.NET 雲原生架構師訓練營（許可權系統 程式碼實現 ActionAccess）--學習筆記

MingsonZheng發表於2022-02-15
架構筆記

目錄

  • 開發任務
  • 程式碼實現

開發任務

  • DotNetNB.Security.Core：定義 core，models，Istore；實現 default memory store
  • DotNetNB.Security.ActionAccess：掃描 action；新增 action authorize filter；新增整合方式

程式碼實現

對於一個 web 專案，Filter 是在構建構建 builder 的時候新增的

builder.Services.AddControllers(options =>
{
    options.Filters.Add<>()
})

這裡不可能讓使用者手動新增，所以需要有一個擴充套件方法給使用者呼叫

using Microsoft.AspNetCore.Mvc;

namespace DotNetNB.Security.ActionAccess
{
    public static class MvcOptionsExtensions
    {
        public static MvcOptions AddActionAccessControl(this MvcOptions options)
        {
            options.Filters.Add<DynamicAuthorizeFilter>();
            return options;
        }
    }
}

建立 Resource，包含 Key 和 Data 兩個屬性

namespace DotNetNB.Security.Core.Models
{
    public class Resource
    {
        public string Key { get; set; }

        public object Data { get; set; }
    }
}

建立 ActionResource，繼承 Resource，包含 ControllerName，ActionName，RouteTemplate 和 HttpVerb 幾個屬性

using DotNetNB.Security.Core.Models;

namespace DotNetNB.Security.ActionAccess
{
    public class ActionResource : Resource
    {

    }

    public class ActionResourceData
    {
        public string? ControllerName { get; set; }

        public string? ActionName { get; set; }
        
        public  string DisplayName { get; set; }

        public string? RouteTemplate { get; set; }

        public string? HttpVerb { get; set; }
    }
}

定義一個 IResourceManager 介面，提供建立資源的方法

using DotNetNB.Security.Core.Models;

namespace DotNetNB.Security.Core
{
    public interface IResourceManager
    {
        public Task CreateAsync(Resource resource);

        public Task CreateAsync(IEnumerable<Resource> resources);
    }
}

參考 ASP .NET Core 原始碼中的 ActionEndpointDataSourceBase：

https://github.com/dotnet/aspnetcore/blob/main/src/Mvc/Mvc.Core/src/Routing/ActionEndpointDataSourceBase.cs

建立 endpoint 的時候有一個 action 的列表 ActionDescriptors

var endpoints = CreateEndpoints(_actions.ActionDescriptors.Items, Conventions);

它的型別是一個 IActionDescriptorCollectionProvider，專門用於掃描獲取所有的 action

private readonly IActionDescriptorCollectionProvider _actions;

在 ActionAccess 模組的 ActionResourceProvider 中把它加進來

using Microsoft.AspNetCore.Mvc.Infrastructure;

namespace DotNetNB.Security.ActionAccess
{
    public class ActionResourceProvider
    {
        private readonly IActionDescriptorCollectionProvider _actionDescriptorCollectionProvider;

        public ActionResourceProvider(IActionDescriptorCollectionProvider actionDescriptorCollectionProvider)
        {
            _actionDescriptorCollectionProvider = actionDescriptorCollectionProvider;
        }
    }
}

在 host 啟動的時候掃描獲取所有的 action 資訊，定義一個 IResourceProvider 介面

namespace DotNetNB.Security.Core
{
    public interface IResourceProvider
    {
        public Task<IEnumerable<Resource>> ExecuteAsync();
    }
}

ActionResourceProvider 實現這個介面，從 ActionDescriptors 獲取 action 資訊，構建 ActionResourceData

public async Task<IEnumerable<Resource>> ExecuteAsync()
{
    var actions = _actionDescriptorCollectionProvider.ActionDescriptors.Items;
    var actionResources = new List<ActionResource>();

    foreach (var action in actions)
    {
        if (action is ControllerActionDescriptor)
        {
            var actionDescriptor = action as ControllerActionDescriptor;
            var httpMethod = action.EndpointMetadata.Where(m => m is HttpMethodMetadata).FirstOrDefault() as HttpMethodMetadata;

            var routeAttribute =
                actionDescriptor?.EndpointMetadata.FirstOrDefault(m => m is RouteAttribute) as RouteAttribute;

            var resourceData = new ActionResourceData();
            resourceData.HttpVerb = httpMethod?.HttpMethods.First();
            resourceData.ActionName = actionDescriptor?.ActionName;
            resourceData.ControllerName = actionDescriptor?.ControllerName;
            resourceData.RouteTemplate = routeAttribute?.Template;
            resourceData.DisplayName = action.DisplayName;

            actionResources.Add(new ActionResource()
            {
                Data = resourceData,
                Key = actionDescriptor.GetSecurityKey()
            });
        }
    }

    return await Task.FromResult(actionResources);
}

參考 ASP .NET Core 原始碼中的 AuthorizeFilter：

https://github.com/dotnet/aspnetcore/blob/main/src/Mvc/Mvc.Core/src/Authorization/AuthorizeFilter.cs

