ComputeHashAsync extension as there is no async version in .net framework or .net core

ComputeHashAsync.cs

using System.IO;
using System.Threading.Tasks;

namespace System.Security.Cryptography
{
    public static class HashAlgorithmExt
    {
        public static async Task<byte[]> ComputeHashAsync(this HashAlgorithm algorithm, Stream stream, int blockSize = 0x14000)
        {
            var buffer = new byte[blockSize];
            int read;
            while ((read = await stream.ReadAsync(buffer, 0, blockSize).ConfigureAwait(false)) == blockSize)
                algorithm.TransformBlock(buffer, 0, read, buffer, 0);
            algorithm.TransformFinalBlock(buffer, 0, read);
            return algorithm.Hash;
        }
    }
}