NAME
setfilexsec — set extended security attributes on a binary file
SYNOPSIS
setfilexsec
-d
filename
setfilexsec
-D
absolutepath
setfilexsec
[-c
compartmentname]
[-f
flags]
[-p
privs]
[-P
privs]
[-r
privs]
[-R
privs]
filename
DESCRIPTION
setfilexsec
sets various extended security attributes of binary files.
The attributes currently include retained privileges, permitted privileges,
compartment, and the privilege start flag.
See
privileges(5)
and
execve(2)
for a description of these attributes.
The security attributes are stored in a configuration file and maintain persistence across reboot.
The attributes
are stored in a configuration file and loaded when the system reboots.
Options
setfilexsec
recognizes the following options:
- -c
Sets the compartment name for the binary executable file.
- -d
Deletes any security information for the file from the configuration file and
the kernel.
- -D
Delete any security information for the file given by
absolutepath
from the configuration file only.
This is used to clear attributes of a deleted file.
- -f
Sets the security attribute flags.
The only defined flag is the privilege start flag.
The
privilege_start
flag
must be either
start_full
or
start_nil.
If the value is
start_full,
when the binary is executed, the process' effective privileges are set
to the newly computed permitted privilege set.
If the value is
start_nil,
when the binary file is executed, the process' effective privileges are set
to
nil
(no privileges).
If this option is not specified and the process start
flag
is not already set for the binary file, the flag is set to
start_nil.
- -p
Adds or changes the minimum permitted privileges.
This must be a subset of the maximum permitted privileges.
- -P
Adds or changes the maximum permitted privileges.
This must be equal to or a superset of the minimum permitted privileges,
minimum retained privileges, and maximum retained privileges.
- -r
Adds or changes the minimum retained privileges.
This must be a subset of the maximum retained privileges as well
as minimum permitted privileges.
- -R
Adds or changes the maximum retained privileges.
This must be equal to or a superset of the minimum retained privileges.
This set must also be a subset of the maximum permitted privileges.
For the third form of the command,
if any of the options are not specified,
setfilexsec
takes the following action:
If the binary's extended attributes are already set (e.g., through a previous
invocation of the
setfilexsec
command), the previous value for the option is used.
If the binary's extended attributes are not set,
they default to null (i.e., empty sets for privileges and empty value for
compartment).
Option Arguments
- privs
This is a list of privileges
seperated by comma
(,).
See the desciption of
priv_list
argument in
priv_str_to_set(3).
- compartmentname
This must be a valid compartment on the system or an empty string ("").
If it is an an empty string,
the compartment part of the security attributes are cleared.
Operands
setfilexsec
recognizes the following operands:
- filename
A binary executable.
Extended attributes set on executable
scripts are ignored by the kernel.
Security Restrictions
The caller must have the following authorization:
hpux.security.xsec.filexsec.unrestricted
—or—
hpux.security.xsec.filexsec.restricted
RETURN VALUE
setfilexsec
returns the following values:
- 0
Successful completion.
The security attributes are updated successfully.
- >0
An error occurs.
An error can be caused by an invalid option, an
invalid argument, or insufficient permissions for the user
to perform the operation.
EXAMPLES
Example 1:
Add a security attributes entry for the binary executable
/web/java
for the first time:
setfilexsec -r cmptread \
-R policy,!changecmpt -p cmptread,cmptwrite \
-P policy -f start_nil -c web /web/java
The
Example 1
command has the following effect:
When a process performs a
exec()
of the binary
/web/java,
the process's attributes are modified as follows:
The retained privilege set includes at least
cmptread
and
cmptwrite.
The retained privilege set does not include
dacwrite.
The permitted privilege set includes at least
cmptread.
The permitted privilege set is equal to the policy privilege set
(depends on the inheritable set before the
exec()).
The process changes its compartment to
web.
Since the process is privilege-aware, the effective privilege set is empty
(and the application
/web/java
may raise the privileges in the permitted privilege set at run time).
Example 2:
Modify the minimum retained privilege set and flags for the same binary:
setfilexsec -r cmptwrite -f start_full /web/java
Because the
start_full
flag
is specified, the effective privilege set is equal to the permitted
privilege set (the application presumably does not manipulate the
privileges at run time).
Example 3:
Delete all extended security attributes for the same binary:
WARNINGS
If a binary file that has extended security attributes set is modified
or replaced, the attributes are no longer applied for that file, but are
still present in system tables.
On reboot, the system would detect that the file contents have changed
using a simple checksum mechanism.
Upon detecting such a scenario, the attributes of the file are
ignored and an error message is issued corresponding to the file entry.
For proper operation, when a file is modified,
run
setfilexsec -d
to remove the extended attributes instead of relying on the checksum
mechanism.
When replacing a binary,
in order to retain the privileges on the binary, run
setfilexsec -d
first to remove the prior privilege attributes, replace the binary,
and then run
setfilexsec
to re-assign attributes.
Note that the NFS protocol is not extended to support
extended security attributes.
Hence the NFS mounted binaries should
not be configured with any extended security attributes.
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