org.xbill.DNS.utils
Class HMAC

java.lang.Object
  org.xbill.DNS.utils.HMAC

public class HMAC
extends Object

A pure java implementation of the HMAC-MD5 secure hash algorithm

Author:

Brian Wellington

Constructor Summary

HMAC(MessageDigest digest, byte[] key)
Creates a new HMAC instance

HMAC(String digestName, byte[] key)
Creates a new HMAC instance

Method Summary

void	clear() Resets the HMAC object for further use
byte[]	sign() Signs the data (computes the secure hash)
void	update(byte[] b) Adds data to the current hash
void	update(byte[] b, int offset, int length) Adds data to the current hash
boolean	verify(byte[] signature) Verifies the data (computes the secure hash and compares it to the input)

Methods inherited from class java.lang.Object

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

Constructor Detail

HMAC

public HMAC(MessageDigest digest,
            byte[] key)

Creates a new HMAC instance

Parameters:

digest - The message digest object.

key - The secret key

HMAC

public HMAC(String digestName,
            byte[] key)

Creates a new HMAC instance

Parameters:

digestName - The name of the message digest function.

key - The secret key.

Method Detail

update

public void update(byte[] b,
                   int offset,
                   int length)

Adds data to the current hash

Parameters:

b - The data

offset - The index at which to start adding to the hash

length - The number of bytes to hash

update

public void update(byte[] b)

Adds data to the current hash

Parameters:

b - The data

sign

public byte[] sign()

Signs the data (computes the secure hash)

Returns:

An array with the signature

verify

public boolean verify(byte[] signature)

Verifies the data (computes the secure hash and compares it to the input)

Parameters:

signature - The signature to compare against

Returns:

true if the signature matched, false otherwise

clear

public void clear()

Resets the HMAC object for further use