misc/unix/rand.c

/* ====================================================================
 * The Apache Software License, Version 1.1
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 */

#include "misc.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#if APR_HAS_RANDOM

#define	XSTR(x)	#x
#define	STR(x)	XSTR(x)

apr_status_t apr_generate_random_bytes(unsigned char * buf, int length) 
{
#ifdef	DEV_RANDOM

    int rnd;
    size_t got, tot;

    if ((rnd = open(STR(DEV_RANDOM), O_RDONLY)) == -1) 
	return errno;

    for (tot=0; tot<length; tot += got)
	if ((got = read(rnd, buf+tot, length-tot)) < 0) 
	    return errno;

    close(rnd);

#else  /* use truerand */

    extern int randbyte(void);	/* from the truerand library */
    unsigned int idx;

    /* this will increase the startup time of the server, unfortunately...
     * (generating 20 bytes takes about 8 seconds)
     */
    for (idx=0; idx<length; idx++)
	buf[idx] = (unsigned char) randbyte();

#endif	/* DEV_RANDOM */

    return APR_SUCCESS;
}

#undef	STR
#undef	XSTR
#endif /* APR_HAS_RANDOM */