自定義授權屬性 - ASP .NET Core 2.2

Question

我想創建一個自定義 Authorize 屬性，以便能夠在失敗時發送個性化響應。 有很多例子，但我找不到我要找的東西。 注冊保單時，我添加了“索賠”。 是否可以在自定義屬性中訪問該注冊聲明而無需通過參數傳遞聲明？ 或者是否有可能知道索賠檢查是否發生，如果沒有，返回個性化回復？ 謝謝！

public static void AddCustomAuthorization(this IServiceCollection serviceCollection)
{
    serviceCollection.AddAuthorization(x =>
    {
        x.AddPolicy(UserPolicy.Read,
            currentPolicy => currentPolicy.RequireClaim(UserClaims.Read));
    });
}

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true)]
public class CustomAuthorizeAttribute : AuthorizeAttribute, IAuthorizationFilter
{
    public void OnAuthorization(AuthorizationFilterContext authorizationFilterContext)
    {
        if (authorizationFilterContext.HttpContext.User.Identity.IsAuthenticated)
        {
            if (!authorizationFilterContext.HttpContext.User.HasClaim(x => x.Value == "CLAIM_NAME")) // ACCESS TO REGISTER CLAIM => currentPolicy => currentPolicy.RequireClaim(UserClaims.Read)
            {
                authorizationFilterContext.Result = new ObjectResult(new ApiResponse(HttpStatusCode.Unauthorized));
            }
        }
    }
}

[HttpGet]
[CustomAuthorizeAttribute(Policy = UserPolicy.Read)]
public async Task<IEnumerable<UserDTO>> Get()
{
    return ...
}

Answer 1

您可以使用IAuthorizationPolicyProvider獲取策略，然后使用ClaimsAuthorizationRequirement.ClaimType獲取聲明名稱。 並且由於它具有異步 API，因此最好使用IAsyncAuthorizationFilter而不是IAuthorizationFilter 。 嘗試這個：

public class CustomAuthorizeAttribute : AuthorizeAttribute, IAsyncAuthorizationFilter
{
    public async Task OnAuthorizationAsync(AuthorizationFilterContext authorizationFilterContext)
    {
        var policyProvider = authorizationFilterContext.HttpContext
            .RequestServices.GetService<IAuthorizationPolicyProvider>();
        var policy = await policyProvider.GetPolicyAsync(UserPolicy.Read);
        var requirement = (ClaimsAuthorizationRequirement)policy.Requirements
            .First(r => r.GetType() == typeof(ClaimsAuthorizationRequirement));

        if (authorizationFilterContext.HttpContext.User.Identity.IsAuthenticated)
        {
            if (!authorizationFilterContext.HttpContext
              .User.HasClaim(x => x.Value == requirement.ClaimType))
            {
                authorizationFilterContext.Result = 
                   new ObjectResult(new ApiResponse(HttpStatusCode.Unauthorized));
            }
        }
    }
}

Answer 2

這個屬性需要一個字符串數組，這在我的例子中是需要的。 我需要將不同的用戶角色傳遞給這個屬性，並根據一些自定義邏輯返回結果。

public class CustomAuthFilter : AuthorizeAttribute, IAuthorizationFilter
{
    public CustomAuthFilter(params string[] args)
    {
        Args = args;
    }

    public string[] Args { get; }

    public void OnAuthorization(AuthorizationFilterContext context)
    {
        //Custom code ...

        //Resolving a custom Services from the container
        var service = context.HttpContext.RequestServices.GetRequiredService<ISample>();
        string name = service.GetName(); // returns "anish"

        //Return based on logic
        context.Result = new UnauthorizedResult();
    }
}

您可以使用此屬性裝飾您的控制器，如下所示

 [CustomAuthFilter("Anish","jiya","sample")]
 public async Task<IActionResult> Index()

Sample 是一個返回硬編碼字符串的類

public class Sample : ISample
{
    public string GetName() => "anish";
}

services.AddScoped(); //注冊ISample，Sample為scoped。

對於異步支持，請使用 IAsyncAuthorizationFilter

public class CustomAuthFilter : AuthorizeAttribute, IAsyncAuthorizationFilter
{

    public CustomAuthFilter(params string[] args)
    {
        Args = args;
    }

    public string[] Args { get; }

    public async Task OnAuthorizationAsync(AuthorizationFilterContext context)
    {
        //DO Whatever...

        //Resolve Services from the container
        var service = context.HttpContext.RequestServices.GetRequiredService<ISample>();
        var httpClientFactory = context.HttpContext.RequestServices.GetRequiredService<IHttpClientFactory>();
        string name = service.GetName();

        using var httpClient = httpClientFactory.CreateClient();

        var resp = await httpClient.GetAsync("https://jsonplaceholder.typicode.com/todos/1");
        var data = await resp.Content.ReadAsStringAsync();

        //Return based on logic
        context.Result = new UnauthorizedResult();

    }
}

希望有幫助..