
    {
        //权限验证失败后执行
        OnChallenge = context =>
        {
            //终止默认的返回结果
            context.HandleResponse();
            string token = context.Request.Headers["Authorization"];


            var result = JsonConvert.SerializeObject(new { code = 401, message = "登录过期" });
            if (string.IsNullOrEmpty(token))
            {
                result = JsonConvert.SerializeObject(new { code = 401, message = "token不能为空" });
                context.Response.ContentType = "application/json";
                //验证失败返回401
                context.Response.StatusCode = StatusCodes.Status200OK;
                context.Response.WriteAsync(result);
                return Task.FromResult(result);
            }

            try
            {
                JwtSecurityTokenHandler tokenheader = new();
                ClaimsPrincipal claimsPrincipal = tokenheader.ValidateToken(token, opt.TokenValidationParameters, out SecurityToken securityToken);
            }
            catch (SecurityTokenExpiredException)
            {
                result = JsonConvert.SerializeObject(new { code = 401, message = "登录已过期" });
                context.Response.ContentType = "application/json";
                //验证失败返回401
                context.Response.StatusCode = StatusCodes.Status200OK;
                context.Response.WriteAsync(result);
                return Task.FromResult(result);
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex);
                result = JsonConvert.SerializeObject(new { code = 402, message = "token令牌无效" });
                context.Response.ContentType = "application/json";
                //验证失败返回401
                context.Response.StatusCode = StatusCodes.Status200OK;
                context.Response.WriteAsync(result);
                return Task.FromResult(result);
            }

            context.Response.ContentType = "application/json";
            //验证失败返回401
            context.Response.StatusCode = StatusCodes.Status200OK;
            context.Response.WriteAsync(result);
            return Task.FromResult(result);
        }
    };
});


app.UseAuthentication();//jwt中间件