1ntp-keygen(8) User Commands ntp-keygen(8)
2
6 ntp-keygen - Create a NTP host key
7
9 ntp-keygen [-flags] [-flag [value]] [--option-name[[=| ]value]]
10 All arguments must be options.
12
15 This program generates cryptographic data files used by the NTPv4
16 authentication and identification schemes. It can generate message
17 digest keys used in symmetric key cryptography and, if the OpenSSL
18 software library has been installed, it can generate host keys, signing
19 keys, certificates, and identity keys and parameters used in Autokey
20 public key cryptography. These files are used for cookie encryption,
21 digital signature, and challenge/response identification algorithms
22 compatible with the Internet standard security infrastructure.
23 The message digest symmetric keys file is generated in a format compat‐
25 ible with NTPv3. All other files are in PEM-encoded printable ASCII
26 format, so they can be embedded as MIME attachments in email to other
27 sites and certificate authorities. By default, files are not
28 encrypted.
29 When used to generate message digest symmetric keys, the program pro‐
31 duces a file containing ten pseudo-random printable ASCII strings suit‐
32 able for the MD5 message digest algorithm included in the distribution.
33 If the OpenSSL library is installed, it produces an additional ten hex-
34 encoded random bit strings suitable for SHA1, AES-128-CMAC, and other
35 message digest algorithms. The message digest symmetric keys file must
36 be distributed and stored using secure means beyond the scope of NTP
37 itself. Besides the keys used for ordinary NTP associations, addi‐
38 tional keys can be defined as passwords for the ntpq(8) and ntpdc(8)
39 utility programs.
40 The remaining generated files are compatible with other OpenSSL appli‐
42 cations and other Public Key Infrastructure (PKI) resources. Certifi‐
43 cates generated by this program are compatible with extant industry
44 practice, although some users might find the interpretation of X509v3
45 extension fields somewhat liberal. However, the identity keys are
46 probably not compatible with anything other than Autokey.
47 Some files used by this program are encrypted using a private password.
49 The -p option specifies the read password for local encrypted files and
50 the -q option the write password for encrypted files sent to remote
51 sites. If no password is specified, the host name returned by the Unix
52 hostname(1) command, normally the DNS name of the host, is used as the
53 the default read password, for convenience. The ntp-keygen program
54 prompts for the password if it reads an encrypted file and the password
55 is missing or incorrect. If an encrypted file is read successfully and
56 no write password is specified, the read password is used as the write
57 password by default.
58 The pw option of the crypto [22mntpd(8) configuration command specifies the
60 read password for previously encrypted local files. This must match
61 the local read password used by this program. If not specified, the
62 host name is used. Thus, if files are generated by this program with‐
63 out an explicit password, they can be read back by ntpd(8) without
64 specifying an explicit password but only on the same host. If the
65 write password used for encryption is specified as the host name, these
66 files can be read by that host with no explicit password.
67 Normally, encrypted files for each host are generated by that host and
69 used only by that host, although exceptions exist as noted later on
70 this page. The symmetric keys file, normally called ntp.keys, is usu‐
71 ally installed in /etc. Other files and links are usually installed in
72 /usr/local/etc, which is normally in a shared filesystem in NFS-mounted
73 networks and cannot be changed by shared clients. In these cases, NFS
74 clients can specify the files in another directory such as /etc using
75 the keysdir [22mntpd(8) configuration file command.
76 This program directs commentary and error messages to the standard
78 error stream stderr and remote files to the standard output stream std‐
79 out where they can be piped to other applications or redirected to
80 files. The names used for generated files and links all begin with the
81 string ntpkey* and include the file type, generating host and
82 filestamp, as described in the Cryptographic Data Files section below.
83 Running the Program
85 The safest way to run the ntp-keygen program is logged in directly as
86 root. The recommended procedure is change to the keys directory, usu‐
87 ally /usr/local/etc, then run the program.
88 To test and gain experience with Autokey concepts, log in as root and
90 change to the keys directory, usually /usr/local/etc. When run for the
91 first time, or if all files with names beginning with ntpkey* have been
92 removed, use the ntp-keygen command without arguments to generate a
93 default RSA host key and matching RSA-MD5 certificate file with expira‐
94 tion date one year hence, which is all that is necessary in many cases.
