情景如下：一个客户端要访问一个api，不需要用户登录，但是又不想直接暴露api给外部使用，这时可以使用identityserver添加访问权限。
客户端通过clientid和secrect访问identitserver的Token Endpoint,获取accesstoken；
接着客户端再使用accesstoken作为头部验证访问webapi。（webapi已经添加了identityserver的相关验证）。
代码实现：其中 "http://localhost:5000"是identityserver地址，"http://localhost:5001"是api地址
identityserver：在identityserver添加api和客户端，如下所示：定义了一个api1资源，client客户端。client客户端指定为ClientCredentials（客户端凭据）模式，并允许其访问api1。
public class Config{// scopes define the API resources in your systempublic static IEnumerable<ApiResource> GetApiResources(){return new List<ApiResource>{new ApiResource("api1", "My API")};}// clients want to access resources (aka scopes)public static IEnumerable<Client> GetClients(){// client credentials clientreturn new List<Client>{new Client{ClientId = "client",AllowedGrantTypes = GrantTypes.ClientCredentials,ClientSecrets = {new Secret("secret".Sha256())},AllowedScopes = { "api1" }}};}}
在startup配置identityserver如下：
public class Startup{public void ConfigureServices(IServiceCollection services){// configure identity server with in-memory stores, keys, clients and scopes services.AddIdentityServer().AddDeveloperSigningCredential().AddInMemoryApiResources(Config.GetApiResources()).AddInMemoryClients(Config.GetClients());}public void Configure(IApplicationBuilder app, IHostingEnvironment env){if (env.IsDevelopment()){app.UseDeveloperExceptionPage();}app.UseIdentityServer();}}
WebApi:在api添加identityserver的验证，代码如下，其中定义了同样的api名称，"http://localhost:5000"是identityserver的地址。
public class Startup{public void ConfigureServices(IServiceCollection services){services.AddMvcCore().AddAuthorization().AddJsonFormatters();services.AddAuthentication("Bearer").AddIdentityServerAuthentication(options =>{options.Authority = "http://localhost:5000";options.RequireHttpsMetadata = false;options.ApiName = "api1";});}public void Configure(IApplicationBuilder app){app.UseAuthentication();app.UseMvc();}}
添加一个需要验证的控制器：
[Route("[controller]")][Authorize]public class IdentityController : ControllerBase{[HttpGet]public IActionResult Get(){return new JsonResult(from c in User.Claims select new { c.Type, c.Value });}}
客户端：
这里使用里IdentityModel类库
实际请求如下：
1.获取accesstoken：http://localhost:5000/connect/token?client_id=client&client_secret=secret&grant_type=client_credentials&scope=api1
2.请求api1
http://localhost:5001/identity
Headers
Authorization:accesstoken
public class Program{public static void Main(string[] args) => MainAsync().GetAwaiter().GetResult();private static async Task MainAsync(){
//获取identitserver的各个端点地址
var disco = await DiscoveryClient.GetAsync("http://localhost:5000");if (disco.IsError){Console.WriteLine(disco.Error);return;}
//获取具有api1访问权限的accesstoken
var tokenClient = new TokenClient(disco.TokenEndpoint, "client", "secret");var tokenResponse = await tokenClient.RequestClientCredentialsAsync("api1");if (tokenResponse.IsError){Console.WriteLine(tokenResponse.Error);return;}Console.WriteLine(tokenResponse.Json);Console.WriteLine("\n\n");
//设置accesstoken为http请求头，并访问api1
var client = new HttpClient();client.SetBearerToken(tokenResponse.AccessToken);var response = await client.GetAsync("http://localhost:5001/identity");if (!response.IsSuccessStatusCode){Console.WriteLine(response.StatusCode);}else{var content = await response.Content.ReadAsStringAsync();Console.WriteLine(JArray.Parse(content));}}}
ps:
1.这里默认的accesstoken为jwt格式，客户端访问api时，api只需要在启动的时候访问identity获取秘钥即可。若为referencetoken,客户端访问api时，api需要授权访问的都会再请求一次identityserver,,而且api必须设置秘钥,client设置AccessTokenType属性为Reference。
2.可自定义AccessTokenLifetime（token存活时间），默认是3600秒，即一小时
