/*
* Portions Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
* All rights reserved.
* This component and the accompanying materials are made available
* under the terms of "Eclipse Public License v1.0"
* which accompanies this distribution, and is available
* at the URL "http://www.eclipse.org/legal/epl-v10.html".
*
* Initial Contributors:
* Nokia Corporation - initial contribution.
*
* Contributors:
*
* Description:
* The original NIST Statistical Test Suite code is placed in public domain.
* (http://csrc.nist.gov/groups/ST/toolkit/rng/documentation_software.html)
*
* This software was developed at the National Institute of Standards and Technology by
* employees of the Federal Government in the course of their official duties. Pursuant
* to title 17 Section 105 of the United States Code this software is not subject to
* copyright protection and is in the public domain. The NIST Statistical Test Suite is
* an experimental system. NIST assumes no responsibility whatsoever for its use by other
* parties, and makes no guarantees, expressed or implied, about its quality, reliability,
* or any other characteristic. We would appreciate acknowledgment if the software is used.
*/
/*
* file: mp.c
*
* DESCRIPTION
*
* These functions comprise a multi-precision integer arithmetic
* and discrete function package.
*/
#include "../include/genutils.h"
#define MAXPLEN 384
/*****************************************
** greater - Test if x > y *
** *
** Returns TRUE (1) if x greater than y, *
** otherwise FALSE (0). *
** *
** Parameters: *
** *
** x Address of array x *
** y Address of array y *
** l Length both x and y in bytes *
** *
******************************************/
int greater(BYTE *x, BYTE *y, int l)
{
int i;
for ( i=0; i<l; i++ )
if ( x[i] != y[i] )
break;
if ( i == l )
return 0;
if ( x[i] > y[i] )
return 1;
return 0;
}
/*****************************************
** less - Test if x < y *
** *
** Returns TRUE (1) if x less than y, *
** otherwise FALSE (0). *
** *
** Parameters: *
** *
** x Address of array x *
** y Address of array y *
** l Length both x and y in bytes *
** *
******************************************/
int less(BYTE *x, BYTE *y, int l)
{
int i;
for ( i=0; i<l; i++ )
if ( x[i] != y[i] )
break;
if ( i == l ) {
return 0;
}
if ( x[i] < y[i] ) {
return 1;
}
return 0;
}
/*****************************************
** bshl - shifts array left *
** by one bit. *
** *
** x = x * 2 *
** *
** Parameters: *
** *
** x Address of array x *
** l Length array x in bytes *
** *
******************************************/
BYTE bshl(BYTE *x, int l)
{
BYTE *p;
int c1, c2;
p = x + l - 1;
c1 = 0;
c2 = 0;
while ( p != x ) {
if ( *p & 0x80 )
c2 = 1;
*p <<= 1; /* shift the word left once (ls bit = 0) */
if ( c1 )
*p |= 1;
c1 = c2;
c2 = 0;
p--;
}
if ( *p & 0x80 )
c2 = 1;
*p <<= 1; /* shift the word left once (ls bit = 0) */
if ( c1 )
*p |= (DIGIT)1;
return (BYTE)c2;
}
/*****************************************
** bshr - shifts array right *
** by one bit. *
** *
** x = x / 2 *
** *
** Parameters: *
** *
** x Address of array x *
** l Length array x in bytes *
** *
******************************************/
void bshr(BYTE *x, int l)
