jcryptoboard-crypto/src/main/java/jcryptoboard/actions/rng/Random.java

   1 package jcryptoboard.actions.rng;
   2
   3 import java.security.NoSuchAlgorithmException;
   4 import java.security.SecureRandom;
   5 import jcryptoboard.api.model.AbstractAction;
   6 import jcryptoboard.api.model.ActionResult;
   7 import org.apache.commons.lang.mutable.MutableInt;
   8
   9 /**
  10  * Created with IntelliJ IDEA.
  11  * User: lhl
  12  * Date: 18.10.12
  13  * Time: 17:37
  14  * To change this template use File | Settings | File Templates.
  15  */
  16 public class Random extends AbstractAction {
  17
  18     private java.util.Random rnd = new java.util.Random();
  19
  20     public void setSecure(String algo) {
  21         try {
  22             rnd = SecureRandom.getInstance(algo);
  23         } catch (NoSuchAlgorithmException e) {
  24             throw new IllegalArgumentException("Invalid SecureRandom algorithm: " + algo);
  25         }
  26         recompute();
  27     }
  28
  29     private void recompute()
  30     {
  31         integer.setValue(rnd.nextInt());
  32         rnd.nextBytes(array);
  33     }
  34
  35     /**
  36      * Updates buffers with new random values.
  37      * @return
  38      */
  39     public ActionResult execute() throws Exception {
  40         recompute();
  41         return nextAction.execute();
  42     }
  43
  44     private byte[] array = new byte[8];
  45     private MutableInt integer = new MutableInt(0);
  46
  47     public Random() {
  48         recompute();
  49     }
  50
  51
  52     /** Returns random integer */
  53     public void setInteger(MutableInt integer) {
  54         this.integer = integer;
  55     }
  56
  57     /** Returns random integer */
  58     public MutableInt getInteger() {
  59         return integer;
  60     }
  61
  62     /**
  63      * Instructs action to provide array of random bytes of given length.
  64      * @param length
  65      */
  66     public void setProvideArray(int length)
  67     {
  68         array = new byte[length];
  69     }
  70
  71     public void setArray(byte[] array) {
  72         if (array == null) {
  73             throw  new NullPointerException("Array buffer for Random must not be null.");
  74         }
  75         this.array = array;
  76     }
  77
  78     /**
  79      * Returns random bytes in array.
  80      * By default 8 bytes are provided. This can by changed by calling setArray or setProvideArray.
  81      */
  82     public byte[] getArray() {
  83         return array;
  84     }
  85
  86     public String getName() {
  87         return "Random";
  88     }
  89 }