IdentityServer4源碼解析_1_項目結構

目錄

• IdentityServer4源碼解析_1_項目結構
• IdentityServer4源碼解析_2_元數據接口
• IdentityServer4源碼解析_3_認證接口
• IdentityServer4源碼解析_4_令牌發放接口
• IdentityServer4源碼解析_5_查詢用戶信息接口
• [IdentityServer4源碼解析_6_結束會話接口]
• [IdentityServer4源碼解析_7_查詢令牌信息接口]
• [IdentityServer4源碼解析_8_撤銷令牌接口]

簡介

Security源碼解析系列介紹了微軟提供的各種認證架構，其中OAuth2.0，OpenIdConnect屬於遠程認證架構，所謂遠程認證，是指token的頒發是由其他站點完成的。

IdentityServer4是基於OpenIdConnect協議的認證中心框架，可以幫助我們快速搭建微服務認證中心。

初學者可能看到生澀的概念比較頭疼，可以將OAuth, OpenIdConnect協議簡單理解成需求文檔，idsv4基於需求提供了一系列的api實現。

對於idsv還不太了解的可以看下面的資料，本系列主要學習梳理idsv4的源碼，結合協議加深理解。

曉晨姐姐系列文章

https://www.cnblogs.com/stulzq/p/8119928.html

官方文檔

https://identityserver4.readthedocs.io/en/latest/

項目結構

項目地址如下

https://github.com/IdentityServer/IdentityServer4

克隆到本地，項目結構如圖

核心項目是IdentityServer4，其余的都是與微軟框架集成、以及處理持久化的項目。
項目結構如圖。Endpoints文件夾就是接口文件，我們先看下依賴注入、中間件的代碼，然后看下每個接口。

依賴注入

public static IIdentityServerBuilder AddIdentityServer(this IServiceCollection services)
{
    var builder = services.AddIdentityServerBuilder();

    builder
        .AddRequiredPlatformServices()
        .AddCookieAuthentication()
        .AddCoreServices()
        .AddDefaultEndpoints()
        .AddPluggableServices()
        .AddValidators()
        .AddResponseGenerators()
        .AddDefaultSecretParsers()
        .AddDefaultSecretValidators();

    // provide default in-memory implementation, not suitable for most production scenarios
    builder.AddInMemoryPersistedGrants();

    return builder;
}

• AddRequiredPlatformServices - 注入平台服務
  • IHttpContextAccessor：HttpContext訪問器
  • IdentityServerOptions：配置類

 public static IIdentityServerBuilder AddRequiredPlatformServices(this IIdentityServerBuilder builder)
{
    builder.Services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();            
    builder.Services.AddOptions();
    builder.Services.AddSingleton(
        resolver => resolver.GetRequiredService<IOptions<IdentityServerOptions>>().Value);
    builder.Services.AddHttpClient();

    return builder;
}

• AddCookieAuthentication - 注入cookie服務
  • 注入名稱為idsrv的cookie認證架構
  • 注入IAuthenticationService的實現IdentityServerAuthenticationService
  • 注入IAuthenticationHandlerProvider的實現FederatedSignoutAuthenticationHandlerProvider

public static IIdentityServerBuilder AddCookieAuthentication(this IIdentityServerBuilder builder)
{
    builder.Services.AddAuthentication(IdentityServerConstants.DefaultCookieAuthenticationScheme)
        .AddCookie(IdentityServerConstants.DefaultCookieAuthenticationScheme)
        .AddCookie(IdentityServerConstants.ExternalCookieAuthenticationScheme);

    builder.Services.AddSingleton<IConfigureOptions<CookieAuthenticationOptions>, ConfigureInternalCookieOptions>();
    builder.Services.AddSingleton<IPostConfigureOptions<CookieAuthenticationOptions>, PostConfigureInternalCookieOptions>();
    builder.Services.AddTransientDecorator<IAuthenticationService, IdentityServerAuthenticationService>();
    builder.Services.AddTransientDecorator<IAuthenticationHandlerProvider, FederatedSignoutAuthenticationHandlerProvider>();

    return builder;
}

• AddCoreServices - 注入核心服務

/// <summary>
/// Adds the core services.
/// </summary>
/// <param name="builder">The builder.</param>
/// <returns></returns>
public static IIdentityServerBuilder AddCoreServices(this IIdentityServerBuilder builder)
{
    builder.Services.AddTransient<SecretParser>();
    builder.Services.AddTransient<SecretValidator>();
    builder.Services.AddTransient<ScopeValidator>();
    builder.Services.AddTransient<ExtensionGrantValidator>();
    builder.Services.AddTransient<BearerTokenUsageValidator>();
    builder.Services.AddTransient<JwtRequestValidator>();

