mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-01 03:53:33 +00:00
53 lines
2.6 KiB
C
53 lines
2.6 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
|
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2020 Justine Alexandra Roberts Tunney │
|
|
│ │
|
|
│ Permission to use, copy, modify, and/or distribute this software for │
|
|
│ any purpose with or without fee is hereby granted, provided that the │
|
|
│ above copyright notice and this permission notice appear in all copies. │
|
|
│ │
|
|
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
|
|
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
|
|
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
|
|
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
|
|
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
|
|
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
|
|
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
|
|
│ PERFORMANCE OF THIS SOFTWARE. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/bits/bits.h"
|
|
#include "libc/dce.h"
|
|
#include "libc/rand/rand.h"
|
|
#include "libc/str/str.h"
|
|
#include "libc/calls/internal.h"
|
|
#include "libc/calls/calls.h"
|
|
#include "libc/sysv/errfuns.h"
|
|
#include "libc/sysv/consts/at.h"
|
|
#include "libc/sysv/consts/nr.h"
|
|
#include "libc/sysv/consts/o.h"
|
|
|
|
/**
|
|
* Reads random bytes from system pseudo random number api.
|
|
* @return 0 on success or -1 w/ errno
|
|
*/
|
|
int devrand(void *buf, size_t size) {
|
|
int fd;
|
|
size_t got;
|
|
ssize_t rc;
|
|
unsigned char *p, *pe;
|
|
fd = -1;
|
|
if (IsWindows()) return enosys();
|
|
if ((fd = openat$sysv(AT_FDCWD, "/dev/urandom", O_RDONLY, 0)) == -1) {
|
|
return -1;
|
|
}
|
|
p = buf;
|
|
pe = p + size;
|
|
while (p < pe) {
|
|
if ((rc = read$sysv(fd, p, pe - p)) == -1) break;
|
|
if (!(got = (size_t)rc)) break;
|
|
p += got;
|
|
}
|
|
close$sysv(fd);
|
|
return p == pe ? 0 : -1;
|
|
}
|