package org.bouncycastle.crypto.engines;
import org.bouncycastle.crypto.BlockCipher;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.DataLengthException;
import org.bouncycastle.crypto.OutputLengthException;
import org.bouncycastle.crypto.params.KeyParameter;
public abstract class SerpentEngineBase
implements BlockCipher
{
protected static final int BLOCK_SIZE = 16;
static final int ROUNDS = 32;
static final int PHI = 0x9E3779B9; // (sqrt(5) - 1) * 2**31
protected boolean encrypting;
protected int[] wKey;
protected int X0, X1, X2, X3; // registers
SerpentEngineBase()
{
}
/**
* initialise a Serpent cipher.
*
* @param encrypting whether or not we are for encryption.
* @param params the parameters required to set up the cipher.
* @throws IllegalArgumentException if the params argument is
* inappropriate.
*/
public void init(
boolean encrypting,
CipherParameters params)
{
if (params instanceof KeyParameter)
{
this.encrypting = encrypting;
this.wKey = makeWorkingKey(((KeyParameter)params).getKey());
return;
}
throw new IllegalArgumentException("invalid parameter passed to " + getAlgorithmName() + " init - " + params.getClass().getName());
}
public String getAlgorithmName()
{
return "Serpent";
}
public int getBlockSize()
{
return BLOCK_SIZE;
}
/**
* Process one block of input from the array in and write it to
* the out array.
*
* @param in the array containing the input data.
* @param inOff offset into the in array the data starts at.
* @param out the array the output data will be copied into.
* @param outOff the offset into the out array the output will start at.
* @return the number of bytes processed and produced.
* @throws DataLengthException if there isn't enough data in in, or
* space in out.
* @throws IllegalStateException if the cipher isn't initialised.
*/
public final int processBlock(
byte[] in,
int inOff,
byte[] out,
int outOff)
{
if (wKey == null)
{
throw new IllegalStateException(getAlgorithmName() + " not initialised");
}
if ((inOff + BLOCK_SIZE) > in.length)
{
throw new DataLengthException("input buffer too short");
}
if ((outOff + BLOCK_SIZE) > out.length)
{
throw new OutputLengthException("output buffer too short");
}
if (encrypting)
{
encryptBlock(in, inOff, out, outOff);
}
else
{
decryptBlock(in, inOff, out, outOff);
}
return BLOCK_SIZE;
}
public void reset()
{
}
protected static int rotateLeft(
int x,
int bits)
{
return (x << bits) | (x >>> -bits);
}
protected static int rotateRight(
int x,
int bits)
{
return (x >>> bits) | (x << -bits);
}
/**
* The sboxes below are based on the work of Brian Gladman and
* Sam Simpson, whose original notice appears below.
* <p>
* For further details see:
* http://fp.gladman.plus.com/cryptography_technology/serpent/
*/
/* Partially optimised Serpent S Box boolean functions derived */
/* using a recursive descent analyser but without a full search */
/* of all subtrees. This set of S boxes is the result of work */
/* by Sam Simpson and Brian Gladman using the spare time on a */
/* cluster of high capacity servers to search for S boxes with */
/* this customised search engine. There are now an average of */
/* 15.375 terms per S box. */
/* */
/* Copyright: Dr B. R Gladman (gladman@seven77.demon.co.uk) */
/* and Sam Simpson (s.simpson@mia.co.uk) */
/* 17th December 1998 */
/* */
/* We hereby give permission for information in this file to be */
/* used freely subject only to acknowledgement of its origin. */
/**
* S0 - { 3, 8,15, 1,10, 6, 5,11,14,13, 4, 2, 7, 0, 9,12 } - 15 terms.
*/
protected final void sb0(int a, int b, int c, int d)
{
int t1 = a ^ d;
int t3 = c ^ t1;
int t4 = b ^ t3;
X3 = (a & d) ^ t4;
int t7 = a ^ (b & t1);
X2 = t4 ^ (c | t7);
int t12 = X3 & (t3 ^ t7);
X1 = (~t3) ^ t12;
X0 = t12 ^ (~t7);
}
/**
* InvSO - {13, 3,11, 0,10, 6, 5,12, 1,14, 4, 7,15, 9, 8, 2 } - 15 terms.
*/
protected final void ib0(int a, int b, int c, int d)
{
int t1 = ~a;
int t2 = a ^ b;
int t4 = d ^ (t1 | t2);
int t5 = c ^ t4;
X2 = t2 ^ t5;
int t8 = t1 ^ (d & t2);
X1 = t4 ^ (X2 & t8);
X3 = (a & t4) ^ (t5 | X1);
X0 = X3 ^ (t5 ^ t8);
}
/**
* S1 - {15,12, 2, 7, 9, 0, 5,10, 1,11,14, 8, 6,13, 3, 4 } - 14 terms.
