iaik.security.md
Class Md2

java.lang.Object
  |
  +--java.security.MessageDigestSpi
        |
        +--java.security.MessageDigest
              |
              +--iaik.security.md.Md2

public class Md2

extends MessageDigest

implements java.lang.Cloneable, java.io.Serializable

This class implements the MD2 message digest algorithm by Burt Kaliski as described in

This class extends the java.security.MessageDigest class and applications should use one of the getInstance methods presented there to create a MessageDigest-MD2 object. Generally, an application wishing to compute the message digest of some data has to perform three steps:

• First an instance of the desired message digest algorithm has to be created using a proper getInstance method, e.g.:

       MessageDigest md2 = MessageDigest.getInstance("MD2");
       

• Second, the data to be hashed is supplied to the MessageDigest object just created by one or more calls to one of the update methods, e.g:
  

       md2.update(m1);
       md2.update(m2); 
       ...
       

• Finally, the hash value can be computed using one of the digest methods:
  

       byte[] hash_value = md2.digest();
       

  
  

There are several ways for combining update and digest methods for computing a message digest. Since this class implements the Cloneable interface, MD2 MessageDigest objects may be used for compute intermediate hashes through cloning (see http://java.sun.com/products/JDK/1.1/docs/guide/security/CryptoSpec.html).

When the hash value successfully has been computed, the MD2 MessageDigest object automatically resets for being able to be supplied with new data to be hashed.

The MD2 algorithm may be combined with a public-key algorithm (e.g. RSA) to be used as digital signature algorithm (see iaik.security.rsa.Md2RSASignature).

See Also:

Md2RSASignature, SHA, Md5, Serialized Form

Constructor Summary

Md2()
Creates a new MD2 message digest object.

Method Summary

java.lang.Object	clone() Returns a clone of this Md2 Object.
void	destroyCriticalData()
byte[]	engineDigest() SPI: Returns the result of this hash computation and resets this MD2 message digest object for being supplied with new data to be hashed.
void	engineReset() SPI: Resets this MD2 message digest object for being supplied with new data.
void	engineUpdate(byte input) SPI: Updates the data to be hashed with the specified byte.
void	engineUpdate(byte[] input, int offset, int len) SPI: Updates the data to be hashed with the specified number of bytes, beginning at the specified offset within the given byte array.
protected void	finalize()

Methods inherited from class java.security.MessageDigest

digest, digest, digest, getAlgorithm, getDigestLength, getInstance, getInstance, getProvider, isEqual, reset, toString, update, update, update

Methods inherited from class java.security.MessageDigestSpi

engineDigest, engineGetDigestLength

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Md2

public Md2()

Creates a new MD2 message digest object.

Applications do not use this constructor. They shall use

MessageDigest.getInstance("MD2");

for creating a MesssageDigest object.

See Also:

MessageDigest.getInstance(java.lang.String)

Method Detail

engineUpdate

public void engineUpdate(byte[] input,
                         int offset,
                         int len)

SPI: Updates the data to be hashed with the specified number of bytes, beginning at the specified offset within the given byte array.

Overrides:

engineUpdate in class MessageDigestSpi

Parameters:

input - the byte array holding the data to be used for this update operation.

offset - the offset, indicating the start position within the given byte array.

len - the number of bytes to be obtained from the given byte array, starting at the given position.

engineUpdate

public void engineUpdate(byte input)

SPI: Updates the data to be hashed with the specified byte.

Overrides:

engineUpdate in class MessageDigestSpi

Parameters:

input - the byte to be used for updating.

engineReset

public void engineReset()

SPI: Resets this MD2 message digest object for being supplied with new data.

This method is called by engineDigest after the actual hash computation has been finished to automatically reset the message digest object for being supplied with new data for starting a new hash computation.

Overrides:

engineReset in class MessageDigestSpi

See Also:

engineDigest()

engineDigest

public byte[] engineDigest()

SPI: Returns the result of this hash computation and resets this MD2 message digest object for being supplied with new data to be hashed.

Overrides:

engineDigest in class MessageDigestSpi

Returns:

a byte array holding the calculated hash value

clone

public java.lang.Object clone()

Returns a clone of this Md2 Object.

Overrides:

clone in class MessageDigest

Returns:

a clone of this Md2 Object

destroyCriticalData

public void destroyCriticalData()

finalize

protected void finalize()

Overrides:

finalize in class java.lang.Object