annotate pmac_process.c @ 3:7faae8f46238 libtomcrypt-orig

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author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:25:41 +0000
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children 5d99163f7e32
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1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
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2 *
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3 * LibTomCrypt is a library that provides various cryptographic
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4 * algorithms in a highly modular and flexible manner.
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5 *
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6 * The library is free for all purposes without any express
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7 * guarantee it works.
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8 *
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9 * Tom St Denis, [email protected], http://libtomcrypt.org
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10 */
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11
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12 /* PMAC implementation by Tom St Denis */
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13 #include "mycrypt.h"
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14
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15 #ifdef PMAC
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16
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17 int pmac_process(pmac_state *state, const unsigned char *buf, unsigned long len)
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18 {
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19 int err, n, x;
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20 unsigned char Z[MAXBLOCKSIZE];
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21
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22 _ARGCHK(state != NULL);
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23 _ARGCHK(buf != NULL);
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24 if ((err = cipher_is_valid(state->cipher_idx)) != CRYPT_OK) {
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25 return err;
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26 }
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27
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28 if ((state->buflen > (int)sizeof(state->block)) || (state->buflen < 0) ||
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29 (state->block_len > (int)sizeof(state->block)) || (state->buflen > state->block_len)) {
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30 return CRYPT_INVALID_ARG;
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31 }
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32
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33 while (len != 0) {
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34 /* ok if the block is full we xor in prev, encrypt and replace prev */
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35 if (state->buflen == state->block_len) {
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36 pmac_shift_xor(state);
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37 for (x = 0; x < state->block_len; x++) {
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38 Z[x] = state->Li[x] ^ state->block[x];
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39 }
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40 cipher_descriptor[state->cipher_idx].ecb_encrypt(Z, Z, &state->key);
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41 for (x = 0; x < state->block_len; x++) {
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42 state->checksum[x] ^= Z[x];
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43 }
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44 state->buflen = 0;
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45 }
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46
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47 /* add bytes */
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48 n = MIN(len, (unsigned long)(state->block_len - state->buflen));
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49 memcpy(state->block + state->buflen, buf, n);
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50 state->buflen += n;
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51 len -= n;
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52 buf += n;
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53 }
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54
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55 #ifdef CLEAN_STACK
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56 zeromem(Z, sizeof(Z));
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57 #endif
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58
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59 return CRYPT_OK;
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60 }
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61
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62 #endif