95 The program also generates soft links from the generic names to the
96 respective files. If run again without options, the program uses the
97 existing keys and parameters and generates a new certificate file with
98 new expiration date one year hence, and soft link.
99 The host key is used to encrypt the cookie when required and so must be
101 RSA type. By default, the host key is also the sign key used to
102 encrypt signatures. When necessary, a different sign key can be speci‐
103 fied and this can be either RSA or DSA type. By default, the message
104 digest type is MD5, but any combination of sign key type and message
105 digest type supported by the OpenSSL library can be specified, includ‐
106 ing those using the AES128CMAC, MD2, MD5, MDC2, SHA, SHA1 and RIPE160
107 message digest algorithms. However, the scheme specified in the cer‐
108 tificate must be compatible with the sign key. Certificates using any
109 digest algorithm are compatible with RSA sign keys; however, only SHA
110 and SHA1 certificates are compatible with DSA sign keys.
111 Private/public key files and certificates are compatible with other
113 OpenSSL applications and very likely other libraries as well. Certifi‐
114 cates or certificate requests derived from them should be compatible
115 with extant industry practice, although some users might find the
116 interpretation of X509v3 extension fields somewhat liberal. However,
117 the identification parameter files, although encoded as the other
118 files, are probably not compatible with anything other than Autokey.
119 Running the program as other than root and using the Unix su(1) command
121 to assume root may not work properly, since by default the OpenSSL
122 library looks for the random seed file .rnd in the user home directory.
123 However, there should be only one .rnd, most conveniently in the root
124 directory, so it is convenient to define the RANDFILE environment vari‐
125 able used by the OpenSSL library as the path to .rnd.
126 Installing the keys as root might not work in NFS-mounted shared file
128 systems, as NFS clients may not be able to write to the shared keys
129 directory, even as root. In this case, NFS clients can specify the
130 files in another directory such as /etc using the keysdir [22mntpd(8) con‐
131 figuration file command. There is no need for one client to read the
132 keys and certificates of other clients or servers, as these data are
133 obtained automatically by the Autokey protocol.
134 Ordinarily, cryptographic files are generated by the host that uses
136 them, but it is possible for a trusted agent (TA) to generate these
137 files for other hosts; however, in such cases files should always be
138 encrypted. The subject name and trusted name default to the hostname
139 of the host generating the files, but can be changed by command line
140 options. It is convenient to designate the owner name and trusted name
141 as the subject and issuer fields, respectively, of the certificate.
142 The owner name is also used for the host and sign key files, while the
143 trusted name is used for the identity files.
144 All files are installed by default in the keys directory
146 /usr/local/etc, which is normally in a shared filesystem in NFS-mounted
147 networks. The actual location of the keys directory and each file can
148 be overridden by configuration commands, but this is not recommended.
149 Normally, the files for each host are generated by that host and used
150 only by that host, although exceptions exist as noted later on this
151 page.
152 Normally, files containing private values, including the host key, sign
154 key and identification parameters, are permitted root read/write-only;
155 while others containing public values are permitted world readable.
156 Alternatively, files containing private values can be encrypted and
157 these files permitted world readable, which simplifies maintenance in
158 shared file systems. Since uniqueness is insured by the hostname and
159 filestamp file name extensions, the files for an NTP server and depen‐
160 dent clients can all be installed in the same shared directory.
161 The recommended practice is to keep the file name extensions when
163 installing a file and to install a soft link from the generic names
164 specified elsewhere on this page to the generated files. This allows
165 new file generations to be activated simply by changing the link. If a
166 link is present, ntpd(8) follows it to the file name to extract the
167 filestamp. If a link is not present, ntpd(8) extracts the filestamp
168 from the file itself. This allows clients to verify that the file and
169 generation times are always current. The ntp-keygen program uses the
170 same filestamp extension for all files generated at one time, so each
171 generation is distinct and can be readily recognized in monitoring
172 data.
173 Run the command on as many hosts as necessary. Designate one of them
175 as the trusted host (TH) using ntp-keygen with the -T option and con‐
176 figure it to synchronize from reliable Internet servers. Then config‐
177 ure the other hosts to synchronize to the TH directly or indirectly. A
178 certificate trail is created when Autokey asks the immediately ascen‐
179 dant host towards the TH to sign its certificate, which is then pro‐
180 vided to the immediately descendant host on request. All group hosts
181 should have acyclic certificate trails ending on the TH.
