tomcrypt/pkcs_5_1.c
2010-06-16 12:38:16 +02:00

88 lines
2.1 KiB
C

/* 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@iahu.ca, http://libtomcrypt.org
*/
#include <mycrypt.h>
/* PKCS #5, Algorithm #1 */
#ifdef PKCS_5
int pkcs_5_alg1(const unsigned char *password, unsigned long password_len,
const unsigned char *salt,
int iteration_count, int hash_idx,
unsigned char *out, unsigned long *outlen)
{
int err;
unsigned long x;
hash_state *md;
unsigned char *buf;
_ARGCHK(password != NULL);
_ARGCHK(salt != NULL);
_ARGCHK(out != NULL);
_ARGCHK(outlen != NULL);
/* test hash IDX */
if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
return err;
}
/* allocate memory */
md = XMALLOC(sizeof(hash_state));
buf = XMALLOC(MAXBLOCKSIZE);
if (md == NULL || buf == NULL) {
if (md != NULL) {
XFREE(md);
}
if (buf != NULL) {
XFREE(buf);
}
return CRYPT_MEM;
}
/* hash initial password + salt */
hash_descriptor[hash_idx].init(md);
if ((err = hash_descriptor[hash_idx].process(md, password, password_len)) != CRYPT_OK) {
goto __ERR;
}
if ((err = hash_descriptor[hash_idx].process(md, salt, 8)) != CRYPT_OK) {
goto __ERR;
}
if ((err = hash_descriptor[hash_idx].done(md, buf)) != CRYPT_OK) {
goto __ERR;
}
while (--iteration_count) {
// code goes here.
x = MAXBLOCKSIZE;
if ((err = hash_memory(hash_idx, buf, hash_descriptor[hash_idx].hashsize, buf, &x)) != CRYPT_OK) {
goto __ERR;
}
}
/* copy upto outlen bytes */
for (x = 0; x < hash_descriptor[hash_idx].hashsize && x < *outlen; x++) {
out[x] = buf[x];
}
*outlen = x;
err = CRYPT_OK;
__ERR:
#ifdef CLEAN_STACK
zeromem(buf, MAXBLOCKSIZE);
zeromem(md, sizeof(hash_state));
#endif
XFREE(buf);
XFREE(md);
return err;
}
#endif