.NETCORE JWT 二

1.自动续期

using **.**.Common.Helper;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.IdentityModel.Tokens;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IdentityModel.Tokens.Jwt;
using System.Linq;
using System.Security.Claims;
using System.Text;
using System.Threading.Tasks;

namespace **.**.Login.Extensions
{
    public static class JwtTokenSetup
    {
        public static void AddJwtTokenSetup(this IServiceCollection services)
        {
            services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
               .AddJwtBearer(options =>
               {
                   options.TokenValidationParameters = new TokenValidationParameters
                   {
                       ValidateIssuer = true,//是否验证Issuer
                       ValidateAudience = true,//是否验证Audience
                       ValidateLifetime = true,//是否验证失效时间
                       ValidateIssuerSigningKey = true,//是否验证SecurityKey
                       ClockSkew = TimeSpan.Zero,
                       ValidAudience = Appsettings.app(new string[] { "Authentication", "Audience" }),//Audience
                       ValidIssuer = Appsettings.app(new string[] { "Authentication", "Issuer" }),//Issuer，这两项和前面签发jwt的设置一致
                       IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Appsettings.app(new string[] { "Authentication", "SecretKey" })))//拿到SecurityKey
                   };
                   options.Events = new JwtBearerEvents
                   {
                       OnTokenValidated = context =>
                       {
                           var claimsIdentity = context.Principal.Identity as ClaimsIdentity;
                           if (claimsIdentity != null)
                           {
                               // 检查 token 的过期时间
                               var expClaim = claimsIdentity.FindFirst(JwtRegisteredClaimNames.Exp);
                               if (expClaim != null)
                               {
                                   var exp = long.Parse(expClaim.Value);
                                   var expirationTime = DateTimeOffset.FromUnixTimeSeconds(exp).UtcDateTime;
                                   var remainingTime = expirationTime - DateTime.UtcNow;

                                   // 如果剩余时间少于5分钟，则生成新的 token
                                   if (remainingTime < TimeSpan.FromMinutes(5))
                                   {
                                       var newToken = GenerateNewToken(claimsIdentity.Claims);
                                       context.Response.Headers.Add("Token-Expired", "true");
                                       context.Response.Headers.Add("New-Token", newToken);
                                   }
                               }
                           }
                           return Task.CompletedTask;
                       },
                       //权限验证失败后执行
                       OnChallenge = context =>
                       {
                           //终止默认的返回结果(必须有)
                           context.HandleResponse();
                           var result = "{\"success\":false,\"code\":\"-1\",\"msg\":\"\",\"obj\":{\"message\":\"Token not provided\",\"status\":\"401\"}}";//JsonConvert.SerializeObject(new { success = false, code = 401, msg = "Token timeout", obj = "" });
                           context.Response.ContentType = "application/json";
                           //验证失败返回401
                           context.Response.StatusCode = StatusCodes.Status200OK;
                           context.Response.WriteAsync(result);
                           return Task.FromResult(0);
                       }
                   };
               });
        }
        private static string GenerateNewToken(IEnumerable<Claim> claims)
        {
            var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Appsettings.app(new string[] { "Authentication", "SecretKey" })));
            var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);
            var token = new JwtSecurityToken(
                issuer: Appsettings.app(new string[] { "Authentication", "Issuer" }),
                audience: Appsettings.app(new string[] { "Authentication", "Audience" }),
                claims: claims,
                expires: DateTime.Now.AddMinutes(Convert.ToInt32(Appsettings.app(new string[] { "Authentication", "Lifetime" }))), // 令牌有效期（例如30分钟）
                signingCredentials: creds);

            return new JwtSecurityTokenHandler().WriteToken(token);
        }
    }
}