1 /* $OpenBSD: util.c,v 1.35 2014/07/14 03:54:50 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 <sys/param.h> 31 #include "archdep.h" 32 33 /* 34 * Stack protector dummies. 35 * Ideally, a scheme to compile these stubs from libc should be used, but 36 * this would end up dragging too much code from libc here. 37 */ 38 long __guard_local __dso_hidden __attribute__((section(".openbsd.randomdata"))); 39 40 void __stack_smash_handler(char [], int); 41 42 void 43 __stack_smash_handler(char func[], int damaged) 44 { 45 extern const char *_dl_progname; 46 char message[100]; 47 48 /* <10> indicates LOG_CRIT */ 49 _dl_strlcpy(message, "<10>ld.so:", sizeof message); 50 _dl_strlcat(message, _dl_progname, sizeof message); 51 _dl_strlcat(message, "stack overflow in function ", sizeof message); 52 _dl_strlcat(message, func, sizeof message); 53 54 _dl_sendsyslog(message, _dl_strlen(message)); 55 _dl_exit(127); 56 } 57 58 char * 59 _dl_strdup(const char *orig) 60 { 61 char *newstr; 62 size_t len; 63 64 len = _dl_strlen(orig)+1; 65 newstr = _dl_malloc(len); 66 if (newstr != NULL) 67 _dl_strlcpy(newstr, orig, len); 68 return (newstr); 69 } 70 71 void 72 _dl_randombuf(void *buf, size_t buflen) 73 { 74 size_t chunk; 75 76 while (buflen != 0) { 77 if (buflen > 256) 78 chunk = 256; 79 else 80 chunk = buflen; 81 if (_dl_getentropy(buf, chunk) != 0) 82 _dl_exit(8); 83 buflen -= chunk; 84 buf += chunk; 85 } 86 } 87 88 u_int32_t 89 _dl_random(void) 90 { 91 u_int32_t rnd; 92 _dl_randombuf(&rnd, sizeof(rnd)); 93 return (rnd); 94 } 95