Package com.coderslagoon.crypto.estreamj.ciphers.dragon

Class Dragon

java.lang.Object

com.coderslagoon.crypto.estreamj.ciphers.dragon.Dragon

All Implemented Interfaces:

ICipher

public class Dragon
extends Object
implements ICipher

First version of Dragon with both 128bit and 256bit key support. Unrolling the main loop and maybe using local integers instead of the NLFSR array might increase the speed quite significantly. However one must also consider the increased code size then. Yet it is definitely a TODO since even the less optimized version performs quite well. Maybe we should to keep two implementations (compact+slower and big+faster) around?

Field Summary

Fields inherited from interface com.coderslagoon.crypto.estreamj.framework.ICipher

MODE_DECRYPT, MODE_ENCRYPT

Constructor Summary

Constructors

Constructor	Description
Dragon(boolean use256bit)

Method Summary

Modifier and Type	Method	Description
void	erase()	Erases all sensitive data.
int	getKeySize()
int	getNonceSize()
int	getWordSize()
boolean	isPatented()
void	process(byte[] inBuf, int inOfs, byte[] outBuf, int outOfs, int len)	Processes data.
static void	register()
void	reset()	Resets the instance, so it can be reused.
void	setupKey(int mode, byte[] key, int ofs)	Sets up a new key with the existing instance.
void	setupNonce(byte[] nonce, int ofs)	Sets up a new nonce with the existing cipher instance.

Methods inherited from class java.lang.Object

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

Constructor Details

Dragon

public Dragon(boolean use256bit)

Method Details

erase

public void erase()

Description copied from interface: ICipher

Erases all sensitive data. Instance MUST be abadonned afterwards.

Specified by:

erase in interface ICipher

getKeySize

public int getKeySize()

Specified by:

getKeySize in interface ICipher

Returns:

key size in bytes

getNonceSize

public int getNonceSize()

Specified by:

getNonceSize in interface ICipher

Returns:

nonce size in bytes.

getWordSize

public int getWordSize()

Specified by:

getWordSize in interface ICipher

Returns:

alignment of data needed during calls into process()

isPatented

public boolean isPatented()

Specified by:

isPatented in interface ICipher

Returns:

true: algorithm is patented, check with vendor for license details / false: free to use in private and commercial applications

process

public void process(byte[] inBuf,
 int inOfs,
 byte[] outBuf,
 int outOfs,
 int len)
             throws ESJException

Description copied from interface: ICipher

Processes data.

Specified by:

process in interface ICipher

Parameters:

inBuf - input buffer

inOfs - where to start reading from the input buffer

outBuf - output buffer

outOfs - where to start writing in the output buffer

len - number of bytes to process, must be aligned to the cipher's word size except on the last call where an arbitrary size can be used

Throws:

ESJException - in any error occurred

reset

public void reset()
           throws ESJException

Description copied from interface: ICipher

Resets the instance, so it can be reused.

Specified by:

reset in interface ICipher

Throws:

ESJException - if any error occurs

setupKey

public void setupKey(int mode,
 byte[] key,
 int ofs)
              throws ESJException

Description copied from interface: ICipher

Sets up a new key with the existing instance.

Specified by:

setupKey in interface ICipher

Parameters:

mode - see MODE_xxx

key - buffer with key material

ofs - where the key starts

Throws:

ESJException - if any error occurs

setupNonce

public void setupNonce(byte[] nonce,
 int ofs)
                throws ESJException

Description copied from interface: ICipher

Sets up a new nonce with the existing cipher instance.

Specified by:

setupNonce in interface ICipher

Parameters:

nonce - buffer with nonce material

ofs - where the nonce starts

Throws:

ESJException - if any error occurs

register

public static void register()