Integrate authorization into Blazor router

eng/GenAPI.exclusions.txt

@@ -5,6 +5,7 @@ T:Microsoft.AspNetCore.Mvc.ApplicationModels.PageParameterModel
 T:Microsoft.AspNetCore.Mvc.ApplicationModels.PagePropertyModel
 # Manually implemented - https://github.com/aspnet/AspNetCore/issues/8825
 T:Microsoft.AspNetCore.Components.AuthorizeView
+T:Microsoft.AspNetCore.Components.AuthorizeViewCore
 T:Microsoft.AspNetCore.Components.CascadingAuthenticationState
 T:Microsoft.AspNetCore.Components.CascadingValue`1
 T:Microsoft.AspNetCore.Components.Forms.DataAnnotationsValidator
@@ -18,6 +19,6 @@ T:Microsoft.AspNetCore.Components.Forms.InputText
 T:Microsoft.AspNetCore.Components.Forms.InputTextArea
 T:Microsoft.AspNetCore.Components.Forms.ValidationMessage`1
 T:Microsoft.AspNetCore.Components.Forms.ValidationSummary
-T:Microsoft.AspNetCore.Components.Layouts.LayoutDisplay
+T:Microsoft.AspNetCore.Components.PageDisplay
 T:Microsoft.AspNetCore.Components.Routing.NavLink
 T:Microsoft.AspNetCore.Components.Routing.Router

src/Components/Components/ref/Microsoft.AspNetCore.Components.netstandard2.0.Manual.cs

@@ -49,24 +49,31 @@ public readonly partial struct RenderTreeFrame
 // Built-in components: https://github.com/aspnet/AspNetCore/issues/8825
 namespace Microsoft.AspNetCore.Components
 {
-    public partial class AuthorizeView : Microsoft.AspNetCore.Components.ComponentBase
+    public partial class AuthorizeView : Microsoft.AspNetCore.Components.AuthorizeViewCore
     {
         public AuthorizeView() { }
         [Microsoft.AspNetCore.Components.ParameterAttribute]
+        public string Policy { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; } }
+        [Microsoft.AspNetCore.Components.ParameterAttribute]
+        public object Resource { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; } }
+        [Microsoft.AspNetCore.Components.ParameterAttribute]
+        public string Roles { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; } }
+        protected override Microsoft.AspNetCore.Authorization.IAuthorizeData[] GetAuthorizeData() { throw null; }
+    }
+
+    public abstract partial class AuthorizeViewCore : Microsoft.AspNetCore.Components.ComponentBase
+    {
+        public AuthorizeViewCore() { }
+        [Microsoft.AspNetCore.Components.ParameterAttribute]
         public Microsoft.AspNetCore.Components.RenderFragment<Microsoft.AspNetCore.Components.AuthenticationState> Authorized { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; } }
         [Microsoft.AspNetCore.Components.ParameterAttribute]
         public Microsoft.AspNetCore.Components.RenderFragment Authorizing { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; } }
         [Microsoft.AspNetCore.Components.ParameterAttribute]
         public Microsoft.AspNetCore.Components.RenderFragment<Microsoft.AspNetCore.Components.AuthenticationState> ChildContent { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; } }
         [Microsoft.AspNetCore.Components.ParameterAttribute]
         public Microsoft.AspNetCore.Components.RenderFragment<Microsoft.AspNetCore.Components.AuthenticationState> NotAuthorized { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; } }
-        [Microsoft.AspNetCore.Components.ParameterAttribute]
-        public string Policy { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; } }
-        [Microsoft.AspNetCore.Components.ParameterAttribute]
-        public string Roles { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; } }
-        [Microsoft.AspNetCore.Components.ParameterAttribute]
-        public object Resource { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; } }
         protected override void BuildRenderTree(Microsoft.AspNetCore.Components.RenderTree.RenderTreeBuilder builder) { }
+        protected abstract Microsoft.AspNetCore.Authorization.IAuthorizeData[] GetAuthorizeData();
         [System.Diagnostics.DebuggerStepThroughAttribute]
         protected override System.Threading.Tasks.Task OnParametersSetAsync() { throw null; }
     }
@@ -218,9 +225,13 @@ void System.IDisposable.Dispose() { }
 
