xref: /freebsd/contrib/ntp/ntpd/invoke-ntp.keys.texi (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1@node ntp.keys Notes
2@section Notes about ntp.keys
3@pindex ntp.keys
4@cindex NTP symmetric key file format
5@ignore
6#
7# EDIT THIS FILE WITH CAUTION  (invoke-ntp.keys.texi)
8#
9# It has been AutoGen-ed  March 21, 2017 at 10:31:04 AM by AutoGen 5.18.5
10# From the definitions    ntp.keys.def
11# and the template file   agtexi-file.tpl
12@end ignore
13
14
15
16This document describes the format of an NTP symmetric key file.
17For a description of the use of this type of file, see the
18"Authentication Support"
19section of the
20@code{ntp.conf(5)}
21page.
22
23@code{ntpd(8)}
24reads its keys from a file specified using the
25@code{-k}
26command line option or the
27@code{keys}
28statement in the configuration file.
29While key number 0 is fixed by the NTP standard
30(as 56 zero bits)
31and may not be changed,
32one or more keys numbered between 1 and 65534
33may be arbitrarily set in the keys file.
34
35The key file uses the same comment conventions
36as the configuration file.
37Key entries use a fixed format of the form
38
39@example
40@kbd{keyno} @kbd{type} @kbd{key} @kbd{opt_IP_list}
41@end example
42
43where
44@kbd{keyno}
45is a positive integer (between 1 and 65534),
46@kbd{type}
47is the message digest algorithm,
48and
49@kbd{key}
50is the key itself, and
51@kbd{opt_IP_list}
52is an optional comma-separated list of IPs
53that are allowed to serve time.
54If
55@kbd{opt_IP_list}
56is empty,
57any properly-authenticated server message will be
58accepted.
59
60The
61@kbd{key}
62may be given in a format
63controlled by the
64@kbd{type}
65field.
66The
67@kbd{type}
68@code{MD5}
69is always supported.
70If
71@code{ntpd}
72was built with the OpenSSL library
73then any digest library supported by that library may be specified.
74However, if compliance with FIPS 140-2 is required the
75@kbd{type}
76must be either
77@code{SHA}
78or
79@code{SHA1}.
80
81What follows are some key types, and corresponding formats:
82
83@table @asis
84@item @code{MD5}
85The key is 1 to 16 printable characters terminated by
86an EOL,
87whitespace,
88or
89a
90@code{#}
91(which is the "start of comment" character).
92
93@item @code{SHA}
94@item @code{SHA1}
95@item @code{RMD160}
96The key is a hex-encoded ASCII string of 40 characters,
97which is truncated as necessary.
98@end table
99
100Note that the keys used by the
101@code{ntpq(8)}
102and
103@code{ntpdc(8)}
104programs are checked against passwords
105requested by the programs and entered by hand,
106so it is generally appropriate to specify these keys in ASCII format.
107
108This section was generated by @strong{AutoGen},
109using the @code{agtexi-cmd} template and the option descriptions for the @code{ntp.keys} program.
110This software is released under the NTP license, <http://ntp.org/license>.
111
112@menu
113* ntp.keys Files::                  Files
114* ntp.keys See Also::               See Also
115* ntp.keys Notes::                  Notes
116@end menu
117
118@node ntp.keys Files
119@subsection ntp.keys Files
120@table @asis
121@item @file{/etc/ntp.keys}
122the default name of the configuration file
123@end table
124@node ntp.keys See Also
125@subsection ntp.keys See Also
126@code{ntp.conf(5)},
127@code{ntpd(1ntpdmdoc)},
128@code{ntpdate(1ntpdatemdoc)},
129@code{ntpdc(1ntpdcmdoc)},
130@code{sntp(1sntpmdoc)}
131@node ntp.keys Notes
132@subsection ntp.keys Notes
133This document was derived from FreeBSD.
134