182 The host key is used to encrypt the cookie when required and so must be
184 RSA type. By default, the host key is also the sign key used to
185 encrypt signatures. A different sign key can be assigned using the -S
186 option and this can be either RSA or DSA type. By default, the signa‐
187 ture message digest type is MD5, but any combination of sign key type
188 and message digest type supported by the OpenSSL library can be speci‐
189 fied using the -c option.
190 The rules say cryptographic media should be generated with proventic
192 filestamps, which means the host should already be synchronized before
193 this program is run. This of course creates a chicken-and-egg problem
194 when the host is started for the first time. Accordingly, the host
195 time should be set by some other means, such as eyeball-and-wristwatch,
196 at least so that the certificate lifetime is within the current year.
197 After that and when the host is synchronized to a proventic source, the
198 certificate should be re-generated.
199 Additional information on trusted groups and identity schemes is on the
201 Autokey Public-Key Authentication page.
202 File names begin with the prefix ntpkey_ and end with the suffix _host‐
204 name. filestamp, where hostname is the owner name, usually the string
205 returned by the Unix hostname(1) command, and filestamp is the NTP sec‐
206 onds when the file was generated, in decimal digits. This both guaran‐
207 tees uniqueness and simplifies maintenance procedures, since all files
208 can be quickly removed by a rm ntpkey* command or all files generated
209 at a specific time can be removed by a rm *filestamp command. To fur‐
210 ther reduce the risk of misconfiguration, the first two lines of a file
211 contain the file name and generation date and time as comments.
212 Trusted Hosts and Groups
214 Each cryptographic configuration involves selection of a signature
215 scheme and identification scheme, called a cryptotype, as explained in
216 the Authentication Options section of ntp.conf(5). The default crypto‐
217 type uses RSA encryption, MD5 message digest and TC identification.
218 First, configure a NTP subnet including one or more low-stratum trusted
219 hosts from which all other hosts derive synchronization directly or
220 indirectly. Trusted hosts have trusted certificates; all other hosts
221 have nontrusted certificates. These hosts will automatically and
222 dynamically build authoritative certificate trails to one or more
223 trusted hosts. A trusted group is the set of all hosts that have,
224 directly or indirectly, a certificate trail ending at a trusted host.
225 The trail is defined by static configuration file entries or dynamic
226 means described on the Automatic NTP Configuration Options section of
227 ntp.conf(5).
228 On each trusted host as root, change to the keys directory. To insure
230 a fresh fileset, remove all ntpkey files. Then run ntp-keygen -T to
231 generate keys and a trusted certificate. On all other hosts do the
232 same, but leave off the -T flag to generate keys and nontrusted cer‐
233 tificates. When complete, start the NTP daemons beginning at the low‐
234 est stratum and working up the tree. It may take some time for Autokey
235 to instantiate the certificate trails throughout the subnet, but set‐
236 ting up the environment is completely automatic.
237 If it is necessary to use a different sign key or different digest/sig‐
239 nature scheme than the default, run ntp-keygen with the -S type option,
240 where type is either RSA or DSA. The most frequent need to do this is
241 when a DSA-signed certificate is used. If it is necessary to use a
242 different certificate scheme than the default, run ntp-keygen with the
243 -c scheme option and selected scheme as needed. If ntp-keygen is run
244 again without these options, it generates a new certificate using the
245 same scheme and sign key, and soft link.
246 After setting up the environment it is advisable to update certificates
248 from time to time, if only to extend the validity interval. Simply run
249 ntp-keygen with the same flags as before to generate new certificates
250 using existing keys, and soft links. However, if the host or sign key
251 is changed, ntpd(8) should be restarted. When ntpd(8) is restarted, it
252 loads any new files and restarts the protocol. Other dependent hosts
253 will continue as usual until signatures are refreshed, at which time
254 the protocol is restarted.
255 Identity Schemes
257 As mentioned on the Autonomous Authentication page, the default TC
258 identity scheme is vulnerable to a middleman attack. However, there
259 are more secure identity schemes available, including PC, IFF, GQ and
260 MV schemes described below. These schemes are based on a TA, one or
261 more trusted hosts and some number of nontrusted hosts. Trusted hosts
262 prove identity using values provided by the TA, while the remaining
263 hosts prove identity using values provided by a trusted host and cer‐
264 tificate trails that end on that host. The name of a trusted host is
265 also the name of its sugroup and also the subject and issuer name on
266 its trusted certificate. The TA is not necessarily a trusted host in
267 this sense, but often is.
