I've copied the code from http://www.java2s.com/Tutorial/Java/0490__Security/DiffieHellmanwithEllipticCurve.htm
Here is my code ..
import java.math.BigInteger;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.MessageDigest;
import java.security.SecureRandom;
import java.security.Security;
import java.security.spec.ECFieldFp;
import java.security.spec.ECParameterSpec;
import java.security.spec.ECPoint;
import java.security.spec.EllipticCurve;
import javax.crypto.KeyAgreement;
public class MainClass {
public static void main(String[] args) throws Exception {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
KeyPairGenerator keyGen = KeyPairGenerator.getInstance("ECDH", "BC");
EllipticCurve curve = new EllipticCurve(new ECFieldFp(new BigInteger(
"fffffffffffffffffffffffffffffffeffffffffffffffff", 16)), new BigInteger(
"fffffffffffffffffffffffffffffffefffffffffffffffc", 16), new BigInteger(
"fffffffffffffffffffffffffffffffefffffffffffffffc", 16));
ECParameterSpec ecSpec = new ECParameterSpec(curve, new ECPoint(new BigInteger(
"fffffffffffffffffffffffffffffffefffffffffffffffc", 16), new BigInteger(
"fffffffffffffffffffffffffffffffefffffffffffffffc", 16)), new BigInteger(
"fffffffffffffffffffffffffffffffefffffffffffffffc", 16), 1);
keyGen.initialize(ecSpec, new SecureRandom());
KeyAgreement aKeyAgree = KeyAgreement.getInstance("ECDH", "BC");
KeyPair aPair = keyGen.generateKeyPair();
KeyAgreement bKeyAgree = KeyAgreement.getInstance("ECDH", "BC");
KeyPair bPair = keyGen.generateKeyPair();
aKeyAgree.init(aPair.getPrivate());
bKeyAgree.init(bPair.getPrivate());
aKeyAgree.doPhase(bPair.getPublic(), true);
bKeyAgree.doPhase(aPair.getPublic(), true);
MessageDigest hash = MessageDigest.getInstance("SHA1", "BC");
System.out.println(new String(hash.digest(aKeyAgree.generateSecret())));
System.out.println(new String(hash.digest(bKeyAgree.generateSecret())));
}
}
but it gives me the following error:
Exception in thread "main" java.lang.IllegalArgumentException: Invalid point
at org.bouncycastle.math.ec.ECAlgorithms.validatePoint(Unknown Source)
at org.bouncycastle.math.ec.AbstractECMultiplier.multiply(Unknown Source)
at org.bouncycastle.crypto.generators.ECKeyPairGenerator.generateKeyPair(Unknown Source)
at org.bouncycastle.jcajce.provider.asymmetric.ec.KeyPairGeneratorSpi$EC.generateKeyPair(Unknown Source)
at MainClass.main(MainClass.java:32)
Could you kindly help me? I have searched but I could not find any solution yet. Thank you so much!
