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, tomstdenis@gmail.com, http://libtomcrypt.com
10 */
11#include "tomcrypt.h"
12
13/**
14   @file pmac_process.c
15   PMAC implementation, process data, by Tom St Denis
16*/
17
18
19#ifdef LTC_PMAC
20
21/**
22  Process data in a PMAC stream
23  @param pmac     The PMAC state
24  @param in       The data to send through PMAC
25  @param inlen    The length of the data to send through PMAC
26  @return CRYPT_OK if successful
27*/
28int pmac_process(pmac_state *pmac, const unsigned char *in, unsigned long inlen)
29{
30   int err, n;
31   unsigned long x;
32   unsigned char Z[MAXBLOCKSIZE];
33
34   LTC_ARGCHK(pmac != NULL);
35   LTC_ARGCHK(in   != NULL);
36   if ((err = cipher_is_valid(pmac->cipher_idx)) != CRYPT_OK) {
37      return err;
38   }
39
40   if ((pmac->buflen > (int)sizeof(pmac->block)) || (pmac->buflen < 0) ||
41       (pmac->block_len > (int)sizeof(pmac->block)) || (pmac->buflen > pmac->block_len)) {
42      return CRYPT_INVALID_ARG;
43   }
44
45#ifdef LTC_FAST
46   if (pmac->buflen == 0 && inlen > 16) {
47      unsigned long y;
48      for (x = 0; x < (inlen - 16); x += 16) {
49          pmac_shift_xor(pmac);
50          for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
51              *((LTC_FAST_TYPE*)(&Z[y])) = *((LTC_FAST_TYPE*)(&in[y])) ^ *((LTC_FAST_TYPE*)(&pmac->Li[y]));
52          }
53          if ((err = cipher_descriptor[pmac->cipher_idx].ecb_encrypt(Z, Z, &pmac->key)) != CRYPT_OK) {
54             return err;
55          }
56          for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
57              *((LTC_FAST_TYPE*)(&pmac->checksum[y])) ^= *((LTC_FAST_TYPE*)(&Z[y]));
58          }
59          in += 16;
60      }
61      inlen -= x;
62   }
63#endif
64
65   while (inlen != 0) {
66       /* ok if the block is full we xor in prev, encrypt and replace prev */
67       if (pmac->buflen == pmac->block_len) {
68          pmac_shift_xor(pmac);
69          for (x = 0; x < (unsigned long)pmac->block_len; x++) {
70               Z[x] = pmac->Li[x] ^ pmac->block[x];
71          }
72          if ((err = cipher_descriptor[pmac->cipher_idx].ecb_encrypt(Z, Z, &pmac->key)) != CRYPT_OK) {
73             return err;
74           }
75          for (x = 0; x < (unsigned long)pmac->block_len; x++) {
76              pmac->checksum[x] ^= Z[x];
77          }
78          pmac->buflen = 0;
79       }
80
81       /* add bytes */
82       n = MIN(inlen, (unsigned long)(pmac->block_len - pmac->buflen));
83       XMEMCPY(pmac->block + pmac->buflen, in, n);
84       pmac->buflen  += n;
85       inlen         -= n;
86       in            += n;
87   }
88
89#ifdef LTC_CLEAN_STACK
90   zeromem(Z, sizeof(Z));
91#endif
92
93   return CRYPT_OK;
94}
95
96#endif
97
98/* $Source: /cvs/libtom/libtomcrypt/src/mac/pmac/pmac_process.c,v $ */
99/* $Revision: 1.8 $ */
100/* $Date: 2006/11/03 00:39:49 $ */
101