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 omac_memory.c
15  OMAC1 support, process a block of memory, Tom St Denis
16*/
17
18#ifdef LTC_OMAC
19
20/**
21   OMAC a block of memory
22   @param cipher    The index of the desired cipher
23   @param key       The secret key
24   @param keylen    The length of the secret key (octets)
25   @param in        The data to send through OMAC
26   @param inlen     The length of the data to send through OMAC (octets)
27   @param out       [out] The destination of the authentication tag
28   @param outlen    [in/out]  The max size and resulting size of the authentication tag (octets)
29   @return CRYPT_OK if successful
30*/
31int omac_memory(int cipher,
32                const unsigned char *key, unsigned long keylen,
33                const unsigned char *in,  unsigned long inlen,
34                      unsigned char *out, unsigned long *outlen)
35{
36   int err;
37   omac_state *omac;
38
39   LTC_ARGCHK(key    != NULL);
40   LTC_ARGCHK(in     != NULL);
41   LTC_ARGCHK(out    != NULL);
42   LTC_ARGCHK(outlen != NULL);
43
44   /* is the cipher valid? */
45   if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
46      return err;
47   }
48
49   /* Use accelerator if found */
50   if (cipher_descriptor[cipher].omac_memory != NULL) {
51      return cipher_descriptor[cipher].omac_memory(key, keylen, in, inlen, out, outlen);
52   }
53
54   /* allocate ram for omac state */
55   omac = XMALLOC(sizeof(omac_state));
56   if (omac == NULL) {
57      return CRYPT_MEM;
58   }
59
60   /* omac process the message */
61   if ((err = omac_init(omac, cipher, key, keylen)) != CRYPT_OK) {
62      goto LBL_ERR;
63   }
64   if ((err = omac_process(omac, in, inlen)) != CRYPT_OK) {
65      goto LBL_ERR;
66   }
67   if ((err = omac_done(omac, out, outlen)) != CRYPT_OK) {
68      goto LBL_ERR;
69   }
70
71   err = CRYPT_OK;
72LBL_ERR:
73#ifdef LTC_CLEAN_STACK
74   zeromem(omac, sizeof(omac_state));
75#endif
76
77   XFREE(omac);
78   return err;
79}
80
81#endif
82
83/* $Source: /cvs/libtom/libtomcrypt/src/mac/omac/omac_memory.c,v $ */
84/* $Revision: 1.6 $ */
85/* $Date: 2006/11/08 23:01:06 $ */
86