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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