1 /*- 2 * Based on code copyright (c) 1995,1997 by 3 * Berkeley Software Design, Inc. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, is permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice immediately at the beginning of the file, without modification, 11 * this list of conditions, and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. This work was done expressly for inclusion into FreeBSD. Other use 16 * is permitted provided this notation is included. 17 * 4. Absolutely no warranty of function or purpose is made by the authors. 18 * 5. Modifications may be freely made to this file providing the above 19 * conditions are met. 20 */ 21 22 #include <sys/cdefs.h> 23 #include <sys/types.h> 24 #include <sys/stat.h> 25 26 #include <errno.h> 27 #include <libutil.h> 28 #include <stddef.h> 29 #include <syslog.h> 30 31 /* 32 * Check for common security problems on a given path 33 * It must be: 34 * 1. A regular file, and exists 35 * 2. Owned and writable only by root (or given owner) 36 * 3. Group ownership is given group or is non-group writable 37 * 38 * Returns: -2 if file does not exist, 39 * -1 if security test failure 40 * 0 otherwise 41 */ 42 43 int 44 _secure_path(const char *path, uid_t uid, gid_t gid) 45 { 46 int r = -1; 47 struct stat sb; 48 const char *msg = NULL; 49 50 if (lstat(path, &sb) < 0) { 51 if (errno == ENOENT) /* special case */ 52 r = -2; /* if it is just missing, skip the log entry */ 53 else 54 msg = "%s: cannot stat %s: %m"; 55 } 56 else if (!S_ISREG(sb.st_mode)) 57 msg = "%s: %s is not a regular file"; 58 else if (sb.st_mode & S_IWOTH) 59 msg = "%s: %s is world writable"; 60 else if ((int)uid != -1 && sb.st_uid != uid && sb.st_uid != 0) { 61 if (uid == 0) 62 msg = "%s: %s is not owned by root"; 63 else 64 msg = "%s: %s is not owned by uid %d"; 65 } else if ((int)gid != -1 && sb.st_gid != gid && (sb.st_mode & S_IWGRP)) 66 msg = "%s: %s is group writeable by non-authorised groups"; 67 else 68 r = 0; 69 if (msg != NULL) 70 syslog(LOG_ERR, msg, "_secure_path", path, uid); 71 return r; 72 } 73