ext/ipp/sources/ippcp/src/gsscramble.c

/*############################################################################
  # Copyright 2013-2018 Intel Corporation
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  ############################################################################*/

/* 
// 
//  Purpose:
//     Cryptography Primitive.
//     Fixed window exponentiation scramble/unscramble
// 
//  Contents:
//     gsScramblePut()
//     gsScrambleGet()
//     gsScrambleGet_sscm()
// 
*/
#include "owncp.h"
#include "gsscramble.h"

int gsGetScrambleBufferSize(int modulusLen, int w)
{
   /* size of resource to store 2^w values of modulusLen*sizeof(BNU_CHUNK_T) each */
   int size = (1<<w) * modulusLen * sizeof(BNU_CHUNK_T);
   /* padd it up to CACHE_LINE_SIZE */
   size += (CACHE_LINE_SIZE - (size % CACHE_LINE_SIZE)) %CACHE_LINE_SIZE;
   ///* add CACHE_LINE_SIZE for alignment purpose*/
   //size += CACHE_LINE_SIZE;
   return size/sizeof(BNU_CHUNK_T);
}

void gsScramblePut(BNU_CHUNK_T* tbl, int idx, const BNU_CHUNK_T* val, int vLen, int w)
{
   int width = 1 << w;
   int i, j;
   for(i=0, j=idx; i<vLen; i++, j+= width) {
      tbl[j] = val[i];
   }
}

void gsScrambleGet(BNU_CHUNK_T* val, int vLen, const BNU_CHUNK_T* tbl, int idx, int w)
{
   int width = 1 << w;
   int i, j;
   for(i=0, j=idx; i<vLen; i++, j+= width) {
      val[i] = tbl[j];
   }
}

void gsScrambleGet_sscm(BNU_CHUNK_T* val, int vLen, const BNU_CHUNK_T* tbl, int idx, int w)
{
   BNU_CHUNK_T mask[1<<MAX_W];

   int width = 1 << w;

   int n, i;
   switch (w) {
   case 6:
      for(n=0; n<(1<<6); n++)
         mask[n] = (BNU_CHUNK_T)0 - (ct_eq_int(n,idx)&1);
      break;
   case 5:
      for(n=0; n<(1<<5); n++)
         mask[n] = (BNU_CHUNK_T)0 - (ct_eq_int(n,idx)&1);
      break;
   case 4:
      for(n=0; n<(1<<4); n++)
         mask[n] = (BNU_CHUNK_T)0 - (ct_eq_int(n,idx)&1);
      break;
   case 3:
      for(n=0; n<(1<<3); n++)
         mask[n] = (BNU_CHUNK_T)0 - (ct_eq_int(n,idx)&1);
      break;
   case 2:
      for(n=0; n<(1<<2); n++)
         mask[n] = (BNU_CHUNK_T)0 - (ct_eq_int(n,idx)&1);
      break;
   default:
      mask[0] = (BNU_CHUNK_T)0 - (ct_eq_int(0,idx)&1);
      mask[1] = (BNU_CHUNK_T)0 - (ct_eq_int(1,idx)&1);
      break;
   }

   for(i=0; i<vLen; i++, tbl += width) {
      BNU_CHUNK_T acc = 0;

      switch (w) {
      case 6:
         for(n=0; n<(1<<6); n++)
            acc |= tbl[n] & mask[n];
         break;
      case 5:
         for(n=0; n<(1<<5); n++)
            acc |= tbl[n] & mask[n];
         break;
      case 4:
         for(n=0; n<(1<<4); n++)
            acc |= tbl[n] & mask[n];
         break;
      case 3:
         for(n=0; n<(1<<3); n++)
            acc |= tbl[n] & mask[n];
         break;
      case 2:
         for(n=0; n<(1<<2); n++)
            acc |= tbl[n] & mask[n];
         break;
      default:
         acc |= tbl[0] & mask[0];
         acc |= tbl[1] & mask[1];
         break;
      }

      val[i] = acc;
   }
}