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/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
It is considered beerware. Prost. Skol. Cheers or whatever.
$id$ */
/* System */
#include <stdint.h>
#include <stdlib.h>
/* Opentracker */
#include "ot_random.h"
#ifdef WANT_INSECURE_RANDOM_FALLBACK
#warning WANT_INSECURE_RANDOM_FALLBACK builds without arc4random. UDP connection ids become predictable and announces can be forged. Do not ship this.
#include <time.h>
void random_init(void) {
#ifdef WANT_DEV_RANDOM
srandomdev();
#else
srandom(time(NULL));
#endif
}
/* random() yields 31 bits, so one draw can never set the top bit. Combine
two of them rather than hand out a value that is quietly half as wide as
its type claims. */
uint32_t random_uint32(void) { return ((uint32_t)random() << 16) ^ (uint32_t)random(); }
void random_bytes(void *buf, size_t len) {
uint8_t *out = buf;
/* random() leaves the top bit clear and its lowest bits are the weakest,
so take a byte from the middle of each draw */
while (len--)
*out++ = (uint8_t)(random() >> 8);
}
#else
#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) && !defined(__DragonFly__) && !defined(__APPLE__) && \
!(defined(__GLIBC__) && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 36)))
#include <bsd/stdlib.h>
#endif
void random_init(void) {}
uint32_t random_uint32(void) { return arc4random(); }
void random_bytes(void *buf, size_t len) { arc4random_buf(buf, len); }
#endif
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