Unify platform callbacks handling using a new OpenIddictClientSystemIntegrationPlatformCallback type

src/OpenIddict.Abstractions/OpenIddictResources.resx

@@ -1480,7 +1480,7 @@ To apply post-logout redirection responses, create a class implementing 'IOpenId
     <value>The web authentication broker is only supported on UWP and requires running Windows 10 version 1709 (Fall Creators) or higher.</value>
   </data>
   <data name="ID0393" xml:space="preserve">
-    <value>The web authentication result cannot be resolved or contains invalid data.</value>
+    <value>The platform callback cannot be resolved or contains invalid data.</value>
   </data>
   <data name="ID0394" xml:space="preserve">
     <value>The issuer attached to the static configuration must be the same as the one configured in the validation options.</value>
@@ -1692,6 +1692,9 @@ To apply post-logout redirection responses, create a class implementing 'IOpenId
   <data name="ID0452" xml:space="preserve">
     <value>Custom tabs intents are only supported on Android.</value>
   </data>
+  <data name="ID0453" xml:space="preserve">
+    <value>The specified intent doesn't contain a valid data URI.</value>
+  </data>
   <data name="ID2000" xml:space="preserve">
     <value>The security token is missing.</value>
   </data>

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationExtensions.cs

@@ -103,17 +103,18 @@ public static class OpenIddictClientSystemIntegrationExtensions
 
         // Register the built-in filters used by the default OpenIddict client system integration event handlers.
         builder.Services.TryAddSingleton<RequireASWebAuthenticationSession>();
-        builder.Services.TryAddSingleton<RequireASWebAuthenticationCallbackUrl>();
         builder.Services.TryAddSingleton<RequireAuthenticationNonce>();
         builder.Services.TryAddSingleton<RequireCustomTabsIntent>();
-        builder.Services.TryAddSingleton<RequireCustomTabsIntentData>();
         builder.Services.TryAddSingleton<RequireEmbeddedWebServerEnabled>();
         builder.Services.TryAddSingleton<RequireHttpListenerContext>();
         builder.Services.TryAddSingleton<RequireInteractiveSession>();
+        builder.Services.TryAddSingleton<RequirePlatformCallback>();
         builder.Services.TryAddSingleton<RequireProtocolActivation>();
         builder.Services.TryAddSingleton<RequireSystemBrowser>();
         builder.Services.TryAddSingleton<RequireWebAuthenticationBroker>();
+#pragma warning disable CS0618
         builder.Services.TryAddSingleton<RequireWebAuthenticationResult>();
+#pragma warning restore CS0618
 
         // Register the built-in event handlers used by the OpenIddict client system integration components.
         // Note: the order used here is not important, as the actual order is set in the options.

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationHandlerFilters.cs

@@ -17,34 +17,6 @@ namespace OpenIddict.Client.SystemIntegration;
 [EditorBrowsable(EditorBrowsableState.Advanced)]
 public static class OpenIddictClientSystemIntegrationHandlerFilters
 {
-    /// <summary>
-    /// Represents a filter that excludes the associated handlers if no AS web
-    /// authentication callback URL can be found in the transaction properties.
-    /// </summary>
-    public sealed class RequireASWebAuthenticationCallbackUrl : IOpenIddictClientHandlerFilter<BaseContext>
-    {
-        /// <inheritdoc/>
-        public ValueTask<bool> IsActiveAsync(BaseContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-#if SUPPORTS_AUTHENTICATION_SERVICES && SUPPORTS_FOUNDATION
-            if (IsASWebAuthenticationSessionSupported())
-            {
-                return new(ContainsASWebAuthenticationSessionResult(context.Transaction));
-            }
-
-            [MethodImpl(MethodImplOptions.NoInlining)]
-            static bool ContainsASWebAuthenticationSessionResult(OpenIddictClientTransaction transaction)
-                => transaction.GetASWebAuthenticationCallbackUrl() is not null;
-#endif
-            return new(false);
-        }
-    }
-
     /// <summary>
     /// Represents a filter that excludes the associated handlers if
     /// the AS web authentication session integration was not enabled.
@@ -133,33 +105,6 @@ public static class OpenIddictClientSystemIntegrationHandlerFilters
             return new(false);
         }
     }
-    /// <summary>
-    /// Represents a filter that excludes the associated handlers if no
-    /// custom tabs intent data can be found in the transaction properties.
-    /// </summary>
-    public sealed class RequireCustomTabsIntentData : IOpenIddictClientHandlerFilter<BaseContext>
-    {
-        /// <inheritdoc/>
-        public ValueTask<bool> IsActiveAsync(BaseContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-#if SUPPORTS_ANDROID && SUPPORTS_ANDROIDX_BROWSER
-            if (IsCustomTabsIntentSupported())
-            {
-                return new(ContainsCustomTabsIntentData(context.Transaction));
-            }
-
-            [MethodImpl(MethodImplOptions.NoInlining)]
-            static bool ContainsCustomTabsIntentData(OpenIddictClientTransaction transaction)
-                => transaction.GetCustomTabsIntentData() is not null;
-#endif
-            return new(false);
-        }
-    }
 
     /// <summary>
     /// Represents a filter that excludes the associated handlers if the embedded web server was not enabled.
@@ -217,6 +162,24 @@ public static class OpenIddictClientSystemIntegrationHandlerFilters
         }
     }
 
+    /// <summary>
+    /// Represents a filter that excludes the associated handlers if no
+    /// platform callback can be found in the transaction properties.
+    /// </summary>
+    public sealed class RequirePlatformCallback : IOpenIddictClientHandlerFilter<BaseContext>
+    {
+        /// <inheritdoc/>
+        public ValueTask<bool> IsActiveAsync(BaseContext context)
+        {
+            if (context is null)
+            {
+                throw new ArgumentNullException(nameof(context));
+            }
+
+            return new(context.Transaction.GetPlatformCallback() is not null);
+        }
+    }
+
     /// <summary>
     /// Represents a filter that excludes the associated handlers if no protocol activation was found.
     /// </summary>
@@ -304,6 +267,7 @@ public static class OpenIddictClientSystemIntegrationHandlerFilters
     /// Represents a filter that excludes the associated handlers if no
     /// web authentication operation was triggered during the transaction.
     /// </summary>
+    [Obsolete("This filter is obsolete and will be removed in a future version.")]
     public sealed class RequireWebAuthenticationResult : IOpenIddictClientHandlerFilter<BaseContext>
     {
         /// <inheritdoc/>

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationHandlers.Authentication.cs

@@ -57,9 +57,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
              */
             ExtractGetOrPostHttpListenerRequest<ExtractRedirectionRequestContext>.Descriptor,
             ExtractProtocolActivationParameters<ExtractRedirectionRequestContext>.Descriptor,
-            ExtractASWebAuthenticationCallbackUrlData<ExtractRedirectionRequestContext>.Descriptor,
-            ExtractCustomTabsIntentData<ExtractRedirectionRequestContext>.Descriptor,
-            ExtractWebAuthenticationResultData<ExtractRedirectionRequestContext>.Descriptor,
+            ExtractPlatformCallbackParameters<ExtractRedirectionRequestContext>.Descriptor,
 
