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 hmac_memory.c
15 HMAC support, process a block of memory, Tom St Denis/Dobes Vandermeer
16 */
17
18 #ifdef LTC_HMAC
19
20 /**
21 HMAC a block of memory to produce the authentication tag
22 @param hash The index of the hash to use
23 @param key The secret key
24 @param keylen The length of the secret key (octets)
25 @param in The data to HMAC
26 @param inlen The length of the data to HMAC (octets)
27 @param out [out] Destination of the authentication tag
28 @param outlen [in/out] Max size and resulting size of authentication tag
29 @return CRYPT_OK if successful
30 */
hmac_memory(int hash,const unsigned char * key,unsigned long keylen,const unsigned char * in,unsigned long inlen,unsigned char * out,unsigned long * outlen)31 int hmac_memory(int hash,
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 hmac_state *hmac;
37 int err;
38
39 LTC_ARGCHK(key != NULL);
40 LTC_ARGCHK(in != NULL);
41 LTC_ARGCHK(out != NULL);
42 LTC_ARGCHK(outlen != NULL);
43
44 /* make sure hash descriptor is valid */
45 if ((err = hash_is_valid(hash)) != CRYPT_OK) {
46 return err;
47 }
48
49 /* is there a descriptor? */
50 if (hash_descriptor[hash].hmac_block != NULL) {
51 return hash_descriptor[hash].hmac_block(key, keylen, in, inlen, out, outlen);
52 }
53
54 /* nope, so call the hmac functions */
55 /* allocate ram for hmac state */
56 hmac = XMALLOC(sizeof(hmac_state));
57 if (hmac == NULL) {
58 return CRYPT_MEM;
59 }
60
61 if ((err = hmac_init(hmac, hash, key, keylen)) != CRYPT_OK) {
62 goto LBL_ERR;
63 }
64
65 if ((err = hmac_process(hmac, in, inlen)) != CRYPT_OK) {
66 goto LBL_ERR;
67 }
68
69 if ((err = hmac_done(hmac, out, outlen)) != CRYPT_OK) {
70 goto LBL_ERR;
71 }
72
73 err = CRYPT_OK;
74 LBL_ERR:
75 #ifdef LTC_CLEAN_STACK
76 zeromem(hmac, sizeof(hmac_state));
77 #endif
78
79 XFREE(hmac);
80 return err;
81 }
82
83 #endif
84
85
86 /* $Source: /cvs/libtom/libtomcrypt/src/mac/hmac/hmac_memory.c,v $ */
87 /* $Revision: 1.6 $ */
88 /* $Date: 2006/11/03 00:39:49 $ */
89