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_encrypt_authenticate_memory.c
14  EAX implementation, encrypt a block of memory, by Tom St Denis
15*/
16#include "tomcrypt.h"
17
18#ifdef EAX_MODE
19
20/**
21   EAX encrypt and produce an authentication tag
22   @param cipher     The index of the cipher desired
23   @param key        The secret key to use
24   @param keylen     The length of the secret key (octets)
25   @param nonce      The session nonce [use once]
26   @param noncelen   The length of the nonce
27   @param header     The header for the session
28   @param headerlen  The length of the header (octets)
29   @param pt         The plaintext
30   @param ptlen      The length of the plaintext (octets)
31   @param ct         [out] The ciphertext
32   @param tag        [out] The destination tag
33   @param taglen     [in/out] The max size and resulting size of the authentication tag
34   @return CRYPT_OK if successful
35*/
36int eax_encrypt_authenticate_memory(int cipher,
37    const unsigned char *key,    unsigned long keylen,
38    const unsigned char *nonce,  unsigned long noncelen,
39    const unsigned char *header, unsigned long headerlen,
40    const unsigned char *pt,     unsigned long ptlen,
41          unsigned char *ct,
42          unsigned char *tag,    unsigned long *taglen)
43{
44   int err;
45   eax_state *eax;
46
47   LTC_ARGCHK(key    != NULL);
48   LTC_ARGCHK(pt     != NULL);
49   LTC_ARGCHK(ct     != NULL);
50   LTC_ARGCHK(tag    != NULL);
51   LTC_ARGCHK(taglen != NULL);
52
53   eax = XMALLOC(sizeof(*eax));
54
55   if ((err = eax_init(eax, cipher, key, keylen, nonce, noncelen, header, headerlen)) != CRYPT_OK) {
56      goto LBL_ERR;
57   }
58
59   if ((err = eax_encrypt(eax, pt, ct, ptlen)) != CRYPT_OK) {
60      goto LBL_ERR;
61   }
62
63   if ((err = eax_done(eax, tag, taglen)) != CRYPT_OK) {
64      goto LBL_ERR;
65   }
66
67   err = CRYPT_OK;
68LBL_ERR:
69#ifdef LTC_CLEAN_STACK
70   zeromem(eax, sizeof(*eax));
71#endif
72
73   XFREE(eax);
74
75   return err;
76}
77
78#endif
79
80/* $Source: /cvs/libtom/libtomcrypt/src/encauth/eax/eax_encrypt_authenticate_memory.c,v $ */
81/* $Revision: 1.4 $ */
82/* $Date: 2006/03/31 14:15:35 $ */
83