268 In some schemes there are separate keys for servers and clients. A
270 server can also be a client of another server, but a client can never
271 be a server for another client. In general, trusted hosts and non‐
272 trusted hosts that operate as both server and client have parameter
273 files that contain both server and client keys. Hosts that operate
274 only as clients have key files that contain only client keys.
275 The PC scheme supports only one trusted host in the group. On trusted
277 host alice run ntp-keygen -P -p password to generate the host key file
278 ntpkey_ RSA key_alice. filestamp and trusted private certificate file
279 ntpkey_ RSA-MD5 _ cert_alice. filestamp, and soft links. Copy both
280 files to all group hosts; they replace the files which would be gener‐
281 ated in other schemes. On each host bob install a soft link from the
282 generic name ntpkey_host_bob to the host key file and soft link ntp‐
283 key_cert_bob to the private certificate file. Note the generic links
284 are on bob, but point to files generated by trusted host alice. In
285 this scheme it is not possible to refresh either the keys or certifi‐
286 cates without copying them to all other hosts in the group, and recre‐
287 ating the soft links.
288 For the IFF scheme proceed as in the TC scheme to generate keys and
290 certificates for all group hosts, then for every trusted host in the
291 group, generate the IFF parameter file. On trusted host alice run ntp-
292 keygen -T -I -p password to produce her parameter file ntpkey_IFF‐
293 par_alice.filestamp, which includes both server and client keys. Copy
294 this file to all group hosts that operate as both servers and clients
295 and install a soft link from the generic ntpkey_iff_alice to this file.
296 If there are no hosts restricted to operate only as clients, there is
297 nothing further to do. As the IFF scheme is independent of keys and
298 certificates, these files can be refreshed as needed.
299 If a rogue client has the parameter file, it could masquerade as a
301 legitimate server and present a middleman threat. To eliminate this
302 threat, the client keys can be extracted from the parameter file and
303 distributed to all restricted clients. After generating the parameter
304 file, on alice run ntp-keygen -e and pipe the output to a file or email
305 program. Copy or email this file to all restricted clients. On these
306 clients install a soft link from the generic ntpkey_iff_alice to this
307 file. To further protect the integrity of the keys, each file can be
308 encrypted with a secret password.
309 For the GQ scheme proceed as in the TC scheme to generate keys and cer‐
311 tificates for all group hosts, then for every trusted host in the
312 group, generate the IFF parameter file. On trusted host alice run ntp-
313 keygen -T -G -p password to produce her parameter file ntp‐
314 key_GQpar_alice.filestamp, which includes both server and client keys.
315 Copy this file to all group hosts and install a soft link from the
316 generic ntpkey_gq_alice to this file. In addition, on each host bob
317 install a soft link from generic ntpkey_gq_bob to this file. As the GQ
318 scheme updates the GQ parameters file and certificate at the same time,
319 keys and certificates can be regenerated as needed.
320 For the MV scheme, proceed as in the TC scheme to generate keys and
322 certificates for all group hosts. For illustration assume trish is the
323 TA, alice one of several trusted hosts and bob one of her clients. On
324 TA trish run ntp-keygen -V n -p password, where n is the number of
325 revokable keys (typically 5) to produce the parameter file ntp‐
326 keys_MVpar_trish.filestamp and client key files ntpkeys_MVkeyd _ trish.
327 filestamp where d is the key number (0 < d < n). Copy the parameter
328 file to alice and install a soft link from the generic ntpkey_mv_alice
329 to this file. Copy one of the client key files to alice for later dis‐
330 tribution to her clients. It does not matter which client key file
331 goes to alice, since they all work the same way. Alice copies the
332 client key file to all of her clients. On client bob install a soft
333 link from generic ntpkey_mvkey_bob to the client key file. As the MV
334 scheme is independent of keys and certificates, these files can be
335 refreshed as needed.
336 Command Line Options
338 -b --imbits= modulus
339 Set the number of bits in the identity modulus for generating
340 identity keys to modulus bits. The number of bits in the iden‐
341 tity modulus defaults to 256, but can be set to values from 256
342 to 2048 (32 to 256 octets). Use the larger moduli with caution,
343 as this can consume considerable computing resources and
344 increases the size of authenticated packets.
