gov.sandia.cognition.hash

Class MD5Hash

java.lang.Object

gov.sandia.cognition.util.AbstractCloneableSerializable

gov.sandia.cognition.hash.AbstractHashFunction

gov.sandia.cognition.hash.MD5Hash

All Implemented Interfaces:

Evaluator<byte[],byte[]>, HashFunction, CloneableSerializable, java.io.Serializable, java.lang.Cloneable

@PublicationReference(author="Wikipedia",title="MD5",type=WebPage,year=2010) @PublicationReference(author="Jon Howell",title="MD5 Java class",type=Misc,year=1999,url="http://www.jonh.net/~jonh/md5/MD5.java",notes="A fairly inefficient implementation, but a correct one!")
public class MD5Hash
extends AbstractHashFunction

Implementation of the MD5 128-bit (16-byte) cryptographic hash function. This algorithm is known to be unsafe for cryptographic purposes and is implemented for historic purposes only. This implementation is based on the Java port of C code by Jon Howell. According to Howell, it is 25-30 times slower than the optimized C version. Do not use MD5.

Since:

3.4.2

Author:

Kevin R. Dixon

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected static byte[]	DEFAULT_SEED Default seed
static int	LENGTH MD5 is a 128-bit (16-byte) length hash.

Constructor Summary

Constructors

Constructor and Description
MD5Hash() Default constructor

Method Summary

Modifier and Type	Method and Description
void	evaluateInto(byte[] input, byte[] output, byte[] seed) Evaluates the input into the given output
byte[]	getDefaultSeed() Gets the default seed for the hash function
int	length() Returns the number of bytes in the output hash code.
void	update(byte[] newbuf, int bufstart, int buflen) Interior MD5 update step

Methods inherited from class gov.sandia.cognition.hash.AbstractHashFunction

clone, evaluate, evaluate, evaluateInto

Methods inherited from class java.lang.Object

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

Field Detail

LENGTH

public static final int LENGTH

MD5 is a 128-bit (16-byte) length hash.

See Also:

Constant Field Values

DEFAULT_SEED

protected static final byte[] DEFAULT_SEED

Default seed

Constructor Detail

MD5Hash

public MD5Hash()

Default constructor

Method Detail

evaluateInto

public void evaluateInto(byte[] input,
                         byte[] output,
                         byte[] seed)

Description copied from interface: HashFunction

Evaluates the input into the given output

Parameters:

input - Input to compute the hash-function value of

output - Output to put the hash-function into

seed - Seed to offset the hash code.

length

public int length()

Description copied from interface: HashFunction

Returns the number of bytes in the output hash code.

Returns:

Number of bytes in the output hash code.

getDefaultSeed

public byte[] getDefaultSeed()

Description copied from interface: HashFunction

Gets the default seed for the hash function

Returns:

Default seed for the hash algorithm

update

public void update(byte[] newbuf,
                   int bufstart,
                   int buflen)

Interior MD5 update step

Parameters:

newbuf - new buffer to update

bufstart - Offset into the buffer to update

buflen - how many bytes to update (not necessarily all of them!)