AuthorizeFilter 中有一個 OnAuthorizationAsync 的方法，首先獲取 policy 執行器，然後執行了認證，接著執行授權，根據授權結果修改 AuthorizationFilterContext，我們許可權主要是 Forbidden 的結果，返回 403 即可

public virtual async Task OnAuthorizationAsync(AuthorizationFilterContext context)
{
    if (context == null)
    {
        throw new ArgumentNullException(nameof(context));
    }

    if (!context.IsEffectivePolicy(this))
    {
        return;
    }

    // IMPORTANT: Changes to authorization logic should be mirrored in security's AuthorizationMiddleware
    var effectivePolicy = await GetEffectivePolicyAsync(context);
    if (effectivePolicy == null)
    {
        return;
    }

    var policyEvaluator = context.HttpContext.RequestServices.GetRequiredService<IPolicyEvaluator>();

    var authenticateResult = await policyEvaluator.AuthenticateAsync(effectivePolicy, context.HttpContext);

    // Allow Anonymous skips all authorization
    if (HasAllowAnonymous(context))
    {
        return;
    }

    var authorizeResult = await policyEvaluator.AuthorizeAsync(effectivePolicy, authenticateResult, context.HttpContext, context);

    if (authorizeResult.Challenged)
    {
        context.Result = new ChallengeResult(effectivePolicy.AuthenticationSchemes.ToArray());
    }
    else if (authorizeResult.Forbidden)
    {
        context.Result = new ForbidResult(effectivePolicy.AuthenticationSchemes.ToArray());
    }
}

DynamicAuthorizeFilter 繼承自 AuthorizeFilter，只獲取 ControllerActionDescriptor 型別的 action，如果 permissions 中不包含 actionKey 則返回 403

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Authorization;
using Microsoft.AspNetCore.Mvc.Controllers;
using Microsoft.AspNetCore.Mvc.Filters;

namespace DotNetNB.Security.ActionAccess
{
    public class DynamicAuthorizeFilter : AuthorizeFilter
    {
        public override async Task OnAuthorizationAsync(AuthorizationFilterContext context)
        {
            var actionDescriptor = context.ActionDescriptor as ControllerActionDescriptor;
            if (actionDescriptor == null)
            {
                return;
            }

            base.OnAuthorizationAsync(context);
            if (context.Result != null)
            {
                return;
            }

            var permissions = context.HttpContext.User.Claims.Where(c => c.Type == Core.ClaimsTypes.Permission);
            var actionKey = actionDescriptor.GetSecurityKey();

            var values = permissions.Select(p => p.Value);
            if (!values.Contains(actionKey))
            {
                context.Result = new ForbidResult();
            }
        }
    }
}

在 ClaimsTypes 中增加一個 Permission 型別的 ClaimsType

namespace DotNetNB.Security.Core
{
    public static class ClaimsTypes
    {
        public const string Permission = "Permission";
    }
}

為了避免重複程式碼，新增一個 GetSecurityKey 的擴充套件方法

using Microsoft.AspNetCore.Mvc.Controllers;
using Microsoft.AspNetCore.Mvc.Internal;

namespace DotNetNB.Security.ActionAccess;

public static string GetSecurityKey(this ControllerActionDescriptor descriptor)
{
    var httpMethod = descriptor.EndpointMetadata.FirstOrDefault(m => m is HttpMethodMetadata) as HttpMethodMetadata;

    return string.Format($"{descriptor?.ControllerName}-{descriptor?.ActionName}-{httpMethod.HttpMethods.First()}");
}

這樣就完成了 DotNetNB.Security.ActionAccess 模組的 ActionResourceProvider 和 DynamicAuthorizeFilter

GitHub原始碼連結：

https://github.com/MingsonZheng/dotnetnb.security

課程連結

https://appsqsyiqlk5791.h5.xiaoeknow.com/v1/course/video/v_5f39bdb8e4b01187873136cf?type=2

知識共享許可協議

本作品採用知識共享署名-非商業性使用-相同方式共享 4.0 國際許可協議進行許可。

歡迎轉載、使用、重新發布，但務必保留文章署名 鄭子銘 （包含連結： http://www.cnblogs.com/MingsonZheng/ ），不得用於商業目的，基於本文修改後的作品務必以相同的許可釋出。

如有任何疑問，請與我聯絡 (MingsonZheng@outlook.com) 。

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