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comparison eax_done.c @ 143:5d99163f7e32 libtomcrypt-orig

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import of libtomcrypt 0.99
author Matt Johnston <matt@ucc.asn.au>
date Sun, 19 Dec 2004 11:34:45 +0000
parents 7faae8f46238
children
comparison
equal deleted inserted replaced
15:6362d3854bb4 143:5d99163f7e32
15 #ifdef EAX_MODE 15 #ifdef EAX_MODE
16 16
17 int eax_done(eax_state *eax, unsigned char *tag, unsigned long *taglen) 17 int eax_done(eax_state *eax, unsigned char *tag, unsigned long *taglen)
18 { 18 {
19 int err; 19 int err;
20 unsigned char headermac[MAXBLOCKSIZE], ctmac[MAXBLOCKSIZE]; 20 unsigned char *headermac, *ctmac;
21 unsigned long x, len; 21 unsigned long x, len;
22 22
23 _ARGCHK(eax != NULL); 23 _ARGCHK(eax != NULL);
24 _ARGCHK(tag != NULL); 24 _ARGCHK(tag != NULL);
25 _ARGCHK(taglen != NULL); 25 _ARGCHK(taglen != NULL);
26 26
27 /* allocate ram */
28 headermac = XMALLOC(MAXBLOCKSIZE);
29 ctmac = XMALLOC(MAXBLOCKSIZE);
30
31 if (headermac == NULL || ctmac == NULL) {
32 if (headermac != NULL) {
33 XFREE(headermac);
34 }
35 if (ctmac != NULL) {
36 XFREE(ctmac);
37 }
38 return CRYPT_MEM;
39 }
40
27 /* finish ctomac */ 41 /* finish ctomac */
28 len = sizeof(ctmac); 42 len = MAXBLOCKSIZE;
29 if ((err = omac_done(&eax->ctomac, ctmac, &len)) != CRYPT_OK) { 43 if ((err = omac_done(&eax->ctomac, ctmac, &len)) != CRYPT_OK) {
30 return err; 44 goto __ERR;
31 } 45 }
32 46
33 /* finish headeromac */ 47 /* finish headeromac */
34 48
35 /* note we specifically don't reset len so the two lens are minimal */ 49 /* note we specifically don't reset len so the two lens are minimal */
36 50
37 if ((err = omac_done(&eax->headeromac, headermac, &len)) != CRYPT_OK) { 51 if ((err = omac_done(&eax->headeromac, headermac, &len)) != CRYPT_OK) {
38 return err; 52 goto __ERR;
39 } 53 }
40 54
41 /* compute N xor H xor C */ 55 /* compute N xor H xor C */
42 for (x = 0; x < len && x < *taglen; x++) { 56 for (x = 0; x < len && x < *taglen; x++) {
43 tag[x] = eax->N[x] ^ headermac[x] ^ ctmac[x]; 57 tag[x] = eax->N[x] ^ headermac[x] ^ ctmac[x];
44 } 58 }
45 *taglen = x; 59 *taglen = x;
46 60
61 err = CRYPT_OK;
62 __ERR:
47 #ifdef CLEAN_STACK 63 #ifdef CLEAN_STACK
48 zeromem(ctmac, sizeof(ctmac)); 64 zeromem(ctmac, MAXBLOCKSIZE);
49 zeromem(headermac, sizeof(headermac)); 65 zeromem(headermac, MAXBLOCKSIZE);
50 zeromem(eax, sizeof(*eax)); 66 zeromem(eax, sizeof(*eax));
51 #endif 67 #endif
52 68
53 return CRYPT_OK; 69 XFREE(ctmac);
70 XFREE(headermac);
71
72 return err;
54 } 73 }
55 74
56 #endif 75 #endif