org.bouncycastle.crypto.engines
Class SerpentEngine

java.lang.Object
  org.bouncycastle.crypto.engines.SerpentEngine

All Implemented Interfaces:

BlockCipher

public class SerpentEngine
extends java.lang.Object
implements BlockCipher

Serpent is a 128-bit 32-round block cipher with variable key lengths, including 128, 192 and 256 bit keys conjectured to be at least as secure as three-key triple-DES.

Serpent was designed by Ross Anderson, Eli Biham and Lars Knudsen as a candidate algorithm for the NIST AES Quest.>

For full details see the The Serpent home page

Field Summary

private static int	BLOCK_SIZE
private boolean	encrypting
(package private) static int	PHI
(package private) static int	ROUNDS
private int[]	wKey
private int	X0
private int	X1
private int	X2
private int	X3

Constructor Summary

SerpentEngine()

Method Summary

private int	bytesToWord(byte[] src, int srcOff)
private void	decryptBlock(byte[] in, int inOff, byte[] out, int outOff) Decrypt one block of ciphertext.
private void	encryptBlock(byte[] in, int inOff, byte[] out, int outOff) Encrypt one block of plaintext.
java.lang.String	getAlgorithmName() Return the name of the algorithm the cipher implements.
int	getBlockSize() Return the block size for this cipher (in bytes).
private void	ib0(int a, int b, int c, int d) InvSO - {13, 3,11, 0,10, 6, 5,12, 1,14, 4, 7,15, 9, 8, 2 } - 15 terms.
private void	ib1(int a, int b, int c, int d) InvS1 - { 5, 8, 2,14,15, 6,12, 3,11, 4, 7, 9, 1,13,10, 0 } - 14 steps.
private void	ib2(int a, int b, int c, int d) InvS2 - {12, 9,15, 4,11,14, 1, 2, 0, 3, 6,13, 5, 8,10, 7 } - 16 steps.
private void	ib3(int a, int b, int c, int d) InvS3 - { 0, 9,10, 7,11,14, 6,13, 3, 5,12, 2, 4, 8,15, 1 } - 15 terms
private void	ib4(int a, int b, int c, int d) InvS4 - { 5, 0, 8, 3,10, 9, 7,14, 2,12,11, 6, 4,15,13, 1 } - 15 terms.
private void	ib5(int a, int b, int c, int d) InvS5 - { 8,15, 2, 9, 4, 1,13,14,11, 6, 5, 3, 7,12,10, 0 } - 16 terms.
private void	ib6(int a, int b, int c, int d) InvS6 - {15,10, 1,13, 5, 3, 6, 0, 4, 9,14, 7, 2,12, 8,11 } - 15 terms.
private void	ib7(int a, int b, int c, int d) InvS7 - { 3, 0, 6,13, 9,14,15, 8, 5,12,11, 7,10, 1, 4, 2 } - 17 terms.
void	init(boolean encrypting, CipherParameters params) initialise a Serpent cipher.
private void	inverseLT() Apply the inverse of the linear transformation to the register set.
private void	LT() Apply the linear transformation to the register set.
private int[]	makeWorkingKey(byte[] key) Expand a user-supplied key material into a session key.
int	processBlock(byte[] in, int inOff, byte[] out, int outOff) Process one block of input from the array in and write it to the out array.
void	reset() Reset the cipher.
private int	rotateLeft(int x, int bits)
private int	rotateRight(int x, int bits)
private void	sb0(int a, int b, int c, int d) S0 - { 3, 8,15, 1,10, 6, 5,11,14,13, 4, 2, 7, 0, 9,12 } - 15 terms.
private void	sb1(int a, int b, int c, int d) S1 - {15,12, 2, 7, 9, 0, 5,10, 1,11,14, 8, 6,13, 3, 4 } - 14 terms.
private void	sb2(int a, int b, int c, int d) S2 - { 8, 6, 7, 9, 3,12,10,15,13, 1,14, 4, 0,11, 5, 2 } - 16 terms.
private void	sb3(int a, int b, int c, int d) S3 - { 0,15,11, 8,12, 9, 6, 3,13, 1, 2, 4,10, 7, 5,14 } - 16 terms.
private void	sb4(int a, int b, int c, int d) S4 - { 1,15, 8, 3,12, 0,11, 6, 2, 5, 4,10, 9,14, 7,13 } - 15 terms.
private void	sb5(int a, int b, int c, int d) S5 - {15, 5, 2,11, 4,10, 9,12, 0, 3,14, 8,13, 6, 7, 1 } - 16 terms.
private void	sb6(int a, int b, int c, int d) S6 - { 7, 2,12, 5, 8, 4, 6,11,14, 9, 1,15,13, 3,10, 0 } - 15 terms.
private void	sb7(int a, int b, int c, int d) S7 - { 1,13,15, 0,14, 8, 2,11, 7, 4,12,10, 9, 3, 5, 6 } - 16 terms.
private void	wordToBytes(int word, byte[] dst, int dstOff)

