
/**************************************************************************
*                                                                         *
*             Java Grande Forum Benchmark Suite - MPJ Version 1.0         *
*                                                                         *
*                            produced by                                  *
*                                                                         *
*                  Java Grande Benchmarking Project                       *
*                                                                         *
*                                at                                       *
*                                                                         *
*                Edinburgh Parallel Computing Centre                      *
*                                                                         * 
*                email: epcc-javagrande@epcc.ed.ac.uk                     *
*                                                                         *
*                  Original version of this code by                       *
*                 Gabriel Zachmann (zach@igd.fhg.de)                      *
*                                                                         *
*      This version copyright (c) The University of Edinburgh, 2001.      *
*                         All rights reserved.                            *
*                                                                         *
**************************************************************************/


/**
* Class IDEATest
*
* This test performs IDEA encryption then decryption. IDEA stands
* for International Data Encryption Algorithm. The test is based
* on code presented in Applied Cryptography by Bruce Schnier,
* which was based on code developed by Xuejia Lai and James L.
* Massey.

**/

package jgf_mpj_benchmarks.section2.crypt;

import java.util.*;
import jgf_mpj_benchmarks.jgfutil.*; 
import mpi.*;

class IDEATest
{

// Declare class data. Byte buffer plain1 holds the original
// data for encryption, crypt1 holds the encrypted data, and
// plain2 holds the decrypted data, which should match plain1
// byte for byte.

int array_rows; 
int p_array_rows;
int ref_p_array_rows;
int rem_p_array_rows;

byte [] plain1 = null;       // Buffer for plaintext data.
byte [] crypt1 = null;       // Buffer for encrypted data.
byte [] plain2 = null;       // Buffer for decrypted data.

byte [] p_plain1 = null;
byte [] p_crypt1 = null;
byte [] p_plain2 = null;

short [] userkey;     // Key for encryption/decryption.
int [] Z;             // Encryption subkey (userkey derived).
int [] DK;            // Decryption subkey (userkey derived).



void Do() throws MPIException
{

  // temporary array for MPI
  int m_length;

  MPI.COMM_WORLD.Barrier();
  // Start the stopwatch.       
  if(JGFCryptBench.rank==0) {
    JGFInstrumentor.startTimer("Section2:Crypt:Kernel"); 		
  }

  // broadcast information
  if(JGFCryptBench.rank==0) {
    for (int i = 0; i < p_array_rows; i++) {
     p_plain1[i] = plain1[i]; 
    }
    for(int k=1;k<JGFCryptBench.nprocess;k++){
     if(k==JGFCryptBench.nprocess-1) {
       m_length = rem_p_array_rows;
     } else {
       m_length = p_array_rows;
     }
     MPI.COMM_WORLD.Ssend(plain1,(p_array_rows*k),m_length,MPI.BYTE,k,k);
    }
  } else {
    MPI.COMM_WORLD.Recv(p_plain1,0,p_array_rows,MPI.BYTE,0,JGFCryptBench.rank);
  }

  cipher_idea(p_plain1, p_crypt1, Z);     // Encrypt plain1.
  cipher_idea(p_crypt1, p_plain2, DK);    // Decrypt.

  MPI.COMM_WORLD.Barrier();

  if(JGFCryptBench.rank==0) {
    for(int k=0; k<p_array_rows;k++){ 
      plain2[k] = p_plain2[k];
    }

    for(int k=1;k<JGFCryptBench.nprocess;k++) {
      MPI.COMM_WORLD.Recv(plain2,(p_array_rows*k),p_array_rows,MPI.BYTE,k,k);
    }
  } else {
    MPI.COMM_WORLD.Ssend(p_plain2,0,p_array_rows,MPI.BYTE,0,JGFCryptBench.rank);
  }

  MPI.COMM_WORLD.Barrier();

  // Stop the stopwatch.
  if(JGFCryptBench.rank==0) {
    JGFInstrumentor.stopTimer("Section2:Crypt:Kernel");
  }
}

/*
* buildTestData
*
* Builds the data used for the test -- each time the test is run.
*/

void buildTestData()
{


    // Create three byte arrays that will be used (and reused) for
    // encryption/decryption operations.

    if(JGFCryptBench.rank==0) {
      plain1 = new byte [array_rows];
      crypt1 = new byte [array_rows];
      plain2 = new byte [array_rows];
    } 

    p_plain1 = new byte [p_array_rows];
    p_crypt1 = new byte [p_array_rows];
    p_plain2 = new byte [p_array_rows];

    Random rndnum = new Random(136506717L);  // Create random number generator.


