org.spongycastle.pqc.crypto.gmss

Class Treehash

java.lang.Object

org.spongycastle.pqc.crypto.gmss.Treehash

public class Treehash
extends java.lang.Object

This class implements a treehash instance for the Merkle tree traversal algorithm. The first node of the stack is stored in this instance itself, additional tail nodes are stored on a tailstack.

Constructor Summary

Constructors

Constructor and Description
Treehash(Digest name, byte[][] statByte, int[] statInt) This constructor regenerates a prior treehash object
Treehash(java.util.Vector tailStack, int maxHeight, Digest digest) Constructor

Method Summary

Methods

Modifier and Type	Method and Description
void	destroy() Destroys a treehash instance after the top node was taken for authentication path.
byte[]	getFirstNode() returns the first node stored in treehash instance itself
int	getFirstNodeHeight() Returns the top node height
int	getLowestNodeHeight() Returns the height of the lowest node stored either in treehash or on the stack.
byte[]	getSeedActive() returns the active seed
byte[][]	getStatByte() Returns the status byte array used by the GMSSPrivateKeyASN.1 class
int[]	getStatInt() Returns the status int array used by the GMSSPrivateKeyASN.1 class
java.util.Vector	getTailStack() Returns the tailstack
void	initialize() initializes the treehash instance.
void	initializeSeed(byte[] seedIn) Method to initialize the seeds needed for the precomputation of right nodes.
void	setFirstNode(byte[] hash) This method sets the first node stored in the treehash instance itself
java.lang.String	toString() returns a String representation of the treehash instance
void	update(GMSSRandom gmssRandom, byte[] leaf) Calculates one update of the treehash instance, i.e.
void	updateNextSeed(GMSSRandom gmssRandom) updates the nextSeed of this treehash instance one step needed for the schedulng of the seeds
boolean	wasFinished() Method to check whether the instance has been finished or not
boolean	wasInitialized() Method to check whether the instance has been initialized or not

Methods inherited from class java.lang.Object

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

Constructor Detail

Treehash

public Treehash(Digest name,
        byte[][] statByte,
        int[] statInt)

This constructor regenerates a prior treehash object

Parameters:

name - an array of strings, containing the name of the used hash function and PRNG and the name of the corresponding provider

statByte - status bytes

statInt - status ints

Treehash

public Treehash(java.util.Vector tailStack,
        int maxHeight,
        Digest digest)

Constructor

Parameters:

tailStack - a vector element where the stack nodes are stored

maxHeight - maximal height of the treehash instance

digest - an array of strings, containing the name of the used hash function and PRNG and the name of the corresponding provider

Method Detail

initializeSeed

public void initializeSeed(byte[] seedIn)

Method to initialize the seeds needed for the precomputation of right nodes. Should be initialized with index 3*2^i for treehash_i

Parameters:

seedIn -

initialize

public void initialize()

initializes the treehash instance. The seeds must already have been initialized to work correctly.

update

public void update(GMSSRandom gmssRandom,
          byte[] leaf)

Calculates one update of the treehash instance, i.e. creates a new leaf and hashes if possible

Parameters:

gmssRandom - an instance of the PRNG

leaf - The byte value of the leaf needed for the update

destroy

public void destroy()

Destroys a treehash instance after the top node was taken for authentication path.

getLowestNodeHeight

public int getLowestNodeHeight()

Returns the height of the lowest node stored either in treehash or on the stack. It must not be set to infinity (as mentioned in the paper) because this cases are considered in the computeAuthPaths method of JDKGMSSPrivateKey

Returns:

Height of the lowest node

getFirstNodeHeight

public int getFirstNodeHeight()

Returns the top node height

Returns:

Height of the first node, the top node

wasInitialized

public boolean wasInitialized()

Method to check whether the instance has been initialized or not

Returns:

true if treehash was already initialized

wasFinished

public boolean wasFinished()

Method to check whether the instance has been finished or not

Returns:

true if treehash has reached its maximum height

getFirstNode

public byte[] getFirstNode()

returns the first node stored in treehash instance itself

Returns:

the first node stored in treehash instance itself

getSeedActive

public byte[] getSeedActive()

returns the active seed

Returns:

the active seed

setFirstNode

public void setFirstNode(byte[] hash)

This method sets the first node stored in the treehash instance itself

Parameters:

hash -

updateNextSeed

public void updateNextSeed(GMSSRandom gmssRandom)

updates the nextSeed of this treehash instance one step needed for the schedulng of the seeds

Parameters:

gmssRandom - the prng used for the seeds

getTailStack

public java.util.Vector getTailStack()

Returns the tailstack

Returns:

the tailstack

getStatByte

public byte[][] getStatByte()

Returns the status byte array used by the GMSSPrivateKeyASN.1 class

Returns:

The status bytes

getStatInt

public int[] getStatInt()

Returns the status int array used by the GMSSPrivateKeyASN.1 class

Returns:

The status ints

toString

public java.lang.String toString()

returns a String representation of the treehash instance

Overrides:

toString in class java.lang.Object