<PackageReference Include="BouncyCastle.Cryptography" Version="2.6.0" />

IXof

public interface IXof : IDigest
int Output(byte[] output, int outOff, int outLen)

Start outputting the results of the final calculation for this XOF. Unlike DoFinal, this method will continue producing output until the XOF is explicitly reset, or signals otherwise.

int OutputFinal(byte[] output, int outOff, int outLen)

Output the results of the final calculation for this XOF to outLen number of bytes.