1/* LibTomCrypt, modular cryptographic library -- Tom St Denis
2 *
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
5 *
6 * The library is free for all purposes without any express
7 * guarantee it works.
8 *
9 * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
10 */
11
12/**
13   @file ocb_shift_xor.c
14   OCB implementation, internal function, by Tom St Denis
15*/
16#include "tomcrypt.h"
17
18#ifdef OCB_MODE
19
20/**
21   Compute the shift/xor for OCB (internal function)
22   @param ocb  The OCB state
23   @param Z    The destination of the shift
24*/
25void ocb_shift_xor(ocb_state *ocb, unsigned char *Z)
26{
27   int x, y;
28   y = ocb_ntz(ocb->block_index++);
29   for (x = 0; x < ocb->block_len; x++) {
30       ocb->Li[x] ^= ocb->Ls[y][x];
31       Z[x]        = ocb->Li[x] ^ ocb->R[x];
32   }
33}
34
35#endif
36
37/* $Source: /cvs/libtom/libtomcrypt/src/encauth/ocb/ocb_shift_xor.c,v $ */
38/* $Revision: 1.4 $ */
39/* $Date: 2006/03/31 14:15:35 $ */
40