AES wraps RSA : Advanced Encryption Standard « Security « Java Tutorial

1. Java Tutorial
2. Security
3. Advanced Encryption Standard

import java.security.Key;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;

public class MainClass {
  public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC");
    SecureRandom random = new SecureRandom();

    KeyPairGenerator fact = KeyPairGenerator.getInstance("RSA", "BC");
    fact.initialize(1024, random);

    KeyPair keyPair = fact.generateKeyPair();
    Key wrapKey = createKeyForAES(256, random);
    cipher.init(Cipher.WRAP_MODE, wrapKey);

    byte[] wrappedKey = cipher.wrap(keyPair.getPrivate());
    cipher.init(Cipher.UNWRAP_MODE, wrapKey);
    Key key = cipher.unwrap(wrappedKey, "RSA", Cipher.PRIVATE_KEY);
    System.out.println(keyPair.getPrivate().equals(key));

  }

  public static SecretKey createKeyForAES(int bitLength, SecureRandom random)
      throws NoSuchAlgorithmException, NoSuchProviderException {
    KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
    generator.init(128, random);
    return generator.generateKey();
  }
}