Use one-shot HashData method in .NET 9.0.

global.json

@@ -1,6 +1,7 @@
 {
   "sdk": {
-    "version": "8.0.100",
+    "version": "9.0.100-preview",
+    "allowPrerelease": true,
     "rollForward": "latestFeature"
   }
 }

src/NGuid/GuidHelpers.cs

@@ -424,9 +424,13 @@ public static Guid CreateVersion8FromName(HashAlgorithmName hashAlgorithmName, G
 	[SkipLocalsInit]
 	public static Guid CreateVersion8FromName(HashAlgorithmName hashAlgorithmName, Guid namespaceId, ReadOnlySpan<byte> name)
 	{
+#if NET9_0_OR_GREATER
+		Span<byte> hashOutput = stackalloc byte[64];
+#else
 		using var algorithm = GetHashAlgorithm(hashAlgorithmName);
-		Span<byte> buffer = name.Length < 500 ? stackalloc byte[16 + name.Length] : new byte[16 + name.Length];
 		Span<byte> hashOutput = stackalloc byte[algorithm.HashSize / 8];
+#endif
+		Span<byte> buffer = name.Length < 500 ? stackalloc byte[16 + name.Length] : new byte[16 + name.Length];
 
 		// convert the hash space and namespace UUIDs to network order
 		if (!namespaceId.TryWriteBytes(buffer))
@@ -435,9 +439,16 @@ public static Guid CreateVersion8FromName(HashAlgorithmName hashAlgorithmName, G
 
 		// compute the hash of [ namespace ID, name ]
 		name.CopyTo(buffer[16..]);
+#if NET9_0_OR_GREATER
+		var hashLength = CryptographicOperations.HashData(hashAlgorithmName, buffer, hashOutput);
+		if (hashLength == 0)
+			throw new InvalidOperationException("Failed to hash data");
+		hashOutput = hashOutput[..hashLength];
+#else
 		var success = algorithm.TryComputeHash(buffer, hashOutput, out var bytesWritten);
 		if (!success || bytesWritten != hashOutput.Length)
 			throw new InvalidOperationException("Failed to hash data");
+#endif
 
 		// the initial bytes from the hash are copied straight to the bytes of the new GUID
 		var newGuid = hashOutput[..16];
@@ -452,6 +463,7 @@ public static Guid CreateVersion8FromName(HashAlgorithmName hashAlgorithmName, G
 	}
 #endif
 
+#if !NET9_0_OR_GREATER
 	private static HashAlgorithm GetHashAlgorithm(HashAlgorithmName hashAlgorithmName) =>
 		hashAlgorithmName.Name switch
 		{
@@ -460,6 +472,7 @@ private static HashAlgorithm GetHashAlgorithm(HashAlgorithmName hashAlgorithmNam
 			"SHA512" => SHA512.Create(),
 			_ => throw new ArgumentException($"Unsupported hash algorithm name: {hashAlgorithmName.Name}", nameof(hashAlgorithmName)),
 		};
+#endif
 
 	/// <summary>
 	/// The namespace for fully-qualified domain names (from RFC 4122, Appendix C).

src/NGuid/NGuid.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;net6.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;net6.0;net8.0;net9.0</TargetFrameworks>
     <Description>Creates GUIDs according to RFC 4122 and the UUID Revision Working Draft.</Description>
     <PackageReadmeFile>README.md</PackageReadmeFile>
     <PackageTags>guid;uuid;rfc4122;uuidv6;uuidv7;uuidv8</PackageTags>

tests/NGuid.Tests/NGuid.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net48;net8.0</TargetFrameworks>
+    <TargetFrameworks>net481;net8.0;net9.0</TargetFrameworks>
     <IsPackable>false</IsPackable>
     <IsTestProject>true</IsTestProject>
     <NoWarn>$(NoWarn);CS1591</NoWarn>