1 /* $OpenBSD: arc4random_linux.h,v 1.12 2019/07/11 10:37:28 inoguchi Exp $ */ 2 3 /* 4 * Copyright (c) 1996, David Mazieres <dm@uun.org> 5 * Copyright (c) 2008, Damien Miller <djm@openbsd.org> 6 * Copyright (c) 2013, Markus Friedl <markus@openbsd.org> 7 * Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org> 8 * 9 * Permission to use, copy, modify, and distribute this software for any 10 * purpose with or without fee is hereby granted, provided that the above 11 * copyright notice and this permission notice appear in all copies. 12 * 13 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 14 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 15 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 16 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 17 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 18 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 19 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 20 */ 21 22 /* 23 * Stub functions for portability. From LibreSSL with some adaptations. 24 */ 25 26 #include <sys/mman.h> 27 28 #include <signal.h> 29 30 /* OpenSSH isn't multithreaded */ 31 #define _ARC4_LOCK() 32 #define _ARC4_UNLOCK() 33 #define _ARC4_ATFORK(f) 34 35 static inline void 36 _getentropy_fail(void) 37 { 38 fatal("getentropy failed"); 39 } 40 41 static volatile sig_atomic_t _rs_forked; 42 43 static inline void 44 _rs_forkhandler(void) 45 { 46 _rs_forked = 1; 47 } 48 49 static inline void 50 _rs_forkdetect(void) 51 { 52 static pid_t _rs_pid = 0; 53 pid_t pid = getpid(); 54 55 if (_rs_pid == 0 || _rs_pid == 1 || _rs_pid != pid || _rs_forked) { 56 _rs_pid = pid; 57 _rs_forked = 0; 58 if (rs) 59 memset(rs, 0, sizeof(*rs)); 60 } 61 } 62 63 static inline int 64 _rs_allocate(struct _rs **rsp, struct _rsx **rsxp) 65 { 66 #if defined(MAP_ANON) && defined(MAP_PRIVATE) 67 if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE, 68 MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) 69 return (-1); 70 71 if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE, 72 MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) { 73 munmap(*rsp, sizeof(**rsp)); 74 *rsp = NULL; 75 return (-1); 76 } 77 #else 78 if ((*rsp = calloc(1, sizeof(**rsp))) == NULL) 79 return (-1); 80 if ((*rsxp = calloc(1, sizeof(**rsxp))) == NULL) { 81 free(*rsp); 82 *rsp = NULL; 83 return (-1); 84 } 85 #endif 86 87 _ARC4_ATFORK(_rs_forkhandler); 88 return (0); 89 } 90