/** * given a message from a given party and the coresponding public key * calculate the next message in the agreement sequence. In this case * this will represent the shared secret. */ public BigInteger calculateAgreement( DHPublicKeyParameters pub, BigInteger message) { if (!pub.getParameters().Equals(dhParams)) { throw new ArgumentException("Diffie-Hellman public key has wrong parameters."); } return(message.modPow(key.getX(), dhParams.getP()).multiply(pub.getY().modPow(privateValue, dhParams.getP())).mod(dhParams.getP())); }
/** * given a short term public key from a given party calculate the next * message in the agreement sequence. */ public BigInteger calculateAgreement( CipherParameters pubKey) { DHPublicKeyParameters pub = (DHPublicKeyParameters)pubKey; if (!pub.getParameters().Equals(dhParams)) { throw new ArgumentException("Diffie-Hellman public key has wrong parameters."); } return(pub.getY().modPow(key.getX(), dhParams.getP())); }
public static PrivateKeyInfo createPrivateKeyInfo(AsymmetricKeyParameter key) { /* * Process DH private key. * The value for L was set to zero implicitly. * This is the same action as found in JCEDHPrivateKey getEncoded method. */ if (key is ElGamalPrivateKeyParameters) { ElGamalPrivateKeyParameters _key = (ElGamalPrivateKeyParameters)key; PrivateKeyInfo info = new PrivateKeyInfo( new AlgorithmIdentifier( OIWObjectIdentifiers.elGamalAlgorithm, new ElGamalParameter( _key.getParameters().getP(), _key.getParameters().getG()).toASN1Object()), new DERInteger(_key.getX())); return(info); } if (key is DSAPrivateKeyParameters) { DSAPrivateKeyParameters _key = (DSAPrivateKeyParameters)key; PrivateKeyInfo info = new PrivateKeyInfo( new AlgorithmIdentifier( X9ObjectIdentifiers.id_dsa, new DSAParameter( _key.getParameters().getP(), _key.getParameters().getQ(), _key.getParameters().getG()).toASN1Object()), new DERInteger(_key.getX())); return(info); } if (key is DHPrivateKeyParameters) { DHPrivateKeyParameters _key = (DHPrivateKeyParameters)key; PrivateKeyInfo info = new PrivateKeyInfo( new AlgorithmIdentifier( PKCSObjectIdentifiers.dhKeyAgreement, new DHParameter( _key.getParameters().getP(), _key.getParameters().getG(), 0 ).toASN1Object() ) , new DERInteger(_key.getX())); return(info); } if (key is RSAPrivateCrtKeyParameters) { RSAPrivateCrtKeyParameters _key = (RSAPrivateCrtKeyParameters)key; PrivateKeyInfo info = new PrivateKeyInfo( new AlgorithmIdentifier( PKCSObjectIdentifiers.rsaEncryption, new DERNull()), new RSAPrivateKeyStructure( _key.getModulus(), _key.getPublicExponent(), _key.getExponent(), _key.getP(), _key.getQ(), _key.getDP(), _key.getDQ(), _key.getQInv()).toASN1Object()); return(info); } if (key is ECPrivateKeyParameters) { ECPrivateKeyParameters _key = (ECPrivateKeyParameters)key; X9ECParameters ecP = new X9ECParameters( _key.getParameters().getCurve(), _key.getParameters().getG(), _key.getParameters().getN(), _key.getParameters().getH(), _key.getParameters().getSeed()); X962Parameters x962 = new X962Parameters(ecP); PrivateKeyInfo info = new PrivateKeyInfo( new AlgorithmIdentifier(X9ObjectIdentifiers.id_ecPublicKey, x962.toASN1Object()), new ECPrivateKeyStructure(_key.getD()).toASN1Object()); return(info); } throw (new Exception("Class provided is not convertable:" + key.GetType())); }