自定义 AuthorizationMiddleware 的行为

应用可以注册 IAuthorizationMiddlewareResultHandler,以自定义 AuthorizationMiddleware 处理授权结果的方式。 应用可将 IAuthorizationMiddlewareResultHandler 用于:

  • 返回自定义的响应。
  • 增强默认质询或禁止响应。

以下代码显示了 IAuthorizationMiddlewareResultHandler 的示例实现,它会针对特定授权失败返回自定义响应:

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Authorization.Policy;

public class SampleAuthorizationMiddlewareResultHandler : IAuthorizationMiddlewareResultHandler
{
    private readonly AuthorizationMiddlewareResultHandler defaultHandler = new();

    public async Task HandleAsync(
        RequestDelegate next,
        HttpContext context,
        AuthorizationPolicy policy,
        PolicyAuthorizationResult authorizeResult)
    {
        // If the authorization was forbidden and the resource had a specific requirement,
        // provide a custom 404 response.
        if (authorizeResult.Forbidden
            && authorizeResult.AuthorizationFailure!.FailedRequirements
                .OfType<Show404Requirement>().Any())
        {
            // Return a 404 to make it appear as if the resource doesn't exist.
            context.Response.StatusCode = StatusCodes.Status404NotFound;
            return;
        }

        // Fall back to the default implementation.
        await defaultHandler.HandleAsync(next, context, policy, authorizeResult);
    }
}

public class Show404Requirement : IAuthorizationRequirement { }

Program.cs 中注册 IAuthorizationMiddlewareResultHandler 的实现:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddSingleton<
    IAuthorizationMiddlewareResultHandler, SampleAuthorizationMiddlewareResultHandler>();

var app = builder.Build();

应用可以注册 IAuthorizationMiddlewareResultHandler,以自定义 AuthorizationMiddleware 处理授权结果的方式。 应用可以将 IAuthorizationMiddlewareResultHandler 用于:

  • 返回自定义的响应。
  • 增强默认质询或禁止响应。

以下代码显示了 IAuthorizationMiddlewareResultHandler 的示例实现,它会针对特定授权失败返回自定义响应:

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Authorization.Policy;
using Microsoft.AspNetCore.Http;
using System.Linq;
using System.Net;
using System.Threading.Tasks;

public class MyAuthorizationMiddlewareResultHandler : IAuthorizationMiddlewareResultHandler
{
   private readonly AuthorizationMiddlewareResultHandler 
        DefaultHandler = new AuthorizationMiddlewareResultHandler();
    
    public async Task HandleAsync(
        RequestDelegate requestDelegate,
        HttpContext httpContext,
        AuthorizationPolicy authorizationPolicy,
        PolicyAuthorizationResult policyAuthorizationResult)
    {
        // if the authorization was forbidden and the resource had specific requirements,
        // provide a custom response.
        if (Show404ForForbiddenResult(policyAuthorizationResult))
        {
            // Return a 404 to make it appear as if the resource does not exist.
            httpContext.Response.StatusCode = (int)HttpStatusCode.NotFound;
            return;
        }

        // Fallback to the default implementation.
        await DefaultHandler.HandleAsync(requestDelegate, httpContext, authorizationPolicy, 
                               policyAuthorizationResult);
    }

    bool Show404ForForbiddenResult(PolicyAuthorizationResult policyAuthorizationResult)
    {
        return policyAuthorizationResult.Forbidden &&
            policyAuthorizationResult.AuthorizationFailure.FailedRequirements.OfType<
                                                           Show404Requirement>().Any();
    }
}

public class Show404Requirement : IAuthorizationRequirement { }

Startup.ConfigureServices 中注册 MyAuthorizationMiddlewareResultHandler

public void ConfigureServices(IServiceCollection services)
{
    services.AddRazorPages();
    services.AddSingleton<IAuthorizationMiddlewareResultHandler,
                          MyAuthorizationMiddlewareResultHandler>();
}