*/
protected final void sb1(int a, int b, int c, int d)
{
int t2 = b ^ (~a);
int t5 = c ^ (a | t2);
X2 = d ^ t5;
int t7 = b ^ (d | t2);
int t8 = t2 ^ X2;
X3 = t8 ^ (t5 & t7);
int t11 = t5 ^ t7;
X1 = X3 ^ t11;
X0 = t5 ^ (t8 & t11);
}
/**
* InvS1 - { 5, 8, 2,14,15, 6,12, 3,11, 4, 7, 9, 1,13,10, 0 } - 14 steps.
*/
protected final void ib1(int a, int b, int c, int d)
{
int t1 = b ^ d;
int t3 = a ^ (b & t1);
int t4 = t1 ^ t3;
X3 = c ^ t4;
int t7 = b ^ (t1 & t3);
int t8 = X3 | t7;
X1 = t3 ^ t8;
int t10 = ~X1;
int t11 = X3 ^ t7;
X0 = t10 ^ t11;
X2 = t4 ^ (t10 | t11);
}
/**
* S2 - { 8, 6, 7, 9, 3,12,10,15,13, 1,14, 4, 0,11, 5, 2 } - 16 terms.
*/
protected final void sb2(int a, int b, int c, int d)
{
int t1 = ~a;
int t2 = b ^ d;
int t3 = c & t1;
X0 = t2 ^ t3;
int t5 = c ^ t1;
int t6 = c ^ X0;
int t7 = b & t6;
X3 = t5 ^ t7;
X2 = a ^ ((d | t7) & (X0 | t5));
X1 = (t2 ^ X3) ^ (X2 ^ (d | t1));
}
/**
* InvS2 - {12, 9,15, 4,11,14, 1, 2, 0, 3, 6,13, 5, 8,10, 7 } - 16 steps.
*/
protected final void ib2(int a, int b, int c, int d)
{
int t1 = b ^ d;
int t2 = ~t1;
int t3 = a ^ c;
int t4 = c ^ t1;
int t5 = b & t4;
X0 = t3 ^ t5;
int t7 = a | t2;
int t8 = d ^ t7;
int t9 = t3 | t8;
X3 = t1 ^ t9;
int t11 = ~t4;
int t12 = X0 | X3;
X1 = t11 ^ t12;
X2 = (d & t11) ^ (t3 ^ t12);
}
/**
* S3 - { 0,15,11, 8,12, 9, 6, 3,13, 1, 2, 4,10, 7, 5,14 } - 16 terms.
*/
protected final void sb3(int a, int b, int c, int d)
{
int t1 = a ^ b;
int t2 = a & c;
int t3 = a | d;
int t4 = c ^ d;
int t5 = t1 & t3;
int t6 = t2 | t5;
X2 = t4 ^ t6;
int t8 = b ^ t3;
int t9 = t6 ^ t8;
int t10 = t4 & t9;
X0 = t1 ^ t10;
int t12 = X2 & X0;
X1 = t9 ^ t12;
X3 = (b | d) ^ (t4 ^ t12);
}
/**
* InvS3 - { 0, 9,10, 7,11,14, 6,13, 3, 5,12, 2, 4, 8,15, 1 } - 15 terms
*/
protected final void ib3(int a, int b, int c, int d)
{
int t1 = a | b;
int t2 = b ^ c;
int t3 = b & t2;
int t4 = a ^ t3;
int t5 = c ^ t4;
int t6 = d | t4;
X0 = t2 ^ t6;
int t8 = t2 | t6;
int t9 = d ^ t8;
X2 = t5 ^ t9;
int t11 = t1 ^ t9;
int t12 = X0 & t11;
X3 = t4 ^ t12;
X1 = X3 ^ (X0 ^ t11);
}
/**
* S4 - { 1,15, 8, 3,12, 0,11, 6, 2, 5, 4,10, 9,14, 7,13 } - 15 terms.
*/
protected final void sb4(int a, int b, int c, int d)
{
int t1 = a ^ d;
int t2 = d & t1;
int t3 = c ^ t2;
int t4 = b | t3;
X3 = t1 ^ t4;
int t6 = ~b;
int t7 = t1 | t6;
X0 = t3 ^ t7;
int t9 = a & X0;
int t10 = t1 ^ t6;
int t11 = t4 & t10;
X2 = t9 ^ t11;
X1 = (a ^ t3) ^ (t10 & X2);
}
/**
* InvS4 - { 5, 0, 8, 3,10, 9, 7,14, 2,12,11, 6, 4,15,13, 1 } - 15 terms.
*/
protected final void ib4(int a, int b, int c, int d)
{
int t1 = c | d;
int t2 = a & t1;
int t3 = b ^ t2;
int t4 = a & t3;
int t5 = c ^ t4;
X1 = d ^ t5;
int t7 = ~a;
int t8 = t5 & X1;
X3 = t3 ^ t8;
int t10 = X1 | t7;
int t11 = d ^ t10;
X0 = X3 ^ t11;
X2 = (t3 & t11) ^ (X1 ^ t7);
}
/**
* S5 - {15, 5, 2,11, 4,10, 9,12, 0, 3,14, 8,13, 6, 7, 1 } - 16 terms.