345 -c --certificate= scheme
347 Select certificate signature encryption/message digest scheme.
348 The scheme can be one of the following: RSA-MD2, RSA-MD5, RSA-
349 MDC2, RSA-SHA, RSA-SHA1, RSA-RIPEMD160, DSA-SHA, or DSA-SHA1.
350 Note that RSA schemes must be used with an RSA sign key and DSA
351 schemes must be used with a DSA sign key. The default without
352 this option is RSA-MD5. If compatibility with FIPS 140-2 is
353 required, either the DSA-SHA or DSA-SHA1 scheme must be used.
354 -C --cipher= cipher
356 Select the OpenSSL cipher to encrypt the files containing pri‐
357 vate keys. The default without this option is three-key triple
358 DES in CBC mode, des-ede3-cbc. The openssl -h command provided
359 with OpenSSL displays available ciphers.
360 -d --debug-level
362 Increase debugging verbosity level. This option displays the
363 cryptographic data produced in eye-friendly billboards.
364 -D --set-debug-level= level
366 Set the debugging verbosity to level. This option displays the
367 cryptographic data produced in eye-friendly billboards.
368 -e --id-key
370 Write the IFF or GQ public parameters from the IFFkey or GQkey
371 client keys file previously specified as unencrypted data to the
372 standard output stream stdout. This is intended for automatic
373 key distribution by email.
374 -G --gq-params
376 Generate a new encrypted GQ parameters and key file for the
377 Guillou-Quisquater (GQ) identity scheme. This option is mutu‐
378 ally exclusive with the -I and -V options.
379 -H --host-key
381 Generate a new encrypted RSA public/private host key file.
382 -I --iffkey
384 Generate a new encrypted IFF key file for the Schnorr (IFF)
385 identity scheme. This option is mutually exclusive with the -G
386 and Fl V options.
387 -i --ident= group
389 Set the optional Autokey group name to group. This is used in
390 the identity scheme parameter file names of IFF, GQ, and MV
391 client parameters files. In that role, the default is the host
392 name if no group is provided. The group name, if specified
393 using -i or -s following an ‘@@’ character, is also used in cer‐
394 tificate subject and issuer names in the form host @@ group and
395 should match the group specified via crypto ident or server
396 ident in the ntpd configuration file.
397 -l --lifetime= days
399 Set the lifetime for certificate expiration to days. The
400 default lifetime is one year (365 days).
401 -m --modulus= bits
403 Set the number of bits in the prime modulus for generating files
404 to bits. The modulus defaults to 512, but can be set from 256
405 to 2048 (32 to 256 octets). Use the larger moduli with caution,
406 as this can consume considerable computing resources and
407 increases the size of authenticated packets.
408 -M --md5key
410 Generate a new symmetric keys file containing 10 MD5 keys, and
411 if OpenSSL is available, 10 SHA keys. An MD5 key is a string of
412 20 random printable ASCII characters, while a SHA key is a
413 string of 40 random hex digits. The file can be edited using a
414 text editor to change the key type or key content. This option
415 is mutually exclusive with all other options.
416 -p --password= passwd
418 Set the password for reading and writing encrypted files to
419 passwd. These include the host, sign and identify key files.
420 By default, the password is the string returned by the Unix
421 hostname command.
422 -P --pvt-cert
424 Generate a new private certificate used by the PC identity
425 scheme. By default, the program generates public certificates.
426 Note: the PC identity scheme is not recommended for new instal‐
427 lations.
428 -q --export-passwd= passwd
430 Set the password for writing encrypted IFF, GQ and MV identity
431 files redirected to stdout to passwd. In effect, these files
432 are decrypted with the -p password, then encrypted with the -q
433 password. By default, the password is the string returned by
434 the Unix hostname command.
435 -s --subject-key= [host] [@@ group]
437 Specify the Autokey host name, where host is the optional host
438 name and group is the optional group name. The host name, and
439 if provided, group name are used in host @@ group form as cer‐
440 tificate subject and issuer. Specifying -s -@@ group is
441 allowed, and results in leaving the host name unchanged, as with
442 -i group. The group name, or if no group is provided, the host
443 name are also used in the file names of IFF, GQ, and MV identity
444 scheme client parameter files. If host is not specified, the
445 default host name is the string returned by the Unix hostname
446 command.