{
BYTE *p;
int c1,c2;
p = x;
c1 = 0;
c2 = 0;
while ( p != x+l-1 ) {
if ( *p & 0x01 )
c2 = 1;
*p >>= 1; /* shift the word right once (ms bit = 0) */
if ( c1 )
*p |= 0x80;
c1 = c2;
c2 = 0;
p++;
}
*p >>= 1; /* shift the word right once (ms bit = 0) */
if ( c1 )
*p |= 0x80;
}
/*****************************************
** Mult - Multiply two integers *
** *
** A = B * C *
** *
** Parameters: *
** *
** A Address of the result *
** B Address of the multiplier *
** C Address of the multiplicand *
** LB Length of B in bytes *
** LC Length of C in bytes *
** *
** NOTE: A MUST be LB+LC in length *
** *
******************************************/
int Mult(BYTE *A, BYTE *B, int LB, BYTE *C, int LC)
{
int i, j;
int k = 0;
DIGIT result;
for ( i=LB-1; i>=0; i-- ) {
result = 0;
for ( j=LC-1; j>=0; j-- ) {
k = i+j+1;
result = (DIGIT)((DIGIT)A[k] + ((DIGIT)(B[i] * C[j])) + (result >> 8));
A[k] = (BYTE)result;
}
A[--k] = (BYTE)(result >> 8);
}
return 0;
}
void ModSqr(BYTE *A, BYTE *B, int LB, BYTE *M, int LM)
{
Square(A, B, LB);
Mod(A, 2*LB, M, LM);
}
void ModMult(BYTE *A, BYTE *B, int LB, BYTE *C, int LC, BYTE *M, int LM)
{
Mult(A, B, LB, C, LC);
Mod(A, (LB+LC), M, LM);
}
/*****************************************
** smult - Multiply array by a scalar. *
** *
** A = b * C *
** *
** Parameters: *
** *
** A Address of the result *
** b Scalar (1 BYTE) *
** C Address of the multiplicand *
** L Length of C in bytes *
** *
** NOTE: A MUST be L+1 in length *
** *
******************************************/
void smult(BYTE *A, BYTE b, BYTE *C, int L)
{
int i;
DIGIT result;
result = 0;
for ( i=L-1; i>0; i-- ) {
result = (DIGIT)(A[i] + ((DIGIT)b * C[i]) + (result >> 8));
A[i] = (BYTE)(result & 0xff);
A[i-1] = (BYTE)(result >> 8);
}
}
/*****************************************
** Square() - Square an integer *
** *
** A = B^2 *
** *
** Parameters: *
** *
** A Address of the result *
** B Address of the operand *
** L Length of B in bytes *
** *
** NOTE: A MUST be 2*L in length *
** *
******************************************/
void Square(BYTE *A, BYTE *B, int L)
{
Mult(A, B, L, B, L);
}
/*****************************************
** ModExp - Modular Exponentiation *
** *
** A = B ** C (MOD M) *
** *
** Parameters: *
** *
** A Address of result *
** B Address of mantissa *
** C Address of exponent *
** M Address of modulus *
** LB Length of B in bytes *
** LC Length of C in bytes *
** LM Length of M in bytes *
** *
** NOTE: The integer B must be less *
** than the modulus M. *
** NOTE: A must be at least 3*LM *
** bytes long. However, the *
** result stored in A will be *
** only LM bytes long. *
******************************************/
void ModExp(BYTE *A, BYTE *B, int LB, BYTE *C, int LC, BYTE *M, int LM)
{
BYTE wmask;
int bits;
bits = LC*8;
wmask = 0x80;
A[LM-1] = 1;
while ( !sniff_bit(C,wmask) ) {
wmask >>= 1;
bits--;
if ( !wmask ) {
wmask = 0x80;
C++;
}
}
while ( bits-- ) {
memset(A+LM, 0x00, LM*2);
/* temp = A*A (MOD M) */
ModSqr(A+LM, A,LM, M,LM);
/* A = lower L bytes of temp */
memcpy(A, A+LM*2, LM);
