Commit Graph

844 Commits

Author SHA1 Message Date
mjg
54983db241 mac: reduce pessimization of sdt probe handling
Prior to the change the code would branch on return value and then check
if probes are enabled. Since vast majority of the time they are not, this
is clearly wasteful. Check probes first.

Sponsored by:	The FreeBSD Foundation
2018-12-19 22:30:26 +00:00
mjg
7e31d1de7e Remove unused argument to priv_check_cred.
Patch mostly generated with cocinnelle:

@@
expression E1,E2;
@@

- priv_check_cred(E1,E2,0)
+ priv_check_cred(E1,E2)

Sponsored by:	The FreeBSD Foundation
2018-12-11 19:32:16 +00:00
mjg
9be8aba618 audi: replace open-coded TDP_AUDITREC checks with the macro
Sponsored by:	The FreeBSD Foundation
2018-12-11 17:14:12 +00:00
mjg
3ecf53c2d0 audit: predict AUDITING_TD as false
By default it is compiled in and disabled.

Sponsored by:	The FreeBSD Foundation
2018-11-29 09:19:48 +00:00
mjg
d1c87d3896 audit: change audit_syscalls_enabled type to bool
So that it fits better in __read_frequently.

Sponsored by:	The FreeBSD Foundation
2018-11-29 08:37:33 +00:00
brooks
f101633ffd Add const to input-only char * arguments.
These arguments are mostly paths handled by NAMEI*() macros which already
take const char * arguments.

This change improves the match between syscalls.master and the public
declerations of system calls.

Reviewed by:	kib (prior version)
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D17812
2018-11-02 20:50:22 +00:00
rwatson
3b657094d5 Rework the logic around quick checks for auditing that take place at
system-call entry and whenever audit arguments or return values are
captured:

1. Expose a single global, audit_syscalls_enabled, which controls
   whether the audit framework is entered, rather than exposing
   components of the policy -- e.g., if the trail is enabled,
   suspended, etc.

2. Introduce a new function audit_syscalls_enabled_update(), which is
   called to update audit_syscalls_enabled whenever an aspect of the
   policy changes, so that the value can be updated.

3. Remove a check of trail enablement/suspension from audit_new() --
   at the point where this function has been entered, we believe that
   system-call auditing is already in force, or we wouldn't get here,
   so simply proceed to more expensive policy checks.

4. Use an audit-provided global, audit_dtrace_enabled, rather than a
   dtaudit-provided global, to provide policy indicating whether
   dtaudit would like system calls to be audited.

5. Do some minor cosmetic renaming to clarify what various variables
   are for.

These changes collectively arrange it so that traditional audit
(trail, pipes) or the DTrace audit provider can enable system-call
probes without the other configured.  Otherwise, dtaudit cannot
capture system-call data without auditd(8) started.

Reviewed by:		gnn
Sponsored by:		DARPA, AFRL
Approved by:		re (gjb)
Differential Revision:	https://reviews.freebsd.org/D17348
2018-10-02 15:58:17 +00:00
rwatson
545428e18d The kernel DTrace audit provider (dtaudit) relies on auditd(8) to load
/etc/security/audit_event to provide a list of audit event-number <->
name mappings.  However, this occurs too late for anonymous tracing.
With this change, adding 'audit_event_load="YES"' to /boot/loader.conf
will cause the boot loader to preload the file, and then the kernel
audit code will parse it to register an initial set of audit event-number
<-> name mappings.  Those mappings can later be updated by auditd(8) if
the configuration file changes.

Reviewed by:	gnn, asomers, markj, allanjude
Discussed with:	jhb
Approved by:	re (kib)
MFC after:	1 week
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D16589
2018-09-03 14:26:43 +00:00
markj
a41798f2a9 Require that MAC label buffers be able to store a non-empty string.
The buffer size may be used to initialize an sbuf in
MAC_POLICY_EXTERNALIZE, and without this constraint it's possible to
trigger an assertion failure in the sbuf code.  With INVARIANTS
disabled, the first attempt to write to the sbuf will fail.

