Package org.bouncycastle.crypto.util

Class JournalingSecureRandom

  • All Implemented Interfaces:
    java.io.Serializable
    public class JournalingSecureRandom
extends java.security.SecureRandom
    A SecureRandom that maintains a journal of its output. This can be used to recreate an output that was based on randomness For the transcript to be reusable, the order of the requests for randomness during recreation must be consistent with the initial requests and no other sources of randomness may be used.
    See Also:
    Serialized Form

    • Constructor Summary

      Constructors 
      Constructor Description
      JournalingSecureRandom()
      Default constructor that takes an arbitrary SecureRandom as initial random
      JournalingSecureRandom​(byte[] transcript, java.security.SecureRandom random)
      Constructor with a prior transcript.
      JournalingSecureRandom​(java.security.SecureRandom random)
      Base constructor - no prior transcript.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void clear()
      Clear the internals
      byte[] getFullTranscript()
      Return the full transcript, such as would be needed to create a copy of this JournalingSecureRandom,
      byte[] getTranscript()
      Return the transcript so far,
      void nextBytes​(byte[] bytes)
      Fill bytes with random data, journaling the random data before returning or re-use previously used random data, depending on the state of the transcript.
      void reset()
      Resets the index to zero such that the randomness will now be reused

      • Methods inherited from class java.security.SecureRandom

        generateSeed, getAlgorithm, getInstance, getInstance, getInstance, getInstance, getInstance, getInstance, getInstanceStrong, getParameters, getProvider, getSeed, next, nextBytes, reseed, reseed, setSeed, setSeed, toString

      • Methods inherited from class java.util.Random

        doubles, doubles, doubles, doubles, ints, ints, ints, ints, longs, longs, longs, longs, nextBoolean, nextDouble, nextFloat, nextGaussian, nextInt, nextInt, nextLong

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Constructor Detail

      • JournalingSecureRandom

        public JournalingSecureRandom()
        Default constructor that takes an arbitrary SecureRandom as initial random

      • JournalingSecureRandom

        public JournalingSecureRandom​(java.security.SecureRandom random)
        Base constructor - no prior transcript.
        Parameters:
        random - source of randomness we will be journaling.

      • JournalingSecureRandom

        public JournalingSecureRandom​(byte[] transcript,
                              java.security.SecureRandom random)
        Constructor with a prior transcript. Both the transcript used and any new randomness are journaled.
        Parameters:
        transcript - initial transcript of randomness.
        random - source of randomness we will be journaling when the transcript runs out.

    • Method Detail

      • nextBytes

        public final void nextBytes​(byte[] bytes)
        Fill bytes with random data, journaling the random data before returning or re-use previously used random data, depending on the state of the transcript.
        Overrides:
        nextBytes in class java.security.SecureRandom
        Parameters:
        bytes - a block of bytes to be filled with random data.

      • clear

        public void clear()
        Clear the internals

      • reset

        public void reset()
        Resets the index to zero such that the randomness will now be reused

      • getTranscript

        public byte[] getTranscript()
        Return the transcript so far,
        Returns:
        a copy of the randomness produced so far.

      • getFullTranscript

        public byte[] getFullTranscript()
        Return the full transcript, such as would be needed to create a copy of this JournalingSecureRandom,
        Returns:
        a copy of the original transcript on construction, plus any randomness added since.