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 #ifdef HAVE_SYS_MMAN_H 27 #include <sys/mman.h> 28 #endif 29 30 #include <signal.h> 31 32 /* OpenSSH isn't multithreaded */ 33 #define _ARC4_LOCK() 34 #define _ARC4_UNLOCK() 35 #define _ARC4_ATFORK(f) 36 37 static inline void 38 _getentropy_fail(void) 39 { 40 fatal("getentropy failed"); 41 } 42 43 static volatile sig_atomic_t _rs_forked; 44 45 static inline void 46 _rs_forkhandler(void) 47 { 48 _rs_forked = 1; 49 } 50 51 static inline void 52 _rs_forkdetect(void) 53 { 54 static pid_t _rs_pid = 0; 55 pid_t pid = getpid(); 56 57 if (_rs_pid == 0 || _rs_pid == 1 || _rs_pid != pid || _rs_forked) { 58 _rs_pid = pid; 59 _rs_forked = 0; 60 if (rs) 61 memset(rs, 0, sizeof(*rs)); 62 } 63 } 64 65 static inline int 66 _rs_allocate(struct _rs **rsp, struct _rsx **rsxp) 67 { 68 #if defined(MAP_ANON) && defined(MAP_PRIVATE) 69 if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE, 70 MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) 71 return (-1); 72 73 if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE, 74 MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) { 75 munmap(*rsp, sizeof(**rsp)); 76 *rsp = NULL; 77 return (-1); 78 } 79 #else 80 if ((*rsp = calloc(1, sizeof(**rsp))) == NULL) 81 return (-1); 82 if ((*rsxp = calloc(1, sizeof(**rsxp))) == NULL) { 83 free(*rsp); 84 *rsp = NULL; 85 return (-1); 86 } 87 #endif 88 89 _ARC4_ATFORK(_rs_forkhandler); 90 return (0); 91 } 92