447 -S --sign-key= [RSA | DSA]
449 Generate a new encrypted public/private sign key file of the
450 specified type. By default, the sign key is the host key and
451 has the same type. If compatibility with FIPS 140-2 is
452 required, the sign key type must be DSA.
453 -T --trusted-cert
455 Generate a trusted certificate. By default, the program gener‐
456 ates a non-trusted certificate.
457 -V --mv-params nkeys
459 Generate nkeys encrypted server keys and parameters for the Mu-
460 Varadharajan (MV) identity scheme. This option is mutually
461 exclusive with the -I and -G options. Note: support for this
462 option should be considered a work in progress.
463 Random Seed File
465 All cryptographically sound key generation schemes must have means to
466 randomize the entropy seed used to initialize the internal pseudo-ran‐
467 dom number generator used by the library routines. The OpenSSL library
468 uses a designated random seed file for this purpose. The file must be
469 available when starting the NTP daemon and ntp-keygen program. If a
470 site supports OpenSSL or its companion OpenSSH, it is very likely that
471 means to do this are already available.
472 It is important to understand that entropy must be evolved for each
474 generation, for otherwise the random number sequence would be pre‐
475 dictable. Various means dependent on external events, such as key‐
476 stroke intervals, can be used to do this and some systems have built-in
477 entropy sources. Suitable means are described in the OpenSSL software
478 documentation, but are outside the scope of this page.
479 The entropy seed used by the OpenSSL library is contained in a file,
481 usually called .rnd, which must be available when starting the NTP dae‐
482 mon or the ntp-keygen program. The NTP daemon will first look for the
483 file using the path specified by the randfile subcommand of the crypto
484 configuration command. If not specified in this way, or when starting
485 the ntp-keygen program, the OpenSSL library will look for the file
486 using the path specified by the RANDFILE environment variable in the
487 user home directory, whether root or some other user. If the RANDFILE
488 environment variable is not present, the library will look for the .rnd
489 file in the user home directory. Since both the ntp-keygen program and
490 ntpd(8) daemon must run as root, the logical place to put this file is
491 in /.rnd or /root/.rnd. If the file is not available or cannot be
492 written, the daemon exits with a message to the system log and the pro‐
493 gram exits with a suitable error message.
494 Cryptographic Data Files
496 All file formats begin with two nonencrypted lines. The first line
497 contains the file name, including the generated host name and
498 filestamp, in the format ntpkey_key _ name. filestamp, where key is the
499 key or parameter type, name is the host or group name and filestamp is
500 the filestamp (NTP seconds) when the file was created. By convention,
501 key names in generated file names include both upper and lower case
502 characters, while key names in generated link names include only lower
503 case characters. The filestamp is not used in generated link names.
504 The second line contains the datestamp in conventional Unix date for‐
505 mat. Lines beginning with ‘#’ are considered comments and ignored by
506 the ntp-keygen program and ntpd(8) daemon.
507 The remainder of the file contains cryptographic data, encoded first
509 using ASN.1 rules, then encrypted if necessary, and finally written in
510 PEM-encoded printable ASCII text, preceded and followed by MIME content
511 identifier lines.
512 The format of the symmetric keys file, ordinarily named ntp.keys, is
514 somewhat different than the other files in the interest of backward
515 compatibility. Ordinarily, the file is generated by this program, but
516 it can be constructed and edited using an ordinary text editor.