Methods inherited from class java.lang.Object

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

Field Detail

BLOCK_SIZE

private static final int BLOCK_SIZE

See Also:

Constant Field Values

ROUNDS

static final int ROUNDS

See Also:

Constant Field Values

PHI

static final int PHI

See Also:

Constant Field Values

encrypting

private boolean encrypting

wKey

private int[] wKey

X0

private int X0

X1

private int X1

X2

private int X2

X3

private int X3

Constructor Detail

SerpentEngine

public SerpentEngine()

Method Detail

init

public void init(boolean encrypting,
                 CipherParameters params)

initialise a Serpent cipher.

Specified by:

init in interface BlockCipher

Parameters:

encrypting - whether or not we are for encryption.

params - the parameters required to set up the cipher.

Throws:

java.lang.IllegalArgumentException - if the params argument is inappropriate.

getAlgorithmName

public java.lang.String getAlgorithmName()

Description copied from interface: BlockCipher

Return the name of the algorithm the cipher implements.

Specified by:

getAlgorithmName in interface BlockCipher

Returns:

the name of the algorithm the cipher implements.

getBlockSize

public int getBlockSize()

Description copied from interface: BlockCipher

Return the block size for this cipher (in bytes).

Specified by:

getBlockSize in interface BlockCipher

Returns:

the block size for this cipher in bytes.

processBlock

public final int processBlock(byte[] in,
                              int inOff,
                              byte[] out,
                              int outOff)

Process one block of input from the array in and write it to the out array.

Specified by:

processBlock in interface BlockCipher

Parameters:

in - the array containing the input data.

inOff - offset into the in array the data starts at.

out - the array the output data will be copied into.

outOff - the offset into the out array the output will start at.

Returns:

the number of bytes processed and produced.

Throws:

DataLengthException - if there isn't enough data in in, or space in out.

java.lang.IllegalStateException - if the cipher isn't initialised.

reset

public void reset()

Description copied from interface: BlockCipher

Reset the cipher. After resetting the cipher is in the same state as it was after the last init (if there was one).

Specified by:

reset in interface BlockCipher

makeWorkingKey

private int[] makeWorkingKey(byte[] key)
                      throws java.lang.IllegalArgumentException

Expand a user-supplied key material into a session key.

Parameters:

key - The user-key bytes (multiples of 4) to use.

Throws:

java.lang.IllegalArgumentException

rotateLeft

private int rotateLeft(int x,
                       int bits)

rotateRight

private int rotateRight(int x,
                        int bits)

bytesToWord

private int bytesToWord(byte[] src,
                        int srcOff)

wordToBytes

private void wordToBytes(int word,
                         byte[] dst,
                         int dstOff)

encryptBlock

private void encryptBlock(byte[] in,
                          int inOff,
                          byte[] out,
                          int outOff)

Encrypt one block of plaintext.

Parameters:

in - the array containing the input data.

inOff - offset into the in array the data starts at.

out - the array the output data will be copied into.

outOff - the offset into the out array the output will start at.

decryptBlock

private void decryptBlock(byte[] in,
                          int inOff,
                          byte[] out,
                          int outOff)

Decrypt one block of ciphertext.