    // todo: remove in 3.0
#pragma warning disable CS0618 // Type or member is obsolete
    builder.Services.AddTransient<BackChannelHttpClient>();
#pragma warning restore CS0618 // Type or member is obsolete

    builder.Services.AddTransient<ReturnUrlParser>();
    builder.Services.AddTransient<IdentityServerTools>();

    builder.Services.AddTransient<IReturnUrlParser, OidcReturnUrlParser>();
    builder.Services.AddScoped<IUserSession, DefaultUserSession>();
    builder.Services.AddTransient(typeof(MessageCookie<>));

    builder.Services.AddCors();
    builder.Services.AddTransientDecorator<ICorsPolicyProvider, CorsPolicyProvider>();

    return builder;
}

• AddDefaultEndpoints - 注入接口
  • AuthorizeCallbackEndpoint：認證回調接口
  • AuthorizeEndpoint：認證接口
  • CheckSessionEndpoint：檢查會話接口
  • DeviceAuthorizationEndpoint：設備認證接口
  • DiscoveryEndpoint：元數據鍵接口
  • DiscoveryEndpoint：元數據接口
  • EndSessionCallbackEndpoint：結束會話回調接口
  • EndSessionEndpoint：結束會話接口
  • IntrospectionEndpoint：查詢令牌信息接口
  • TokenRevocationEndpoint：撤銷令牌接口
  • TokenEndpoint：發放令牌接口
  • UserInfoEndpoint：查詢用戶信息接口

注入所有默認接口，包括接口名稱和地址。請求進來之后，路由類EndPointRouter通過路由來尋找匹配的處理器。

 public static IIdentityServerBuilder AddDefaultEndpoints(this IIdentityServerBuilder builder)
{
    builder.Services.AddTransient<IEndpointRouter, EndpointRouter>();

    builder.AddEndpoint<AuthorizeCallbackEndpoint>(EndpointNames.Authorize, ProtocolRoutePaths.AuthorizeCallback.EnsureLeadingSlash());
    builder.AddEndpoint<AuthorizeEndpoint>(EndpointNames.Authorize, ProtocolRoutePaths.Authorize.EnsureLeadingSlash());
    builder.AddEndpoint<CheckSessionEndpoint>(EndpointNames.CheckSession, ProtocolRoutePaths.CheckSession.EnsureLeadingSlash());
    builder.AddEndpoint<DeviceAuthorizationEndpoint>(EndpointNames.DeviceAuthorization, ProtocolRoutePaths.DeviceAuthorization.EnsureLeadingSlash());
    builder.AddEndpoint<DiscoveryKeyEndpoint>(EndpointNames.Discovery, ProtocolRoutePaths.DiscoveryWebKeys.EnsureLeadingSlash());
    builder.AddEndpoint<DiscoveryEndpoint>(EndpointNames.Discovery, ProtocolRoutePaths.DiscoveryConfiguration.EnsureLeadingSlash());
    builder.AddEndpoint<EndSessionCallbackEndpoint>(EndpointNames.EndSession, ProtocolRoutePaths.EndSessionCallback.EnsureLeadingSlash());
    builder.AddEndpoint<EndSessionEndpoint>(EndpointNames.EndSession, ProtocolRoutePaths.EndSession.EnsureLeadingSlash());
    builder.AddEndpoint<IntrospectionEndpoint>(EndpointNames.Introspection, ProtocolRoutePaths.Introspection.EnsureLeadingSlash());
    builder.AddEndpoint<TokenRevocationEndpoint>(EndpointNames.Revocation, ProtocolRoutePaths.Revocation.EnsureLeadingSlash());
    builder.AddEndpoint<TokenEndpoint>(EndpointNames.Token, ProtocolRoutePaths.Token.EnsureLeadingSlash());
    builder.AddEndpoint<UserInfoEndpoint>(EndpointNames.UserInfo, ProtocolRoutePaths.UserInfo.EnsureLeadingSlash());

