Subversion Repositories planix.SVN

#include "os.h"
#include <libsec.h>

static void
init(Chachastate *cs)
{
        ulong seed[11];
        int i;

        for(i=0; i<nelem(seed); i++)
                seed[i] = truerand();

        setupChachastate(cs, (uchar*)&seed[0], 32, (uchar*)&seed[8], 12, 20);
        memset(seed, 0, sizeof(seed));
}

static void
fill(Chachastate *cs, uchar *p, int n)
{
        Chachastate c;

        c = *cs;
        chacha_encrypt((uchar*)&cs->input[4], 32, &c);
        if(++cs->input[13] == 0)
                if(++cs->input[14] == 0)
                        ++cs->input[15];

        chacha_encrypt(p, n, &c);
        memset(&c, 0, sizeof(c));
}

void
genrandom(uchar *p, int n)
{
        static QLock lk;
        static Chachastate cs;

        qlock(&lk);
        if(cs.rounds == 0)
                init(&cs);
        cs.input[4] ^= getpid();        /* fork protection */
        fill(&cs, p, n);
        qunlock(&lk);
}