KGC_TEST/miracl/source/mrcrt.c

150 lines
5.1 KiB
C

/***************************************************************************
*
Copyright 2013 CertiVox UK Ltd. *
*
This file is part of CertiVox MIRACL Crypto SDK. *
*
The CertiVox MIRACL Crypto SDK provides developers with an *
extensive and efficient set of cryptographic functions. *
For further information about its features and functionalities please *
refer to http://www.certivox.com *
*
* The CertiVox MIRACL Crypto SDK is free software: you can *
redistribute it and/or modify it under the terms of the *
GNU Affero General Public License as published by the *
Free Software Foundation, either version 3 of the License, *
or (at your option) any later version. *
*
* The CertiVox MIRACL Crypto SDK is distributed in the hope *
that it will be useful, but WITHOUT ANY WARRANTY; without even the *
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. *
See the GNU Affero General Public License for more details. *
*
* You should have received a copy of the GNU Affero General Public *
License along with CertiVox MIRACL Crypto SDK. *
If not, see <http://www.gnu.org/licenses/>. *
*
You can be released from the requirements of the license by purchasing *
a commercial license. Buying such a license is mandatory as soon as you *
develop commercial activities involving the CertiVox MIRACL Crypto SDK *
without disclosing the source code of your own applications, or shipping *
the CertiVox MIRACL Crypto SDK with a closed source product. *
*
***************************************************************************/
/*
* MIRACL Chinese Remainder Thereom routines (for use with big moduli)
* mrcrt.c
*/
#include <stdlib.h>
#include "miracl.h"
#ifndef MR_STATIC
BOOL crt_init(_MIPD_ big_chinese *c,int r,big *moduli)
{ /* calculate CRT constants */
int i,j,k;
#ifdef MR_OS_THREADS
miracl *mr_mip=get_mip();
#endif
if (r<2 || mr_mip->ERNUM) return FALSE;
for (i=0;i<r;i++) if (size(moduli[i])<2) return FALSE;
MR_IN(73)
c->M=(big *)mr_alloc(_MIPP_ r,sizeof(big));
if (c->M==NULL)
{
mr_berror(_MIPP_ MR_ERR_OUT_OF_MEMORY);
MR_OUT
return FALSE;
}
c->C=(big *)mr_alloc(_MIPP_ r*(r-1)/2,sizeof(big));
if (c->C==NULL)
{
mr_free(c->M);
mr_berror(_MIPP_ MR_ERR_OUT_OF_MEMORY);
MR_OUT
return FALSE;
}
c->V=(big *)mr_alloc(_MIPP_ r,sizeof(big));
if (c->V==NULL)
{
mr_free(c->M);
mr_free(c->C);
mr_berror(_MIPP_ MR_ERR_OUT_OF_MEMORY);
MR_OUT
return FALSE;
}
for (k=0,i=0;i<r;i++)
{
c->V[i]=mirvar(_MIPP_ 0);
c->M[i]=mirvar(_MIPP_ 0);
copy(moduli[i],c->M[i]);
for (j=0;j<i;j++,k++)
{
c->C[k]=mirvar(_MIPP_ 0);
invmodp(_MIPP_ c->M[j],c->M[i],c->C[k]);
}
}
c->NP=r;
MR_OUT
return TRUE;
}
void crt_end(big_chinese *c)
{ /* clean up after CRT */
int i,j,k;
if (c->NP<2) return;
for (k=0,i=0;i<c->NP;i++)
{
mirkill(c->M[i]);
for (j=0;j<i;j++)
mirkill(c->C[k++]);
mirkill(c->V[i]);
}
mr_free(c->M);
mr_free(c->V);
mr_free(c->C);
c->NP=0;
}
#endif
void crt(_MIPD_ big_chinese *c,big *u,big x)
{ /* Chinese Remainder Thereom *
* Calculate x given remainders u[i] mod M[i] */
int i,j,k;
#ifdef MR_OS_THREADS
miracl *mr_mip=get_mip();
#endif
if (c->NP<2 || mr_mip->ERNUM) return;
MR_IN(74)
copy(u[0],c->V[0]);
for (k=0,i=1;i<c->NP;i++)
{ /* Knuth page 274 */
subtract(_MIPP_ u[i],c->V[0],c->V[i]);
mad(_MIPP_ c->V[i],c->C[k],c->C[k],c->M[i],c->M[i],c->V[i]);
k++;
for (j=1;j<i;j++,k++)
{
subtract(_MIPP_ c->V[i],c->V[j],c->V[i]);
mad(_MIPP_ c->V[i],c->C[k],c->C[k],c->M[i],c->M[i],c->V[i]);
}
if (size(c->V[i])<0) add(_MIPP_ c->V[i],c->M[i],c->V[i]);
}
zero(x);
convert(_MIPP_ 1,mr_mip->w1);
for (i=0;i<c->NP;i++)
{
multiply(_MIPP_ mr_mip->w1,c->V[i],mr_mip->w2);
add(_MIPP_ x,mr_mip->w2,x);
multiply(_MIPP_ mr_mip->w1,c->M[i],mr_mip->w1);
}
MR_OUT
}