Uses k_size as an signed integer buf_incrwritepos() and mp_to_unsigned_bin() functions use k_size as signed integer argument. k_size is also used in an assertion that compared it to curve_size which is a signed long. Only buf_getwriteptr() is using k_size as unsigned. So it safe to use it as signed.

#ifndef DROPBEAR_LTC_PRNG_H_DROPBEAR
#define DROPBEAR_LTC_PRNG_H_DROPBEAR

#include "options.h"
#include "includes.h"

#ifdef DROPBEAR_LTC_PRNG

extern const struct ltc_prng_descriptor dropbear_prng_desc;

#endif /* DROPBEAR_LTC_PRNG */

#endif /* DROPBEAR_LTC_PRNG_H_DROPBEAR */