de.flexiprovider.core.md
Class MDFamilyDigest

java.lang.Object
  |
  +--java.security.MessageDigestSpi
        |
        +--de.flexiprovider.api.MessageDigest
              |
              +--de.flexiprovider.core.md.MDFamilyDigest

Direct Known Subclasses:

MD4, MD5, RIPEMD128, RIPEMD160, RIPEMD256, RIPEMD320

public abstract class MDFamilyDigest

extends MessageDigest

This class is the base class for all message digests of the MD family (MD4, MD5, RIPEMD128, ...).

Author:

Martin Döring

Field Summary

protected int[]	state state of the engine
protected int[]	x internal buffer for processing

Constructor Summary

protected

MDFamilyDigest(int digestLength) Constructor.

Method Summary

int	getDigestLength()
protected void	initMessageDigest(int[] initialState) Initialize the function with an initial state.
protected void	padMessageDigest() this method performs the padding.
protected abstract void	processBlock() Compute the hash value of the current block.
protected static int	rotateLeft(int x, int n) Left rotate the given word by the specified amount.
void	update(byte b) Update the engine with a single byte
void	update(byte[] bytes, int offset, int len) add a block of data from the array bytes to the message digest.

Methods inherited from class de.flexiprovider.api.MessageDigest

digest, digest, digest, engineDigest, engineGetDigestLength, engineReset, engineUpdate, engineUpdate, reset, update

Methods inherited from class java.security.MessageDigestSpi

clone, engineDigest

Methods inherited from class java.lang.Object

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

Field Detail

x

protected int[] x

internal buffer for processing

state

protected int[] state

state of the engine

Constructor Detail

MDFamilyDigest

protected MDFamilyDigest(int digestLength)

Constructor.

Parameters:

digestLength - the digest length

Method Detail

initMessageDigest

protected void initMessageDigest(int[] initialState)

Initialize the function with an initial state.

Parameters:

initialState - the initial state

getDigestLength

public int getDigestLength()

Overrides:

getDigestLength in class MessageDigest

Returns:

the digest length in bytes.

update

public void update(byte b)

Update the engine with a single byte

Overrides:

update in class MessageDigest

Parameters:

b - byte to be added.

update

public void update(byte[] bytes,
                   int offset,
                   int len)

add a block of data from the array bytes to the message digest. The block starts offset bytes into the array, and is of size length.

Overrides:

update in class MessageDigest

Parameters:

bytes - byte array to process

offset - offset into the array to start from

len - number of bytes to process

padMessageDigest

protected void padMessageDigest()

this method performs the padding. A single 1-bit is appended and then 0-bits, until only 64 bits are left free in the final block to enter the total length of the entered message.

processBlock

protected abstract void processBlock()

Compute the hash value of the current block.

rotateLeft

protected static int rotateLeft(int x,
                                int n)

Left rotate the given word by the specified amount.

Parameters:

x - the word

n - the rotation amount

Returns:

the rotated word