             /*
              * Redirection response handling:
@@ -68,9 +66,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
             AttachCacheControlHeader<ApplyRedirectionResponseContext>.Descriptor,
             ProcessEmptyHttpResponse.Descriptor,
             ProcessProtocolActivationResponse<ApplyRedirectionResponseContext>.Descriptor,
-            ProcessASWebAuthenticationSessionResponse<ApplyRedirectionResponseContext>.Descriptor,
-            ProcessCustomTabsIntentResponse<ApplyRedirectionResponseContext>.Descriptor,
-            ProcessWebAuthenticationResultResponse<ApplyRedirectionResponseContext>.Descriptor
+            ProcessPlatformCallbackResponse<ApplyRedirectionResponseContext>.Descriptor
         ]);
 
         /// <summary>
@@ -123,7 +119,8 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0446));
                 }
 
-                var source = new TaskCompletionSource<NSUrl>(TaskCreationOptions.RunContinuationsAsynchronously);
+                var source = new TaskCompletionSource<OpenIddictClientSystemIntegrationPlatformCallback>(
+                    TaskCreationOptions.RunContinuationsAsynchronously);
 
                 // OpenIddict represents the complete interactive authentication dance as a two-phase process:
                 //   - The challenge, during which the user is redirected to the authorization server, either
@@ -161,11 +158,11 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     throw new InvalidOperationException(SR.GetResourceString(SR.ID0448));
                 }
 
-                NSUrl url;
+                OpenIddictClientSystemIntegrationPlatformCallback callback;
 
                 try
                 {
-                    url = await source.Task.WaitAsync(context.CancellationToken);
+                    callback = await source.Task.WaitAsync(context.CancellationToken);
                 }
 
                 // Since the result of this operation is known by the time the task signaled by ASWebAuthenticationSession
@@ -195,7 +192,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     return;
                 }
 
-                await _service.HandleASWebAuthenticationCallbackUrlAsync(url, context.CancellationToken);
+                await _service.HandlePlatformCallbackAsync(callback, context.CancellationToken);
                 context.HandleRequest();
                 return;
 
@@ -250,7 +247,43 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     {
                         if (url is not null)
                         {
-                            source.SetResult(url);
+                            var parameters = new Dictionary<string, OpenIddictParameter>(StringComparer.Ordinal);
+
+                            if (!string.IsNullOrEmpty(url.Query))
+                            {
+                                foreach (var parameter in OpenIddictHelpers.ParseQuery(url.Query))
+                                {
+                                    parameters[parameter.Key] = parameter.Value.Count switch
+                                    {
+                                        0 => default,
+                                        1 => parameter.Value[0],
+                                        _ => parameter.Value.ToArray()
+                                    };
+                                }
+                            }
+
+                            // Note: the fragment is always processed after the query string to ensure that
+                            // parameters extracted from the fragment are preferred to parameters extracted
+                            // from the query string when they are present in both parts.
+
+                            if (!string.IsNullOrEmpty(url.Fragment))
+                            {
+                                foreach (var parameter in OpenIddictHelpers.ParseFragment(url.Fragment))
+                                {
+                                    parameters[parameter.Key] = parameter.Value.Count switch
+                                    {
+                                        0 => default,
+                                        1 => parameter.Value[0],
+                                        _ => parameter.Value.ToArray()
+                                    };
+                                }
+                            }
+
+                            source.SetResult(new OpenIddictClientSystemIntegrationPlatformCallback(url!, parameters)
+                            {
+                                // Attach the raw URL to the callback properties.
+                                Properties = { [typeof(NSUrl).FullName!] = url }
+                            });
                         }
 
                         else if (error is not null)
@@ -426,8 +459,47 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                             parameter => new StringValues((string?[]?) parameter.Value))),
                     callbackUri: new Uri(context.RedirectUri, UriKind.Absolute)))
                 {
-                    case { ResponseStatus: WebAuthenticationStatus.Success } result:
-                        await _service.HandleWebAuthenticationResultAsync(result, context.CancellationToken);
+                    case { ResponseStatus: WebAuthenticationStatus.Success } result
+                        when Uri.TryCreate(result.ResponseData, UriKind.Absolute, out Uri? uri):
+                        var parameters = new Dictionary<string, OpenIddictParameter>(StringComparer.Ordinal);
+
+                        if (!string.IsNullOrEmpty(uri.Query))
+                        {
+                            foreach (var parameter in OpenIddictHelpers.ParseQuery(uri.Query))
+                            {
+                                parameters[parameter.Key] = parameter.Value.Count switch
+                                {
+                                    0 => default,
+                                    1 => parameter.Value[0],
+                                    _ => parameter.Value.ToArray()
+                                };
+                            }
+                        }
+
+                        // Note: the fragment is always processed after the query string to ensure that
+                        // parameters extracted from the fragment are preferred to parameters extracted
+                        // from the query string when they are present in both parts.
+
+                        if (!string.IsNullOrEmpty(uri.Fragment))
+                        {
+                            foreach (var parameter in OpenIddictHelpers.ParseFragment(uri.Fragment))
+                            {
+                                parameters[parameter.Key] = parameter.Value.Count switch
+                                {
+                                    0 => default,
+                                    1 => parameter.Value[0],
+                                    _ => parameter.Value.ToArray()
+                                };
+                            }
+                        }
+
+                        var callback = new OpenIddictClientSystemIntegrationPlatformCallback(uri, parameters)
+                        {
+                            // Attach the authentication result to the properties.
+                            Properties = { [typeof(WebAuthenticationResult).FullName!] = result }
+                        };
+
+                        await _service.HandlePlatformCallbackAsync(callback, context.CancellationToken);
                         context.HandleRequest();
                         return;
 

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationHandlers.Session.cs

@@ -57,9 +57,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
              */
             ExtractGetOrPostHttpListenerRequest<ExtractPostLogoutRedirectionRequestContext>.Descriptor,
             ExtractProtocolActivationParameters<ExtractPostLogoutRedirectionRequestContext>.Descriptor,
-            ExtractASWebAuthenticationCallbackUrlData<ExtractPostLogoutRedirectionRequestContext>.Descriptor,
-            ExtractCustomTabsIntentData<ExtractPostLogoutRedirectionRequestContext>.Descriptor,
-            ExtractWebAuthenticationResultData<ExtractPostLogoutRedirectionRequestContext>.Descriptor,
+            ExtractPlatformCallbackParameters<ExtractPostLogoutRedirectionRequestContext>.Descriptor,
 
             /*
              * Post-logout redirection response handling:
@@ -68,9 +66,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
             AttachCacheControlHeader<ApplyPostLogoutRedirectionResponseContext>.Descriptor,
             ProcessEmptyHttpResponse.Descriptor,
             ProcessProtocolActivationResponse<ApplyPostLogoutRedirectionResponseContext>.Descriptor,
-            ProcessASWebAuthenticationSessionResponse<ApplyPostLogoutRedirectionResponseContext>.Descriptor,
-            ProcessCustomTabsIntentResponse<ApplyPostLogoutRedirectionResponseContext>.Descriptor,
-            ProcessWebAuthenticationResultResponse<ApplyPostLogoutRedirectionResponseContext>.Descriptor
+            ProcessPlatformCallbackResponse<ApplyPostLogoutRedirectionResponseContext>.Descriptor
         ]);
 