 namespace Microsoft.AspNetCore.Components.Layouts
 {
-    public partial class LayoutDisplay : Microsoft.AspNetCore.Components.IComponent
+    public partial class PageDisplay : Microsoft.AspNetCore.Components.IComponent
     {
-        public LayoutDisplay() { }
+        public PageDisplay() { }
+        [Microsoft.AspNetCore.Components.ParameterAttribute]
+        public Microsoft.AspNetCore.Components.RenderFragment AuthorizingContent { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; }}
+        [Microsoft.AspNetCore.Components.ParameterAttribute]
+        public Microsoft.AspNetCore.Components.RenderFragment<Microsoft.AspNetCore.Components.AuthenticationState> NotAuthorizedContent { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; }}
         [Microsoft.AspNetCore.Components.ParameterAttribute]
         public System.Type Page { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } private set { throw null; }}
         [Microsoft.AspNetCore.Components.ParameterAttribute]

src/Components/Components/src/Auth/AttributeAuthorizeDataCache.cs

@@ -0,0 +1,42 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Concurrent;
+using System.Linq;
+using System.Reflection;
+using Microsoft.AspNetCore.Authorization;
+
+namespace Microsoft.AspNetCore.Components.Auth
+{
+    internal static class AttributeAuthorizeDataCache
+    {
+        private static ConcurrentDictionary<Type, IAuthorizeData[]> _cache
+            = new ConcurrentDictionary<Type, IAuthorizeData[]>();
+
+        public static IAuthorizeData[] GetAuthorizeDataForType(Type type)
+        {
+            IAuthorizeData[] result;
+            if (!_cache.TryGetValue(type, out result))
+            {
+                result = ComputeAuthorizeDataForType(type);
+                _cache[type] = result; // Safe race - doesn't matter if it overwrites
+            }
+
+            return result;
+        }
+
+        private static IAuthorizeData[] ComputeAuthorizeDataForType(Type type)
+        {
+            // Allow Anonymous skips all authorization
+            var allAttributes = type.GetCustomAttributes(inherit: true);
+            if (allAttributes.OfType<IAllowAnonymous>().Any())
+            {
+                return null;
+            }
+
+            var authorizeDataAttributes = allAttributes.OfType<IAuthorizeData>().ToArray();
+            return authorizeDataAttributes.Length > 0 ? authorizeDataAttributes : null;
+        }
+    }
+}

src/Components/Components/src/Auth/AuthorizeView.cs

@@ -0,0 +1,39 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNetCore.Authorization;
+
+namespace Microsoft.AspNetCore.Components
+{
+    /// <summary>
+    /// Displays differing content depending on the user's authorization status.
+    /// </summary>
+    public class AuthorizeView : AuthorizeViewCore
+    {
+        private readonly IAuthorizeData[] selfAsAuthorizeData;
+
+        /// <summary>
+        /// Constructs an instance of <see cref="AuthorizeView"/>.
+        /// </summary>
+        public AuthorizeView()
+        {
+            selfAsAuthorizeData = new[] { new AuthorizeDataAdapter(this) };
+        }
+
+        /// <summary>
+        /// The policy name that determines whether the content can be displayed.
+        /// </summary>
+        [Parameter] public string Policy { get; private set; }
+
+        /// <summary>
+        /// A comma delimited list of roles that are allowed to display the content.
+        /// </summary>
+        [Parameter] public string Roles { get; private set; }
+
+        /// <summary>
+        /// Gets the data used for authorization.
+        /// </summary>
+        protected override IAuthorizeData[] GetAuthorizeData()
+            => selfAsAuthorizeData;
+    }
+}

