ntp.keys(5) File Formats ntp.keys(5)NAMEntp.keys - NTP symmetric key file format configuration file
SYNOPSIS
[--option-name] [--option-name value]
All arguments must be options.
DESCRIPTION
This document describes the format of an NTP symmetric key file. For a
description of the use of this type of file, see the "Authentication
Support" section of the ntp.conf(5) page.
ntpd(8) reads its keys from a file specified using the -k command line
option or the keys statement in the configuration file. While key num‐
ber 0 is fixed by the NTP standard (as 56 zero bits) and may not be
changed, one or more keys numbered between 1 and 65534 may be arbitrar‐
ily set in the keys file.
The key file uses the same comment conventions as the configuration
file. Key entries use a fixed format of the form
keyno type key opt_IP_list
where keyno is a positive integer (between 1 and 65534), type is the
message digest algorithm, and key is the key itself, and opt_IP_list is
an optional comma-separated list of IPs that are allowed to serve time.
If opt_IP_list is empty, any properly-authenticated server message will
be accepted.
The key may be given in a format controlled by the type field. The
type MD5 is always supported. If ntpd was built with the OpenSSL
library then any digest library supported by that library may be speci‐
fied. However, if compliance with FIPS 140-2 is required the type must
be either SHA or SHA1.
What follows are some key types, and corresponding formats:
MD5 The key is 1 to 16 printable characters terminated by an EOL,
whitespace, or a # (which is the "start of comment" character).
SHA
SHA1
RMD160 The key is a hex-encoded ASCII string of 40 characters, which is
truncated as necessary.
Note that the keys used by the ntpq(8) and ntpdc(8) programs are
checked against passwords requested by the programs and entered by
hand, so it is generally appropriate to specify these keys in ASCII
format.
FILES
/etc/ntp.keys the default name of the configuration file
SEE ALSOntp.conf(5), ntpd(1), ntpdate(1), ntpdc(1), sntp(1)AUTHORS
The University of Delaware and Network Time Foundation
COPYRIGHT
Copyright (C) 1992-2016 The University of Delaware and Network Time
Foundation all rights reserved. This program is released under the
terms of the NTP license, <http://ntp.org/license>.
BUGS
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
NOTES
This document was derived from FreeBSD.
This manual page was AutoGen-erated from the ntp.keys option defini‐
tions.
4.2.8p6 20 Jan 2016 ntp.keys(5)