    // Allocate three arrays to hold keys: userkey is the 128-bit key.
    // Z is the set of 16-bit encryption subkeys derived from userkey,
    // while DK is the set of 16-bit decryption subkeys also derived
    // from userkey. NOTE: The 16-bit values are stored here in
    // 32-bit int arrays so that the values may be used in calculations
    // as if they are unsigned. Each 64-bit block of plaintext goes
    // through eight processing rounds involving six of the subkeys
    // then a final output transform with four of the keys; (8 * 6)
    // + 4 = 52 subkeys.

    userkey = new short [8];  // User key has 8 16-bit shorts.
    Z = new int [52];         // Encryption subkey (user key derived).
    DK = new int [52];        // Decryption subkey (user key derived).

    // Generate user key randomly; eight 16-bit values in an array.

    for (int i = 0; i < 8; i++)
    {
        // Again, the random number function returns int. Converting
        // to a short type preserves the bit pattern in the lower 16
        // bits of the int and discards the rest.

      userkey[i] = (short) rndnum.nextInt();
    }

    // Compute encryption and decryption subkeys.

    calcEncryptKey();
    calcDecryptKey();

    // Fill plain1 with "text."
    // do on process 0 for reference 

    if(JGFCryptBench.rank==0) {    
      for (int i = 0; i < array_rows; i++)
      {
        plain1[i] = (byte) i; 

        // Converting to a byte
        // type preserves the bit pattern in the lower 8 bits of the
        // int and discards the rest.
      }
    }

}

/*
* calcEncryptKey
*
* Builds the 52 16-bit encryption subkeys Z[] from the user key and
* stores in 32-bit int array. The routing corrects an error in the
* source code in the Schnier book. Basically, the sense of the 7-
* and 9-bit shifts are reversed. It still works reversed, but would
* encrypted code would not decrypt with someone else's IDEA code.
*/

private void calcEncryptKey()
{
    int j;                       // Utility variable.

    for (int i = 0; i < 52; i++) // Zero out the 52-int Z array.
        Z[i] = 0;

    for (int i = 0; i < 8; i++)  // First 8 subkeys are userkey itself.
    {
        Z[i] = userkey[i] & 0xffff;     // Convert "unsigned"
                                        // short to int.
    }

    // Each set of 8 subkeys thereafter is derived from left rotating
    // the whole 128-bit key 25 bits to left (once between each set of
    // eight keys and then before the last four). Instead of actually
    // rotating the whole key, this routine just grabs the 16 bits
    // that are 25 bits to the right of the corresponding subkey
    // eight positions below the current subkey. That 16-bit extent
    // straddles two array members, so bits are shifted left in one
    // member and right (with zero fill) in the other. For the last
    // two subkeys in any group of eight, those 16 bits start to
    // wrap around to the first two members of the previous eight.

    for (int i = 8; i < 52; i++)
    {
        j = i % 8;
        if (j < 6)
        {
            Z[i] = ((Z[i -7]>>>9) | (Z[i-6]<<7)) // Shift and combine.
                    & 0xFFFF;                    // Just 16 bits.
            continue;                            // Next iteration.
        }

        if (j == 6)    // Wrap to beginning for second chunk.
        {
            Z[i] = ((Z[i -7]>>>9) | (Z[i-14]<<7))
                    & 0xFFFF;
            continue;
        }

         // j == 7 so wrap to beginning for both chunks.

        Z[i] = ((Z[i -15]>>>9) | (Z[i-14]<<7))
                    & 0xFFFF;
    }
}

/*
* calcDecryptKey
*
* Builds the 52 16-bit encryption subkeys DK[] from the encryption-
* subkeys Z[]. DK[] is a 32-bit int array holding 16-bit values as
* unsigned.
*/

private void calcDecryptKey()
{
    int j, k;                 // Index counters.
    int t1, t2, t3;           // Temps to hold decrypt subkeys.

    t1 = inv(Z[0]);           // Multiplicative inverse (mod x10001).
    t2 = - Z[1] & 0xffff;     // Additive inverse, 2nd encrypt subkey.
    t3 = - Z[2] & 0xffff;     // Additive inverse, 3rd encrypt subkey.

