Mercurial > dropbear

comparison libtomcrypt/src/mac/omac/omac_process.c @ 285:1b9e69c058d2

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3) to branch 'au.asn.ucc.matt.dropbear' (head fdf4a7a3b97ae5046139915de7e40399cceb2c01)
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:23:58 +0000
parents
children 0cbe8f6dbf9e
comparison
equal deleted inserted replaced
281:997e6f7dc01e 285:1b9e69c058d2
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, [email protected], http://libtomcrypt.org
10 */
11 #include "tomcrypt.h"
12
13 /**
14 @file omac_process.c
15 OMAC1 support, process data, Tom St Denis
16 */
17
18
19 #ifdef OMAC
20
21 /**
22 Process data through OMAC
23 @param omac The OMAC state
24 @param in The input data to send through OMAC
25 @param inlen The length of the input (octets)
26 @return CRYPT_OK if successful
27 */
28 int omac_process(omac_state *omac, const unsigned char *in, unsigned long inlen)
29 {
30 unsigned long n, x;
31 int err;
32
33 LTC_ARGCHK(omac != NULL);
34 LTC_ARGCHK(in != NULL);
35 if ((err = cipher_is_valid(omac->cipher_idx)) != CRYPT_OK) {
36 return err;
37 }
38
39 if ((omac->buflen > (int)sizeof(omac->block)) || (omac->buflen < 0) ||
40 (omac->blklen > (int)sizeof(omac->block)) || (omac->buflen > omac->blklen)) {
41 return CRYPT_INVALID_ARG;
42 }
43
44 #ifdef LTC_FAST
45 if (omac->buflen == 0 && inlen > 16) {
46 int y;
47 for (x = 0; x < (inlen - 16); x += 16) {
48 for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
49 *((LTC_FAST_TYPE*)(&omac->prev[y])) ^= *((LTC_FAST_TYPE*)(&in[y]));
50 }
51 in += 16;
52 cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->prev, omac->prev, &omac->key);
53 }
54 inlen -= x;
55 }
56 #endif
57
58 while (inlen != 0) {
59 /* ok if the block is full we xor in prev, encrypt and replace prev */
60 if (omac->buflen == omac->blklen) {
61 for (x = 0; x < (unsigned long)omac->blklen; x++) {
62 omac->block[x] ^= omac->prev[x];
63 }
64 cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->block, omac->prev, &omac->key);
65 omac->buflen = 0;
66 }
67
68 /* add bytes */
69 n = MIN(inlen, (unsigned long)(omac->blklen - omac->buflen));
70 XMEMCPY(omac->block + omac->buflen, in, n);
71 omac->buflen += n;
72 inlen -= n;
73 in += n;
74 }
75
76 return CRYPT_OK;
77 }
78
79 #endif
80
81
82 /* $Source: /cvs/libtom/libtomcrypt/src/mac/omac/omac_process.c,v $ */
83 /* $Revision: 1.6 $ */
84 /* $Date: 2005/05/05 14:35:58 $ */