/// <summary>
/// Initializes a new instance of the <see cref="HmacSha2"/> class.
/// </summary>
/// <param name="sha2"></param>
/// <param name="key"></param>
protected HmacSha2(Sha2 sha2, ReadOnlySpan <byte> key)
{
if (sha2 is null)
{
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.sha);
}
Sha2 = sha2;
_keys = new byte[BlockSize * 2];
_innerPadKey = new ReadOnlyMemory <byte>(_keys, 0, BlockSize);
_outerPadKey = new ReadOnlyMemory <byte>(_keys, BlockSize, BlockSize);
if (key.Length > BlockSize)
{
Span <byte> keyPrime = stackalloc byte[sha2.HashSize];
Sha2.ComputeHash(key, keyPrime, default, default);
public static void ComputeHash(this Sha2 sha2, ReadOnlySpan <byte> source, Span <byte> destination)
{
sha2.ComputeHash(source, destination, default, default);
