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_GENSIGNKEY_H
#define DROPBEAR_GENSIGNKEY_H

#include "signkey.h"

int signkey_generate(enum signkey_type type, int bits, const char* filename);

#endif