pmac_shift_xor.c

来自「该压缩包中包括 tom的加密函数库及pdf说明 ,以及Rinick s ECC：」· C语言 代码 · 共 45 行

/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, [e-mail], http://libtomcrypt.org
 */
#include "tomcrypt.h"

/** 
   @file pmac_shift_xor.c
   PMAC implementation, internal function, by Tom St Denis 
*/

#ifdef PMAC

/**
  Internal function.  Performs the state update (adding correct multiple)
  @param pmac   The PMAC state.
*/
void pmac_shift_xor(pmac_state *pmac)
{
   int x, y;
   y = pmac_ntz(pmac->block_index++);
#ifdef LTC_FAST
   for (x = 0; x < pmac->block_len; x += sizeof(LTC_FAST_TYPE)) {
       *((LTC_FAST_TYPE*)((unsigned char *)pmac->Li + x)) ^=
       *((LTC_FAST_TYPE*)((unsigned char *)pmac->Ls[y] + x));
   }
#else
   for (x = 0; x < pmac->block_len; x++) {
       pmac->Li[x] ^= pmac->Ls[y][x];
   }
#endif
}

#endif

/* $Source: /cvs/libtom/libtomcrypt/src/mac/pmac/pmac_shift_xor.c,v $ */
/* $Revision: 1.4 $ */
/* $Date: 2005/05/05 14:35:59 $ */