    return builder;
}

• AddPluggableServices - 注入可插拔服務

public static IIdentityServerBuilder AddPluggableServices(this IIdentityServerBuilder builder)
{
    builder.Services.TryAddTransient<IPersistedGrantService, DefaultPersistedGrantService>();
    builder.Services.TryAddTransient<IKeyMaterialService, DefaultKeyMaterialService>();
    builder.Services.TryAddTransient<ITokenService, DefaultTokenService>();
    builder.Services.TryAddTransient<ITokenCreationService, DefaultTokenCreationService>();
    builder.Services.TryAddTransient<IClaimsService, DefaultClaimsService>();
    builder.Services.TryAddTransient<IRefreshTokenService, DefaultRefreshTokenService>();
    builder.Services.TryAddTransient<IDeviceFlowCodeService, DefaultDeviceFlowCodeService>();
    builder.Services.TryAddTransient<IConsentService, DefaultConsentService>();
    builder.Services.TryAddTransient<ICorsPolicyService, DefaultCorsPolicyService>();
    builder.Services.TryAddTransient<IProfileService, DefaultProfileService>();
    builder.Services.TryAddTransient<IConsentMessageStore, ConsentMessageStore>();
    builder.Services.TryAddTransient<IMessageStore<LogoutMessage>, ProtectedDataMessageStore<LogoutMessage>>();
    builder.Services.TryAddTransient<IMessageStore<EndSession>, ProtectedDataMessageStore<EndSession>>();
    builder.Services.TryAddTransient<IMessageStore<ErrorMessage>, ProtectedDataMessageStore<ErrorMessage>>();
    builder.Services.TryAddTransient<IIdentityServerInteractionService, DefaultIdentityServerInteractionService>();
    builder.Services.TryAddTransient<IDeviceFlowInteractionService, DefaultDeviceFlowInteractionService>();
    builder.Services.TryAddTransient<IAuthorizationCodeStore, DefaultAuthorizationCodeStore>();
    builder.Services.TryAddTransient<IRefreshTokenStore, DefaultRefreshTokenStore>();
    builder.Services.TryAddTransient<IReferenceTokenStore, DefaultReferenceTokenStore>();
    builder.Services.TryAddTransient<IUserConsentStore, DefaultUserConsentStore>();
    builder.Services.TryAddTransient<IHandleGenerationService, DefaultHandleGenerationService>();
    builder.Services.TryAddTransient<IPersistentGrantSerializer, PersistentGrantSerializer>();
    builder.Services.TryAddTransient<IEventService, DefaultEventService>();
    builder.Services.TryAddTransient<IEventSink, DefaultEventSink>();
    builder.Services.TryAddTransient<IUserCodeService, DefaultUserCodeService>();
    builder.Services.TryAddTransient<IUserCodeGenerator, NumericUserCodeGenerator>();
    builder.Services.TryAddTransient<IBackChannelLogoutService, DefaultBackChannelLogoutService>();

    builder.AddJwtRequestUriHttpClient();
    builder.AddBackChannelLogoutHttpClient();
    //builder.Services.AddHttpClient<BackChannelLogoutHttpClient>();
    //builder.Services.AddHttpClient<JwtRequestUriHttpClient>();

    builder.Services.AddTransient<IClientSecretValidator, ClientSecretValidator>();
    builder.Services.AddTransient<IApiSecretValidator, ApiSecretValidator>();

    builder.Services.TryAddTransient<IDeviceFlowThrottlingService, DistributedDeviceFlowThrottlingService>();
    builder.Services.AddDistributedMemoryCache();

