【.NET Core】ASP.NET Core之IdentityServer4(1)：快速入门

本文中的IdentityServer4基于上节的jenkins 进行docker自动化部署。
使用了MariaDB,EF Core,AspNetIdentity,Docker

Demo地址：https://sso.neverc.cn
Demo源码：https://github.com/NeverCL/Geek.IdentityServer4

简介

OpenID Connect ：常用的认证协议有SAML2p, WS-Federation and OpenID Connect – SAML2p。OpenID Connect是其中最新的协议。

OAuth 2.0 ：OAuth 2.0 是一种授权协议。通过Access Token可以访问受保护的API接口。

OpenID Connect和OAuth 2.0非常相似，实际上，OpenID Connect是OAuth 2.0之上的一个扩展。
身份认证和API访问这两个基本的安全问题被合并为一个协议 - 往往只需一次往返安全令牌服务。

IdentityServer4基于ASP.NET Core 2对这两种协议的实现。

支持规范：https://identityserver4.readthedocs.io/en/release/intro/specs.html

关键词

IdentityServer：提供OpenID Connect and OAuth 2.0 protocols.

User：IdentityServer中的用户

Client：第三方应用，包括web applications, native mobile or desktop applications, SPAs etc.

Resource：包含Identity data 和 APIs。这是认证授权中的标识。

Identity Token：标识认证信息，至少包含user的sub claim。

Access Token：标识授权信息，可以包含Client 和 user的claim信息。

授权方式

Client Credentials

Client Credentials是最简单的一种授权方式。

步骤：

1. 创建IdentityServer
   1. 定义APIs
   2. 定义Client
2. 创建API
   1. 定义Authentication
3. 使用Client
   1. 请求Token
   2. 使用Token

IdentityServer：

dotnet new web -o Geek.IdentityServer4 && dotnet add Geek.IdentityServer4 package IdentityServer4

Startup：

services.AddIdentityServer()
    .AddDeveloperSigningCredential()
    .AddInMemoryApiResources(Config.GetApiResources())
    .AddInMemoryClients(Config.GetClients());
...
app.UseIdentityServer();

Config：

public static IEnumerable<ApiResource> GetApiResources()
{
    return new List<ApiResource>
    {
        new ApiResource("api1")
    };
}

public static IEnumerable<Client> GetClients()
{
    return new List<Client>
    {
        new Client
        {
            ClientId = "client",
            AllowedGrantTypes = GrantTypes.ClientCredentials,
            ClientSecrets = { new Secret("secret".Sha256()) },
            Claims = { new Claim("name","名称") },
            AllowedScopes = { "api1" }
        },
    }
}

API：

dotnet new web -o Geek.Api && dotnet add Geek.Api package IdentityServer4.AccessTokenValidation

Startup:

services.AddMvc();
services.AddAuthentication("Bearer")//AddIdentityServerAuthentication 默认SchemeName：Bearer
    .AddIdentityServerAuthentication(opt =>
    {
        opt.ApiName = "api1";
        opt.Authority = "https://sso.neverc.cn";
    });
...
app.UseAuthentication();
app.UseMvc();

Controller：

[Route("identity")]
[Authorize]
public class IdentityController : ControllerBase
{
    [HttpGet]
    public IActionResult Get()
    {
        return new JsonResult(from c in User.Claims select new { c.Type, c.Value });
    }
}

Client：

dotnet new web -o Geek.Client && dotnet add Geek.Client package IdentityServer4.IdentityModel

Program：

var disco = await DiscoveryClient.GetAsync("https://sso.neverc.cn");
var tokenClient = new TokenClient(disco.TokenEndpoint, "client", "secret");
var tokenResponse = await tokenClient.RequestClientCredentialsAsync("api1");

var client = new HttpClient();
client.SetBearerToken(tokenResponse.AccessToken);
var response = await client.GetAsync("http://localhost:5001/identity");
var content = await response.Content.ReadAsStringAsync();
Console.WriteLine(JArray.Parse(content));

ResourceOwnerPassword

这种认证方式需要User提供用户名和密码，所以Client为非常可信的应用才可能使用这种方式。

步骤：

1. 定义RO Client 和 User
2. 使用Client

Identity Server

Config:

public static IEnumerable<Client> GetClients()
{
    ...
    new Client
    {
        ClientId = "ro.client",
        AllowedGrantTypes = GrantTypes.ResourceOwnerPassword,

        ClientSecrets = { new Secret("secret".Sha256()) },
        AllowedScopes = { "api1" }
    }
}
public static List<TestUser> GetUsers()
{
    return new List<TestUser>
    {
        new TestUser
        {
            SubjectId = "1",
            Username = "alice",
            Password = "password",
        }
    }
}

Startup：

services.AddIdentityServer()
    .AddDeveloperSigningCredential()
    .AddInMemoryApiResources(Config.GetApiResources())
    .AddInMemoryClients(Config.GetClients())
    .AddTestUsers(Config.GetUsers());