memset(A+LM, 0x00, 2*LM);
if ( sniff_bit(C,wmask) ) {
memset(A+LM, 0x00, (LM+LB));
ModMult(A+LM, B,LB, A,LM, M,LM); /* temp = B * A (MOD M) */
memcpy(A, A+LM+(LM+LB)-LM, LM); /* A = lower LM bytes of temp */
memset(A+LM, 0x00, 2*LM);
}
wmask >>= 1;
if ( !wmask ) {
wmask = 0x80;
C++;
}
}
}
/* DivMod:
*
* computes:
* quot = x / n
* rem = x % n
* returns:
* length of "quot"
*
* len of rem is lenx+1
*/
int DivMod(BYTE *x, int lenx, BYTE *n, int lenn, BYTE *quot, BYTE *rem)
{
BYTE *tx, *tn, *ttx, *ts, bmult[1];
int i, shift, lgth_x, lgth_n, t_len, lenq;
DIGIT tMSn, mult;
ULONG tMSx;
int underflow;
tx = x;
tn = n;
/* point to the MSD of n */
for ( i=0, lgth_n=lenn; i<lenn; i++, lgth_n-- ) {
if ( *tn )
break;
tn++;
}
if ( !lgth_n )
return 0;
/* point to the MSD of x */
for ( i=0, lgth_x=lenx; i<lenx; i++, lgth_x-- ) {
if ( *tx )
break;
tx++;
}
if ( !lgth_x )
return 0;
if ( lgth_x < lgth_n )
lenq = 1;
else
lenq = lgth_x - lgth_n + 1;
memset(quot, 0x00, lenq);
/* Loop while x > n, WATCH OUT if lgth_x == lgth_n */
while ( (lgth_x > lgth_n) || ((lgth_x == lgth_n) && !less(tx, tn, lgth_n)) ) {
shift = 1;
if ( lgth_n == 1 ) {
if ( *tx < *tn ) {
tMSx = (DIGIT) (((*tx) << 8) | *(tx+1));
tMSn = *tn;
shift = 0;
}
else {
tMSx = *tx;
tMSn = *tn;
}
}
else if ( lgth_n > 1 ) {
tMSx = (DIGIT) (((*tx) << 8) | *(tx+1));
tMSn = (DIGIT) (((*tn) << 8) | *(tn+1));
if ( (tMSx < tMSn) || ((tMSx == tMSn) && less(tx, tn, lgth_n)) ) {
tMSx = (tMSx << 8) | *(tx+2);
shift = 0;
}
}
else {
tMSx = (DIGIT) (((*tx) << 8) | *(tx+1));
tMSn = *tn;
shift = 0;
}
mult = (DIGIT) (tMSx / tMSn);
if ( mult > 0xff )
mult = 0xff;
bmult[0] = (BYTE)(mult & 0xff);
ts = rem;
do {
memset(ts, 0x00, lgth_x+1);
Mult(ts, tn, lgth_n, bmult, 1);
underflow = 0;
if ( shift ) {
if ( ts[0] != 0 )
underflow = 1;
else {
for ( i=0; i<lgth_x; i++ )
ts[i] = ts[i+1];
ts[lgth_x] = 0x00;
}
}
if ( greater(ts, tx, lgth_x) || underflow ) {
bmult[0]--;
underflow = 1;
}
else
underflow = 0;
} while ( underflow );
sub(tx, lgth_x, ts, lgth_x);
if ( shift )
quot[lenq - (lgth_x - lgth_n) - 1] = bmult[0];
else
quot[lenq - (lgth_x - lgth_n)] = bmult[0];
ttx = tx;
t_len = lgth_x;
for ( i=0, lgth_x=t_len; i<t_len; i++, lgth_x-- ) {
if ( *ttx )
break;
ttx++;
}
tx = ttx;
}
memset(rem, 0x00, lenn);
if ( lgth_x )
memcpy(rem+lenn-lgth_x, tx, lgth_x);
return lenq;
}
/*
* Mod - Computes an integer modulo another integer
*
* x = x (mod n)
*
*/
void Mod(BYTE *x, int lenx, BYTE *n, int lenn)
{
BYTE quot[MAXPLEN+1], rem[2*MAXPLEN+1];
memset(quot, 0x00, sizeof(quot));
memset(rem, 0x00, sizeof(rem));
if ( DivMod(x, lenx, n, lenn, quot, rem) ) {
memset(x, 0x00, lenx);
memcpy(x+lenx-lenn, rem, lenn);
}
}
/*
* Div - Computes the integer division of two numbers
*
* x = x / n
*
*/
void Div(BYTE *x, int lenx, BYTE *n, int lenn)
{
BYTE quot[MAXPLEN+1], rem[2*MAXPLEN+1];
int lenq;
memset(quot, 0x00, sizeof(quot));
memset(rem, 0x00, sizeof(rem));
if ( (lenq = DivMod(x, lenx, n, lenn, quot, rem)) != 0 ) {
memset(x, 0x00, lenx);
memcpy(x+lenx-lenq, quot, lenq);
}
}
/*****************************************