Reported by:	pho
Reviewed by:	delphij
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D16527
2018-08-01 03:46:07 +00:00
avg
db248ffff1 fix incorrect operator in the AUDITPIPE_SET_QLIMIT bounds check
PR:		229983
Submitted by:	Aniket Pandey <aniketp@iitk.ac.in>
Reported by:	Aniket Pandey <aniketp@iitk.ac.in>
MFC after:	1 week
2018-07-23 16:56:49 +00:00
asomers
fdd4863d45 Fix audit of chflagsat, lgetfh, and setfib
These syscalls were always supposed to have been auditted, but due to
oversights never were.

PR:		228374
Reported by:	aniketp
Reviewed by:	aniketp
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D16388
2018-07-22 14:11:52 +00:00
ian
86596b2682 Make it possible to run ntpd as a non-root user, add ntpd uid and gid.
Code analysis and runtime analysis using truss(8) indicate that the only
privileged operations performed by ntpd are adjusting system time, and
(re-)binding to privileged UDP port 123. These changes add a new mac(4)
policy module, mac_ntpd(4), which grants just those privileges to any
process running with uid 123.

This also adds a new user and group, ntpd:ntpd, (uid:gid 123:123), and makes
them the owner of the /var/db/ntp directory, so that it can be used as a
location where the non-privileged daemon can write files such as the
driftfile, and any optional logfile or stats files.

Because there are so many ways to configure ntpd, the question of how to
configure it to run without root privs can be a bit complex, so that will be
addressed in a separate commit. These changes are just what's required to
grant the limited subset of privs to ntpd, and the small change to ntpd to
prevent it from exiting with an error if running as non-root.

Differential Revision:	https://reviews.freebsd.org/D16281
2018-07-19 23:55:29 +00:00
asomers
eab3b9a210 auditon(2): fix A_SETPOLICY with 64-bit values
A_SETPOLICY is supposed to work with either 64 or 32-bit values, but due to a
typo the 64-bit version has never worked correctly.

Submitted by:	aniketp
Reviewed by:	asomers, cem
MFC after:	2 weeks
Sponsored by:	Google, Inc. (GSoC 2018)
Differential Revision:	https://reviews.freebsd.org/D16222
2018-07-15 21:10:19 +00:00
stevek
789878934e Add mpo_vnode_check_setmode MAC method to MAC/veriexec.
In the method, disallow changing SUID/SGID on verified files.

Obtained from:	Juniper Networks, Inc.
2018-07-14 17:21:16 +00:00
stevek
e520cd3b60 Fix a typo which could cause a build breakage when building with MAC/veriexec
enabled in the kernel config.

Remove unused mac_veriexec_print_db prototype in internal header file.
2018-07-14 17:15:28 +00:00
stevek
3425d2cb80 Remove RIPEMD-160 fingerprint modules for veriexec, since it has very
little practical use and would not be recommended for anyone to use in
a production environment.

Reviewed by:	sjg
2018-07-14 16:59:17 +00:00
stevek
c98c9817c7 Fix build breakage in veriexec for 32-bit architectures.
fsid_t and ino_t are 64-bit entities, use uintmax_t typecast to ensure we
can print it on 32-bit or 64-bit architectures by using the %ju format for
prints.

Obtained from:	Juniper Networks, Inc.
2018-06-20 06:54:38 +00:00
stevek
ccddba56e4 MAC/veriexec implements a verified execution environment using the MAC
framework.

The code is organized into a few distinct pieces:

* The meta-data store (in veriexec_metadata.c) which maps a file system
  identifier, file identifier, and generation key tuple to veriexec
  meta-data record.

* Fingerprint management (in veriexec_fingerprint.c) which deals with
  calculating the cryptographic hash for a file and verifying it. It also
  manages the loadable fingerprint modules.

