org.bouncycastle.crypto.digests

Class SHA256Digest

java.lang.Object

org.bouncycastle.crypto.digests.GeneralDigest

org.bouncycastle.crypto.digests.SHA256Digest

All Implemented Interfaces:

Digest, EncodableDigest, ExtendedDigest, SavableDigest, Memoable

public class SHA256Digest
extends GeneralDigest
implements SavableDigest

FIPS 180-2 implementation of SHA-256.

         block  word  digest
 SHA-1   512    32    160
 SHA-256 512    32    256
 SHA-384 1024   64    384
 SHA-512 1024   64    512
 

Field Summary

Fields inherited from class org.bouncycastle.crypto.digests.GeneralDigest

purpose

Constructor Summary

Constructors

Constructor and Description
SHA256Digest() Standard constructor
SHA256Digest(byte[] encodedState) State constructor - create a digest initialised with the state of a previous one.
SHA256Digest(CryptoServicePurpose purpose) Standard constructor, with purpose
SHA256Digest(SHA256Digest t) Copy constructor.

Method Summary

Modifier and Type	Method and Description
Memoable	copy() Produce a copy of this object with its configuration and in its current state.
protected CryptoServiceProperties	cryptoServiceProperties()
int	doFinal(byte[] out, int outOff) close the digest, producing the final digest value.
java.lang.String	getAlgorithmName() return the algorithm name
int	getDigestSize() return the size, in bytes, of the digest produced by this message digest.
byte[]	getEncodedState() Return an encoded byte array for the digest's internal state
static SavableDigest	newInstance()
static SavableDigest	newInstance(byte[] encoded)
static SavableDigest	newInstance(CryptoServicePurpose purpose)
static SavableDigest	newInstance(Digest digest)
protected void	processBlock()
protected void	processLength(long bitLength)
protected void	processWord(byte[] in, int inOff)
void	reset() reset the chaining variables
void	reset(Memoable other) Restore a copied object state into this object.

Methods inherited from class org.bouncycastle.crypto.digests.GeneralDigest

copyIn, finish, getByteLength, populateState, update, update

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.bouncycastle.crypto.ExtendedDigest

getByteLength

Methods inherited from interface org.bouncycastle.crypto.Digest

update, update

Constructor Detail

SHA256Digest

public SHA256Digest()

Standard constructor

SHA256Digest

public SHA256Digest(CryptoServicePurpose purpose)

Standard constructor, with purpose

SHA256Digest

public SHA256Digest(SHA256Digest t)

Copy constructor. This will copy the state of the provided message digest.

SHA256Digest

public SHA256Digest(byte[] encodedState)

State constructor - create a digest initialised with the state of a previous one.

Parameters:

encodedState - the encoded state from the originating digest.

Method Detail

newInstance

public static SavableDigest newInstance()

newInstance

public static SavableDigest newInstance(CryptoServicePurpose purpose)

newInstance

public static SavableDigest newInstance(Digest digest)

newInstance

public static SavableDigest newInstance(byte[] encoded)

getAlgorithmName

public java.lang.String getAlgorithmName()

Description copied from interface: Digest

return the algorithm name

Specified by:

getAlgorithmName in interface Digest

Returns:

the algorithm name

getDigestSize

public int getDigestSize()

Description copied from interface: Digest

return the size, in bytes, of the digest produced by this message digest.

Specified by:

getDigestSize in interface Digest

Returns:

the size, in bytes, of the digest produced by this message digest.

processWord

protected void processWord(byte[] in,
                           int inOff)

Specified by:

processWord in class GeneralDigest

processLength

protected void processLength(long bitLength)

Specified by:

processLength in class GeneralDigest

doFinal

public int doFinal(byte[] out,
                   int outOff)

Description copied from interface: Digest

close the digest, producing the final digest value. The doFinal call leaves the digest reset.

Specified by:

doFinal in interface Digest

Parameters:

out - the array the digest is to be copied into.

outOff - the offset into the out array the digest is to start at.

reset

public void reset()

reset the chaining variables

Specified by:

reset in interface Digest

Overrides:

reset in class GeneralDigest

processBlock

protected void processBlock()

Specified by:

processBlock in class GeneralDigest

copy

public Memoable copy()

Description copied from interface: Memoable

Produce a copy of this object with its configuration and in its current state.

The returned object may be used simply to store the state, or may be used as a similar object starting from the copied state.

Specified by:

copy in interface Memoable

reset

public void reset(Memoable other)

Description copied from interface: Memoable

Restore a copied object state into this object.

Implementations of this method should try to avoid or minimise memory allocation to perform the reset.

Specified by:

reset in interface Memoable

Parameters:

other - an object originally copied from an object of the same type as this instance.

getEncodedState

public byte[] getEncodedState()

Description copied from interface: EncodableDigest

Return an encoded byte array for the digest's internal state

Specified by:

getEncodedState in interface EncodableDigest

Returns:

an encoding of the digests internal state.

cryptoServiceProperties

protected CryptoServiceProperties cryptoServiceProperties()

Specified by:

cryptoServiceProperties in class GeneralDigest