         /// <summary>
@@ -123,7 +119,8 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0446));
                 }
 
-                var source = new TaskCompletionSource<NSUrl>(TaskCreationOptions.RunContinuationsAsynchronously);
+                var source = new TaskCompletionSource<OpenIddictClientSystemIntegrationPlatformCallback>(
+                    TaskCreationOptions.RunContinuationsAsynchronously);
 
                 // OpenIddict represents the complete interactive logout dance as a two-phase process:
                 //   - The sign-out, during which the user is redirected to the authorization server, either
@@ -161,11 +158,11 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     throw new InvalidOperationException(SR.GetResourceString(SR.ID0448));
                 }
 
-                NSUrl url;
+                OpenIddictClientSystemIntegrationPlatformCallback callback;
 
                 try
                 {
-                    url = await source.Task.WaitAsync(context.CancellationToken);
+                    callback = await source.Task.WaitAsync(context.CancellationToken);
                 }
 
                 // Since the result of this operation is known by the time the task signaled by ASWebAuthenticationSession
@@ -195,7 +192,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     return;
                 }
 
-                await _service.HandleASWebAuthenticationCallbackUrlAsync(url, context.CancellationToken);
+                await _service.HandlePlatformCallbackAsync(callback, context.CancellationToken);
                 context.HandleRequest();
                 return;
 
@@ -250,7 +247,43 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     {
                         if (url is not null)
                         {
-                            source.SetResult(url);
+                            var parameters = new Dictionary<string, OpenIddictParameter>(StringComparer.Ordinal);
+
+                            if (!string.IsNullOrEmpty(url.Query))
+                            {
+                                foreach (var parameter in OpenIddictHelpers.ParseQuery(url.Query))
+                                {
+                                    parameters[parameter.Key] = parameter.Value.Count switch
+                                    {
+                                        0 => default,
+                                        1 => parameter.Value[0],
+                                        _ => parameter.Value.ToArray()
+                                    };
+                                }
+                            }
+
+                            // Note: the fragment is always processed after the query string to ensure that
+                            // parameters extracted from the fragment are preferred to parameters extracted
+                            // from the query string when they are present in both parts.
+
+                            if (!string.IsNullOrEmpty(url.Fragment))
+                            {
+                                foreach (var parameter in OpenIddictHelpers.ParseFragment(url.Fragment))
+                                {
+                                    parameters[parameter.Key] = parameter.Value.Count switch
+                                    {
+                                        0 => default,
+                                        1 => parameter.Value[0],
+                                        _ => parameter.Value.ToArray()
+                                    };
+                                }
+                            }
+
+                            source.SetResult(new OpenIddictClientSystemIntegrationPlatformCallback(url!, parameters)
+                            {
+                                // Attach the raw URL to the callback properties.
+                                Properties = { [typeof(NSUrl).FullName!] = url }
+                            });
                         }
 
                         else if (error is not null)
@@ -426,8 +459,47 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                             parameter => new StringValues((string?[]?) parameter.Value))),
                     callbackUri: new Uri(context.PostLogoutRedirectUri, UriKind.Absolute)))
                 {
-                    case { ResponseStatus: WebAuthenticationStatus.Success } result:
-                        await _service.HandleWebAuthenticationResultAsync(result, context.CancellationToken);
+                    case { ResponseStatus: WebAuthenticationStatus.Success } result
+                        when Uri.TryCreate(result.ResponseData, UriKind.Absolute, out Uri? uri):
+                        var parameters = new Dictionary<string, OpenIddictParameter>(StringComparer.Ordinal);
+
+                        if (!string.IsNullOrEmpty(uri.Query))
+                        {
+                            foreach (var parameter in OpenIddictHelpers.ParseQuery(uri.Query))
+                            {
+                                parameters[parameter.Key] = parameter.Value.Count switch
+                                {
+                                    0 => default,
+                                    1 => parameter.Value[0],
+                                    _ => parameter.Value.ToArray()
+                                };
+                            }
+                        }
+
+                        // Note: the fragment is always processed after the query string to ensure that
+                        // parameters extracted from the fragment are preferred to parameters extracted
+                        // from the query string when they are present in both parts.
+
+                        if (!string.IsNullOrEmpty(uri.Fragment))
+                        {
+                            foreach (var parameter in OpenIddictHelpers.ParseFragment(uri.Fragment))
+                            {
+                                parameters[parameter.Key] = parameter.Value.Count switch
+                                {
+                                    0 => default,
+                                    1 => parameter.Value[0],
+                                    _ => parameter.Value.ToArray()
+                                };
+                            }
+                        }
+
+                        var callback = new OpenIddictClientSystemIntegrationPlatformCallback(uri, parameters)
+                        {
+                            // Attach the authentication result to the properties.
+                            Properties = { [typeof(WebAuthenticationResult).FullName!] = result }
+                        };
+
+                        await _service.HandlePlatformCallbackAsync(callback, context.CancellationToken);
                         context.HandleRequest();
                         return;
 

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationHandlers.cs

@@ -9,7 +9,6 @@ using System.ComponentModel;
 using System.Diagnostics;
 using System.Net;
 using System.Runtime.CompilerServices;
-using System.Runtime.Versioning;
 using System.Security.Claims;
 using System.Text;
 using Microsoft.Extensions.Hosting;
@@ -24,18 +23,6 @@ using static OpenIddict.Client.SystemIntegration.OpenIddictClientSystemIntegrati
 using IHostApplicationLifetime = Microsoft.Extensions.Hosting.IApplicationLifetime;
 #endif
 
-#if SUPPORTS_ANDROID
-using NativeUri = Android.Net.Uri;
-#endif
-
-#if SUPPORTS_FOUNDATION
-using Foundation;
-#endif
-
-#if SUPPORTS_WINDOWS_RUNTIME
-using Windows.Security.Authentication.Web;
-#endif
-
 namespace OpenIddict.Client.SystemIntegration;
 
 [EditorBrowsable(EditorBrowsableState.Never)]
@@ -47,9 +34,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
          */
         ResolveRequestUriFromHttpListenerRequest.Descriptor,
         ResolveRequestUriFromProtocolActivation.Descriptor,
-        ResolveRequestUriFromASWebAuthenticationCallbackUrl.Descriptor,
-        ResolveRequestUriFromCustomTabsIntentData.Descriptor,
-        ResolveRequestUriFromWebAuthenticationResult.Descriptor,
+        ResolveRequestUriFromPlatformCallback.Descriptor,
         InferEndpointTypeFromDynamicAddress.Descriptor,
         RejectUnknownHttpRequests.Descriptor,
 
