org.bouncycastle.crypto.digests

Class SHA1Digest

java.lang.Object

org.bouncycastle.crypto.digests.GeneralDigest

org.bouncycastle.crypto.digests.SHA1Digest

All Implemented Interfaces:

Digest, EncodableDigest, ExtendedDigest, Memoable

public class SHA1Digest
extends GeneralDigest
implements EncodableDigest

implementation of SHA-1 as outlined in "Handbook of Applied Cryptography", pages 346 - 349. It is interesting to ponder why the, apart from the extra IV, the other difference here from MD5 is the "endianness" of the word processing!

Constructor Summary

Constructors

Constructor and Description
SHA1Digest() Standard constructor
SHA1Digest(byte[] encodedState) State constructor - create a digest initialised with the state of a previous one.
SHA1Digest(SHA1Digest 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.
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
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

Constructor Detail

SHA1Digest

public SHA1Digest()

Standard constructor

SHA1Digest

public SHA1Digest(SHA1Digest t)

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

SHA1Digest

public SHA1Digest(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

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.