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comparison eax_done.c @ 0:d7da3b1e1540 libtomcrypt

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put back the 0.95 makefile which was inadvertently merged over
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:21:40 +0000
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children 5d99163f7e32
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-1:000000000000 0:d7da3b1e1540
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
12 /* EAX Implementation by Tom St Denis */
13 #include "mycrypt.h"
14
15 #ifdef EAX_MODE
16
17 int eax_done(eax_state *eax, unsigned char *tag, unsigned long *taglen)
18 {
19 int err;
20 unsigned char headermac[MAXBLOCKSIZE], ctmac[MAXBLOCKSIZE];
21 unsigned long x, len;
22
23 _ARGCHK(eax != NULL);
24 _ARGCHK(tag != NULL);
25 _ARGCHK(taglen != NULL);
26
27 /* finish ctomac */
28 len = sizeof(ctmac);
29 if ((err = omac_done(&eax->ctomac, ctmac, &len)) != CRYPT_OK) {
30 return err;
31 }
32
33 /* finish headeromac */
34
35 /* note we specifically don't reset len so the two lens are minimal */
36
37 if ((err = omac_done(&eax->headeromac, headermac, &len)) != CRYPT_OK) {
38 return err;
39 }
40
41 /* compute N xor H xor C */
42 for (x = 0; x < len && x < *taglen; x++) {
43 tag[x] = eax->N[x] ^ headermac[x] ^ ctmac[x];
44 }
45 *taglen = x;
46
47 #ifdef CLEAN_STACK
48 zeromem(ctmac, sizeof(ctmac));
49 zeromem(headermac, sizeof(headermac));
50 zeromem(eax, sizeof(*eax));
51 #endif
52
53 return CRYPT_OK;
54 }
55
56 #endif