Mercurial > dropbear
diff src/encauth/gcm/gcm_mult_h.c @ 381:999a5eb4ed10 libtomcrypt-dropbear
propagate from branch 'au.asn.ucc.matt.ltc.orig' (head 52840647ac7f5c707c3bd158d119a15734a7ef28)
to branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Thu, 11 Jan 2007 02:39:21 +0000 |
parents | d5faf4814ddb |
children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/encauth/gcm/gcm_mult_h.c Thu Jan 11 02:39:21 2007 +0000 @@ -0,0 +1,58 @@ +/* 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 $ */