* MAC policy implementation (in mac_veriexec.c) which implements the
  following MAC methods:

mpo_init
  Initializes the veriexec state, meta-data store, fingerprint modules,
  and registers mount and unmount EVENTHANDLERs

mpo_syscall
  Implements the following per-policy system calls:
  MAC_VERIEXEC_CHECK_FD_SYSCALL
    Check a file descriptor to see if the referenced file has a valid
    fingerprint.
  MAC_VERIEXEC_CHECK_PATH_SYSCALL
    Check a path to see if the referenced file has a valid fingerprint.

mpo_kld_check_load
  Check if loading a kld is allowed. This checks if the referenced vnode
  has a valid fingerprint.

mpo_mount_destroy_label
  Clears the veriexec slot data in a mount point label.

mpo_mount_init_label
  Initializes the veriexec slot data in a mount point label.
  The file system identifier is saved in the veriexec slot data.

mpo_priv_check
  Check if a process is allowed to write to /dev/kmem and /dev/mem
  devices.
  If a process is flagged as trusted, it is allowed to write.

mpo_proc_check_debug
  Check if a process is allowed to be debugged. If a process is not
  flagged with VERIEXEC_NOTRACE, then debugging is allowed.

mpo_vnode_check_exec
  Check is an exectuable is allowed to run. If veriexec is not enforcing
  or the executable has a valid fingerprint, then it is allowed to run.
  NOTE: veriexec will complain about mismatched fingerprints if it is
  active, regardless of the state of the enforcement.

mpo_vnode_check_open
  Check is a file is allowed to be opened. If verification was not
  requested, veriexec is not enforcing, or the file has a valid
  fingerprint, then veriexec will allow the file to be opened.

mpo_vnode_copy_label
  Copies the veriexec slot data from one label to another.

mpo_vnode_destroy_label
  Clears the veriexec slot data in a vnode label.

mpo_vnode_init_label
  Initializes the veriexec slot data in a vnode label.
  The fingerprint status for the file is stored in the veriexec slot data.

* Some sysctls, under security.mac.veriexec, for setting debug level,
  fetching the current state in a human-readable form, and dumping the
  fingerprint database are implemented.

* The MAC policy implementation source file also contains some utility
  functions.

* A set of fingerprint modules for the following cryptographic hash
  algorithms:
  RIPEMD-160, SHA1, SHA2-256, SHA2-384, SHA2-512

* Loadable module builds for MAC/veriexec and fingerprint modules.

 WARNING: Using veriexec with NFS (or other network-based) file systems is
          not recommended as one cannot guarantee the integrity of the files
          served, nor the uniqueness of file system identifiers which are
          used as key in the meta-data store.

Reviewed by:	ian, jtl
Obtained from:	Juniper Networks, Inc.
Differential Revision:	https://reviews.freebsd.org/D8554
2018-06-20 00:41:30 +00:00
asomers
e5a9e099fe audit(4): fix the definition of ARG_TERMID_ADDR
Due to a copy/paste error in r168688, ARG_TERMID_ADDR has the same
definition as ARG_SADDRUNIX.  Fix it.

The header change, while publicly visible, is guarded by #ifdef KERNEL, and
I can't find any kmod ports that use it.  So I'm not bumping
__FreeBSD_version.

PR:		228820
Submitted by:	aniketp
Sponsored by:	Google, Inc. (GSoC 2018)
Differential Revision:	https://reviews.freebsd.org/D15702
2018-06-13 14:55:31 +00:00
asomers
1922e9d3dc #include <bsm/audit.h> in security/audit/audit_ioctl.h
security/audit/audit_ioctl.h uses a type from bsm/audit.h, so needs to
include it.  And it needs to know the type's size, so it can't just
forward-declare.

PR:		228470
Submitted by:	aniketp
MFC after:	2 weeks
Sponsored by:	Google, Inc. (GSoC 2018)
Differential Revision:	https://reviews.freebsd.org/D15561
2018-05-30 21:50:23 +00:00
asomers
7c423a65c9 Fix "Bad tailq" panic when auditing auditon(A_SETCLASS, ...)
Due to an oversight in r195280, auditon(A_SETCLASS, ...) would cause a tailq
element to get added to the tailq twice, resulting in a circular tailq. This
panics when INVARIANTS are on.

MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D15381
2018-05-28 20:47:39 +00:00
brooks
ac0325b4db Use an accessor function to access ifr_data.
This fixes 32-bit compat (no ioctl command defintions are required
as struct ifreq is the same size).  This is believed to be sufficent to
fully support ifconfig on 32-bit systems.

Reviewed by:	kib
Obtained from:	CheriBSD
MFC after:	1 week
Relnotes:	yes
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14900
2018-03-30 18:50:13 +00:00
asomers
8d48e36cad audit(4): fix a typo in a comment
no functional change
2018-03-17 17:56:08 +00:00
eugen
7000d8296a mac_portacl(4): stop panicing INVARIANTS-enabled kernel by loading .ko
when kernel already has options MAC_PORTACL.

PR:		183817
Approved by:	avg (mentor)
MFC after:	1 week
2018-02-25 23:10:13 +00:00
brooks
90ef28a07c Reduce duplication in __mac_*_(file|link)(2) implementation.
Reviewed by:	rwatson
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14175
2018-02-15 18:57:22 +00:00
kan
c8da6fae2c Do pass removing some write-only variables from the kernel.
This reduces noise when kernel is compiled by newer GCC versions,
such as one used by external toolchain ports.

Reviewed by: kib, andrew(sys/arm and sys/arm64), emaste(partial), erj(partial)
Reviewed by: jhb (sys/dev/pci/* sys/kern/vfs_aio.c and sys/kern/kern_synch.c)
Differential Revision: https://reviews.freebsd.org/D10385
2017-12-25 04:48:39 +00:00
pfg
4736ccfd9c sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00
mjg
fb0f2cc9b2 Sprinkle __read_frequently on few obvious places.
Note that some of annotated variables should probably change their types
to something smaller, preferably bit-sized.
2017-09-06 20:33:33 +00:00
emaste
074c17e1e4 Correct bitwise test in mac_bsdextended ugidfw_rule_valid()
PR:		218039
CID:		1008934
Reported by:	Coverity, PVS-Studio
Reviewed by:	kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D10300
2017-06-13 01:17:58 +00:00
kib
e75ba1d5c4 Commit the 64-bit inode project.
Extend the ino_t, dev_t, nlink_t types to 64-bit ints.  Modify
struct dirent layout to add d_off, increase the size of d_fileno
to 64-bits, increase the size of d_namlen to 16-bits, and change
the required alignment.  Increase struct statfs f_mntfromname[] and
f_mntonname[] array length MNAMELEN to 1024.

ABI breakage is mitigated by providing compatibility using versioned
symbols, ingenious use of the existing padding in structures, and
by employing other tricks.  Unfortunately, not everything can be
fixed, especially outside the base system.  For instance, third-party
APIs which pass struct stat around are broken in backward and
forward incompatible ways.

Kinfo sysctl MIBs ABI is changed in backward-compatible way, but
there is no general mechanism to handle other sysctl MIBS which
return structures where the layout has changed. It was considered
that the breakage is either in the management interfaces, where we
usually allow ABI slip, or is not important.

Struct xvnode changed layout, no compat shims are provided.

For struct xtty, dev_t tty device member was reduced to uint32_t.
It was decided that keeping ABI compat in this case is more useful
than reporting 64-bit dev_t, for the sake of pstat.

Update note: strictly follow the instructions in UPDATING.  Build
and install the new kernel with COMPAT_FREEBSD11 option enabled,
then reboot, and only then install new world.

Credits: The 64-bit inode project, also known as ino64, started life
many years ago as a project by Gleb Kurtsou (gleb).  Kirk McKusick
(mckusick) then picked up and updated the patch, and acted as a
flag-waver.  Feedback, suggestions, and discussions were carried
by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles),
and Rick Macklem (rmacklem).  Kris Moore (kris) performed an initial
ports investigation followed by an exp-run by Antoine Brodin (antoine).
Essential and all-embracing testing was done by Peter Holm (pho).
The heavy lifting of coordinating all these efforts and bringing the
project to completion were done by Konstantin Belousov (kib).

