private_ntru_mgf1_t *this, size_t mask_len, u_char *mask)
{
u_char buf[HASH_SIZE_SHA512];
- size_t len;
+ size_t hash_len;
+
+ hash_len = this->hasher->get_hash_size(this->hasher);
while (mask_len > 0)
{
this->overflow = TRUE;
}
- if (!this->hasher->get_hash(this->hasher, this->state, buf))
+ /* get the next or final mask block from the hash function */
+ if (!this->hasher->get_hash(this->hasher, this->state,
+ (mask_len < hash_len) ? buf : mask))
{
return FALSE;
}
-
- len = min(mask_len, this->hasher->get_hash_size(this->hasher));
- memcpy(mask, buf, len);
- mask_len -= len;
- mask += len;
+ if (mask_len < hash_len)
+ {
+ memcpy(mask, buf, mask_len);
+ return TRUE;
+ }
+ mask_len -= hash_len;
+ mask += hash_len;
}
-
return TRUE;
}