gnu.crypto.hash
Class Sha256Standalone

java.lang.Object
  extended by gnu.crypto.hash.BaseHashStandalone
      extended by gnu.crypto.hash.Sha256Standalone
All Implemented Interfaces:
IMessageDigestStandalone, java.lang.Cloneable

public class Sha256Standalone
extends BaseHashStandalone

Implementation of SHA2-1 [SHA-256] per the IETF Draft Specification.

References:

  1. Descriptions of SHA-256, SHA-384, and SHA-512,
  2. http://csrc.nist.gov/cryptval/shs/sha256-384-512.pdf
Modified by jrandom@i2p.net to remove unnecessary gnu-crypto dependencies, and renamed from Sha256 to avoid conflicts with JVMs using gnu-crypto as their JCE provider.

Version:
$Revision: 1.2 $

Field Summary
 
Fields inherited from class gnu.crypto.hash.BaseHashStandalone
blockSize, buffer, count, hashSize, name
 
Constructor Summary
Sha256Standalone()
          Trivial 0-arguments constructor.
 
Method Summary
 java.lang.Object clone()
          Returns a clone copy of this instance.
protected  byte[] getResult()
          Constructs the result from the contents of the current context.
protected  byte[] padBuffer()
          Returns the byte array to use as padding before completing a hash operation.
protected  void resetContext()
          Resets the instance for future re-use.
 boolean selfTest()
          A basic test.
protected  void transform(byte[] in, int offset)
          The block digest transformation per se.
 
Methods inherited from class gnu.crypto.hash.BaseHashStandalone
blockSize, digest, hashSize, name, reset, update, update, update
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Sha256Standalone

public Sha256Standalone()
Trivial 0-arguments constructor.

Method Detail

clone

public java.lang.Object clone()
Description copied from interface: IMessageDigestStandalone

Returns a clone copy of this instance.

Specified by:
clone in interface IMessageDigestStandalone
Specified by:
clone in class BaseHashStandalone
Returns:
a clone copy of this instance.

transform

protected void transform(byte[] in,
                         int offset)
Description copied from class: BaseHashStandalone

The block digest transformation per se.

Specified by:
transform in class BaseHashStandalone
Parameters:
in - the blockSize long block, as an array of bytes to digest.
offset - the index where the data to digest is located within the input buffer.

padBuffer

protected byte[] padBuffer()
Description copied from class: BaseHashStandalone

Returns the byte array to use as padding before completing a hash operation.

Specified by:
padBuffer in class BaseHashStandalone
Returns:
the bytes to pad the remaining bytes in the buffer before completing a hash operation.

getResult

protected byte[] getResult()
Description copied from class: BaseHashStandalone

Constructs the result from the contents of the current context.

Specified by:
getResult in class BaseHashStandalone
Returns:
the output of the completed hash operation.

resetContext

protected void resetContext()
Description copied from class: BaseHashStandalone
Resets the instance for future re-use.

Specified by:
resetContext in class BaseHashStandalone

selfTest

public boolean selfTest()
Description copied from interface: IMessageDigestStandalone

A basic test. Ensures that the digest of a pre-determined message is equal to a known pre-computed value.

Specified by:
selfTest in interface IMessageDigestStandalone
Specified by:
selfTest in class BaseHashStandalone
Returns:
true if the implementation passes a basic self-test. Returns false otherwise.