void derive_key_whirlpool (char *pwd, int pwd_len, char *salt, int salt_len, int iterations, char *dk, int dklen)
{
char u[WHIRLPOOL_DIGESTSIZE];
int b, l, r;
if (dklen % WHIRLPOOL_DIGESTSIZE)
{
l = 1 + dklen / WHIRLPOOL_DIGESTSIZE;
}
else
{
l = dklen / WHIRLPOOL_DIGESTSIZE;
}
r = dklen - (l - 1) * WHIRLPOOL_DIGESTSIZE;
/* first l - 1 blocks */
for (b = 1; b < l; b++)
{
derive_u_whirlpool (pwd, pwd_len, salt, salt_len, iterations, u, b);
memcpy (dk, u, WHIRLPOOL_DIGESTSIZE);
dk += WHIRLPOOL_DIGESTSIZE;
}
/* last block */
derive_u_whirlpool (pwd, pwd_len, salt, salt_len, iterations, u, b);
memcpy (dk, u, r);
/* Prevent possible leaks. */
burn (u, sizeof(u));
}
void derive_key_whirlpool (char *pwd, int pwd_len, char *salt, int salt_len, uint32 iterations, char *dk, int dklen)
{
hmac_whirlpool_ctx hmac;
char key[WHIRLPOOL_DIGESTSIZE];
int b, l, r;
/* If the password is longer than the hash algorithm block size,
let pwd = whirlpool(pwd), as per HMAC specifications. */
if (pwd_len > WHIRLPOOL_BLOCKSIZE)
{
WHIRLPOOL_CTX tctx;
WHIRLPOOL_init (&tctx);
WHIRLPOOL_add ((unsigned char *) pwd, pwd_len * 8, &tctx);
WHIRLPOOL_finalize (&tctx, (unsigned char *) key);
pwd = key;
pwd_len = WHIRLPOOL_DIGESTSIZE;
burn (&tctx, sizeof(tctx)); // Prevent leaks
}
if (dklen % WHIRLPOOL_DIGESTSIZE)
{
l = 1 + dklen / WHIRLPOOL_DIGESTSIZE;
}
else
{
l = dklen / WHIRLPOOL_DIGESTSIZE;
}
r = dklen - (l - 1) * WHIRLPOOL_DIGESTSIZE;
/* first l - 1 blocks */
for (b = 1; b < l; b++)
{
derive_u_whirlpool (pwd, pwd_len, salt, salt_len, iterations, b, &hmac);
memcpy (dk, hmac.u, WHIRLPOOL_DIGESTSIZE);
dk += WHIRLPOOL_DIGESTSIZE;
}
/* last block */
derive_u_whirlpool (pwd, pwd_len, salt, salt_len, iterations, b, &hmac);
memcpy (dk, hmac.u, r);
/* Prevent possible leaks. */
burn (&hmac, sizeof(hmac));
burn (key, sizeof(key));
}
