/* LibTomCrypt, modular cryptographic library -- Tom St Denis
*
* LibTomCrypt is a library that provides various cryptographic
* algorithms in a highly modular and flexible manner.
*
* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
*/
#include "tomcrypt.h"
#include <stdarg.h>
/**
@file hmac_memory_multi.c
HMAC support, process multiple blocks of memory, Tom St Denis/Dobes Vandermeer
*/
#ifdef LTC_HMAC
/**
HMAC multiple blocks of memory to produce the authentication tag
@param hash The index of the hash to use
@param key The secret key
@param keylen The length of the secret key (octets)
@param out [out] Destination of the authentication tag
@param outlen [in/out] Max size and resulting size of authentication tag
@param in The data to HMAC
@param inlen The length of the data to HMAC (octets)
@param ... tuples of (data,len) pairs to HMAC, terminated with a (NULL,x) (x=don't care)
@return CRYPT_OK if successful
*/
int 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, ...)
{
hmac_state *hmac;
int err;
va_list args;
const unsigned char *curptr;
unsigned long curlen;
LTC_ARGCHK(key != NULL);
LTC_ARGCHK(in != NULL);
LTC_ARGCHK(out != NULL);
LTC_ARGCHK(outlen != NULL);
/* allocate ram for hmac state */
hmac = XMALLOC(sizeof(hmac_state));
if (hmac == NULL) {
return CRYPT_MEM;
}
if ((err = hmac_init(hmac, hash, key, keylen)) != CRYPT_OK) {
goto LBL_ERR;
}
va_start(args, inlen);
curptr = in;
curlen = inlen;
for (;;) {
/* process buf */
if ((err = hmac_process(hmac, curptr, curlen)) != CRYPT_OK) {
goto LBL_ERR;
}
/* step to next */
curptr = va_arg(args, const unsigned char*);
if (curptr == NULL) {
break;
}
curlen = va_arg(args, unsigned long);
}
if ((err = hmac_done(hmac, out, outlen)) != CRYPT_OK) {
goto LBL_ERR;
}
LBL_ERR:
#ifdef LTC_CLEAN_STACK
zeromem(hmac, sizeof(hmac_state));
#endif
XFREE(hmac);
va_end(args);
return err;
}
#endif
/* $Source: /cvs/libtom/libtomcrypt/src/mac/hmac/hmac_memory_multi.c,v $ */
/* $Revision: 1.5 $ */
/* $Date: 2006/11/03 00:39:49 $ */