kc3-lang/libbsd/src/getentropy_bsd.c

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• Hash : e42381dc
  Author :
  Date : 2018-05-15T00:41:26
  

  Update getentropy() code from OpenBSD Includes changes to handle the Linux syscall blocking when there is not enough entropy during boot, by switching it to non-blocking mode and falling back to the alternative implementations. Man page URL reference fixes. Build fixes for Mac OS X. Fixes: https://bugs.debian.org/898088

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• src/getentropy_bsd.c

• /*	$OpenBSD: getentropy_freebsd.c,v 1.3 2016/08/07 03:27:21 tb Exp $	*/
  
  /*
   * Copyright (c) 2014 Pawel Jakub Dawidek <pjd@FreeBSD.org>
   * Copyright (c) 2014 Brent Cook <bcook@openbsd.org>
   *
   * Permission to use, copy, modify, and 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.
   *
   * Emulation of getentropy(2) as documented at:
   * http://man.openbsd.org/getentropy.2
   */
  
  #include <sys/types.h>
  #include <sys/sysctl.h>
  
  #include <errno.h>
  #include <stddef.h>
  
  /*
   * Derived from lib/libc/gen/arc4random.c from FreeBSD.
   */
  static size_t
  getentropy_sysctl(unsigned char *buf, size_t size)
  {
  	int mib[2];
  	size_t len, done;
  
  	mib[0] = CTL_KERN;
  	mib[1] = KERN_ARND;
  	done = 0;
  
  	do {
  		len = size;
  		if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
  			return (done);
  		done += len;
  		buf += len;
  		size -= len;
  	} while (size > 0);
  
  	return (done);
  }
  
  int
  getentropy(void *buf, size_t len)
  {
  	if (len <= 256 && getentropy_sysctl(buf, len) == len)
  		return (0);
  
  	errno = EIO;
  	return (-1);
  }
  

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