1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2018 Conrad Meyer <cem@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/param.h> 30 #include <sys/random.h> 31 32 #include <errno.h> 33 #include <signal.h> 34 #include <unistd.h> 35 #include <ssp/ssp.h> 36 37 #include "libc_private.h" 38 39 static inline void 40 _getentropy_fail(void) 41 { 42 raise(SIGKILL); 43 } 44 45 int 46 __ssp_real(getentropy)(void *buf, size_t buflen) 47 { 48 ssize_t rd; 49 50 if (buflen > 256) { 51 errno = EIO; 52 return (-1); 53 } 54 55 while (buflen > 0) { 56 rd = getrandom(buf, buflen, 0); 57 if (rd == -1) { 58 switch (errno) { 59 case EINTR: 60 continue; 61 case EFAULT: 62 return (-1); 63 default: 64 _getentropy_fail(); 65 } 66 } 67 68 /* This cannot happen. */ 69 if (rd == 0) 70 _getentropy_fail(); 71 72 buf = (char *)buf + rd; 73 buflen -= rd; 74 } 75 76 return (0); 77 } 78