AsymmetricCipherKeypair includes both private and public keys, but AsymmetricKeyPair includes only public - Java Security

Java examples for Security:DES

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Description

AsymmetricCipherKeypair includes both private and public keys, but AsymmetricKeyPair includes only public

Demo Code

import java.security.Security;
import java.util.Date;
import java.sql.Timestamp;
import javax.crypto.KeyGenerator;

import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.engines.AESEngine;
import org.bouncycastle.crypto.modes.CBCBlockCipher;
import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.params.ParametersWithIV;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

public class aes {

    public static void GetTimestamp(String info) {
        System.out.println(info + new Timestamp((new Date()).getTime()));
    }//from w  ww .  j av  a  2s. c  o m

    public static byte[] cipherData(PaddedBufferedBlockCipher cipher,
            byte[] data) throws Exception {
        byte[] outputBuffer = new byte[cipher.getOutputSize(data.length)];

        int length1 = cipher.processBytes(data, 0, data.length,
                outputBuffer, 0);
        int length2 = cipher.doFinal(outputBuffer, length1);

        byte[] result = new byte[length1 + length2];

        System.arraycopy(outputBuffer, 0, result, 0, result.length);

        return result;
    }

    public static byte[] encrypt(byte[] plain, CipherParameters ivAndKey)
            throws Exception {
        PaddedBufferedBlockCipher aes = new PaddedBufferedBlockCipher(
                new CBCBlockCipher(new AESEngine()));

        aes.init(true, ivAndKey);

        return cipherData(aes, plain);

    }

    public static byte[] decrypt(byte[] cipher, CipherParameters ivAndKey)
            throws Exception {
        PaddedBufferedBlockCipher aes = new PaddedBufferedBlockCipher(
                new CBCBlockCipher(new AESEngine()));
        aes.init(false, ivAndKey);

        return cipherData(aes, cipher);
    }

    public static void main(String[] args) throws Exception {
        Security.addProvider(new BouncyCastleProvider());

        KeyGenerator keyGen = KeyGenerator.getInstance("AES");
        keyGen.init(256); //key is 256 bits
        byte[] password = keyGen.generateKey().getEncoded();

        KeyGenerator ivGen = KeyGenerator.getInstance("AES");
        ivGen.init(128); //iv is 128 bits
        byte[] iv = ivGen.generateKey().getEncoded();

        CipherParameters ivAndKey = new ParametersWithIV(new KeyParameter(
                password), iv);

        byte[] plainText = "Plain text".getBytes("UTF-8");

        GetTimestamp("Encryption started: ");
        byte[] encryptedMessage = encrypt(plainText, ivAndKey);
        System.out.println(encryptedMessage);
        GetTimestamp("Encryption ended: ");

        GetTimestamp("Decryption started: ");
        byte[] decryptedMessage = decrypt(encryptedMessage, ivAndKey);
        System.out.println(new String(decryptedMessage));
        GetTimestamp("Decryption ended: ");

    }

}

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