*/
protected final void sb5(int a, int b, int c, int d)
{
int t1 = ~a;
int t2 = a ^ b;
int t3 = a ^ d;
int t4 = c ^ t1;
int t5 = t2 | t3;
X0 = t4 ^ t5;
int t7 = d & X0;
int t8 = t2 ^ X0;
X1 = t7 ^ t8;
int t10 = t1 | X0;
int t11 = t2 | t7;
int t12 = t3 ^ t10;
X2 = t11 ^ t12;
X3 = (b ^ t7) ^ (X1 & t12);
}
/**
* InvS5 - { 8,15, 2, 9, 4, 1,13,14,11, 6, 5, 3, 7,12,10, 0 } - 16 terms.
*/
protected final void ib5(int a, int b, int c, int d)
{
int t1 = ~c;
int t2 = b & t1;
int t3 = d ^ t2;
int t4 = a & t3;
int t5 = b ^ t1;
X3 = t4 ^ t5;
int t7 = b | X3;
int t8 = a & t7;
X1 = t3 ^ t8;
int t10 = a | d;
int t11 = t1 ^ t7;
X0 = t10 ^ t11;
X2 = (b & t10) ^ (t4 | (a ^ c));
}
/**
* S6 - { 7, 2,12, 5, 8, 4, 6,11,14, 9, 1,15,13, 3,10, 0 } - 15 terms.
*/
protected final void sb6(int a, int b, int c, int d)
{
int t1 = ~a;
int t2 = a ^ d;
int t3 = b ^ t2;
int t4 = t1 | t2;
int t5 = c ^ t4;
X1 = b ^ t5;
int t7 = t2 | X1;
int t8 = d ^ t7;
int t9 = t5 & t8;
X2 = t3 ^ t9;
int t11 = t5 ^ t8;
X0 = X2 ^ t11;
X3 = (~t5) ^ (t3 & t11);
}
/**
* InvS6 - {15,10, 1,13, 5, 3, 6, 0, 4, 9,14, 7, 2,12, 8,11 } - 15 terms.
*/
protected final void ib6(int a, int b, int c, int d)
{
int t1 = ~a;
int t2 = a ^ b;
int t3 = c ^ t2;
int t4 = c | t1;
int t5 = d ^ t4;
X1 = t3 ^ t5;
int t7 = t3 & t5;
int t8 = t2 ^ t7;
int t9 = b | t8;
X3 = t5 ^ t9;
int t11 = b | X3;
X0 = t8 ^ t11;
X2 = (d & t1) ^ (t3 ^ t11);
}
/**
* S7 - { 1,13,15, 0,14, 8, 2,11, 7, 4,12,10, 9, 3, 5, 6 } - 16 terms.
*/
protected final void sb7(int a, int b, int c, int d)
{
int t1 = b ^ c;
int t2 = c & t1;
int t3 = d ^ t2;
int t4 = a ^ t3;
int t5 = d | t1;
int t6 = t4 & t5;
X1 = b ^ t6;
int t8 = t3 | X1;
int t9 = a & t4;
X3 = t1 ^ t9;
int t11 = t4 ^ t8;
int t12 = X3 & t11;
X2 = t3 ^ t12;
X0 = (~t11) ^ (X3 & X2);
}
/**
* InvS7 - { 3, 0, 6,13, 9,14,15, 8, 5,12,11, 7,10, 1, 4, 2 } - 17 terms.
*/
protected final void ib7(int a, int b, int c, int d)
{
int t3 = c | (a & b);
int t4 = d & (a | b);
X3 = t3 ^ t4;
int t6 = ~d;
int t7 = b ^ t4;
int t9 = t7 | (X3 ^ t6);
X1 = a ^ t9;
X0 = (c ^ t7) ^ (d | X1);
X2 = (t3 ^ X1) ^ (X0 ^ (a & X3));
}
/**
* Apply the linear transformation to the register set.
*/
protected final void LT()
{
int x0 = rotateLeft(X0, 13);
int x2 = rotateLeft(X2, 3);
int x1 = X1 ^ x0 ^ x2 ;
int x3 = X3 ^ x2 ^ x0 << 3;
X1 = rotateLeft(x1, 1);
X3 = rotateLeft(x3, 7);
X0 = rotateLeft(x0 ^ X1 ^ X3, 5);
X2 = rotateLeft(x2 ^ X3 ^ (X1 << 7), 22);
}
/**
* Apply the inverse of the linear transformation to the register set.
*/
protected final void inverseLT()
{
int x2 = rotateRight(X2, 22) ^ X3 ^ (X1 << 7);
int x0 = rotateRight(X0, 5) ^ X1 ^ X3;
int x3 = rotateRight(X3, 7);
int x1 = rotateRight(X1, 1);
X3 = x3 ^ x2 ^ x0 << 3;
X1 = x1 ^ x0 ^ x2;
X2 = rotateRight(x2, 3);
X0 = rotateRight(x0, 13);
}
protected abstract int[] makeWorkingKey(byte[] key);
protected abstract void encryptBlock(byte[] input, int inOff, byte[] output, int outOff);
protected abstract void decryptBlock(byte[] input, int inOff, byte[] output, int outOff);
}