_secure_path(3)

NAME

_secure_path - determine if a file appears to be secure

LIBRARY

System Utilities Library (libutil, -lutil)

SYNOPSIS

#include <sys/types.h>
#include <libutil.h>
int
_secure_path(const char *path, uid_t uid, gid_t gid);

DESCRIPTION

This function does some basic security checking on a given

path. It is
intended to be used by processes running with root privi

leges in order to
decide whether or not to trust the contents of a given file.

It uses a
method often used to detect system compromise.

A file is considered `secure' if it meets the following con

ditions:

1. The file exists, and is a regular file (not a symlink,

device spe
cial or named pipe, etc.),

2. Is not world writable.

3. Is owned by the given uid or uid 0, if uid is not -1,

4. Is not group writable or it has group ownership by the

given gid, if
gid is not -1.

RETURN VALUES

This function returns zero if the file exists and may be

considered
secure, -2 if the file does not exist, and -1 otherwise to

indicate a
security failure. The syslog(3) function is used to log any

failure of
this function, including the reason, at LOG_ERR priority.

SEE ALSO

lstat(2), syslog(3)

HISTORY

Code from which this function was derived was contributed to

the FreeBSD
project by Berkeley Software Design, Inc.

BUGS

The checks carried out are rudimentary and no attempt is

made to eliminate race conditions between use of this function and access

to the file
referenced.

BSD May 2, 1997

BSD