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comparison pmac_done.c @ 3:7faae8f46238 libtomcrypt-orig

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Branch renaming
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:25:41 +0000
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-1:000000000000 3:7faae8f46238
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 /* PMAC implementation by Tom St Denis */
13 #include "mycrypt.h"
14
15 #ifdef PMAC
16
17 int pmac_done(pmac_state *state, unsigned char *out, unsigned long *outlen)
18 {
19 int err, x;
20
21 _ARGCHK(state != NULL);
22 _ARGCHK(out != NULL);
23 if ((err = cipher_is_valid(state->cipher_idx)) != CRYPT_OK) {
24 return err;
25 }
26
27 if ((state->buflen > (int)sizeof(state->block)) || (state->buflen < 0) ||
28 (state->block_len > (int)sizeof(state->block)) || (state->buflen > state->block_len)) {
29 return CRYPT_INVALID_ARG;
30 }
31
32
33 /* handle padding. If multiple xor in L/x */
34
35 if (state->buflen == state->block_len) {
36 /* xor Lr against the checksum */
37 for (x = 0; x < state->block_len; x++) {
38 state->checksum[x] ^= state->block[x] ^ state->Lr[x];
39 }
40 } else {
41 /* otherwise xor message bytes then the 0x80 byte */
42 for (x = 0; x < state->buflen; x++) {
43 state->checksum[x] ^= state->block[x];
44 }
45 state->checksum[x] ^= 0x80;
46 }
47
48 /* encrypt it */
49 cipher_descriptor[state->cipher_idx].ecb_encrypt(state->checksum, state->checksum, &state->key);
50
51 /* store it */
52 for (x = 0; x < state->block_len && x <= (int)*outlen; x++) {
53 out[x] = state->checksum[x];
54 }
55 *outlen = x;
56
57 #ifdef CLEAN_STACK
58 zeromem(state, sizeof(*state));
59 #endif
60 return CRYPT_OK;
61 }
62
63 #endif
64