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
12/**
13    @file eax_decrypt.c
14    EAX implementation, decrypt block, by Tom St Denis
15*/
16#include "tomcrypt.h"
17
18#ifdef EAX_MODE
19
20/**
21   Decrypt data with the EAX protocol
22   @param eax     The EAX state
23   @param ct      The ciphertext
24   @param pt      [out] The plaintext
25   @param length  The length (octets) of the ciphertext
26   @return CRYPT_OK if successful
27*/
28int eax_decrypt(eax_state *eax, const unsigned char *ct, unsigned char *pt,
29                unsigned long length)
30{
31   int err;
32
33   LTC_ARGCHK(eax != NULL);
34   LTC_ARGCHK(pt  != NULL);
35   LTC_ARGCHK(ct  != NULL);
36
37   /* omac ciphertext */
38   if ((err = omac_process(&eax->ctomac, ct, length)) != CRYPT_OK) {
39      return err;
40   }
41
42   /* decrypt  */
43   return ctr_decrypt(ct, pt, length, &eax->ctr);
44}
45
46#endif
47
48/* $Source: /cvs/libtom/libtomcrypt/src/encauth/eax/eax_decrypt.c,v $ */
49/* $Revision: 1.4 $ */
50/* $Date: 2006/03/31 14:15:35 $ */
51