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comparison src/mac/omac/omac_process.c @ 192:9cc34777b479 libtomcrypt

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propagate from branch 'au.asn.ucc.matt.ltc-orig' (head 9ba8f01f44320e9cb9f19881105ae84f84a43ea9) to branch 'au.asn.ucc.matt.dropbear.ltc' (head dbf51c569bc34956ad948e4cc87a0eeb2170b768)
author Matt Johnston <matt@ucc.asn.au>
date Sun, 08 May 2005 06:36:47 +0000
parents 1c15b283127b
children 39d5d58461d6
comparison
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164:cd1143579f00 192:9cc34777b479
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 int err, n, x;
31
32 LTC_ARGCHK(omac != NULL);
33 LTC_ARGCHK(in != NULL);
34 if ((err = cipher_is_valid(omac->cipher_idx)) != CRYPT_OK) {
35 return err;
36 }
37
38 if ((omac->buflen > (int)sizeof(omac->block)) || (omac->buflen < 0) ||
39 (omac->blklen > (int)sizeof(omac->block)) || (omac->buflen > omac->blklen)) {
40 return CRYPT_INVALID_ARG;
41 }
42
43 #ifdef LTC_FAST
44 if (omac->buflen == 0 && inlen > 16) {
45 int y;
46 for (x = 0; x < (inlen - 16); x += 16) {
47 for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
48 *((LTC_FAST_TYPE*)(&omac->prev[y])) ^= *((LTC_FAST_TYPE*)(&in[y]));
49 }
50 in += 16;
51 cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->prev, omac->prev, &omac->key);
52 }
53 inlen -= x;
54 }
55 #endif
56
57 while (inlen != 0) {
58 /* ok if the block is full we xor in prev, encrypt and replace prev */
59 if (omac->buflen == omac->blklen) {
60 for (x = 0; x < omac->blklen; x++) {
61 omac->block[x] ^= omac->prev[x];
62 }
63 cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->block, omac->prev, &omac->key);
64 omac->buflen = 0;
65 }
66
67 /* add bytes */
68 n = MIN(inlen, (unsigned long)(omac->blklen - omac->buflen));
69 XMEMCPY(omac->block + omac->buflen, in, n);
70 omac->buflen += n;
71 inlen -= n;
72 in += n;
73 }
74
75 return CRYPT_OK;
76 }
77
78 #endif
79