@@ -215,26 +200,23 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
     }
 
     /// <summary>
-    /// Contains the logic responsible for resolving the request URI from the AS web authentication session callback URL.
-    /// Note: this handler is not used when the OpenID Connect request is not an AS web authentication session callback URL.
+    /// Contains the logic responsible for resolving the request URI from the platform callback details.
+    /// Note: this handler is not used when the OpenID Connect request is not a platform callback.
     /// </summary>
-    public sealed class ResolveRequestUriFromASWebAuthenticationCallbackUrl : IOpenIddictClientHandler<ProcessRequestContext>
+    public sealed class ResolveRequestUriFromPlatformCallback : IOpenIddictClientHandler<ProcessRequestContext>
     {
         /// <summary>
         /// Gets the default descriptor definition assigned to this handler.
         /// </summary>
         public static OpenIddictClientHandlerDescriptor Descriptor { get; }
             = OpenIddictClientHandlerDescriptor.CreateBuilder<ProcessRequestContext>()
-                .AddFilter<RequireASWebAuthenticationCallbackUrl>()
-                .UseSingletonHandler<ResolveRequestUriFromASWebAuthenticationCallbackUrl>()
+                .AddFilter<RequirePlatformCallback>()
+                .UseSingletonHandler<ResolveRequestUriFromPlatformCallback>()
                 .SetOrder(ResolveRequestUriFromProtocolActivation.Descriptor.Order + 1_000)
                 .SetType(OpenIddictClientHandlerType.BuiltIn)
                 .Build();
 
         /// <inheritdoc/>
-        [SupportedOSPlatform("ios12.0")]
-        [SupportedOSPlatform("maccatalyst13.1")]
-        [SupportedOSPlatform("macos10.15")]
         public ValueTask HandleAsync(ProcessRequestContext context)
         {
             if (context is null)
@@ -242,10 +224,9 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                 throw new ArgumentNullException(nameof(context));
             }
 
-#if SUPPORTS_AUTHENTICATION_SERVICES && SUPPORTS_FOUNDATION
-            (context.BaseUri, context.RequestUri) = context.Transaction.GetASWebAuthenticationCallbackUrl() switch
+            (context.BaseUri, context.RequestUri) = context.Transaction.GetPlatformCallback() switch
             {
-                NSUrl url when Uri.TryCreate(url.AbsoluteString, UriKind.Absolute, out Uri? uri) => (
+                { CallbackUri: Uri uri } => (
                     BaseUri: new UriBuilder(uri) { Path = null, Query = null, Fragment = null }.Uri,
                     RequestUri: uri),
 
@@ -253,52 +234,6 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
             };
 
             return default;
-#else
-            throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0446));
-#endif
-        }
-    }
-
-    /// <summary>
-    /// Contains the logic responsible for resolving the request URI from the custom tabs intent data.
-    /// Note: this handler is not used when the OpenID Connect request is not an custom tabs intent callback.
-    /// </summary>
-    public sealed class ResolveRequestUriFromCustomTabsIntentData : IOpenIddictClientHandler<ProcessRequestContext>
-    {
-        /// <summary>
-        /// Gets the default descriptor definition assigned to this handler.
-        /// </summary>
-        public static OpenIddictClientHandlerDescriptor Descriptor { get; }
-            = OpenIddictClientHandlerDescriptor.CreateBuilder<ProcessRequestContext>()
-                .AddFilter<RequireCustomTabsIntentData>()
-                .UseSingletonHandler<ResolveRequestUriFromCustomTabsIntentData>()
-                .SetOrder(ResolveRequestUriFromASWebAuthenticationCallbackUrl.Descriptor.Order + 1_000)
-                .SetType(OpenIddictClientHandlerType.BuiltIn)
-                .Build();
-
-        /// <inheritdoc/>
-        [SupportedOSPlatform("android21.0")]
-        public ValueTask HandleAsync(ProcessRequestContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-#if SUPPORTS_ANDROID
-            (context.BaseUri, context.RequestUri) = context.Transaction.GetCustomTabsIntentData() switch
-            {
-                NativeUri url when Uri.TryCreate(url.ToString(), UriKind.Absolute, out Uri? uri) => (
-                    BaseUri: new UriBuilder(uri) { Path = null, Query = null, Fragment = null }.Uri,
-                    RequestUri: uri),
-
-                _ => throw new InvalidOperationException(SR.GetResourceString(SR.ID0393))
-            };
-
-            return default;
-#else
-            throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0452));
-#endif
         }
     }
 
@@ -306,6 +241,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
     /// Contains the logic responsible for resolving the request URI from the web authentication result.
     /// Note: this handler is not used when the OpenID Connect request is not a web authentication result.
     /// </summary>
+    [Obsolete("This event handler is obsolete and will be removed in a future version.")]
     public sealed class ResolveRequestUriFromWebAuthenticationResult : IOpenIddictClientHandler<ProcessRequestContext>
     {
         /// <summary>
@@ -315,35 +251,13 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
             = OpenIddictClientHandlerDescriptor.CreateBuilder<ProcessRequestContext>()
                 .AddFilter<RequireWebAuthenticationResult>()
                 .UseSingletonHandler<ResolveRequestUriFromWebAuthenticationResult>()
-                .SetOrder(ResolveRequestUriFromCustomTabsIntentData.Descriptor.Order + 1_000)
+                .SetOrder(ResolveRequestUriFromPlatformCallback.Descriptor.Order + 1_000)
                 .SetType(OpenIddictClientHandlerType.BuiltIn)
                 .Build();
 
         /// <inheritdoc/>
-        [SupportedOSPlatform("windows10.0.17763")]
         public ValueTask HandleAsync(ProcessRequestContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-#if SUPPORTS_WINDOWS_RUNTIME
-            (context.BaseUri, context.RequestUri) = context.Transaction.GetWebAuthenticationResult() switch
-            {
-                { ResponseStatus: WebAuthenticationStatus.Success, ResponseData: string data } when
-                    Uri.TryCreate(data, UriKind.Absolute, out Uri? uri) => (
-                        BaseUri: new UriBuilder(uri) { Path = null, Query = null, Fragment = null }.Uri,
-                        RequestUri: uri),
-
-                _ => throw new InvalidOperationException(SR.GetResourceString(SR.ID0393))
-            };
-
-            return default;
-#else
-            throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0392));
-#endif
-        }
+            => throw new NotSupportedException(SR.GetResourceString(SR.ID0403));
     }
 
     /// <summary>
@@ -671,26 +585,23 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
     }
 
     /// <summary>
-    /// Contains the logic responsible for extracting OpenID Connect requests from the callback URL of an AS session.
-    /// Note: this handler is not used when the OpenID Connect request is not an AS web authentication session callback.
+    /// Contains the logic responsible for extracting OpenID Connect requests from the URI of a platform callback.
+    /// Note: this handler is not used when the OpenID Connect request is not a platform callback.
     /// </summary>
-    public sealed class ExtractASWebAuthenticationCallbackUrlData<TContext> : IOpenIddictClientHandler<TContext> where TContext : BaseValidatingContext
+    public sealed class ExtractPlatformCallbackParameters<TContext> : IOpenIddictClientHandler<TContext> where TContext : BaseValidatingContext
     {
         /// <summary>
         /// Gets the default descriptor definition assigned to this handler.
         /// </summary>
         public static OpenIddictClientHandlerDescriptor Descriptor { get; }
             = OpenIddictClientHandlerDescriptor.CreateBuilder<TContext>()
-                .AddFilter<RequireASWebAuthenticationCallbackUrl>()
-                .UseSingletonHandler<ExtractASWebAuthenticationCallbackUrlData<TContext>>()
+                .AddFilter<RequirePlatformCallback>()
+                .UseSingletonHandler<ExtractPlatformCallbackParameters<TContext>>()
                 .SetOrder(ExtractProtocolActivationParameters<TContext>.Descriptor.Order + 1_000)
                 .SetType(OpenIddictClientHandlerType.BuiltIn)
                 .Build();
 