    return builder;
}

• AddValidators - 注入校驗類

public static IIdentityServerBuilder AddValidators(this IIdentityServerBuilder builder)
{
    // core
    builder.Services.TryAddTransient<IEndSessionRequestValidator, EndSessionRequestValidator>();
    builder.Services.TryAddTransient<ITokenRevocationRequestValidator, TokenRevocationRequestValidator>();
    builder.Services.TryAddTransient<IAuthorizeRequestValidator, AuthorizeRequestValidator>();
    builder.Services.TryAddTransient<ITokenRequestValidator, TokenRequestValidator>();
    builder.Services.TryAddTransient<IRedirectUriValidator, StrictRedirectUriValidator>();
    builder.Services.TryAddTransient<ITokenValidator, TokenValidator>();
    builder.Services.TryAddTransient<IIntrospectionRequestValidator, IntrospectionRequestValidator>();
    builder.Services.TryAddTransient<IResourceOwnerPasswordValidator, NotSupportedResourceOwnerPasswordValidator>();
    builder.Services.TryAddTransient<ICustomTokenRequestValidator, DefaultCustomTokenRequestValidator>();
    builder.Services.TryAddTransient<IUserInfoRequestValidator, UserInfoRequestValidator>();
    builder.Services.TryAddTransient<IClientConfigurationValidator, DefaultClientConfigurationValidator>();
    builder.Services.TryAddTransient<IDeviceAuthorizationRequestValidator, DeviceAuthorizationRequestValidator>();
    builder.Services.TryAddTransient<IDeviceCodeValidator, DeviceCodeValidator>();

    // optional
    builder.Services.TryAddTransient<ICustomTokenValidator, DefaultCustomTokenValidator>();
    builder.Services.TryAddTransient<ICustomAuthorizeRequestValidator, DefaultCustomAuthorizeRequestValidator>();
    
    return builder;
}

• AddResponseGenerators - 注入響應生成類

public static IIdentityServerBuilder AddResponseGenerators(this IIdentityServerBuilder builder)
{
    builder.Services.TryAddTransient<ITokenResponseGenerator, TokenResponseGenerator>();
    builder.Services.TryAddTransient<IUserInfoResponseGenerator, UserInfoResponseGenerator>();
    builder.Services.TryAddTransient<IIntrospectionResponseGenerator, IntrospectionResponseGenerator>();
    builder.Services.TryAddTransient<IAuthorizeInteractionResponseGenerator, AuthorizeInteractionResponseGenerator>();
    builder.Services.TryAddTransient<IAuthorizeResponseGenerator, AuthorizeResponseGenerator>();
    builder.Services.TryAddTransient<IDiscoveryResponseGenerator, DiscoveryResponseGenerator>();
    builder.Services.TryAddTransient<ITokenRevocationResponseGenerator, TokenRevocationResponseGenerator>();
    builder.Services.TryAddTransient<IDeviceAuthorizationResponseGenerator, DeviceAuthorizationResponseGenerator>();

    return builder;
}

• AddDefaultSecretParsers & AddDefaultSecretValidators

/// <summary>
/// Adds the default secret parsers.
/// </summary>
/// <param name="builder">The builder.</param>
/// <returns></returns>
public static IIdentityServerBuilder AddDefaultSecretParsers(this IIdentityServerBuilder builder)
{
    builder.Services.AddTransient<ISecretParser, BasicAuthenticationSecretParser>();
    builder.Services.AddTransient<ISecretParser, PostBodySecretParser>();

    return builder;
}

/// <summary>
/// Adds the default secret validators.
/// </summary>
/// <param name="builder">The builder.</param>
/// <returns></returns>
public static IIdentityServerBuilder AddDefaultSecretValidators(this IIdentityServerBuilder builder)
{
    builder.Services.AddTransient<ISecretValidator, HashedSharedSecretValidator>();

    return builder;
}

IdentityServerOptions - 配置類

 /// <summary>
/// The IdentityServerOptions class is the top level container for all configuration settings of IdentityServer.
/// </summary>
public class IdentityServerOptions
{
    /// <summary>
    /// Gets or sets the unique name of this server instance, e.g. https://myissuer.com.
    /// If not set, the issuer name is inferred from the request
    /// </summary>
    /// <value>
    /// Unique name of this server instance, e.g. https://myissuer.com
    /// </value>
    public string IssuerUri { get; set; }

