/* 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, tomstdenis@gmail.com, http://libtomcrypt.com *//**   @file gcm_mult_h.c   GCM implementation, do the GF mult, by Tom St Denis*/#include "tomcrypt.h"#if defined(GCM_MODE)/**  GCM multiply by H  @param gcm   The GCM state which holds the H value  @param I     The value to multiply H by */void gcm_mult_h(gcm_state *gcm, unsigned char *I){   unsigned char T[16];#ifdef GCM_TABLES   int x, y;#ifdef GCM_TABLES_SSE2   asm("movdqa (%0),%%xmm0"::"r"(&gcm->PC[0][I[0]][0]));   for (x = 1; x < 16; x++) {      asm("pxor (%0),%%xmm0"::"r"(&gcm->PC[x][I[x]][0]));   }   asm("movdqa %%xmm0,(%0)"::"r"(&T));#else   XMEMCPY(T, &gcm->PC[0][I[0]][0], 16);   for (x = 1; x < 16; x++) {#ifdef LTC_FAST       for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {           *((LTC_FAST_TYPE *)(T + y)) ^= *((LTC_FAST_TYPE *)(&gcm->PC[x][I[x]][y]));       }#else       for (y = 0; y < 16; y++) {           T[y] ^= gcm->PC[x][I[x]][y];       }#endif /* LTC_FAST */   }#endif /* GCM_TABLES_SSE2 */#else        gcm_gf_mult(gcm->H, I, T); #endif   XMEMCPY(I, T, 16);}#endif/* $Source: /cvs/libtom/libtomcrypt/src/encauth/gcm/gcm_mult_h.c,v $ *//* $Revision: 1.4 $ *//* $Date: 2006/08/23 20:40:23 $ */