import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
import sun.misc.BASE64Decoder;
public class MainClass {
public static void main(String[] args) throws Exception {
System.out.println(decrypt(new char[] { 'a', 'b', 'c', 'd' }, "plaintext1234567890"));
}
private static String decrypt(char[] password, String text) throws Exception {
String salt = text.substring(0, 12);
String ciphertext = text.substring(12, text.length());
BASE64Decoder decoder = new BASE64Decoder();
byte[] saltArray = decoder.decodeBuffer(salt);
byte[] ciphertextArray = decoder.decodeBuffer(ciphertext);
PBEKeySpec keySpec = new PBEKeySpec(password);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithSHAAndTwofish-CBC");
SecretKey key = keyFactory.generateSecret(keySpec);
PBEParameterSpec paramSpec = new PBEParameterSpec(saltArray, 1000);
Cipher cipher = Cipher.getInstance("PBEWithSHAAndTwofish-CBC");
cipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
return new String(cipher.doFinal(ciphertextArray));
}
}