1 // SPDX-License-Identifier: BSD-2-Clause
2 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
3  *
4  * LibTomCrypt is a library that provides various cryptographic
5  * algorithms in a highly modular and flexible manner.
6  *
7  * The library is free for all purposes without any express
8  * guarantee it works.
9  */
10 #include "tomcrypt_private.h"
11 
12 /**
13    @file pmac_shift_xor.c
14    PMAC implementation, internal function, by Tom St Denis
15 */
16 
17 #ifdef LTC_PMAC
18 
19 /**
20   Internal function.  Performs the state update (adding correct multiple)
21   @param pmac   The PMAC state.
22 */
pmac_shift_xor(pmac_state * pmac)23 void pmac_shift_xor(pmac_state *pmac)
24 {
25    int x, y;
26    y = pmac_ntz(pmac->block_index++);
27 #ifdef LTC_FAST
28    for (x = 0; x < pmac->block_len; x += sizeof(LTC_FAST_TYPE)) {
29        *(LTC_FAST_TYPE_PTR_CAST((unsigned char *)pmac->Li + x)) ^=
30        *(LTC_FAST_TYPE_PTR_CAST((unsigned char *)pmac->Ls[y] + x));
31    }
32 #else
33    for (x = 0; x < pmac->block_len; x++) {
34        pmac->Li[x] ^= pmac->Ls[y][x];
35    }
36 #endif
37 }
38 
39 #endif
40 
41 /* ref:         $Format:%D$ */
42 /* git commit:  $Format:%H$ */
43 /* commit time: $Format:%ai$ */
44