1：創建授權服務器項目：AuthorizationServer，添加包：IdentityServer4

2：創建資源服務器項目：ResourcesServer，添加包：IdentityServer4.AccesstokenValidation

3：創建請求客戶端項目：ClientCredentials，添加包:IdentityModel

AuthorizationServer代碼示例：

  public class Config
    {
        /// <summary>
        /// 定義用戶可以訪問的資源
        /// </summary>
 

        /// <returns></returns>
        public static List<ApiResource> GetApiResources()
        {
            return new List<ApiResource> {
                /*
                 具有單個作用域的簡單API，這樣定義的話，作用域（scope）和Api名稱（ApiName）相同
                 */
                new ApiResource("
 
api","描述"),

                 //如果需要更多控制，則擴展版本
                new ApiResource{
                    Name="userinfo", //資源名稱，對應客戶端的：ApiName，必須是唯一的
                    Description="描述",
                    DisplayName="", //顯示的名稱
                  
                    //ApiSecrets =
                    
 
//{
                    //    new Secret("secret11".Sha256())
                    //},

                    //作用域，對應下面的Cliet的 AllowedScopes
                    Scopes={
                        new Scope
                        {
                            Name = "apiInfo.read_full",
                            DisplayName = "完全的訪問權限",
                            UserClaims={ "super" }
                        },
                        new Scope
                        {
                            Name = "apiinfo.read_only",
                            DisplayName = "只讀權限"
                        }
                    },
                },
            };
        }

        /// <summary>
        /// 客戶端合法性驗證
        /// </summary>
        /// <returns></returns>
        public static List<Client> GetClients()
        {
            #region 客戶端模式 ClientCredentials
            var ClientCredentials = new Client
            {

                /******************客戶端 請求對應的字段*******************
                 client_id：客戶端的ID，必選
                 grant_type：授權類型，必選，此處固定值“code”
                 client_secret：客戶端的密碼，必選
                 scope：申請的權限範圍，可選，如果傳了必須是正確的，否則也不通過
                 ************************************/

                //這個Client集合裏面，ClientId必須是唯一的
                ClientId = "780987652", // 客戶端ID，客戶端傳過來的必須是這個，驗證才能通過,
                AllowedGrantTypes = GrantTypes.ClientCredentials,// 授權類型，指客戶端可以使用的模式
                ClientSecrets = { new Secret("secret".Sha256()) }, //客戶端密鑰
                //ClientSecrets={new Secret("secret".Sha512()) },
                //RequireClientSecret = false, //不驗證secret ，一般是信得過的第三方

                ClientName = "客戶端名稱",
                Description = "描述",
                //Claims = new List<Claim> {
                //    new Claim("super","super")
                //},
                /*
                 權限範圍，對應的ApiResouce，這裏是客戶端模式，對應的是用戶資源，所以是ApiResouce
                 如果是oidc 這對應的是identityResouece，身份資源
                 所以是取決於AllowedGrantTypes的類型

                允許客戶端訪問的API作用域
                 */
                AllowedScopes = { "apiInfo.read_full" } //
            };

            var ClientCredentials1 = new Client
            {
                ClientId = "userinfo",
                AllowedGrantTypes = GrantTypes.ClientCredentials, //客戶端輸入：client_credentials
                ClientSecrets = { new Secret("secret".Sha256()) },
                ClientName = "客戶端名稱",
                AllowedScopes = { "apiInfo.read_full" } //
            };
            #endregion
            #region 密碼模式 ResourceOwnerPassword
            var pwd = new Client
            {
                ClientId = "userinfo_pwd",
                AllowedGrantTypes = GrantTypes.ResourceOwnerPassword,//客戶端輸入：password
                ClientSecrets = { new Secret("secret".Sha256()) },
                ClientName = "客戶端名稱",
                RefreshTokenUsage = TokenUsage.ReUse,
                AlwaysIncludeUserClaimsInIdToken = true,
                AllowOfflineAccess = true,
                AllowedScopes = { "apiInfo.read_full" } //
            };
            #endregion

            return new List<Client> {
               ClientCredentials,
               //ClientCredentials1,
               //pwd,
           };
        }


        /// <summary>
        /// 密碼模式，需要用的到用戶名和密碼，正式操作是在數據庫中找
        /// </summary>
        /// <returns></returns>
        public static List<TestUser> GetTestUsers()
        {
            return new List<TestUser> {
                new TestUser
                {
                    SubjectId="100000", //用戶ID
                    Username="cnblogs", //用戶名
                    Password="123", //密碼
                    Claims=new List<Claim>{
                        new Claim("name","name")
                    }
                }
            };
        }
    }

Startup.cs配置：

public void ConfigureServices(IServiceCollection services)
        {
            services.Configure<CookiePolicyOptions>(options =>
            {
                // This lambda determines whether user consent for non-essential cookies is needed for a given request.
                options.CheckConsentNeeded = context => true;
                options.MinimumSameSitePolicy = SameSiteMode.None;
            });


            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

            //註冊ids中間件
            services.AddIdentityServer()
               //設置開發者臨時簽名憑據
               .AddDeveloperSigningCredential()
               
