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 #include <stdarg.h>
13
14 /**
15 @file hmac_memory_multi.c
16 HMAC support, process multiple blocks of memory, Tom St Denis/Dobes Vandermeer
17 */
18
19 #ifdef LTC_HMAC
20
21 /**
22 HMAC multiple blocks of memory to produce the authentication tag
23 @param hash The index of the hash to use
24 @param key The secret key
25 @param keylen The length of the secret key (octets)
26 @param out [out] Destination of the authentication tag
27 @param outlen [in/out] Max size and resulting size of authentication tag
28 @param in The data to HMAC
29 @param inlen The length of the data to HMAC (octets)
30 @param ... tuples of (data,len) pairs to HMAC, terminated with a (NULL,x) (x=don't care)
31 @return CRYPT_OK if successful
32 */
hmac_memory_multi(int hash,const unsigned char * key,unsigned long keylen,unsigned char * out,unsigned long * outlen,const unsigned char * in,unsigned long inlen,...)33 int hmac_memory_multi(int hash,
34 const unsigned char *key, unsigned long keylen,
35 unsigned char *out, unsigned long *outlen,
36 const unsigned char *in, unsigned long inlen, ...)
37
38 {
39 hmac_state *hmac;
40 int err;
41 va_list args;
42 const unsigned char *curptr;
43 unsigned long curlen;
44
45 LTC_ARGCHK(key != NULL);
46 LTC_ARGCHK(in != NULL);
47 LTC_ARGCHK(out != NULL);
48 LTC_ARGCHK(outlen != NULL);
49
50 /* allocate ram for hmac state */
51 hmac = XMALLOC(sizeof(hmac_state));
52 if (hmac == NULL) {
53 return CRYPT_MEM;
54 }
55
56 if ((err = hmac_init(hmac, hash, key, keylen)) != CRYPT_OK) {
57 goto LBL_ERR;
58 }
59
60 va_start(args, inlen);
61 curptr = in;
62 curlen = inlen;
63 for (;;) {
64 /* process buf */
65 if ((err = hmac_process(hmac, curptr, curlen)) != CRYPT_OK) {
66 goto LBL_ERR;
67 }
68 /* step to next */
69 curptr = va_arg(args, const unsigned char*);
70 if (curptr == NULL) {
71 break;
72 }
73 curlen = va_arg(args, unsigned long);
74 }
75 if ((err = hmac_done(hmac, out, outlen)) != CRYPT_OK) {
76 goto LBL_ERR;
77 }
78 LBL_ERR:
79 #ifdef LTC_CLEAN_STACK
80 zeromem(hmac, sizeof(hmac_state));
81 #endif
82 XFREE(hmac);
83 va_end(args);
84 return err;
85 }
86
87 #endif
88
89
90 /* $Source: /cvs/libtom/libtomcrypt/src/mac/hmac/hmac_memory_multi.c,v $ */
91 /* $Revision: 1.5 $ */
92 /* $Date: 2006/11/03 00:39:49 $ */
93