Subversion Repositories planix.SVN

#include "os.h"
#include <mp.h>
#include "dat.h"

// convert an mpint into a big endian byte array (most significant byte first; left adjusted)
//   return number of bytes converted
//   if p == nil, allocate and result array
int
mptobe(mpint *b, uchar *p, uint n, uchar **pp)
{
        int m;

        m = (mpsignif(b)+7)/8;
        if(m == 0)
                m++;
        if(p == nil){
                n = m;
                p = malloc(n);
                if(p == nil)
                        sysfatal("mptobe: %r");
                setmalloctag(p, getcallerpc(&b));
        } else {
                if(n < m)
                        return -1;
                if(n > m)
                        memset(p+m, 0, n-m);
        }
        if(pp != nil)
                *pp = p;
        mptober(b, p, m);
        return m;
}