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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 XMEMCPY(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 |
