TestEncrypt.java

package testencrypt;

import java.security.Key;
import java.security.SecureRandom;
import java.util.Arrays;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.util.Base64;

/**
 *
 * @author jpralves
 */
public class TestEncrypt {

//    public static String src; // = "pbe test";
    public static String bytesToHex(byte[] bytes) {
        StringBuilder result = new StringBuilder();
        for (byte byt : bytes) {
            result.append(Integer.toString((byt & 0xff) + 0x100, 16).substring(1));
        }
        return result.toString();
    }

    public static String jdkPBE_cipher(String ciphername, String password, String src) {
        byte[] salt;
        byte[] cipheredResult;
        byte[] result = null;
        try {
            PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray());
            SecretKeyFactory factory = SecretKeyFactory.getInstance(ciphername);
            Key key = factory.generateSecret(pbeKeySpec);

            int saltBlockLen = Cipher.getInstance(factory.getAlgorithm()).getBlockSize();
            SecureRandom random = new SecureRandom();
            salt = random.generateSeed(saltBlockLen);

            PBEParameterSpec pbeParameterSpac = new PBEParameterSpec(salt, 1000);
            Cipher cipher = Cipher.getInstance(ciphername);
            cipher.init(Cipher.ENCRYPT_MODE, key, pbeParameterSpac);
            cipheredResult = cipher.doFinal(src.getBytes());

            result = new byte[salt.length + cipheredResult.length];
            // put salt at the beggining
            System.arraycopy(salt, 0, result, 0, salt.length);
            // append the ciphered result
            System.arraycopy(cipheredResult, 0, result, salt.length, cipheredResult.length);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return new String(Base64.getEncoder().encode(result));
    }

    public static String jdkPBE_decipher(String ciphername, String password, String src) {
        byte[] srcbytes;
        byte[] result = null;
        try {
            srcbytes = Base64.getDecoder().decode(src);
            PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray());
            SecretKeyFactory factory = SecretKeyFactory.getInstance(ciphername);
            Key key = factory.generateSecret(pbeKeySpec);
            // Salt is at the beggining
            int saltBlockLen = Cipher.getInstance(factory.getAlgorithm()).getBlockSize();
            byte[] salt = Arrays.copyOfRange(srcbytes, 0, saltBlockLen);
            byte[] bytestodecode = Arrays.copyOfRange(srcbytes, saltBlockLen, srcbytes.length);
            PBEParameterSpec pbeParameterSpac = new PBEParameterSpec(salt, 1000);
            Cipher cipher = Cipher.getInstance(ciphername);
            cipher.init(Cipher.DECRYPT_MODE, key, pbeParameterSpac);
            byte[] iv = cipher.getIV();
            System.out.println(iv);
            result = cipher.doFinal(bytestodecode);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return new String(result);
    }

    /**
     * @param args the command line arguments
     *
     * e|d PBEWITHMD5andDES password valor
     */
    public static void main(String[] args) {
        // TODO code application logic here
        if (args.length > 3 && args[0].equals("e")) {
            //...
            String ciphername = args[1];
            String password = args[2];
            String codetocipher = args[3];
            System.out.println("encrypted msg:[" + jdkPBE_cipher(ciphername, password, codetocipher) + "]");
        } else if (args.length > 3 && args[0].equals("d")) {
            String ciphername = args[1];
            String password = args[2];
            String codetodecipher = args[3];
            System.out.println("decrypted msg:[" + jdkPBE_decipher(ciphername, password, codetodecipher) + "]");

        } else {
            System.out.println("Args: operation ciphername password msg");
            System.out.println("Ex. to encrypt: e PBEWITHMD5andDES strangepassword \"uma mensagem\"");
            System.out.println("Ex. to decrypt: d PBEWITHMD5andDES strangepassword ZrpxVeCnVvbHGdWgGTtZdv6Jg+IMfbla");
        }

    }

}