Client

var disco = await DiscoveryClient.GetAsync("https://sso.neverc.cn");
var tokenClient = new TokenClient(disco.TokenEndpoint, "ro.client", "secret");
var tokenResponse = await tokenClient.RequestResourceOwnerPasswordAsync("alice", "password", "api1");
var client = new HttpClient();
client.SetBearerToken(tokenResponse.AccessToken);
var response = await client.GetAsync("http://localhost:5001/identity");
var content = await response.Content.ReadAsStringAsync();
Console.WriteLine(JArray.Parse(content));

区分Client Credentials 和 ResourceOwnerPassword 可通过 sub claim来区分

Implicit

Implicit为隐式模式，通过浏览器端直接传输id_token

步骤：

1. 配置IdentityServer
   1. 定义IdentityResources
   2. 定义mvc client
   3. 添加Mvc UI
2. 创建mvc client

IdentityServer

public static IEnumerable<IdentityResource> GetIdentityResources()
{
    return new List<IdentityResource>
    {
        new IdentityResources.OpenId(),
        new IdentityResources.Profile()
    };
}

...
new Client
{
    ClientId = "mvc",
    ClientName = "MVC Client",
    AllowedGrantTypes = GrantTypes.Implicit,
    ClientSecrets = { new Secret("secret".Sha256()) },
    RedirectUris = { "http://localhost:5002/signin-oidc" },
    PostLogoutRedirectUris = { "http://localhost:5002/signout-callback-oidc" },
    AllowedScopes = new List<string>
    {
        IdentityServerConstants.StandardScopes.OpenId,
        IdentityServerConstants.StandardScopes.Profile,
    }
}

services.AddIdentityServer()
    .AddDeveloperSigningCredential()
    .AddInMemoryApiResources(Config.GetApiResources())
    .AddInMemoryClients(Config.GetClients())
    .AddTestUsers(Config.GetUsers())
    .AddInMemoryIdentityResources(Config.GetIdentityResources());

添加MvcUI：

在IdentityServer项目中powershell执行:

iex ((New-Object System.Net.WebClient).DownloadString('https://raw.githubusercontent.com/IdentityServer/IdentityServer4.Quickstart.UI/release/get.ps1'))

MvcClient

public void ConfigureServices(IServiceCollection services)
{
    JwtSecurityTokenHandler.DefaultInboundClaimTypeMap.Clear();
    services.AddMvc();
    services.AddAuthentication(options =>
    {
        options.DefaultScheme = "Cookies";
        options.DefaultChallengeScheme = "oidc";
    })
    .AddCookie("Cookies")
    .AddOpenIdConnect("oidc", options =>
    {
        options.SignInScheme = "Cookies";
        options.Authority = "https://sso.neverc.cn";
        options.ClientId = "mvc";
        options.SaveTokens = true;
    });
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    app.UseAuthentication();
    app.UseMvcWithDefaultRoute();
}

public class HomeController : ControllerBase
{
    [Authorize]
    public ActionResult Index()
    {
        return new JsonResult(from c in User.Claims select new { c.Type, c.Value });
    }
}

Hybrid

在Implicit方式中，id_token在浏览器中传输是适用的，但是access_token不应该暴露在浏览器中。
Hybrid模式则是在Implicit的基础上，再传输code，适用code模式来获取access_token。

步骤：

1. 定义Client
2. 使用Client

IdentityServer配置

Config：

new Client
{
    ClientId = "hybrid",
    AllowedGrantTypes = GrantTypes.Hybrid,
    ClientSecrets = { new Secret("secret".Sha256()) },
    RedirectUris           = { "http://localhost:5002/signin-oidc" },
    PostLogoutRedirectUris = { "http://localhost:5002/signout-callback-oidc" },
    AllowedScopes = {
        IdentityServerConstants.StandardScopes.OpenId,
        IdentityServerConstants.StandardScopes.Profile,
        "api1"
    },
};

MvcClient配置

Startup：

.AddOpenIdConnect("oidc", options =>
{
    options.SignInScheme = "Cookies";
    options.Authority = "https://sso.neverc.cn";
    options.ClientId = "mvc";
    options.ClientSecret = "secret";
    options.ResponseType = "code id_token";
    options.SaveTokens = true;
    options.Scope.Add("api1");
});

Controller：

public async Task<IActionResult> CallApiUsingUserAccessToken()
{
    var accessToken = await HttpContext.GetTokenAsync("access_token");

    var client = new HttpClient();
    client.SetBearerToken(accessToken);
    var content = await client.GetStringAsync("http://localhost:5001/identity");

    ViewBag.Json = JArray.Parse(content).ToString();
    return View("json");
}

在登录完成后，即可通过认证得到的access_token调用CallApiUsingUserAccessToken来调用API服务。

总结

本文为IdentityServer4做了基本的介绍。
实际上IdentityServer4还可以非常灵活的与ASP.NET Identity 以及 EF Core等组合使用。
另外基于ASP.NET Core，所以IdentityServer4也支持跨平台。