distinguish impl

Author: DeagleGross

src/DataProtection/DataProtection/src/KeyManagement/KeyRingBasedDataProtectionProvider.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using Microsoft.AspNetCore.DataProtection.AuthenticatedEncryption;
 using Microsoft.AspNetCore.DataProtection.KeyManagement.Internal;
 using Microsoft.AspNetCore.Shared;
 using Microsoft.Extensions.Logging;
@@ -23,6 +24,17 @@ public IDataProtector CreateProtector(string purpose)
     {
         ArgumentNullThrowHelper.ThrowIfNull(purpose);
 
+        var currentKeyRing = _keyRingProvider.GetCurrentKeyRing();
+        var encryptor = currentKeyRing.DefaultAuthenticatedEncryptor;
+        if (encryptor is ISpanAuthenticatedEncryptor)
+        {
+            return new KeyRingBasedSpanDataProtector(
+                logger: _logger,
+                keyRingProvider: _keyRingProvider,
+                originalPurposes: null,
+                newPurpose: purpose);
+        }
+
         return new KeyRingBasedDataProtector(
             logger: _logger,
             keyRingProvider: _keyRingProvider,

src/DataProtection/DataProtection/src/KeyManagement/KeyRingBasedDataProtector.cs

@@ -62,10 +62,21 @@ private static string[] ConcatPurposes(string[]? originalPurposes, string newPur
         }
     }
 
-    public virtual IDataProtector CreateProtector(string purpose)
+    public IDataProtector CreateProtector(string purpose)
     {
         ArgumentNullThrowHelper.ThrowIfNull(purpose);
 
+        var currentKeyRing = _keyRingProvider.GetCurrentKeyRing();
+        var encryptor = currentKeyRing.DefaultAuthenticatedEncryptor;
+        if (encryptor is ISpanAuthenticatedEncryptor)
+        {
+            return new KeyRingBasedSpanDataProtector(
+                logger: _logger,
+                keyRingProvider: _keyRingProvider,
+                originalPurposes: Purposes,
+                newPurpose: purpose);
+        }
+
         return new KeyRingBasedDataProtector(
             logger: _logger,
             keyRingProvider: _keyRingProvider,

src/DataProtection/DataProtection/src/KeyManagement/KeyRingBasedSpanDataProtector.cs

@@ -19,17 +19,6 @@ public KeyRingBasedSpanDataProtector(IKeyRingProvider keyRingProvider, ILogger?
     {
     }
 
-    public override IDataProtector CreateProtector(string purpose)
-    {
-        ArgumentNullThrowHelper.ThrowIfNull(purpose);
-
-        return new KeyRingBasedDataProtector(
-            logger: _logger,
-            keyRingProvider: _keyRingProvider,
-            originalPurposes: Purposes,
-            newPurpose: purpose);
-    }
-
     public int GetProtectedSize(ReadOnlySpan<byte> plainText)
     {
         // Get the current key ring to access the encryptor