1         [HttpGet]
 2         [Route("api/login")]
 3         public IActionResult Login(string userName,string pwd)
 4         {
 5             if (!string.IsNullOrEmpty(userName) && !string.IsNullOrEmpty(pwd))
 6             {
 7                 var claims = new[]
 8                 {
 9                     new Claim(JwtRegisteredClaimNames.Nbf,$"{new DateTimeOffset(DateTime.Now).ToUnixTimeSeconds()}") ,
10                     new Claim (JwtRegisteredClaimNames.Exp,$"{new DateTimeOffset(DateTime.Now.AddMinutes(30)).ToUnixTimeSeconds()}"),
11                     new Claim(ClaimTypes.Name, userName)
12                 };
13                 var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Const.SecurityKey));
14                 var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);
15                 var token = new JwtSecurityToken(
16                     issuer: Const.Domain,
17                     audience: Const.Domain,
18                     claims: claims,
19                     expires: DateTime.Now.AddMinutes(30),
20                     signingCredentials: creds);
21 
22                 return Ok(new
23                 {
24                     token = new JwtSecurityTokenHandler().WriteToken(token)
25                 });
26             }
27             else
28             {
29                 return BadRequest(new { message = "username or password is incorrect." });
30             }
31         }

1     public class Const
2     {
3         /// <summary>
4         /// 这里为了演示，写死一个密钥。实际生产环境可以从配置文件读取,这个是用网上工具随便生成的一个密钥
5         /// </summary>
6         public const string SecurityKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDI2a2EJ7m872v0afyoSDJT2o1+SitIeJSWtLJU8/Wz2m7gStexajkeD+Lka6DSTy8gt9UwfgVQo6uKjVLG5Ex7PiGOODVqAEghBuS7JzIYU5RvI543nNDAPfnJsas96mSA7L/mD7RTE2drj6hf3oZjJpMPZUQI/B1Qjb5H3K3PNwIDAQAB";
7         public const string Domain = "http://localhost:5000";
8     }

 1         public void ConfigureServices(IServiceCollection services)
 2         {
 3 
 4             #region JWT验证
 5             services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
 6                 .AddJwtBearer(options => {
 7                     options.TokenValidationParameters = new TokenValidationParameters
 8                     {
 9                         ValidateIssuer = true,//是否验证Issuer
10                         ValidateAudience = true,//是否验证Audience
11                         ValidateLifetime = true,//是否验证失效时间
12                         ClockSkew = TimeSpan.FromSeconds(30),
13                         ValidateIssuerSigningKey = true,//是否验证SecurityKey
14                         ValidAudience = Const.Domain,//Audience
15                         ValidIssuer = Const.Domain,//Issuer，这两项和前面签发jwt的设置一致
16                         IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Const.SecurityKey))//拿到SecurityKey
17                     };
18                 });
19             #endregion            
　　　　　　　　　services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
20         }

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseRouting();

            //开启JWT验证中间件
            //.net core3比.net core2多加一个UseAuthentication,而且必须在UseAuthorization前面
            //这是认证
            app.UseAuthentication();
            //这是授权
            app.UseAuthorization();


            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }

1         [HttpGet]
2         [Route("api/get")]
3         //JWT验证标识
4         [Authorize]
5         public ActionResult<IEnumerable<string>> Get()
6         {
7             return new string[] { "value1", "value2" };
8         }