    /// <summary>
    /// Gets or sets the origin of this server instance, e.g. https://myorigin.com.
    /// If not set, the origin name is inferred from the request
    /// Note: Do not set a URL or include a path.
    /// </summary>
    /// <value>
    /// Origin of this server instance, e.g. https://myorigin.com
    /// </value>
    public string PublicOrigin { get; set; }

    /// <summary>
    /// Gets or sets the value for the JWT typ header for access tokens.
    /// </summary>
    /// <value>
    /// The JWT typ value.
    /// </value>
    public string AccessTokenJwtType { get; set; } = "at+jwt";

    /// <summary>
    /// Emits an aud claim with the format issuer/resources. That's needed for some older access token validation plumbing. Defaults to false.
    /// </summary>
    public bool EmitLegacyResourceAudienceClaim { get; set; } = false;

    /// <summary>
    /// Gets or sets the endpoint configuration.
    /// </summary>
    /// <value>
    /// The endpoints configuration.
    /// </value>
    public EndpointsOptions Endpoints { get; set; } = new EndpointsOptions();

    /// <summary>
    /// Gets or sets the discovery endpoint configuration.
    /// </summary>
    /// <value>
    /// The discovery endpoint configuration.
    /// </value>
    public DiscoveryOptions Discovery { get; set; } = new DiscoveryOptions();

    /// <summary>
    /// Gets or sets the authentication options.
    /// </summary>
    /// <value>
    /// The authentication options.
    /// </value>
    public AuthenticationOptions Authentication { get; set; } = new AuthenticationOptions();

    /// <summary>
    /// Gets or sets the events options.
    /// </summary>
    /// <value>
    /// The events options.
    /// </value>
    public EventsOptions Events { get; set; } = new EventsOptions();

    /// <summary>
    /// Gets or sets the max input length restrictions.
    /// </summary>
    /// <value>
    /// The length restrictions.
    /// </value>
    public InputLengthRestrictions InputLengthRestrictions { get; set; } = new InputLengthRestrictions();

    /// <summary>
    /// Gets or sets the options for the user interaction.
    /// </summary>
    /// <value>
    /// The user interaction options.
    /// </value>
    public UserInteractionOptions UserInteraction { get; set; } = new UserInteractionOptions();

    /// <summary>
    /// Gets or sets the caching options.
    /// </summary>
    /// <value>
    /// The caching options.
    /// </value>
    public CachingOptions Caching { get; set; } = new CachingOptions();

    /// <summary>
    /// Gets or sets the cors options.
    /// </summary>
    /// <value>
    /// The cors options.
    /// </value>
    public CorsOptions Cors { get; set; } = new CorsOptions();

    /// <summary>
    /// Gets or sets the Content Security Policy options.
    /// </summary>
    public CspOptions Csp { get; set; } = new CspOptions();

    /// <summary>
    /// Gets or sets the validation options.
    /// </summary>
    public ValidationOptions Validation { get; set; } = new ValidationOptions();

    /// <summary>
    /// Gets or sets the device flow options.
    /// </summary>
    public DeviceFlowOptions DeviceFlow { get; set; } = new DeviceFlowOptions();

    /// <summary>
    /// Gets or sets the mutual TLS options.
    /// </summary>
    public MutualTlsOptions MutualTls { get; set; } = new MutualTlsOptions();
}

UserIdentityServer - 中間件邏輯

• 執行校驗
• BaseUrlMiddleware中間件：設置BaseUrl
• 配置CORS跨域：CorsPolicyProvider根據client信息生成動態策略
• IdentityServerMiddlewareOptions默認調用了UseAuthentication，所以如果使用IdentityServer不用重復注冊Authentication中間件
• 使用MutualTlsTokenEndpointMiddleware中間件：要求客戶端、服務端都使用https，默認不開啟
• 使用IdentityServerMiddleware中間件：IEndpointRouter根據請求尋找匹配的IEndpointHandler，如果找到的話則由EndPointHandler處理請求。

public static IApplicationBuilder UseIdentityServer(this IApplicationBuilder app, IdentityServerMiddlewareOptions options = null)
{
    app.Validate();

    app.UseMiddleware<BaseUrlMiddleware>();

    app.ConfigureCors();

