using Org.BouncyCastle.Crypto; namespace Org.BouncyCastle.Pqc.Crypto.NtruPrime { public class SNtruPrimeKemExtractor : IEncapsulatedSecretExtractor { private NtruPrimeEngine _primeEngine; private readonly SNtruPrimeKeyParameters _primeKey; public int EncapsulationLength => _primeEngine.CipherTextSize; public SNtruPrimeKemExtractor(SNtruPrimeKeyParameters privParams) { _primeKey = privParams; InitCipher(_primeKey.Parameters); } private void InitCipher(SNtruPrimeParameters param) { _primeEngine = param.PrimeEngine; } public byte[] ExtractSecret(byte[] encapsulation) { byte[] array = new byte[_primeEngine.SessionKeySize]; _primeEngine.kem_dec(array, encapsulation, ((SNtruPrimePrivateKeyParameters)_primeKey).privKey); return array; } } }