1*38a52bd3SEd Maste /* $OpenBSD: arc4random_linux.h,v 1.12 2019/07/11 10:37:28 inoguchi Exp $ */ 2*38a52bd3SEd Maste 3*38a52bd3SEd Maste /* 4*38a52bd3SEd Maste * Copyright (c) 1996, David Mazieres <dm@uun.org> 5*38a52bd3SEd Maste * Copyright (c) 2008, Damien Miller <djm@openbsd.org> 6*38a52bd3SEd Maste * Copyright (c) 2013, Markus Friedl <markus@openbsd.org> 7*38a52bd3SEd Maste * Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org> 8*38a52bd3SEd Maste * 9*38a52bd3SEd Maste * Permission to use, copy, modify, and distribute this software for any 10*38a52bd3SEd Maste * purpose with or without fee is hereby granted, provided that the above 11*38a52bd3SEd Maste * copyright notice and this permission notice appear in all copies. 12*38a52bd3SEd Maste * 13*38a52bd3SEd Maste * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 14*38a52bd3SEd Maste * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 15*38a52bd3SEd Maste * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 16*38a52bd3SEd Maste * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 17*38a52bd3SEd Maste * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 18*38a52bd3SEd Maste * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 19*38a52bd3SEd Maste * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 20*38a52bd3SEd Maste */ 21*38a52bd3SEd Maste 22*38a52bd3SEd Maste /* 23*38a52bd3SEd Maste * Stub functions for portability. From LibreSSL with some adaptations. 24*38a52bd3SEd Maste */ 25*38a52bd3SEd Maste 26*38a52bd3SEd Maste #include <sys/mman.h> 27*38a52bd3SEd Maste 28*38a52bd3SEd Maste #include <signal.h> 29*38a52bd3SEd Maste 30*38a52bd3SEd Maste /* OpenSSH isn't multithreaded */ 31*38a52bd3SEd Maste #define _ARC4_LOCK() 32*38a52bd3SEd Maste #define _ARC4_UNLOCK() 33*38a52bd3SEd Maste #define _ARC4_ATFORK(f) 34*38a52bd3SEd Maste 35*38a52bd3SEd Maste static inline void 36*38a52bd3SEd Maste _getentropy_fail(void) 37*38a52bd3SEd Maste { 38*38a52bd3SEd Maste fatal("getentropy failed"); 39*38a52bd3SEd Maste } 40*38a52bd3SEd Maste 41*38a52bd3SEd Maste static volatile sig_atomic_t _rs_forked; 42*38a52bd3SEd Maste 43*38a52bd3SEd Maste static inline void 44*38a52bd3SEd Maste _rs_forkhandler(void) 45*38a52bd3SEd Maste { 46*38a52bd3SEd Maste _rs_forked = 1; 47*38a52bd3SEd Maste } 48*38a52bd3SEd Maste 49*38a52bd3SEd Maste static inline void 50*38a52bd3SEd Maste _rs_forkdetect(void) 51*38a52bd3SEd Maste { 52*38a52bd3SEd Maste static pid_t _rs_pid = 0; 53*38a52bd3SEd Maste pid_t pid = getpid(); 54*38a52bd3SEd Maste 55*38a52bd3SEd Maste if (_rs_pid == 0 || _rs_pid == 1 || _rs_pid != pid || _rs_forked) { 56*38a52bd3SEd Maste _rs_pid = pid; 57*38a52bd3SEd Maste _rs_forked = 0; 58*38a52bd3SEd Maste if (rs) 59*38a52bd3SEd Maste memset(rs, 0, sizeof(*rs)); 60*38a52bd3SEd Maste } 61*38a52bd3SEd Maste } 62*38a52bd3SEd Maste 63*38a52bd3SEd Maste static inline int 64*38a52bd3SEd Maste _rs_allocate(struct _rs **rsp, struct _rsx **rsxp) 65*38a52bd3SEd Maste { 66*38a52bd3SEd Maste if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE, 67*38a52bd3SEd Maste MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) 68*38a52bd3SEd Maste return (-1); 69*38a52bd3SEd Maste 70*38a52bd3SEd Maste if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE, 71*38a52bd3SEd Maste MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) { 72*38a52bd3SEd Maste munmap(*rsp, sizeof(**rsp)); 73*38a52bd3SEd Maste *rsp = NULL; 74*38a52bd3SEd Maste return (-1); 75*38a52bd3SEd Maste } 76*38a52bd3SEd Maste 77*38a52bd3SEd Maste _ARC4_ATFORK(_rs_forkhandler); 78*38a52bd3SEd Maste return (0); 79*38a52bd3SEd Maste } 80