** sub - Subtract two integers *
** *
** A = A - B *
** *
** *
** Parameters: *
** *
** A Address of subtrahend integer *
** B Address of subtractor integer *
** L Length of A and B in bytes *
** *
** NOTE: In order to save RAM, B is *
** two's complemented twice, *
** rather than using a copy of B *
** *
******************************************/
void sub(BYTE *A, int LA, BYTE *B, int LB)
{
BYTE *tb;
tb = (BYTE *)calloc(LA, 1);
memcpy(tb, B, LB);
negate(tb, LB);
add(A, LA, tb, LA);
FREE(tb);
}
/*****************************************
** negate - Negate an integer *
** *
** A = -A *
** *
** *
** Parameters: *
** *
** A Address of integer to negate *
** L Length of A in bytes *
** *
******************************************/
int negate(BYTE *A, int L)
{
int i, tL;
DIGIT accum;
/* Take one's complement of A */
for ( i=0; i<L; i++ )
A[i] = (BYTE)(~(A[i]));
/* Add one to get two's complement of A */
accum = 1;
tL = L-1;
while ( accum && (tL >= 0) ) {
accum = (DIGIT)(accum + A[tL]);
A[tL--] = (BYTE)(accum & 0xff);
accum = (DIGIT)(accum >> 8);
}
return accum;
}
/*
* add()
*
* A = A + B
*
* LB must be <= LA
*
*/
BYTE add(BYTE *A, int LA, BYTE *B, int LB)
{
int i, indexA, indexB;
DIGIT accum;
indexA = LA - 1; /* LSD of result */
indexB = LB - 1; /* LSD of B */
accum = 0;
for ( i = 0; i < LB; i++ ) {
accum = (DIGIT)(accum + A[indexA]);
accum = (DIGIT)(accum + B[indexB--]);
A[indexA--] = (BYTE)(accum & 0xff);
accum = (DIGIT)(accum >> 8);
}
if ( LA > LB )
while ( accum && (indexA >= 0) ) {
accum = (DIGIT)(accum + A[indexA]);
A[indexA--] = (BYTE)(accum & 0xff);
accum = (DIGIT)(accum >> 8);
}
return (BYTE)accum;
}
void prettyprintBstr(char *S, BYTE *A, int L)
{
int i, extra, ctrb, ctrl;
if ( L == 0 )
printf("%s <empty>", S);
else
printf("%s\n\t", S);
extra = L % 24;
if ( extra ) {
ctrb = 0;
for ( i=0; i<24-extra; i++ ) {
printf(" ");
if ( ++ctrb == 4) {
printf(" ");
ctrb = 0;
}
}
for ( i=0; i<extra; i++ ) {
printf("%02X", A[i]);
if ( ++ctrb == 4) {
printf(" ");
ctrb = 0;
}
}
printf("\n\t");
}
ctrb = ctrl = 0;
for ( i=extra; i<L; i++ ) {
printf("%02X", A[i]);
if ( ++ctrb == 4) {
ctrl++;
if ( ctrl == 6 ) {
printf("\n\t");
ctrl = 0;
}
else
printf(" ");
ctrb = 0;
}
}
printf("\n\n");
}
/**********************************************************************/
/* Performs byte reverse for PC based implementation (little endian) */
/**********************************************************************/
void byteReverse(ULONG *buffer, int byteCount)
{
ULONG value;
int count;
byteCount /= sizeof( ULONG );
for( count = 0; count < byteCount; count++ ) {
value = ( buffer[ count ] << 16 ) | ( buffer[ count ] >> 16 );
buffer[ count ] = ( ( value & 0xFF00FF00L ) >> 8 ) | ( ( value & 0x00FF00FFL ) << 8 );
}
}
void
ahtopb (char *ascii_hex, BYTE *p_binary, int bin_len)
{
BYTE nibble;
int i;
for ( i=0; i<bin_len; i++ ) {
nibble = ascii_hex[i * 2];
if ( nibble > 'F' )
nibble -= 0x20;
if ( nibble > '9' )
nibble -= 7;
nibble -= '0';
p_binary[i] = (BYTE)(nibble << 4);
nibble = ascii_hex[i * 2 + 1];
if ( nibble > 'F' )
nibble -= 0x20;
if ( nibble > '9' )
nibble -= 7;
nibble -= '0';
p_binary[i] = (BYTE)(p_binary[i] + nibble);
}
}