<PackageReference Include="BouncyCastle.Cryptography" Version="2.8.0-beta.349" />

Org.BouncyCastle.Crypto.Agreement.Kdf.RawUkmKekGenerator

X9.63 based key derivation function for ECDH CMS, with the user keying material itself as the SharedInfo.
namespace Org.BouncyCastle.Crypto.Agreement.Kdf { internal sealed class RawUkmKekGenerator : IDerivationFunction { public IDigest Digest { get; } public void Init(IDerivationParameters param); public int GenerateBytes(byte[] outBytes, int outOff, int length); public int GenerateBytes(Span<byte> output); } }