src/Components/Components/src/Auth/AuthorizeViewCore.cs

@@ -0,0 +1,111 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Security.Claims;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Components.RenderTree;
+
+namespace Microsoft.AspNetCore.Components
+{
+    /// <summary>
+    /// A base class for components that display differing content depending on the user's authorization status.
+    /// </summary>
+    public abstract class AuthorizeViewCore : ComponentBase
+    {
+        private AuthenticationState currentAuthenticationState;
+        private bool isAuthorized;
+
+        /// <summary>
+        /// The content that will be displayed if the user is authorized.
+        /// </summary>
+        [Parameter] public RenderFragment<AuthenticationState> ChildContent { get; private set; }
+
+        /// <summary>
+        /// The content that will be displayed if the user is not authorized.
+        /// </summary>
+        [Parameter] public RenderFragment<AuthenticationState> NotAuthorized { get; private set; }
+
+        /// <summary>
+        /// The content that will be displayed if the user is authorized.
+        /// If you specify a value for this parameter, do not also specify a value for <see cref="ChildContent"/>.
+        /// </summary>
+        [Parameter] public RenderFragment<AuthenticationState> Authorized { get; private set; }
+
+        /// <summary>
+        /// The content that will be displayed while asynchronous authorization is in progress.
+        /// </summary>
+        [Parameter] public RenderFragment Authorizing { get; private set; }
+
+        /// <summary>
+        /// The resource to which access is being controlled.
+        /// </summary>
+        [Parameter] public object Resource { get; private set; }
+
+        [CascadingParameter] private Task<AuthenticationState> AuthenticationState { get; set; }
+
+        [Inject] private IAuthorizationPolicyProvider AuthorizationPolicyProvider { get; set; }
+
+        [Inject] private IAuthorizationService AuthorizationService { get; set; }
+
+        /// <inheritdoc />
+        protected override void BuildRenderTree(RenderTreeBuilder builder)
+        {
+            if (currentAuthenticationState == null)
+            {
+                builder.AddContent(0, Authorizing);
+            }
+            else if (isAuthorized)
+            {
+                var authorizedContent = Authorized ?? ChildContent;
+                builder.AddContent(1, authorizedContent?.Invoke(currentAuthenticationState));
+            }
+            else
+            {
+                builder.AddContent(2, NotAuthorized?.Invoke(currentAuthenticationState));
+            }
+        }
+
+        /// <inheritdoc />
+        protected override async Task OnParametersSetAsync()
+        {
+            // We allow 'ChildContent' for convenience in basic cases, and 'Authorized' for symmetry
+            // with 'NotAuthorized' in other cases. Besides naming, they are equivalent. To avoid
+            // confusion, explicitly prevent the case where both are supplied.
+            if (ChildContent != null && Authorized != null)
+            {
+                throw new InvalidOperationException($"Do not specify both '{nameof(Authorized)}' and '{nameof(ChildContent)}'.");
+            }
+
+            if (AuthenticationState == null)
+            {
+                throw new InvalidOperationException($"Authorization requires a cascading parameter of type Task<{nameof(AuthenticationState)}>. Consider using {typeof(CascadingAuthenticationState).Name} to supply this.");
+            }
+
+            // First render in pending state
+            // If the task has already completed, this render will be skipped
+            currentAuthenticationState = null;
+
+            // Then render in completed state
+            // Importantly, we *don't* call StateHasChanged between the following async steps,
+            // otherwise we'd display an incorrect UI state while waiting for IsAuthorizedAsync
+            currentAuthenticationState = await AuthenticationState;
+            isAuthorized = await IsAuthorizedAsync(currentAuthenticationState.User);
+        }
+
+        /// <summary>
+        /// Gets the data required to apply authorization rules.
+        /// </summary>
+        protected abstract IAuthorizeData[] GetAuthorizeData();
+
+        private async Task<bool> IsAuthorizedAsync(ClaimsPrincipal user)
+        {
+            var authorizeData = GetAuthorizeData();
+            var policy = await AuthorizationPolicy.CombineAsync(
+                AuthorizationPolicyProvider, authorizeData);
+            var result = await AuthorizationService.AuthorizeAsync(user, Resource, policy);
+            return result.Succeeded;
+        }
+    }
+}