         /// <inheritdoc/>
-        [SupportedOSPlatform("ios12.0")]
-        [SupportedOSPlatform("maccatalyst13.1")]
-        [SupportedOSPlatform("macos10.15")]
         public ValueTask HandleAsync(TContext context)
         {
             if (context is null)
@@ -698,105 +609,14 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                 throw new ArgumentNullException(nameof(context));
             }
 
-#if SUPPORTS_AUTHENTICATION_SERVICES && SUPPORTS_FOUNDATION
-            if (context.Transaction.GetASWebAuthenticationCallbackUrl()
-                is not NSUrl url || !Uri.TryCreate(url.AbsoluteString, UriKind.Absolute, out Uri? uri))
+            if (context.Transaction.GetPlatformCallback() is not OpenIddictClientSystemIntegrationPlatformCallback callback)
             {
                 throw new InvalidOperationException(SR.GetResourceString(SR.ID0393));
             }
 
-            var parameters = new Dictionary<string, StringValues>(StringComparer.Ordinal);
-
-            if (!string.IsNullOrEmpty(uri.Query))
-            {
-                foreach (var parameter in OpenIddictHelpers.ParseQuery(uri.Query))
-                {
-                    parameters[parameter.Key] = parameter.Value;
-                }
-            }
-
-            // Note: the fragment is always processed after the query string to ensure that
-            // parameters extracted from the fragment are preferred to parameters extracted
-            // from the query string when they are present in both parts.
-
-            if (!string.IsNullOrEmpty(uri.Fragment))
-            {
-                foreach (var parameter in OpenIddictHelpers.ParseFragment(uri.Fragment))
-                {
-                    parameters[parameter.Key] = parameter.Value;
-                }
-            }
-
-            context.Transaction.Request = new OpenIddictRequest(parameters);
+            context.Transaction.Request = new OpenIddictRequest(callback.Parameters);
 
             return default;
-#else
-            throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0446));
-#endif
-        }
-    }
-
-    /// <summary>
-    /// Contains the logic responsible for extracting OpenID Connect requests from the callback URL of a custom tabs intent.
-    /// Note: this handler is not used when the OpenID Connect request is not a custom tabs intent result.
-    /// </summary>
-    public sealed class ExtractCustomTabsIntentData<TContext> : IOpenIddictClientHandler<TContext> where TContext : BaseValidatingContext
-    {
-        /// <summary>
-        /// Gets the default descriptor definition assigned to this handler.
-        /// </summary>
-        public static OpenIddictClientHandlerDescriptor Descriptor { get; }
-            = OpenIddictClientHandlerDescriptor.CreateBuilder<TContext>()
-                .AddFilter<RequireCustomTabsIntentData>()
-                .UseSingletonHandler<ExtractCustomTabsIntentData<TContext>>()
-                .SetOrder(ExtractProtocolActivationParameters<TContext>.Descriptor.Order + 1_000)
-                .SetType(OpenIddictClientHandlerType.BuiltIn)
-                .Build();
-
-        /// <inheritdoc/>
-        [SupportedOSPlatform("android21.0")]
-        public ValueTask HandleAsync(TContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-#if SUPPORTS_ANDROID
-            if (context.Transaction.GetCustomTabsIntentData()
-                is not NativeUri url || !Uri.TryCreate(url.ToString(), UriKind.Absolute, out Uri? uri))
-            {
-                throw new InvalidOperationException(SR.GetResourceString(SR.ID0393));
-            }
-
-            var parameters = new Dictionary<string, StringValues>(StringComparer.Ordinal);
-
-            if (!string.IsNullOrEmpty(uri.Query))
-            {
-                foreach (var parameter in OpenIddictHelpers.ParseQuery(uri.Query))
-                {
-                    parameters[parameter.Key] = parameter.Value;
-                }
-            }
-
-            // Note: the fragment is always processed after the query string to ensure that
-            // parameters extracted from the fragment are preferred to parameters extracted
-            // from the query string when they are present in both parts.
-
-            if (!string.IsNullOrEmpty(uri.Fragment))
-            {
-                foreach (var parameter in OpenIddictHelpers.ParseFragment(uri.Fragment))
-                {
-                    parameters[parameter.Key] = parameter.Value;
-                }
-            }
-
-            context.Transaction.Request = new OpenIddictRequest(parameters);
-
-            return default;
-#else
-            throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0446));
-#endif
         }
     }
 
@@ -805,6 +625,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
     /// requests from the response data of a web authentication result.
     /// Note: this handler is not used when the OpenID Connect request is not a web authentication result.
     /// </summary>
+    [Obsolete("This event handler is obsolete and will be removed in a future version.")]
     public sealed class ExtractWebAuthenticationResultData<TContext> : IOpenIddictClientHandler<TContext> where TContext : BaseValidatingContext
     {
         /// <summary>
@@ -814,56 +635,13 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
             = OpenIddictClientHandlerDescriptor.CreateBuilder<TContext>()
                 .AddFilter<RequireWebAuthenticationResult>()
                 .UseSingletonHandler<ExtractWebAuthenticationResultData<TContext>>()
-                .SetOrder(ExtractCustomTabsIntentData<TContext>.Descriptor.Order + 1_000)
+                .SetOrder(ExtractPlatformCallbackParameters<TContext>.Descriptor.Order + 1_000)
                 .SetType(OpenIddictClientHandlerType.BuiltIn)
                 .Build();
 
         /// <inheritdoc/>
-        [SupportedOSPlatform("windows10.0.17763")]
         public ValueTask HandleAsync(TContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-#if SUPPORTS_WINDOWS_RUNTIME
-            if (context.Transaction.GetWebAuthenticationResult()
-                is not { ResponseStatus: WebAuthenticationStatus.Success, ResponseData: string data } ||
-                !Uri.TryCreate(data, UriKind.Absolute, out Uri? uri))
-            {
-                throw new InvalidOperationException(SR.GetResourceString(SR.ID0393));
-            }
-
-            var parameters = new Dictionary<string, StringValues>(StringComparer.Ordinal);
-
-            if (!string.IsNullOrEmpty(uri.Query))
-            {
-                foreach (var parameter in OpenIddictHelpers.ParseQuery(uri.Query))
-                {
-                    parameters[parameter.Key] = parameter.Value;
-                }
-            }
-
-            // Note: the fragment is always processed after the query string to ensure that
-            // parameters extracted from the fragment are preferred to parameters extracted
-            // from the query string when they are present in both parts.
-
-            if (!string.IsNullOrEmpty(uri.Fragment))
-            {
-                foreach (var parameter in OpenIddictHelpers.ParseFragment(uri.Fragment))
-                {
-                    parameters[parameter.Key] = parameter.Value;
-                }
-            }
-
-            context.Transaction.Request = new OpenIddictRequest(parameters);
-
-            return default;
-#else
-            throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0392));
-#endif
-        }
+            => throw new NotSupportedException(SR.GetResourceString(SR.ID0403));
     }
 
