1 /* $OpenBSD: util.c,v 1.43 2016/08/12 20:39:01 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 1998 Per Fogelstrom, Opsycon AB 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29 #include <sys/types.h> 30 #include <syslog.h> 31 #include "archdep.h" 32 #include "resolve.h" 33 34 /* 35 * Stack protector dummies. 36 * Ideally, a scheme to compile these stubs from libc should be used, but 37 * this would end up dragging too much code from libc here. 38 */ 39 long __guard_local __dso_hidden __attribute__((section(".openbsd.randomdata"))); 40 41 void __stack_smash_handler(char [], int); 42 43 void 44 __stack_smash_handler(char func[], int damaged) 45 { 46 char message[256]; 47 48 /* <10> indicates LOG_CRIT */ 49 _dl_strlcpy(message, "<10>ld.so:", sizeof message); 50 _dl_strlcat(message, __progname, sizeof message); 51 if (_dl_strlen(message) > sizeof(message)/2) 52 _dl_strlcpy(message + sizeof(message)/2, "...", 53 sizeof(message) - sizeof(message)/2); 54 _dl_strlcat(message, "stack overflow in function ", sizeof message); 55 _dl_strlcat(message, func, sizeof message); 56 57 _dl_sendsyslog(message, _dl_strlen(message), LOG_CONS); 58 _dl_exit(127); 59 } 60 61 char * 62 _dl_strdup(const char *orig) 63 { 64 char *newstr; 65 size_t len; 66 67 len = _dl_strlen(orig)+1; 68 newstr = _dl_malloc(len); 69 if (newstr != NULL) 70 _dl_strlcpy(newstr, orig, len); 71 return (newstr); 72 } 73 74 void 75 _dl_arc4randombuf(void *v, size_t buflen) 76 { 77 static char bytes[256]; 78 static u_int reserve; 79 char *buf = v; 80 size_t chunk; 81 82 while (buflen != 0) { 83 if (reserve == 0) { 84 if (_dl_getentropy(bytes, sizeof(bytes)) != 0) 85 _dl_exit(8); 86 reserve = sizeof(bytes); 87 } 88 if (buflen > reserve) 89 chunk = reserve; 90 else 91 chunk = buflen; 92 #if 0 93 memcpy(buf, bytes + reserve - chunk, chunk); 94 memset(bytes + reserve - chunk, 0, chunk); 95 #else 96 { 97 char *d = buf; 98 char *s = bytes + reserve - chunk; 99 u_int l; 100 for (l = chunk; l > 0; l--, s++, d++) { 101 *d = *s; 102 *s = 0; 103 } 104 } 105 #endif 106 reserve -= chunk; 107 buflen -= chunk; 108 buf += chunk; 109 } 110 } 111 112 u_int32_t 113 _dl_arc4random(void) 114 { 115 u_int32_t rnd; 116 _dl_arc4randombuf(&rnd, sizeof(rnd)); 117 return (rnd); 118 } 119