517 # ntpkey_MD5key_bk.ntp.org.3595864945
518 # Thu Dec 12 19:22:25 2013
519 1 MD5 L";Nw<`.I<f4U0)247"i # MD5 key
520 2 MD5 &>l0%XXK9O'51VwV<xq~ # MD5 key
521 3 MD5 lb4zLW~d^!K:]RsD'qb6 # MD5 key
522 4 MD5 Yue:tL[+vR)M`n~bY,'? # MD5 key
523 5 MD5 B;fx'Kgr/&4ZTbL6=RxA # MD5 key
524 6 MD5 4eYwa`o}3i@@@@V@@..R9!l # MD5 key
525 7 MD5 `A.([h+;wTQ|xfi%Sn_! # MD5 key
526 8 MD5 45:V,r4]l6y^JH6"Sh?F # MD5 key
527 9 MD5 3-5vcn*6l29DS?Xdsg)* # MD5 key
528 10 MD5 2late4Me # MD5 key
529 11 SHA1 a27872d3030a9025b8446c751b4551a7629af65c # SHA1 key
530 12 SHA1 21bc3b4865dbb9e920902abdccb3e04ff97a5e74 # SHA1 key
531 13 SHA1 2b7736fe24fef5ba85ae11594132ab5d6f6daba9 # SHA1 key
532 14 SHA a5332809c8878dd3a5b918819108a111509aeceb # SHA key
533 15 MD2 2fe16c88c760ff2f16d4267e36c1aa6c926e6964 # MD2 key
534 16 MD4 b2691811dc19cfc0e2f9bcacd74213f29812183d # MD4 key
535 17 MD5 e4d6735b8bdad58ec5ffcb087300a17f7fef1f7c # MD5 key
536 18 MDC2 a8d5e2315c025bf3a79174c87fbd10477de2eabc # MDC2 key
537 19 RIPEMD160 77ca332cafb30e3cafb174dcd5b80ded7ba9b3d2 # RIPEMD160 key
538 20 AES128CMAC f92ff73eee86c1e7dc638d6489a04e4e555af878 # AES128CMAC key
539 Figure 1. Typical Symmetric Key File
540 Figure 1 shows a typical symmetric keys file used by the reference
542 implementation. Following the header the keys are entered one per line
543 in the format
544 keyno type key
545 where keyno is a positive integer in the range 1-65535; type is the key
546 type for the message digest algorithm, which in the absence of the
547 OpenSSL library must be MD5 to designate the MD5 message digest algo‐
548 rithm; if the OpenSSL library is installed, the key type can be any
549 message digest algorithm supported by that library; however, if compat‐
550 ibility with FIPS 140-2 is required, the key type must be either SHA or
551 SHA1; key is the key itself, which is a printable ASCII string 20 char‐
552 acters or less in length: each character is chosen from the 93 print‐
553 able characters in the range 0x21 through 0x7e ( ‘’! through ‘~’ )
554 excluding space and the ‘#’ character, and terminated by whitespace or
555 a ‘#’ character. An OpenSSL key consists of a hex-encoded ASCII string
556 of 40 characters, which is truncated as necessary.
557 Note that the keys used by the ntpq(8) and ntpdc(8) programs are
559 checked against passwords requested by the programs and entered by
560 hand, so it is generally appropriate to specify these keys in human
561 readable ASCII format.
562 The ntp-keygen program generates a symmetric keys file ntp‐
564 key_MD5key_hostname. filestamp. Since the file contains private shared
565 keys, it should be visible only to root and distributed by secure means
566 to other subnet hosts. The NTP daemon loads the file ntp.keys, so ntp-
567 keygen installs a soft link from this name to the generated file. Sub‐
568 sequently, similar soft links must be installed by manual or automated
569 means on the other subnet hosts. While this file is not used with the
570 Autokey Version 2 protocol, it is needed to authenticate some remote
571 configuration commands used by the ntpq(8) and ntpdc(8) utilities.
572
574 -b imbits, --imbits=imbits
575 identity modulus bits. This option takes an integer number as
576 its argument. The value of imbits is constrained to being:
577 in the range 256 through 2048
578 The number of bits in the identity modulus. The default is 256.
580 -c scheme, --certificate=scheme
582 certificate scheme.
583 scheme is one of RSA-MD2, RSA-MD5, RSA-MDC2, RSA-SHA, RSA-SHA1,
585 RSA-RIPEMD160, DSA-SHA, or DSA-SHA1.
586 Select the certificate signature encryption/message digest
588 scheme. Note that RSA schemes must be used with a RSA sign key
589 and DSA schemes must be used with a DSA sign key. The default
590 without this option is RSA-MD5.
591 -C cipher, --cipher=cipher
593 privatekey cipher.
594 Select the cipher which is used to encrypt the files containing
596 private keys. The default is three-key triple DES in CBC mode,
597 equivalent to "-C des-ede3-cbc". The openssl tool lists ciphers
598 available in "openssl -h" output.
599 -d, --debug-level
601 Increase debug verbosity level. This option may appear an
602 unlimited number of times.