     /// <summary>
@@ -2056,7 +1834,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                 // the server support response_mode=fragment, use it if the response types contain
                 // a value that prevents response_mode=query from being used (token/id_token).
                 ({ Count: > 0 } client, { Count: > 0 } server) when
-                    OpenIddictClientSystemIntegrationHelpers.IsWebAuthenticationBrokerSupported()                     &&
+                    IsWebAuthenticationBrokerSupported()                                                              &&
                     IsAuthenticationMode(OpenIddictClientSystemIntegrationAuthenticationMode.WebAuthenticationBroker) &&
                     client.Contains(ResponseModes.Fragment) && server.Contains(ResponseModes.Fragment)                &&
                     (types.Contains(ResponseTypes.IdToken) || types.Contains(ResponseTypes.Token))
@@ -2067,7 +1845,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                 // assume it is supported and use it if the response types contain a value that
                 // prevents response_mode=query from being used (token/id_token).
                 ({ Count: > 0 } client, { Count: 0 }) when
-                    OpenIddictClientSystemIntegrationHelpers.IsWebAuthenticationBrokerSupported()                     &&
+                    IsWebAuthenticationBrokerSupported()                                                              &&
                     IsAuthenticationMode(OpenIddictClientSystemIntegrationAuthenticationMode.WebAuthenticationBroker) &&
                     client.Contains(ResponseModes.Fragment)                                                           &&
                     (types.Contains(ResponseTypes.IdToken) || types.Contains(ResponseTypes.Token))
@@ -2129,7 +1907,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                 // When using the web authentication broker on Windows, if both
                 // the client and the server support response_mode=fragment, use it.
                 ({ Count: > 0 } client, { Count: > 0 } server) when
-                    OpenIddictClientSystemIntegrationHelpers.IsWebAuthenticationBrokerSupported()                     &&
+                    IsWebAuthenticationBrokerSupported()                                                              &&
                     IsAuthenticationMode(OpenIddictClientSystemIntegrationAuthenticationMode.WebAuthenticationBroker) &&
                     client.Contains(ResponseModes.Fragment) && server.Contains(ResponseModes.Fragment)
                     => ResponseModes.Fragment,
@@ -2610,43 +2388,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
             = OpenIddictClientHandlerDescriptor.CreateBuilder<TContext>()
                 .AddFilter<RequireProtocolActivation>()
                 .UseSingletonHandler<ProcessProtocolActivationResponse<TContext>>()
-                .SetOrder(ProcessWebAuthenticationResultResponse<TContext>.Descriptor.Order - 1_000)
-                .SetType(OpenIddictClientHandlerType.BuiltIn)
-                .Build();
-
-        /// <inheritdoc/>
-        public ValueTask HandleAsync(TContext context)
-        {
-            if (context is null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            // For both protocol activations (initial or redirected) and web-view-like results,
-            // no proper response can be generated and eventually displayed to the user. In this
-            // case, simply stop processing the response and mark the request as fully handled.
-            //
-            // Note: this logic applies to both successful and errored responses.
-
-            context.HandleRequest();
-            return default;
-        }
-    }
-
-    /// <summary>
-    /// Contains the logic responsible for marking OpenID Connect responses returned via a custom tabs intent web as processed.
-    /// </summary>
-    public sealed class ProcessCustomTabsIntentResponse<TContext> : IOpenIddictClientHandler<TContext>
-        where TContext : BaseRequestContext
-    {
-        /// <summary>
-        /// Gets the default descriptor definition assigned to this handler.
-        /// </summary>
-        public static OpenIddictClientHandlerDescriptor Descriptor { get; }
-            = OpenIddictClientHandlerDescriptor.CreateBuilder<TContext>()
-                .AddFilter<RequireCustomTabsIntentData>()
-                .UseSingletonHandler<ProcessCustomTabsIntentResponse<TContext>>()
-                .SetOrder(int.MaxValue)
+                .SetOrder(ProcessPlatformCallbackResponse<TContext>.Descriptor.Order - 1_000)
                 .SetType(OpenIddictClientHandlerType.BuiltIn)
                 .Build();
 
@@ -2670,10 +2412,9 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
     }
 
     /// <summary>
-    /// Contains the logic responsible for marking OpenID Connect responses
-    /// returned via AS web authentication callback URLs as processed.
+    /// Contains the logic responsible for marking OpenID Connect responses returned via a platform callback.
     /// </summary>
-    public sealed class ProcessASWebAuthenticationSessionResponse<TContext> : IOpenIddictClientHandler<TContext>
+    public sealed class ProcessPlatformCallbackResponse<TContext> : IOpenIddictClientHandler<TContext>
         where TContext : BaseRequestContext
     {
         /// <summary>
@@ -2681,8 +2422,8 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
         /// </summary>
         public static OpenIddictClientHandlerDescriptor Descriptor { get; }
             = OpenIddictClientHandlerDescriptor.CreateBuilder<TContext>()
-                .AddFilter<RequireASWebAuthenticationCallbackUrl>()
-                .UseSingletonHandler<ProcessASWebAuthenticationSessionResponse<TContext>>()
+                .AddFilter<RequirePlatformCallback>()
+                .UseSingletonHandler<ProcessPlatformCallbackResponse<TContext>>()
                 .SetOrder(int.MaxValue)
                 .SetType(OpenIddictClientHandlerType.BuiltIn)
                 .Build();
@@ -2710,6 +2451,7 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
     /// Contains the logic responsible for marking OpenID Connect
     /// responses returned via web authentication results as processed.
     /// </summary>
+    [Obsolete("This handler is obsolete and will be removed in a future version.")]
     public sealed class ProcessWebAuthenticationResultResponse<TContext> : IOpenIddictClientHandler<TContext>
         where TContext : BaseRequestContext
     {

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationHelpers.cs

@@ -44,6 +44,14 @@ namespace OpenIddict.Client.SystemIntegration;
 /// </summary>
 public static class OpenIddictClientSystemIntegrationHelpers
 {
+    /// <summary>
+    /// Gets the <see cref="OpenIddictClientSystemIntegrationPlatformCallback"/> associated with the current context.
+    /// </summary>
+    /// <param name="transaction">The transaction instance.</param>
+    /// <returns>The <see cref="OpenIddictClientSystemIntegrationPlatformCallback"/> instance or <see langword="null"/> if it couldn't be found.</returns>
+    public static OpenIddictClientSystemIntegrationPlatformCallback? GetPlatformCallback(this OpenIddictClientTransaction transaction)
+        => transaction.GetProperty<OpenIddictClientSystemIntegrationPlatformCallback>(typeof(OpenIddictClientSystemIntegrationPlatformCallback).FullName!);
+
     /// <summary>
     /// Gets the <see cref="OpenIddictClientSystemIntegrationActivation"/> associated with the current context.
     /// </summary>
@@ -60,39 +68,17 @@ public static class OpenIddictClientSystemIntegrationHelpers
     public static HttpListenerContext? GetHttpListenerContext(this OpenIddictClientTransaction transaction)
         => transaction.GetProperty<HttpListenerContext>(typeof(HttpListenerContext).FullName!);
 