    DK[51] = inv(Z[3]);       // Multiplicative inverse (mod x10001).
    DK[50] = t3;
    DK[49] = t2;
    DK[48] = t1;

    j = 47;                   // Indices into temp and encrypt arrays.
    k = 4;
    for (int i = 0; i < 7; i++)
    {
        t1 = Z[k++];
        DK[j--] = Z[k++];
        DK[j--] = t1;
        t1 = inv(Z[k++]);
        t2 = -Z[k++] & 0xffff;
        t3 = -Z[k++] & 0xffff;
        DK[j--] = inv(Z[k++]);
        DK[j--] = t2;
        DK[j--] = t3;
        DK[j--] = t1;
    }

    t1 = Z[k++];
    DK[j--] = Z[k++];
    DK[j--] = t1;
    t1 = inv(Z[k++]);
    t2 = -Z[k++] & 0xffff;
    t3 = -Z[k++] & 0xffff;
    DK[j--] = inv(Z[k++]);
    DK[j--] = t3;
    DK[j--] = t2;
    DK[j--] = t1;
}

/*
* cipher_idea
*
* IDEA encryption/decryption algorithm. It processes plaintext in
* 64-bit blocks, one at a time, breaking the block into four 16-bit
* unsigned subblocks. It goes through eight rounds of processing
* using 6 new subkeys each time, plus four for last step. The source
* text is in array text1, the destination text goes into array text2
* The routine represents 16-bit subblocks and subkeys as type int so
* that they can be treated more easily as unsigned. Multiplication
* modulo 0x10001 interprets a zero sub-block as 0x10000; it must to
* fit in 16 bits.
*/

private void cipher_idea(byte [] text1, byte [] text2, int [] key)

{

int i1 = 0;                 // Index into first text array.
int i2 = 0;                 // Index into second text array.
int ik;                     // Index into key array.
int x1, x2, x3, x4, t1, t2; // Four "16-bit" blocks, two temps.
int r;                      // Eight rounds of processing.

for (int i = 0; i < text1.length; i += 8)
{

    ik = 0;                 // Restart key index.
    r = 8;                  // Eight rounds of processing.

    // Load eight plain1 bytes as four 16-bit "unsigned" integers.
    // Masking with 0xff prevents sign extension with cast to int.

    x1 = text1[i1++] & 0xff;          // Build 16-bit x1 from 2 bytes,
    x1 |= (text1[i1++] & 0xff) << 8;  // assuming low-order byte first.
    x2 = text1[i1++] & 0xff;
    x2 |= (text1[i1++] & 0xff) << 8;
    x3 = text1[i1++] & 0xff;
    x3 |= (text1[i1++] & 0xff) << 8;
    x4 = text1[i1++] & 0xff;
    x4 |= (text1[i1++] & 0xff) << 8;

    do {
        // 1) Multiply (modulo 0x10001), 1st text sub-block
        // with 1st key sub-block.

        x1 = (int) ((long) x1 * key[ik++] % 0x10001L & 0xffff);

        // 2) Add (modulo 0x10000), 2nd text sub-block
        // with 2nd key sub-block.

        x2 = x2 + key[ik++] & 0xffff;

        // 3) Add (modulo 0x10000), 3rd text sub-block
        // with 3rd key sub-block.

        x3 = x3 + key[ik++] & 0xffff;

        // 4) Multiply (modulo 0x10001), 4th text sub-block
        // with 4th key sub-block.

        x4 = (int) ((long) x4 * key[ik++] % 0x10001L & 0xffff);

        // 5) XOR results from steps 1 and 3.

        t2 = x1 ^ x3;

        // 6) XOR results from steps 2 and 4.
        // Included in step 8.

        // 7) Multiply (modulo 0x10001), result of step 5
        // with 5th key sub-block.

        t2 = (int) ((long) t2 * key[ik++] % 0x10001L & 0xffff);

        // 8) Add (modulo 0x10000), results of steps 6 and 7.

        t1 = t2 + (x2 ^ x4) & 0xffff;

        // 9) Multiply (modulo 0x10001), result of step 8
        // with 6th key sub-block.

        t1 = (int) ((long) t1 * key[ik++] % 0x10001L & 0xffff);

        // 10) Add (modulo 0x10000), results of steps 7 and 9.

        t2 = t1 + t2 & 0xffff;

        // 11) XOR results from steps 1 and 9.

        x1 ^= t1;

        // 14) XOR results from steps 4 and 10. (Out of order).

        x4 ^= t2;

        // 13) XOR results from steps 2 and 10. (Out of order).

        t2 ^= x2;

        // 12) XOR results from steps 3 and 9. (Out of order).

        x2 = x3 ^ t1;

        x3 = t2;        // Results of x2 and x3 now swapped.

    } while(--r != 0);  // Repeats seven more rounds.

    // Final output transform (4 steps).