Parameters:

in - the array containing the input data.

inOff - offset into the in array the data starts at.

out - the array the output data will be copied into.

outOff - the offset into the out array the output will start at.

sb0

private void sb0(int a,
                 int b,
                 int c,
                 int d)

S0 - { 3, 8,15, 1,10, 6, 5,11,14,13, 4, 2, 7, 0, 9,12 } - 15 terms.

ib0

private void ib0(int a,
                 int b,
                 int c,
                 int d)

InvSO - {13, 3,11, 0,10, 6, 5,12, 1,14, 4, 7,15, 9, 8, 2 } - 15 terms.

sb1

private void sb1(int a,
                 int b,
                 int c,
                 int d)

S1 - {15,12, 2, 7, 9, 0, 5,10, 1,11,14, 8, 6,13, 3, 4 } - 14 terms.

ib1

private void ib1(int a,
                 int b,
                 int c,
                 int d)

InvS1 - { 5, 8, 2,14,15, 6,12, 3,11, 4, 7, 9, 1,13,10, 0 } - 14 steps.

sb2

private void sb2(int a,
                 int b,
                 int c,
                 int d)

S2 - { 8, 6, 7, 9, 3,12,10,15,13, 1,14, 4, 0,11, 5, 2 } - 16 terms.

ib2

private void ib2(int a,
                 int b,
                 int c,
                 int d)

InvS2 - {12, 9,15, 4,11,14, 1, 2, 0, 3, 6,13, 5, 8,10, 7 } - 16 steps.

sb3

private void sb3(int a,
                 int b,
                 int c,
                 int d)

S3 - { 0,15,11, 8,12, 9, 6, 3,13, 1, 2, 4,10, 7, 5,14 } - 16 terms.

ib3

private void ib3(int a,
                 int b,
                 int c,
                 int d)

InvS3 - { 0, 9,10, 7,11,14, 6,13, 3, 5,12, 2, 4, 8,15, 1 } - 15 terms

sb4

private void sb4(int a,
                 int b,
                 int c,
                 int d)

S4 - { 1,15, 8, 3,12, 0,11, 6, 2, 5, 4,10, 9,14, 7,13 } - 15 terms.

ib4

private void ib4(int a,
                 int b,
                 int c,
                 int d)

InvS4 - { 5, 0, 8, 3,10, 9, 7,14, 2,12,11, 6, 4,15,13, 1 } - 15 terms.

sb5

private void sb5(int a,
                 int b,
                 int c,
                 int d)

S5 - {15, 5, 2,11, 4,10, 9,12, 0, 3,14, 8,13, 6, 7, 1 } - 16 terms.

ib5

private void ib5(int a,
                 int b,
                 int c,
                 int d)

InvS5 - { 8,15, 2, 9, 4, 1,13,14,11, 6, 5, 3, 7,12,10, 0 } - 16 terms.

sb6

private void sb6(int a,
                 int b,
                 int c,
                 int d)

S6 - { 7, 2,12, 5, 8, 4, 6,11,14, 9, 1,15,13, 3,10, 0 } - 15 terms.

ib6

private void ib6(int a,
                 int b,
                 int c,
                 int d)

InvS6 - {15,10, 1,13, 5, 3, 6, 0, 4, 9,14, 7, 2,12, 8,11 } - 15 terms.

sb7

private void sb7(int a,
                 int b,
                 int c,
                 int d)

S7 - { 1,13,15, 0,14, 8, 2,11, 7, 4,12,10, 9, 3, 5, 6 } - 16 terms.

ib7

private void ib7(int a,
                 int b,
                 int c,
                 int d)

InvS7 - { 3, 0, 6,13, 9,14,15, 8, 5,12,11, 7,10, 1, 4, 2 } - 17 terms.

LT

private void LT()

Apply the linear transformation to the register set.

inverseLT

private void inverseLT()

Apply the inverse of the linear transformation to the register set.