xref: /freebsd/lib/libutil/_secure_path.c (revision 547fa0d9b785fb498d3d0db63618b781d2b83591)
156c04344SDavid Nugent /*-
256c04344SDavid Nugent  * Based on code copyright (c) 1995,1997 by
356c04344SDavid Nugent  * Berkeley Software Design, Inc.
456c04344SDavid Nugent  * All rights reserved.
556c04344SDavid Nugent  *
656c04344SDavid Nugent  * Redistribution and use in source and binary forms, with or without
756c04344SDavid Nugent  * modification, is permitted provided that the following conditions
856c04344SDavid Nugent  * are met:
956c04344SDavid Nugent  * 1. Redistributions of source code must retain the above copyright
1056c04344SDavid Nugent  *    notice immediately at the beginning of the file, without modification,
1156c04344SDavid Nugent  *    this list of conditions, and the following disclaimer.
1256c04344SDavid Nugent  * 2. Redistributions in binary form must reproduce the above copyright
1356c04344SDavid Nugent  *    notice, this list of conditions and the following disclaimer in the
1456c04344SDavid Nugent  *    documentation and/or other materials provided with the distribution.
1556c04344SDavid Nugent  * 3. This work was done expressly for inclusion into FreeBSD.  Other use
1656c04344SDavid Nugent  *    is permitted provided this notation is included.
1756c04344SDavid Nugent  * 4. Absolutely no warranty of function or purpose is made by the authors.
1856c04344SDavid Nugent  * 5. Modifications may be freely made to this file providing the above
1956c04344SDavid Nugent  *    conditions are met.
2056c04344SDavid Nugent  */
2156c04344SDavid Nugent 
228719c58fSMatthew Dillon #include <sys/cdefs.h>
238719c58fSMatthew Dillon __FBSDID("$FreeBSD$");
2456c04344SDavid Nugent 
2556c04344SDavid Nugent #include <sys/types.h>
2656c04344SDavid Nugent #include <sys/stat.h>
27163ae670SBruce Evans 
2856c04344SDavid Nugent #include <errno.h>
2956c04344SDavid Nugent #include <libutil.h>
30163ae670SBruce Evans #include <stddef.h>
31163ae670SBruce Evans #include <syslog.h>
3256c04344SDavid Nugent 
3356c04344SDavid Nugent /*
3456c04344SDavid Nugent  * Check for common security problems on a given path
3556c04344SDavid Nugent  * It must be:
3656c04344SDavid Nugent  * 1. A regular file, and exists
3756c04344SDavid Nugent  * 2. Owned and writaable only by root (or given owner)
3856c04344SDavid Nugent  * 3. Group ownership is given group or is non-group writable
3956c04344SDavid Nugent  *
4056c04344SDavid Nugent  * Returns:	-2 if file does not exist,
4156c04344SDavid Nugent  *		-1 if security test failure
4256c04344SDavid Nugent  *		0  otherwise
4356c04344SDavid Nugent  */
4456c04344SDavid Nugent 
4556c04344SDavid Nugent int
4656c04344SDavid Nugent _secure_path(const char *path, uid_t uid, gid_t gid)
4756c04344SDavid Nugent {
4856c04344SDavid Nugent     int		r = -1;
4956c04344SDavid Nugent     struct stat	sb;
5056c04344SDavid Nugent     const char	*msg = NULL;
5156c04344SDavid Nugent 
5256c04344SDavid Nugent     if (lstat(path, &sb) < 0) {
5356c04344SDavid Nugent 	if (errno == ENOENT) /* special case */
5456c04344SDavid Nugent 	    r = -2;  /* if it is just missing, skip the log entry */
5556c04344SDavid Nugent 	else
5656c04344SDavid Nugent 	    msg = "%s: cannot stat %s: %m";
5756c04344SDavid Nugent     }
5856c04344SDavid Nugent     else if (!S_ISREG(sb.st_mode))
5956c04344SDavid Nugent     	msg = "%s: %s is not a regular file";
6056c04344SDavid Nugent     else if (sb.st_mode & S_IWOTH)
6156c04344SDavid Nugent     	msg = "%s: %s is world writable";
62547fa0d9SMark Murray     else if ((int)uid != -1 && sb.st_uid != uid && sb.st_uid != 0) {
6356c04344SDavid Nugent     	if (uid == 0)
6456c04344SDavid Nugent     		msg = "%s: %s is not owned by root";
6556c04344SDavid Nugent     	else
6656c04344SDavid Nugent     		msg = "%s: %s is not owned by uid %d";
67547fa0d9SMark Murray     } else if ((int)gid != -1 && sb.st_gid != gid && (sb.st_mode & S_IWGRP))
6856c04344SDavid Nugent     	msg = "%s: %s is group writeable by non-authorised groups";
6956c04344SDavid Nugent     else
7056c04344SDavid Nugent     	r = 0;
7156c04344SDavid Nugent     if (msg != NULL)
7256c04344SDavid Nugent 	syslog(LOG_ERR, msg, "_secure_path", path, uid);
7356c04344SDavid Nugent     return r;
7456c04344SDavid Nugent }
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