Mercurial > dropbear
view libtomcrypt/src/encauth/gcm/gcm_mult_h.c @ 1294:56aba7dedbea
options for disabling "normal" DH
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Mon, 02 May 2016 23:48:16 +0200 |
parents | 0cbe8f6dbf9e |
children | f849a5ca2efc |
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/* 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, [email protected], 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 $ */