-#if SUPPORTS_AUTHENTICATION_SERVICES && SUPPORTS_FOUNDATION
-    /// <summary>
-    /// Gets the AS web authentication callback URL associated with the current context.
-    /// </summary>
-    /// <param name="transaction">The transaction instance.</param>
-    /// <returns>The <see cref="NSUrl"/> instance or <see langword="null"/> if it couldn't be found.</returns>
-    [SupportedOSPlatform("ios12.0")]
-    [SupportedOSPlatform("maccatalyst13.1")]
-    [SupportedOSPlatform("macos10.15")]
-    public static NSUrl? GetASWebAuthenticationCallbackUrl(this OpenIddictClientTransaction transaction)
-        => transaction.GetProperty<NSUrl>(typeof(NSUrl).FullName!);
-#endif
-
-#if SUPPORTS_ANDROID && SUPPORTS_ANDROIDX_BROWSER
-    /// <summary>
-    /// Gets the custom tabs intent data associated with the current context.
-    /// </summary>
-    /// <param name="transaction">The transaction instance.</param>
-    /// <returns>The <see cref="NativeUri"/> instance or <see langword="null"/> if it couldn't be found.</returns>
-    [SupportedOSPlatform("android21.0")]
-    public static NativeUri? GetCustomTabsIntentData(this OpenIddictClientTransaction transaction)
-        => transaction.GetProperty<NativeUri>(typeof(NativeUri).FullName!);
-#endif
-
 #if SUPPORTS_WINDOWS_RUNTIME
     /// <summary>
     /// Gets the <see cref="WebAuthenticationResult"/> associated with the current context.
     /// </summary>
     /// <param name="transaction">The transaction instance.</param>
     /// <returns>The <see cref="HttpListenerContext"/> instance or <see langword="null"/> if it couldn't be found.</returns>
-    [SupportedOSPlatform("windows10.0.17763")]
+    [Obsolete("This extension is obsolete and will be removed in a future version."), SupportedOSPlatform("windows10.0.17763")]
     public static WebAuthenticationResult? GetWebAuthenticationResult(this OpenIddictClientTransaction transaction)
-        => transaction.GetProperty<WebAuthenticationResult>(typeof(WebAuthenticationResult).FullName!);
+        => transaction.GetPlatformCallback() is OpenIddictClientSystemIntegrationPlatformCallback callback &&
+            callback.Properties.TryGetValue(typeof(WebAuthenticationResult).FullName!, out object? property) &&
+            property is WebAuthenticationResult result ? result : null;
 #endif
 
     /// <summary>

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationPlatformCallback.cs

@@ -0,0 +1,62 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
+ * See https://github.com/openiddict/openiddict-core for more information concerning
+ * the license and the contributors participating to this project.
+ */
+
+using System.Collections.Immutable;
+using System.ComponentModel;
+using OpenIddict.Extensions;
+
+namespace OpenIddict.Client.SystemIntegration;
+
+/// <summary>
+/// Represents a generic platform callback.
+/// </summary>
+[EditorBrowsable(EditorBrowsableState.Advanced)]
+public sealed class OpenIddictClientSystemIntegrationPlatformCallback
+{
+    /// <summary>
+    /// Creates a new instance of the <see cref="OpenIddictClientSystemIntegrationPlatformCallback"/> class.
+    /// </summary>
+    /// <param name="uri">The callback URI.</param>
+    /// <param name="parameters">The callback parameters.</param>
+    /// <exception cref="ArgumentNullException"><paramref name="uri"/> is <see langword="null"/>.</exception>
+    /// <exception cref="ArgumentNullException"><paramref name="parameters"/> is <see langword="null"/>.</exception>
+    public OpenIddictClientSystemIntegrationPlatformCallback(
+        Uri uri, IReadOnlyDictionary<string, OpenIddictParameter> parameters)
+    {
+        if (uri is null)
+        {
+            throw new ArgumentNullException(nameof(uri));
+        }
+
+        if (!uri.IsAbsoluteUri || OpenIddictHelpers.IsImplicitFileUri(uri))
+        {
+            throw new ArgumentException(SR.GetResourceString(SR.ID0144), nameof(uri));
+        }
+
+        if (parameters is null)
+        {
+            throw new ArgumentNullException(nameof(parameters));
+        }
+
+        CallbackUri = uri;
+        Parameters = parameters.ToImmutableDictionary();
+    }
+
+    /// <summary>
+    /// Gets the callback URI.
+    /// </summary>
+    public Uri CallbackUri { get; }
+
+    /// <summary>
+    /// Gets the parameters attached to this instance.
+    /// </summary>
+    public ImmutableDictionary<string, OpenIddictParameter> Parameters { get; }
+
+    /// <summary>
+    /// Gets the additional properties attached to this instance.
+    /// </summary>
+    public Dictionary<string, object> Properties { get; } = new(StringComparer.Ordinal);
+}

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationService.cs

@@ -7,22 +7,13 @@
 using System.ComponentModel;
 using System.IO.Pipes;
 using System.Net;
-using System.Runtime.Versioning;
 using System.Security.Principal;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
+using OpenIddict.Extensions;
 
 #if SUPPORTS_ANDROID
 using Android.Content;
-using NativeUri = Android.Net.Uri;
-#endif
-
-#if SUPPORTS_FOUNDATION
-using Foundation;
-#endif
-
-#if SUPPORTS_WINDOWS_RUNTIME
-using Windows.Security.Authentication.Web;
 #endif
 
 namespace OpenIddict.Client.SystemIntegration;
@@ -51,18 +42,6 @@ public sealed class OpenIddictClientSystemIntegrationService
         _provider = provider ?? throw new ArgumentNullException(nameof(provider));
     }
 