Sponsored by:	The FreeBSD Foundation (emaste, kib)
Differential revision:	https://reviews.freebsd.org/D10439
2017-05-23 09:29:05 +00:00
rwatson
88c3c9069d Break audit_bsm_klib.c into two files: one (audit_bsm_klib.c)
retaining various utility functions used during BSM generation,
and a second (audit_bsm_db.c) that contains the various in-kernel
databases supporting various audit activities (the class and
event-name tables).

(No functional change is intended.)

Obtained from:	TrustedBSD Project
MFC after:	3 weeks
Sponsored by:	DARPA, AFRL
2017-04-03 10:15:58 +00:00
rwatson
c7eb7cd2dd Correct macro names and signatures for !AUDIT versions of canonical
path auditing.

Obtained from:	TrustedBSD Project
MFC after:	3 weeks
Sponsored by:	DARPA, AFRL
2017-03-31 14:13:13 +00:00
rwatson
a374d6c3a6 Audit arguments to POSIX message queues, semaphores, and shared memory.
This requires minor changes to the audit framework to allow capturing
paths that are not filesystem paths (i.e., will not be canonicalised
relative to the process current working directory and/or filesystem
root).

Obtained from:	TrustedBSD Project
MFC after:	3 weeks
Sponsored by:	DARPA, AFRL
2017-03-31 13:43:00 +00:00
rwatson
c0efcd5fde Audit arguments to System V IPC system calls implementing sempahores,
message queues, and shared memory.

Obtained from:	TrustedBSD Project
MFC after:	3 weeks
Sponsored by:	DARPA, AFRL
2017-03-30 22:26:15 +00:00
rwatson
0bae9c75d9 Various BSM generation improvements when auditing AUE_ACCEPT,
AUE_PROCCTL, AUE_SENDFILE, AUE_ACL_*, and AUE_POSIX_FALLOCATE.
Audit AUE_SHMUNLINK path in the path token rather than as a
text string, and AUE_SHMOPEN flags as an integer token rather
than a System V IPC address token.

Obtained from:	TrustedBSD Project
MFC after:	3 weeks
Sponsored by:	DARPA, AFRL
2017-03-30 21:39:03 +00:00
rwatson
277c03b353 Don't ifdef KDTRACE_HOOKS struct, variable, and function prototype
definitions for the DTrace audit provider, so that the dtaudit module
can compile in the absence of kernel DTrace support.  This doesn't
really make run-time sense (since the binary dependencies for the
module won't be present), but it allows the dtaudit module to compile
successfully regardless of the kernel configuration.

MFC after:	3 weeks
Sponsored by:	DARPA, AFRL
Reported by:	kib
2017-03-30 12:35:56 +00:00
rwatson
67e972eb25 When handling msgsys(2), semsys(2), and shmsys(2) multiplex system calls,
map the 'which' argument into a suitable audit event identifier for the
specific operation requested.

Obtained from:	TrustedBSD Project
MFC after:	3 weeks
Sponsored by:	DARPA, AFRL
2017-03-29 23:31:35 +00:00
rwatson
67c4e33a20 Add an experimental DTrace audit provider, which allows users of DTrace to
instrument security event auditing rather than relying on conventional BSM
trail files or audit pipes:

- Add a set of per-event 'commit' probes, which provide access to
  particular auditable events at the time of commit in system-call return.
  These probes gain access to audit data via the in-kernel audit_record
  data structure, providing convenient access to system-call arguments and
  return values in a single probe.

- Add a set of per-event 'bsm' probes, which provide access to particular
  auditable events at the time of BSM record generation in the audit
  worker thread. These probes have access to the in-kernel audit_record
  data structure and BSM representation as would be written to a trail
  file or audit pipe -- i.e., asynchronously in the audit worker thread.

DTrace probe arguments consist of the name of the audit event (to support
future mechanisms of instrumenting multiple events via a single probe --
e.g., using classes), a pointer to the in-kernel audit record, and an
optional pointer to the BSM data and its length. For human convenience,
upper-case audit event names (AUE_...) are converted to lower case in
DTrace.

