org.bouncycastle.crypto.digests
Class SHA1Digest

java.lang.Object
  org.bouncycastle.crypto.digests.GeneralDigest
      org.bouncycastle.crypto.digests.SHA1Digest

All Implemented Interfaces:

Digest, ExtendedDigest

public class SHA1Digest
extends GeneralDigest

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 "endienness" of the word processing!

Field Summary

private static int	DIGEST_LENGTH
private int	H1
private int	H2
private int	H3
private int	H4
private int	H5
private int[]	X
private int	xOff
private static int	Y1
private static int	Y2
private static int	Y3
private static int	Y4

Constructor Summary

SHA1Digest()
Standard constructor

SHA1Digest(SHA1Digest t)
Copy constructor.

Method Summary

int	doFinal(byte[] out, int outOff) close the digest, producing the final digest value.
private int	f(int u, int v, int w)
private int	g(int u, int v, int w)
java.lang.String	getAlgorithmName() return the algorithm name
int	getDigestSize() return the size, in bytes, of the digest produced by this message digest.
private int	h(int u, int v, int w)
protected void	processBlock()
protected void	processLength(long bitLength)
protected void	processWord(byte[] in, int inOff)
void	reset() reset the chaining variables
private void	unpackWord(int word, byte[] out, int outOff)

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

finish, getByteLength, update, update

Methods inherited from class java.lang.Object

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

Field Detail

DIGEST_LENGTH

private static final int DIGEST_LENGTH

See Also:

Constant Field Values

H1

private int H1

H2

private int H2

H3

private int H3

H4

private int H4

H5

private int H5

X

private int[] X

xOff

private int xOff

Y1

private static final int Y1

See Also:

Constant Field Values

Y2

private static final int Y2

See Also:

Constant Field Values

Y3

private static final int Y3

See Also:

Constant Field Values

Y4

private static final int Y4

See Also:

Constant Field Values

Constructor Detail

SHA1Digest

public SHA1Digest()

Standard constructor

SHA1Digest

public SHA1Digest(SHA1Digest t)

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

Method Detail

getAlgorithmName

public java.lang.String getAlgorithmName()

Description copied from interface: Digest

return the algorithm name

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.

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

unpackWord

private void unpackWord(int word,
                        byte[] out,
                        int outOff)

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.

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

f

private int f(int u,
              int v,
              int w)

h

private int h(int u,
              int v,
              int w)

g

private int g(int u,
              int v,
              int w)

processBlock

protected void processBlock()

Specified by:

processBlock in class GeneralDigest