usr/src/lib/libc/port/gen/getentropy.c

   1 /*
   2  * This file and its contents are supplied under the terms of the
   3  * Common Development and Distribution License ("CDDL"), version 1.0.
   4  * You may only use this file in accordance with the terms of version
   5  * 1.0 of the CDDL.
   6  *
   7  * A full copy of the text of the CDDL should have accompanied this
   8  * source.  A copy of the CDDL is also available via the Internet at
   9  * http://www.illumos.org/license/CDDL.
  10  */
  11
  12 /*
  13  * Copyright (c) 2015, Joyent, Inc.
  14  */
  15
  16 /*
  17  * getentropy(3C) is an OpenBSD compatible wrapper around getrandom(2).
  18  */
  19
  20 #include <errno.h>
  21 #include <sys/random.h>
  22
  23 int
  24 getentropy(void *buf, size_t buflen)
  25 {
  26         int ret;
  27
  28         if (buflen > 256) {
  29                 errno = EIO;
  30                 return (-1);
  31         }
  32
  33         ret = getrandom(buf, buflen, 0);
  34         if (ret == -1 || ret != buflen) {
  35                 if (errno != EFAULT)
  36                         errno = EIO;
  37                 return (-1);
  38         }
  39
  40         return (0);
  41 }