/// <summary>
/// Computes double SHA256 of data: SHA256(SHA256(data))
/// </summary>
/// <param name="data">Input: bytes to be hashed.</param>
/// <returns>SHA256 of SHA256 of data.</returns>
public static UInt256 Hash256(this ReadOnlyByteSpan data)
{
var hash = new UInt256();
data.Hash256(hash.Span);
return(hash);
}
/// <summary>
/// Appends first 4 bytes of double SHA256 hash to bytes before standard Base58 encoding.
/// </summary>
/// <param name="bytes"></param>
/// <returns></returns>
public override string Encode(ReadOnlyByteSpan bytes)
{
var checksum = bytes.Hash256();
var buf = new byte[bytes.Length + 4];
bytes.CopyTo(buf);
checksum.Span.Slice(0, 4).CopyTo(buf.AsSpan().Slice(bytes.Length));
return(Encoders.Base58.Encode(buf));
}