DTrace scripts can now cause additional audit-based data to be collected
on system calls, and inspect internal and BSM representations of the data.
They do not affect data captured in the audit trail or audit pipes
configured in the system. auditd(8) must be configured and running in
order to provide a database of event information, as well as other audit
configuration parameters (e.g., to capture command-line arguments or
environmental variables) for the provider to operate.

Reviewed by:	gnn, jonathan, markj
Sponsored by:	DARPA, AFRL
MFC after:	3 weeks
Differential Revision:	https://reviews.freebsd.org/D10149
2017-03-29 19:58:00 +00:00
rwatson
1eefe93a8f Introduce an audit event identifier -> audit event name mapping
database in the kernel audit implementation, similar the exist
class mapping database.  This will be used by the DTrace audit
provider to map audit event identifiers originating in the
system-call table back into strings for the purposes of setting
probe names.  The database is initialised and maintained by
auditd(8), which reads values in from the audit_events
configuration file, and then manages them using the A_GETEVENT
and A_SETEVENT auditon(2) operations.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, AFRL
MFC after:	3 weeks
2017-03-27 10:38:53 +00:00
rwatson
4315cc14ea Extend comment describing path canonicalisation in audit.
Sponsored by:	DARPA, AFRL
Obtained from:	TrustedBSD Project
MFC after:	3 days
2017-03-27 08:29:17 +00:00
rwatson
312591fedd Audit 'fd' and 'cmd' arguments to fcntl(2), and when generating BSM,
always audit the file-descriptor number and vnode information for all
fnctl(2) commands, not just locking-related ones.  This was likely an
oversight in the original adaptation of this code from XNU.

MFC after:	3 days
Sponsored by:	DARPA, AFRL
2016-11-22 00:41:24 +00:00
bdrewery
30f99dbeef Fix improper use of "its".
Sponsored by:	Dell EMC Isilon
2016-11-08 23:59:41 +00:00
jhb
b3eaf2f302 Don't check aq64_minfree which is unsigned for negative values.
This fixes a tautological comparison warning.

Reviewed by:	rwatson
Differential Revision:	https://reviews.freebsd.org/D7682
2016-09-08 19:47:57 +00:00
rwatson
e2edde369a Audit the accepted (or rejected) username argument to setlogin(2).
(NB: This was likely a mismerge from XNU in audit support, where the
text argument to setlogin(2) is captured -- but as a text token,
whereas this change uses the dedicated login-name field in struct
audit_record.)

MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2016-08-20 20:28:08 +00:00
rwatson
c3c54bd15a Add AUE_WAIT6 handling to the BSM conversion switch statement, reusing
the BSM encoding used for AUE_WAIT4.

MFC after:	3 days
Sponsored by:	DARPA, AFRL
2016-07-11 13:06:17 +00:00
rwatson
a898890305 Implement AUE_PREAD and AUE_PWRITE BSM conversion support, eliminating
console warnings when pread(2) and pwrite(2) are used with full
system-call auditing enabled.  We audit the same file-descriptor data
for these calls as we do read(2) and write(2).

Approved by:	re (kib)
MFC after:	3 days
Sponsored by:	DARPA, AFRL
2016-06-13 09:22:20 +00:00
pfg
9d9aae4d84 sys/security: minor spelling fixes.
No functional change.
2016-05-06 16:59:04 +00:00
pfg
42747553f4 sys: use our nitems() macro when param.h is available.
This should cover all the remaining cases in the kernel.

Discussed in:	freebsd-current
2016-04-21 19:40:10 +00:00
pfg
fc65edc1cd Remove slightly used const values that can be replaced with nitems().
Suggested by:	jhb
2016-04-21 15:38:28 +00:00
pfg
99e1acfb71 audit(8): leave unsigned comparison for last.
aq64_minfree is unsigned so comparing to find out if it is less
than zero is a nonsense. Move the comparison to the last position
as we don't want to spend time if any of the others triggers first.

hile it would be tempting to just remove it, it may be important to
keep  it for portability with platforms where may be signed(?) or
in case we may want to change it in the future.
2016-04-08 03:26:21 +00:00