minor improvements

Author: DeagleGross

src/DataProtection/DataProtection/src/AuthenticatedEncryption/AuthenticatedEncryptorExtensions.cs

@@ -43,7 +43,6 @@ public static bool TryEncrypt(
         out int bytesWritten)
     {
         var destinationBufferOffsets = destination.Slice(preBufferSize, destination.Length - (preBufferSize + postBufferSize));
-        // var plaintextWithOffsets = plaintext.Slice((int)preBufferSize, plaintext.Length - (int)(preBufferSize + postBufferSize));
         return encryptor.TryEncrypt(plaintext, additionalAuthenticatedData, destinationBufferOffsets, out bytesWritten);
     }
 #endif

src/DataProtection/DataProtection/src/Cng/CbcAuthenticatedEncryptor.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using System.Runtime.CompilerServices;
 using Microsoft.AspNetCore.Cryptography;
 using Microsoft.AspNetCore.Cryptography.Cng;
 using Microsoft.AspNetCore.Cryptography.SafeHandles;
@@ -363,7 +364,7 @@ public override bool TryEncrypt(ReadOnlySpan<byte> plaintext, ReadOnlySpan<byte>
                             byte* pbOutputHmac = &pbOutputCiphertext[cbOutputCiphertext];
 
                             // Copy key modifier and IV to destination
-                            UnsafeBufferUtil.BlockCopy(from: pbKeyModifierAndIV, to: pbOutputKeyModifier, byteCount: cbKeyModifierAndIV);
+                            Unsafe.CopyBlock(pbOutputKeyModifier, pbKeyModifierAndIV, cbKeyModifierAndIV);
                             bytesWritten += checked((int)cbKeyModifierAndIV);
 
                             // Perform CBC encryption directly into destination
@@ -512,7 +513,6 @@ private uint GetCbcEncryptedOutputSizeWithPadding(uint cbInput)
         byte* pbDummyIV = stackalloc byte[checked((int)_symmetricAlgorithmBlockSizeInBytes)];
         byte* pbDummyInput = stackalloc byte[checked((int)cbInput)];
 
-        uint dwResult;
         var ntstatus = UnsafeNativeMethods.BCryptEncrypt(
             hKey: tempKeyHandle,
             pbInput: pbDummyInput,
@@ -522,7 +522,7 @@ private uint GetCbcEncryptedOutputSizeWithPadding(uint cbInput)
             cbIV: _symmetricAlgorithmBlockSizeInBytes,
             pbOutput: null,  // NULL output = size query only
             cbOutput: 0,
-            pcbResult: out dwResult,
+            pcbResult: out var dwResult,
             dwFlags: BCryptEncryptFlags.BCRYPT_BLOCK_PADDING);
         UnsafeNativeMethods.ThrowExceptionForBCryptStatus(ntstatus);
 
@@ -536,7 +536,6 @@ private uint GetCbcEncryptedOutputSizeWithPadding(BCryptKeyHandle symmetricKeyHa
 
         // Calling BCryptEncrypt with a null output pointer will cause it to return the total number
         // of bytes required for the output buffer.
-        uint dwResult;
         var ntstatus = UnsafeNativeMethods.BCryptEncrypt(
             hKey: symmetricKeyHandle,
             pbInput: pbInput,
@@ -546,7 +545,7 @@ private uint GetCbcEncryptedOutputSizeWithPadding(BCryptKeyHandle symmetricKeyHa
             cbIV: _symmetricAlgorithmBlockSizeInBytes,
             pbOutput: null,
             cbOutput: 0,
-            pcbResult: out dwResult,
+            pcbResult: out var dwResult,
             dwFlags: BCryptEncryptFlags.BCRYPT_BLOCK_PADDING);
         UnsafeNativeMethods.ThrowExceptionForBCryptStatus(ntstatus);
 

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

@@ -124,7 +124,6 @@ public bool TryProtect(ReadOnlySpan<byte> plaintext, Span<byte> destination, out
             // If the default key id has been updated since the last call to Protect, also write back the updated template.
             var aad = _aadTemplate.GetAadForKey(defaultKeyId, isProtecting: true);
 
-            // We allocate a 20-byte pre-buffer so that we can inject the magic header and key id into the return value.
             var success = defaultEncryptorInstance.TryEncrypt(
                 plaintext: plaintext,
                 additionalAuthenticatedData: aad,

src/DataProtection/DataProtection/src/SP800_108/SP800_108_CTR_HMACSHA512Extensions.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Runtime.CompilerServices;
 using Microsoft.AspNetCore.Cryptography;
 
 namespace Microsoft.AspNetCore.DataProtection.SP800_108;
@@ -24,9 +25,9 @@ public static void DeriveKeyWithContextHeader(this ISP800_108_CTR_HMACSHA512Prov
 
             fixed (byte* pbContextHeader = contextHeader)
             {
-                UnsafeBufferUtil.BlockCopy(from: pbContextHeader, to: pbCombinedContext, byteCount: contextHeader.Length);
+                Unsafe.CopyBlock(pbCombinedContext, pbContextHeader, (uint)contextHeader.Length);
             }
-            UnsafeBufferUtil.BlockCopy(from: pbContext, to: &pbCombinedContext[contextHeader.Length], byteCount: cbContext);
+            Unsafe.CopyBlock(&pbCombinedContext[contextHeader.Length], pbContext, cbContext);
 
             // At this point, combinedContext := { contextHeader || context }
             provider.DeriveKey(pbLabel, cbLabel, pbCombinedContext, cbCombinedContext, pbDerivedKey, cbDerivedKey);