C# HashAlgorithm Helper Class

HashAlgorithmHelper.cs

public static class HashAlgorithmHelper
{
    public static byte[] UpdateHash(this HashAlgorithm hash, byte[] buffer)
    {
        hash.TransformBlock(buffer, 0, buffer.Length, null, 0);
        hash.TransformFinalBlock(new byte[0], 0, 0);
        hash.Final();
        return hash.Hash;
    }

    public static void Update(this HashAlgorithm hash, byte[] buffer, int offset, int count)
    {
        hash.TransformBlock(buffer, offset, count, null, 0);
    }

    public static void Update(this HashAlgorithm hash, byte[] buffer, int BufferLength)
    {
        hash.TransformBlock(buffer, 0, BufferLength, null, 0);
    }

    public static byte[] Final(this HashAlgorithm hash)
    {
        hash.TransformFinalBlock(new byte[0], 0, 0);
        return hash.Hash;
    }

    public static void Update(this HashAlgorithm hash, byte[] buffer)
    {
        hash.TransformBlock(buffer, 0, buffer.Length, null, 0);
    }
}