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 xcbc_process.c
14 XCBC Support, process blocks with XCBC
15 */
16
17 #ifdef LTC_XCBC
18
19 /** Process data through XCBC-MAC
20 @param xcbc The XCBC-MAC state
21 @param in Input data to process
22 @param inlen Length of input in octets
23 Return CRYPT_OK on success
24 */
xcbc_process(xcbc_state * xcbc,const unsigned char * in,unsigned long inlen)25 int xcbc_process(xcbc_state *xcbc, const unsigned char *in, unsigned long inlen)
26 {
27 int err;
28 #ifdef LTC_FAST
29 int x;
30 #endif
31
32 LTC_ARGCHK(xcbc != NULL);
33 LTC_ARGCHK(in != NULL);
34
35 /* check structure */
36 if ((err = cipher_is_valid(xcbc->cipher)) != CRYPT_OK) {
37 return err;
38 }
39
40 if ((xcbc->blocksize > cipher_descriptor[xcbc->cipher]->block_length) || (xcbc->blocksize < 0) ||
41 (xcbc->buflen > xcbc->blocksize) || (xcbc->buflen < 0)) {
42 return CRYPT_INVALID_ARG;
43 }
44
45 #ifdef LTC_FAST
46 if (xcbc->buflen == 0) {
47 while (inlen > (unsigned long)xcbc->blocksize) {
48 for (x = 0; x < xcbc->blocksize; x += sizeof(LTC_FAST_TYPE)) {
49 *(LTC_FAST_TYPE_PTR_CAST(&(xcbc->IV[x]))) ^= *(LTC_FAST_TYPE_PTR_CAST(&(in[x])));
50 }
51 cipher_descriptor[xcbc->cipher]->ecb_encrypt(xcbc->IV, xcbc->IV, &xcbc->key);
52 in += xcbc->blocksize;
53 inlen -= xcbc->blocksize;
54 }
55 }
56 #endif
57
58 while (inlen) {
59 if (xcbc->buflen == xcbc->blocksize) {
60 cipher_descriptor[xcbc->cipher]->ecb_encrypt(xcbc->IV, xcbc->IV, &xcbc->key);
61 xcbc->buflen = 0;
62 }
63 xcbc->IV[xcbc->buflen++] ^= *in++;
64 --inlen;
65 }
66 return CRYPT_OK;
67 }
68
69 #endif
70
71 /* ref: $Format:%D$ */
72 /* git commit: $Format:%H$ */
73 /* commit time: $Format:%ai$ */
74
75