               //in-men 方式把信息添加到內存中
               .AddInMemoryApiResources(Config.GetApiResources())
               .AddInMemoryClients(Config.GetClients())
               .AddTestUsers(Config.GetTestUsers());

        }

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
          //使用ids中間件
            app.UseIdentityServer();
}

ResourcesServer 資源服務器認證示例：

 public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

            //默認的認證方式是Bearer認證
            services.AddAuthentication("Bearer")
            //配置要驗證的信息
            .AddIdentityServerAuthentication(options =>
            {
                //令牌或者說AccessToken頒發的地址，Token中會包含該地址
                //第一次會去認證服務器獲取配置信息
                options.Authority = "http://localhost:5003"; //必填
                options.ApiName = "userinfo";
                options.ApiSecret = "secret";
                //options.SaveToken = true;
                options.RequireHttpsMetadata = false;//暫時取消Https驗證，
            });

            //services.AddAuthorization(options => {
            //    options.AddPolicy("client", policy => policy.RequireClaim("client_id"));
            //});
        }
 public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
 app.UseAuthentication();

}

資源接口:

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using System.Linq;

namespace ResourcesServer.Controllers
{
    [Route("identity")]
    [Authorize]
    public class IdentityController : ControllerBase
    {
        /// <summary>
        /// 獲取當前的信息
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        public ActionResult Get()
        {
            return new JsonResult(User.Claims.Select(
                c => new { c.Type, c.Value }));
        }

        [HttpGet]
        [Route("userInfo")]
        public ActionResult GetUserInfo()
        {
            return new JsonResult(User.Claims.Select(
                c => new { c.Type, c.Value }));
        }
      
    }
}

通過Postman請求授權服務器獲取access_token

參數:

client_id:780987652
client_secret:secret
grant_type:client_credentials

然後通過該access_token 請求資源服務器獲取資源

nbf：非必須。not before。如果當前時間在nbf裏的時間之前，則Token不被接受；一般都會留一些余地，比如幾分鐘。

exp：#非必須。expire 指定token的生命周期。unix時間戳格式

iss：#非必須。issuer 請求實體，可以是發起請求的用戶的信息，也可是jwt的簽發者。

aud：#非必須。接收該JWT的一方。

詳細信息參考：https://www.cnblogs.com/zjutzz/p/5790180.html

可以把access_token放到jwt.io 看下：

可以通過 http://localhost:5003/.well-known/openid-configuration 查看配置信息

ClientCredentials第三方代碼請求方式：

using IdentityModel;
using IdentityModel.Client;
using Newtonsoft.Json.Linq;
using System;
using System.Net.Http;
using System.Text;

namespace ClientCredentials
{
    /// <summary>
    /// 客戶端模式，請求授權服務器獲取token，請求資源服務器獲取資源
    /// 依賴包：IdentityModel
    /// </summary>
    class Program
    {
        static void Main(string[] args)
        {
            string Authority = "http://localhost:5003";
            string ApiResurce = "http://localhost:5002/";
            var tokenCliet = new HttpClient()
            {
                BaseAddress = new Uri(ApiResurce)
            };

            /*
             這樣做的目的是：
             資源服務器會去授權服務器認證，所以在客戶端可以先判斷下授權服務器是否掛了
             */
            DiscoveryCache _cache = new DiscoveryCache(Authority);
            var disco1 =  _cache.GetAsync().Result;
            if (disco1.IsError) throw new Exception(disco1.Error);
            //或者
            var disco = tokenCliet.GetDiscoveryDocumentAsync(Authority).Result;
            if (disco.IsError) throw new Exception(disco.Error);


            var response = tokenCliet.RequestClientCredentialsTokenAsync(new ClientCredentialsTokenRequest
            {
                Address = disco.TokenEndpoint,
                ClientId = "780987652",
                ClientSecret= "secret",
                //GrantType= "client_credentials"
            }).Result;

            if (response.IsError) throw new Exception(response.Error);

            var token = response.AccessToken;

            //把token，Decode
            if (response.AccessToken.Contains("."))
            {
                //Console.WriteLine("\nAccess Token (decoded):");
                Console.ForegroundColor = ConsoleColor.Green;
                Console.WriteLine("\nAccess Token (decoded):");
                Console.ResetColor();

                var parts = response.AccessToken.Split(‘.‘);
                var header = parts[0];
                var claims = parts[1];

                Console.WriteLine(JObject.Parse(Encoding.UTF8.GetString(Base64Url.Decode(header))));
                Console.WriteLine(JObject.Parse(Encoding.UTF8.GetString(Base64Url.Decode(claims))));
            }
            //設置請求的Token
            tokenCliet.SetBearerToken(token);
            //請求並返回字符串
            var apiResource1 = tokenCliet.GetStringAsync("identity").Result;
            var userinfo = tokenCliet.GetStringAsync("identity/userinfo").Result;

           var j =  JObject.Parse(userinfo);
            //或者
            var getVal = tokenCliet.GetAsync("api/values").Result;
            if (getVal.IsSuccessStatusCode)
            {
                Console.WriteLine(getVal.Content.ReadAsStringAsync().Result);
            }
            Console.ReadLine();
        }
    }
}

Access Token (decoded)的結果

OAuth2認證和授權：ClientCredentials認證