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_done.c
14 PMAC implementation, terminate a session, by Tom St Denis
15 */
16
17 #ifdef LTC_PMAC
18
pmac_done(pmac_state * pmac,unsigned char * out,unsigned long * outlen)19 int pmac_done(pmac_state *pmac, unsigned char *out, unsigned long *outlen)
20 {
21 int err, x;
22
23 LTC_ARGCHK(pmac != NULL);
24 LTC_ARGCHK(out != NULL);
25 if ((err = cipher_is_valid(pmac->cipher_idx)) != CRYPT_OK) {
26 return err;
27 }
28
29 if ((pmac->buflen > (int)sizeof(pmac->block)) || (pmac->buflen < 0) ||
30 (pmac->block_len > (int)sizeof(pmac->block)) || (pmac->buflen > pmac->block_len)) {
31 return CRYPT_INVALID_ARG;
32 }
33
34
35 /* handle padding. If multiple xor in L/x */
36
37 if (pmac->buflen == pmac->block_len) {
38 /* xor Lr against the checksum */
39 for (x = 0; x < pmac->block_len; x++) {
40 pmac->checksum[x] ^= pmac->block[x] ^ pmac->Lr[x];
41 }
42 } else {
43 /* otherwise xor message bytes then the 0x80 byte */
44 for (x = 0; x < pmac->buflen; x++) {
45 pmac->checksum[x] ^= pmac->block[x];
46 }
47 pmac->checksum[x] ^= 0x80;
48 }
49
50 /* encrypt it */
51 if ((err = cipher_descriptor[pmac->cipher_idx]->ecb_encrypt(pmac->checksum, pmac->checksum, &pmac->key)) != CRYPT_OK) {
52 return err;
53 }
54 cipher_descriptor[pmac->cipher_idx]->done(&pmac->key);
55
56 /* store it */
57 for (x = 0; x < pmac->block_len && x < (int)*outlen; x++) {
58 out[x] = pmac->checksum[x];
59 }
60 *outlen = x;
61
62 #ifdef LTC_CLEAN_STACK
63 zeromem(pmac, sizeof(*pmac));
64 #endif
65 return CRYPT_OK;
66 }
67
68 #endif
69
70
71 /* ref: $Format:%D$ */
72 /* git commit: $Format:%H$ */
73 /* commit time: $Format:%ai$ */
74