-    /// <summary>
-    /// Handles the specified protocol activation.
-    /// </summary>
-    /// <param name="activation">The protocol activation details.</param>
-    /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns>A <see cref="Task"/> that can be used to monitor the asynchronous operation.</returns>
-    /// <exception cref="ArgumentNullException"><paramref name="activation"/> is <see langword="null"/>.</exception>
-    [EditorBrowsable(EditorBrowsableState.Advanced)]
-    public Task HandleProtocolActivationAsync(
-        OpenIddictClientSystemIntegrationActivation activation, CancellationToken cancellationToken = default)
-        => HandleRequestAsync(activation ?? throw new ArgumentNullException(nameof(activation)), cancellationToken);
-
 #if SUPPORTS_ANDROID && SUPPORTS_ANDROIDX_BROWSER
     /// <summary>
     /// Handles the specified intent.
@@ -73,46 +52,93 @@ public sealed class OpenIddictClientSystemIntegrationService
     /// <exception cref="ArgumentNullException"><paramref name="intent"/> is <see langword="null"/>.</exception>
     [EditorBrowsable(EditorBrowsableState.Advanced)]
     public Task HandleCustomTabsIntentAsync(Intent intent, CancellationToken cancellationToken = default)
-        => HandleRequestAsync(intent?.Data ?? throw new ArgumentNullException(nameof(intent)), cancellationToken);
+    {
+        if (intent is null)
+        {
+            throw new ArgumentNullException(nameof(intent));
+        }
+
+        if (intent.Data is null)
+        {
+            throw new ArgumentException(SR.GetResourceString(SR.ID0453), nameof(intent));
+        }
+
+        var parameters = new Dictionary<string, OpenIddictParameter>(StringComparer.Ordinal);
+
+        if (!string.IsNullOrEmpty(intent.Data.Query))
+        {
+            foreach (var parameter in OpenIddictHelpers.ParseQuery(intent.Data.Query))
+            {
+                parameters[parameter.Key] = parameter.Value.Count switch
+                {
+                    0 => default,
+                    1 => parameter.Value[0],
+                    _ => parameter.Value.ToArray()
+                };
+            }
+        }
+
+        // Note: the fragment is always processed after the query string to ensure that
+        // parameters extracted from the fragment are preferred to parameters extracted
+        // from the query string when they are present in both parts.
+
+        if (!string.IsNullOrEmpty(intent.Data.Fragment))
+        {
+            foreach (var parameter in OpenIddictHelpers.ParseFragment(intent.Data.Fragment))
+            {
+                parameters[parameter.Key] = parameter.Value.Count switch
+                {
+                    0 => default,
+                    1 => parameter.Value[0],
+                    _ => parameter.Value.ToArray()
+                };
+            }
+        }
+
+        var uri = new Uri(intent.Data.ToString()!, UriKind.Absolute);
+        var callback = new OpenIddictClientSystemIntegrationPlatformCallback(uri, parameters)
+        {
+            // Attach the intent to the properties.
+            Properties = { [typeof(Intent).FullName!] = intent }
+        };
+
+        return HandlePlatformCallbackAsync(callback, cancellationToken);
+    }
 #endif
 
     /// <summary>
-    /// Handles the specified HTTP request.
+    /// Handles the specified platform callback.
     /// </summary>
-    /// <param name="request">The HTTP request received by the embedded web server.</param>
+    /// <param name="callback">The platform callback details.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>A <see cref="Task"/> that can be used to monitor the asynchronous operation.</returns>
-    /// <exception cref="ArgumentNullException"><paramref name="request"/> is <see langword="null"/>.</exception>
-    internal Task HandleHttpRequestAsync(HttpListenerContext request, CancellationToken cancellationToken = default)
-        => HandleRequestAsync(request ?? throw new ArgumentNullException(nameof(request)), cancellationToken);
+    /// <exception cref="ArgumentNullException"><paramref name="callback"/> is <see langword="null"/>.</exception>
+    [EditorBrowsable(EditorBrowsableState.Never)]
+    public Task HandlePlatformCallbackAsync(
+        OpenIddictClientSystemIntegrationPlatformCallback callback, CancellationToken cancellationToken = default)
+        => HandleRequestAsync(callback ?? throw new ArgumentNullException(nameof(callback)), cancellationToken);
 
-#if SUPPORTS_AUTHENTICATION_SERVICES && SUPPORTS_FOUNDATION
     /// <summary>
-    /// Handles the specified AS web authentication session callback URL.
+    /// Handles the specified protocol activation.
     /// </summary>
-    /// <param name="url">The AS web authentication session callback URL.</param>
+    /// <param name="activation">The protocol activation details.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>A <see cref="Task"/> that can be used to monitor the asynchronous operation.</returns>
-    /// <exception cref="ArgumentNullException"><paramref name="url"/> is <see langword="null"/>.</exception>
-    [SupportedOSPlatform("ios12.0")]
-    [SupportedOSPlatform("maccatalyst13.1")]
-    [SupportedOSPlatform("macos10.15")]
-    internal Task HandleASWebAuthenticationCallbackUrlAsync(NSUrl url, CancellationToken cancellationToken = default)
-        => HandleRequestAsync(url, cancellationToken);
-#endif
+    /// <exception cref="ArgumentNullException"><paramref name="activation"/> is <see langword="null"/>.</exception>
+    [EditorBrowsable(EditorBrowsableState.Advanced)]
+    public Task HandleProtocolActivationAsync(
+        OpenIddictClientSystemIntegrationActivation activation, CancellationToken cancellationToken = default)
+        => HandleRequestAsync(activation ?? throw new ArgumentNullException(nameof(activation)), cancellationToken);
 
-#if SUPPORTS_WINDOWS_RUNTIME
     /// <summary>
-    /// Handles the specified web authentication result.
+    /// Handles the specified HTTP request.
     /// </summary>
-    /// <param name="result">The web authentication result.</param>
+    /// <param name="request">The HTTP request received by the embedded web server.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>A <see cref="Task"/> that can be used to monitor the asynchronous operation.</returns>
-    /// <exception cref="ArgumentNullException"><paramref name="result"/> is <see langword="null"/>.</exception>
-    [SupportedOSPlatform("windows10.0.17763")]
-    internal Task HandleWebAuthenticationResultAsync(WebAuthenticationResult result, CancellationToken cancellationToken = default)
-        => HandleRequestAsync(result ?? throw new ArgumentNullException(nameof(result)), cancellationToken);
-#endif
+    /// <exception cref="ArgumentNullException"><paramref name="request"/> is <see langword="null"/>.</exception>
+    internal Task HandleHttpRequestAsync(HttpListenerContext request, CancellationToken cancellationToken = default)
+        => HandleRequestAsync(request ?? throw new ArgumentNullException(nameof(request)), cancellationToken);
 
     /// <summary>
     /// Handles the request using the specified property.

src/OpenIddict.Client.WebIntegration/OpenIddictClientWebIntegrationHandlers.Discovery.cs

@@ -263,7 +263,7 @@ public static partial class OpenIddictClientWebIntegrationHandlers
         /// Contains the logic responsible for amending the client authentication methods
         /// supported by the device authorization endpoint for the providers that require it.
         /// </summary>
-        [Obsolete("This class is obsolete and will be removed in a future version.", error: true)]
+        [Obsolete("This event handler is obsolete and will be removed in a future version.", error: true)]
         public sealed class AmendDeviceAuthorizationEndpointClientAuthenticationMethods : IOpenIddictClientHandler<HandleConfigurationResponseContext>
         {
             /// <summary>
@@ -285,7 +285,7 @@ public static partial class OpenIddictClientWebIntegrationHandlers
         /// Contains the logic responsible for amending the client authentication
         /// methods supported by the token endpoint for the providers that require it.
         /// </summary>
-        [Obsolete("This class is obsolete and will be removed in a future version.", error: true)]
+        [Obsolete("This event handler is obsolete and will be removed in a future version.", error: true)]
         public sealed class AmendTokenEndpointClientAuthenticationMethods : IOpenIddictClientHandler<HandleConfigurationResponseContext>
         {
             /// <summary>

src/OpenIddict.Server/OpenIddictServerHandlers.Protection.cs

@@ -1562,7 +1562,7 @@ public static partial class OpenIddictServerHandlers
         /// Contains the logic responsible for beautifying user-typed tokens.
         /// Note: this handler is not used when the degraded mode is enabled.
         /// </summary>
-        [Obsolete("This class is obsolete and will be removed in a future version.", error: true)]
+        [Obsolete("This event handler is obsolete and will be removed in a future version.", error: true)]
         public sealed class BeautifyToken : IOpenIddictServerHandler<GenerateTokenContext>
         {
             /// <summary>