com.knowgate.encryption

Class MD5

java.lang.Object

com.knowgate.encryption.MD5

All Implemented Interfaces:

HashProvider

public class MD5
extends Object
implements HashProvider

Implementation of RSA's MD5 hash generator

Version:

$Revision: 1.1.1.1 $

Author:

Santeri Paavolainen <sjpaavol@cc.helsinki.fi>

Constructor Summary

Constructors

Constructor and Description
MD5() Class constructor
MD5(Object ob) Initialize class, and update hash with ob.toString()

Method Summary

Modifier and Type	Method and Description
String	asHex() Returns 32-character hex representation of this objects hash
static String	asHex(byte[] hash) Turns array of bytes into string representing each byte as unsigned hex number.
byte[]	Final() Returns array of bytes (16 bytes) representing hash as of the current state of this object.
void	Init() Initialize MD5 internal state (object can be reused just by calling Init() after every Final()
void	Update(byte b) Updates hash with a single byte
void	Update(byte[] buffer) Updates hash with given array of bytes
void	Update(byte[] buffer, int length) Plain update, updates this object with offset zero
void	Update(byte[] buffer, int offset, int length) Plain update, updates this object
void	Update(int i) Update buffer with a single integer (only & 0xff part is used, as a byte)
void	Update(com.knowgate.encryption.MD5State stat, byte[] buffer, int offset, int length) Updates hash with the bytebuffer given (using at maximum length bytes from that buffer)
void	Update(String s) Update buffer with given string.

Methods inherited from class java.lang.Object

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

Constructor Detail

MD5

public MD5()

Class constructor

MD5

public MD5(Object ob)

Initialize class, and update hash with ob.toString()

Parameters:

ob - Object, ob.toString() is used to update hash after initialization

Method Detail

Init

public void Init()

Initialize MD5 internal state (object can be reused just by calling Init() after every Final()

Update

public void Update(com.knowgate.encryption.MD5State stat,
                   byte[] buffer,
                   int offset,
                   int length)
            throws NullPointerException

Updates hash with the bytebuffer given (using at maximum length bytes from that buffer)

Parameters:

stat - Which state is updated

buffer - Array of bytes to be hashed

offset - Offset to buffer array

length - Use at maximum `length' bytes (absolute maximum is buffer.length)

Throws:

NullPointerException

Update

public void Update(byte[] buffer,
                   int offset,
                   int length)

Plain update, updates this object

Parameters:

buffer - Array of bytes to use for updating the hash

offset - int

length - int

Update

public void Update(byte[] buffer,
                   int length)

Plain update, updates this object with offset zero

Parameters:

buffer - Array of bytes to use for updating the hash

length - int

Update

public void Update(byte[] buffer)
            throws NullPointerException

Updates hash with given array of bytes

Parameters:

buffer - Array of bytes to use for updating the hash

Throws:

NullPointerException

Update

public void Update(byte b)

Updates hash with a single byte

Parameters:

b - Single byte to update the hash

Update

public void Update(String s)
            throws NullPointerException,
                   IllegalStateException

Update buffer with given string.

Specified by:

Update in interface HashProvider

Parameters:

s - String to be update to hash (is used as s.getBytes())

Throws:

NullPointerException - if s is null

IllegalStateException - if s is an empty String

Update

public void Update(int i)

Update buffer with a single integer (only & 0xff part is used, as a byte)

Parameters:

i - Integer value, which is then converted to byte as i & 0xff

Final

public byte[] Final()

Returns array of bytes (16 bytes) representing hash as of the current state of this object. Note: getting a hash does not invalidate the hash object, it only creates a copy of the real state which is finalized.

Specified by:

Final in interface HashProvider

Returns:

Array of 16 bytes, the hash of all updated bytes

asHex

public static String asHex(byte[] hash)

Turns array of bytes into string representing each byte as unsigned hex number.

Parameters:

hash - Array of bytes to convert to hex-string

Returns:

Generated hex string

asHex

public String asHex()

Returns 32-character hex representation of this objects hash

Specified by:

asHex in interface HashProvider

Returns:

String of this object's hash