    // 1) Multiply (modulo 0x10001), 1st text-block
    // with 1st key sub-block.

    x1 = (int) ((long) x1 * key[ik++] % 0x10001L & 0xffff);

    // 2) Add (modulo 0x10000), 2nd text sub-block
    // with 2nd key sub-block. It says x3, but that is to undo swap
    // of subblocks 2 and 3 in 8th processing round.

    x3 = x3 + key[ik++] & 0xffff;

    // 3) Add (modulo 0x10000), 3rd text sub-block
    // with 3rd key sub-block. It says x2, but that is to undo swap
    // of subblocks 2 and 3 in 8th processing round.

    x2 = x2 + key[ik++] & 0xffff;

    // 4) Multiply (modulo 0x10001), 4th text-block
    // with 4th key sub-block.

    x4 = (int) ((long) x4 * key[ik++] % 0x10001L & 0xffff);

    // Repackage from 16-bit sub-blocks to 8-bit byte array text2.

    text2[i2++] = (byte) x1;
    text2[i2++] = (byte) (x1 >>> 8);
    text2[i2++] = (byte) x3;                // x3 and x2 are switched
    text2[i2++] = (byte) (x3 >>> 8);        // only in name.
    text2[i2++] = (byte) x2;
    text2[i2++] = (byte) (x2 >>> 8);
    text2[i2++] = (byte) x4;
    text2[i2++] = (byte) (x4 >>> 8);

}   // End for loop.

}   // End routine.

/*
* mul
*
* Performs multiplication, modulo (2**16)+1. This code is structured
* on the assumption that untaken branches are cheaper than taken
* branches, and that the compiler doesn't schedule branches.
* Java: Must work with 32-bit int and one 64-bit long to keep
* 16-bit values and their products "unsigned." The routine assumes
* that both a and b could fit in 16 bits even though they come in
* as 32-bit ints. Lots of "& 0xFFFF" masks here to keep things 16-bit.
* Also, because the routine stores mod (2**16)+1 results in a 2**16
* space, the result is truncated to zero whenever the result would
* zero, be 2**16. And if one of the multiplicands is 0, the result
* is not zero, but (2**16) + 1 minus the other multiplicand (sort
* of an additive inverse mod 0x10001).

* NOTE: The java conversion of this routine works correctly, but
* is half the speed of using Java's modulus division function (%)
* on the multiplication with a 16-bit masking of the result--running
* in the Symantec Caje IDE. So it's not called for now; the test
* uses Java % instead.
*/

private int mul(int a, int b) throws ArithmeticException
{
    long p;             // Large enough to catch 16-bit multiply
                        // without hitting sign bit.
    if (a != 0)
    {
        if(b != 0)
        {
            p = (long) a * b;
            b = (int) p & 0xFFFF;       // Lower 16 bits.
            a = (int) p >>> 16;         // Upper 16 bits.

            return (b - a + (b < a ? 1 : 0) & 0xFFFF);
        }
        else
            return ((1 - a) & 0xFFFF);  // If b = 0, then same as
                                        // 0x10001 - a.
    }
    else                                // If a = 0, then return
        return((1 - b) & 0xFFFF);       // same as 0x10001 - b.
}

/*
* inv
*
* Compute multiplicative inverse of x, modulo (2**16)+1 using
* extended Euclid's GCD (greatest common divisor) algorithm.
* It is unrolled twice to avoid swapping the meaning of
* the registers. And some subtracts are changed to adds.
* Java: Though it uses signed 32-bit ints, the interpretation
* of the bits within is strictly unsigned 16-bit.
*/

private int inv(int x)
{
    int t0, t1;
    int q, y;

    if (x <= 1)             // Assumes positive x.
        return(x);          // 0 and 1 are self-inverse.

    t1 = 0x10001 / x;       // (2**16+1)/x; x is >= 2, so fits 16 bits.
    y = 0x10001 % x;
    if (y == 1)
        return((1 - t1) & 0xFFFF);

    t0 = 1;
    do {
        q = x / y;
        x = x % y;
        t0 += q * t1;
        if (x == 1) return(t0);
        q = y / x;
        y = y % x;
        t1 += q * t0;
    } while (y != 1);

    return((1 - t1) & 0xFFFF);
}

/*
* freeTestData
*
* Nulls arrays and forces garbage collection to free up memory.
*/

void freeTestData()
{
    plain1 = null;
    crypt1 = null;
    plain2 = null;
    p_plain1 = null;
    p_crypt1 = null;
    p_plain2 = null;
    userkey = null;
    Z = null;
    DK = null;

    System.gc();                // Force garbage collection.
}


}