    // it seems ok if we have UseAuthentication more than once in the pipeline --
    // this will just re-run the various callback handlers and the default authN 
    // handler, which just re-assigns the user on the context. claims transformation
    // will run twice, since that's not cached (whereas the authN handler result is)
    // related: https://github.com/aspnet/Security/issues/1399
    if (options == null) options = new IdentityServerMiddlewareOptions();
    options.AuthenticationMiddleware(app);

    app.UseMiddleware<MutualTlsTokenEndpointMiddleware>();
    app.UseMiddleware<IdentityServerMiddleware>();

    return app;
}

核心中間件IdentityServerMiddleware的代碼，邏輯比較清晰

• IEndpointRouter路由類旬齋匹配接口
• 匹配接口處理請求返回結果IEndpointResult
• IEndpointResult執行結果，寫入上下文，返回報文

 public async Task Invoke(HttpContext context, IEndpointRouter router, IUserSession session, IEventService events)
{
    // this will check the authentication session and from it emit the check session
    // cookie needed from JS-based signout clients.
    await session.EnsureSessionIdCookieAsync();

    try
    {
        var endpoint = router.Find(context);
        if (endpoint != null)
        {
            _logger.LogInformation("Invoking IdentityServer endpoint: {endpointType} for {url}", endpoint.GetType().FullName, context.Request.Path.ToString());

            var result = await endpoint.ProcessAsync(context);

            if (result != null)
            {
                _logger.LogTrace("Invoking result: {type}", result.GetType().FullName);
                await result.ExecuteAsync(context);
            }

            return;
        }
    }
    catch (Exception ex)
    {
        await events.RaiseAsync(new UnhandledExceptionEvent(ex));
        _logger.LogCritical(ex, "Unhandled exception: {exception}", ex.Message);
        throw;
    }

    await _next(context);
}

看一下路由類的處理邏輯
之前AddDefaultEndpoints注入了所有默認接口，路由類可以通過依賴注入拿到所有接口信息，將請求地址與接口地址對比得到匹配的接口，然后從容器拿到對應的接口處理器。

public EndpointRouter(IEnumerable<Endpoint> endpoints, IdentityServerOptions options, ILogger<EndpointRouter> logger)
{
    _endpoints = endpoints;
    _options = options;
    _logger = logger;
}

public IEndpointHandler Find(HttpContext context)
{
    if (context == null) throw new ArgumentNullException(nameof(context));

    foreach(var endpoint in _endpoints)
    {
        var path = endpoint.Path;
        if (context.Request.Path.Equals(path, StringComparison.OrdinalIgnoreCase))
        {
            var endpointName = endpoint.Name;
            _logger.LogDebug("Request path {path} matched to endpoint type {endpoint}", context.Request.Path, endpointName);

            return GetEndpointHandler(endpoint, context);
        }
    }

    _logger.LogTrace("No endpoint entry found for request path: {path}", context.Request.Path);

    return null;
}

 private IEndpointHandler GetEndpointHandler(Endpoint endpoint, HttpContext context)
{
    if (_options.Endpoints.IsEndpointEnabled(endpoint))
    {
        var handler = context.RequestServices.GetService(endpoint.Handler) as IEndpointHandler;
        if (handler != null)
        {
            _logger.LogDebug("Endpoint enabled: {endpoint}, successfully created handler: {endpointHandler}", endpoint.Name, endpoint.Handler.FullName);
            return handler;
        }
        else
        {
            _logger.LogDebug("Endpoint enabled: {endpoint}, failed to create handler: {endpointHandler}", endpoint.Name, endpoint.Handler.FullName);
        }
    }
    else
    {
        _logger.LogWarning("Endpoint disabled: {endpoint}", endpoint.Name);
    }

    return null;
}

總結

主干流程大致如圖

idsv的代碼量還是比較大的，有很多的類，但是代碼還是要寫的挺規范清晰，梳理下來脈絡還是很明了的。