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/* 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 hash_memory_multi.c
Hash (multiple buffers) memory helper, Tom St Denis
*/
/**
Hash multiple (non-adjacent) blocks of memory at once.
@param hash The index of the hash you wish to use
@param out [out] Where to store the digest
@param outlen [in/out] Max size and resulting size of the digest
@param in The data you wish to hash
@param inlen The length of the data to hash (octets)
@param ... tuples of (data,len) pairs to hash, terminated with a (NULL,x) (x=don't care)
@return CRYPT_OK if successful
*/
int hash_memory_multi(int hash, unsigned char *out, unsigned long *outlen,
const unsigned char *in, unsigned long inlen, ...)
{
hash_state *md;
int err;
va_list args;
const unsigned char *curptr;
unsigned long curlen;
LTC_ARGCHK(in != NULL);
LTC_ARGCHK(out != NULL);
LTC_ARGCHK(outlen != NULL);
if ((err = hash_is_valid(hash)) != CRYPT_OK) {
return err;
}
if (*outlen < hash_descriptor[hash].hashsize) {
*outlen = hash_descriptor[hash].hashsize;
return CRYPT_BUFFER_OVERFLOW;
}
md = XMALLOC(sizeof(hash_state));
if (md == NULL) {
return CRYPT_MEM;
}
if ((err = hash_descriptor[hash].init(md)) != CRYPT_OK) {
goto LBL_ERR;
}
va_start(args, inlen);
curptr = in;
curlen = inlen;
for (;;) {
/* process buf */
if ((err = hash_descriptor[hash].process(md, 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);
}
err = hash_descriptor[hash].done(md, out);
*outlen = hash_descriptor[hash].hashsize;
LBL_ERR:
#ifdef LTC_CLEAN_STACK
zeromem(md, sizeof(hash_state));
#endif
XFREE(md);
va_end(args);
return err;
}
/* $Source: /cvs/libtom/libtomcrypt/src/hashes/helper/hash_memory_multi.c,v $ */
/* $Revision: 1.5 $ */
/* $Date: 2006/06/16 21:53:41 $ */
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