如何在ASP.NET Core 2.0中配置基于路由的预约身份验证

Question

在ASP.NET Core 1.x中，我可以在Configure中使用身份验证方法，但现在在ASP.NET Core 2.0中，我必须在ConfigureSreservices中设置所有内容，而不能在ConfigureMethod中配置。例如：

public void ConfigureServices(IServiceCollection services)
{
    services.AddAuthentication()
            .AddCookie()
            .AddXX();
}

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

app.UseOpenIdConnectAuthentication();

app.Map(new PathString("/MyPath"), i => i.UseMyAuthMethod());

Answer 1

在2.0中，执行每路由身份验证的最佳选项是使用自定义IAuthenticationSchemeProvider:

public class CustomAuthenticationSchemeProvider : AuthenticationSchemeProvider
{
    private readonly IHttpContextAccessor httpContextAccessor;

    public CustomAuthenticationSchemeProvider(
        IHttpContextAccessor httpContextAccessor,
        IOptions<AuthenticationOptions> options)
        : base(options)
    {
        this.httpContextAccessor = httpContextAccessor;
    }

    private async Task<AuthenticationScheme> GetRequestSchemeAsync()
    {
        var request = httpContextAccessor.HttpContext?.Request;
        if (request == null)
        {
            throw new ArgumentNullException("The HTTP request cannot be retrieved.");
        }

        // For API requests, use authentication tokens.
        if (request.Path.StartsWithSegments("/api"))
        {
            return await GetSchemeAsync(OAuthValidationDefaults.AuthenticationScheme);
        }

        // For the other requests, return null to let the base methods
        // decide what's the best scheme based on the default schemes
        // configured in the global authentication options.
        return null;
    }

    public override async Task<AuthenticationScheme> GetDefaultAuthenticateSchemeAsync() =>
        await GetRequestSchemeAsync() ??
        await base.GetDefaultAuthenticateSchemeAsync();

    public override async Task<AuthenticationScheme> GetDefaultChallengeSchemeAsync() =>
        await GetRequestSchemeAsync() ??
        await base.GetDefaultChallengeSchemeAsync();

    public override async Task<AuthenticationScheme> GetDefaultForbidSchemeAsync() =>
        await GetRequestSchemeAsync() ??
        await base.GetDefaultForbidSchemeAsync();

    public override async Task<AuthenticationScheme> GetDefaultSignInSchemeAsync() =>
        await GetRequestSchemeAsync() ??
        await base.GetDefaultSignInSchemeAsync();

    public override async Task<AuthenticationScheme> GetDefaultSignOutSchemeAsync() =>
        await GetRequestSchemeAsync() ??
        await base.GetDefaultSignOutSchemeAsync();
}

不要忘记在DI容器中注册它（理想情况下，作为一个单例）：

// IHttpContextAccessor is not registered by default
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
services.AddSingleton<IAuthenticationSchemeProvider, CustomAuthenticationSchemeProvider>();