603 -D number, --set-debug-level=number
606 Set the debug verbosity level. This option may appear an unlim‐
607 ited number of times. This option takes an integer number as
608 its argument.
609 -e, --id-key
612 Write IFF or GQ identity keys.
613 Write the public parameters from the IFF or GQ client keys to
615 the standard output. This is intended for automatic key distri‐
616 bution by email.
617 -G, --gq-params
619 Generate GQ parameters and keys.
620 Generate parameters and keys for the GQ identification scheme,
622 obsoleting any that may exist.
623 -H, --host-key
625 generate RSA host key.
626 Generate new host keys, obsoleting any that may exist.
628 -I, --iffkey
630 generate IFF parameters.
631 Generate parameters for the IFF identification scheme, obsolet‐
633 ing any that may exist.
634 -i group, --ident=group
636 set Autokey group name.
637 Set the optional Autokey group name to name. This is used in
639 the file name of IFF, GQ, and MV client parameters files. In
640 that role, the default is the host name if this option is not
641 provided. The group name, if specified using -i/--ident or
642 using -s/--subject-name following an '@@' character, is also a
643 part of the self-signed host certificate subject and issuer
644 names in the form host@@group and should match the ntpd configu‐
645 ration file.
646 -l lifetime, --lifetime=lifetime
648 set certificate lifetime. This option takes an integer number
649 as its argument.
650 Set the certificate expiration to lifetime days from now.
652 -m modulus, --modulus=modulus
654 prime modulus. This option takes an integer number as its argu‐
655 ment. The value of modulus is constrained to being:
656 in the range 256 through 2048
657 The number of bits in the prime modulus. The default is 512.
659 -M, --md5key
661 generate symmetric keys.
662 Generate symmetric keys, obsoleting any that may exist.
664 -P, --pvt-cert
666 generate PC private certificate.
667 Generate a private certificate. By default, the program gener‐
669 ates public certificates.
670 -p passwd, --password=passwd
672 local private password.
673 Local files containing private data are encrypted with the DES-
675 CBC algorithm and the specified password. The same password
676 must be specified to the local ntpd via the "crypto pw password"
677 configuration command. The default password is the local host‐
678 name.
679 -q passwd, --export-passwd=passwd
681 export IFF or GQ group keys with password.
682 Export IFF or GQ identity group keys to the standard output,
684 encrypted with the DES-CBC algorithm and the specified password.
685 The same password must be specified to the remote ntpd via the
686 "crypto pw password" configuration command. See also the option
687 --id-key (-e) for unencrypted exports.
688 -s host@group, --subject-name=host@group
690 set host and optionally group name.
691 Set the Autokey host name, and optionally, group name specified
693 following an '@@' character. The host name is used in the file
694 name of generated host and signing certificates, without the
695 group name. The host name, and if provided, group name are used
696 in host@@group form for the host certificate subject and issuer
697 fields. Specifying '-s @@group' is allowed, and results in
698 leaving the host name unchanged while appending @@group to the
699 subject and issuer fields, as with -i group. The group name, or
700 if not provided, the host name are also used in the file names
701 of IFF, GQ, and MV client parameter files.
702 -S sign, --sign-key=sign
704 generate sign key (RSA or DSA).
705 Generate a new sign key of the designated type, obsoleting any
707 that may exist. By default, the program uses the host key as
708 the sign key.
709 -T, --trusted-cert
711 trusted certificate (TC scheme).
712 Generate a trusted certificate. By default, the program gener‐
714 ates a non-trusted certificate.
715 -V num, --mv-params=num
717 generate <num> MV parameters. This option takes an integer num‐
718 ber as its argument.
719 Generate parameters and keys for the Mu-Varadharajan (MV) iden‐
721 tification scheme.
722 -v num, --mv-keys=num
724 update <num> MV keys. This option takes an integer number as
725 its argument.
726 This option has not been fully documented.
728 -?, --help
730 Display usage information and exit.
731 -!, --more-help
733 Pass the extended usage information through a pager.
734 -> [cfgfile], --save-opts [=cfgfile]
736 Save the option state to cfgfile. The default is the last con‐
737 figuration file listed in the OPTION PRESETS section, below.
738 The command will exit after updating the config file.
739 -< cfgfile, --load-opts=cfgfile, --no-load-opts
741 Load options from cfgfile. The no-load-opts form will disable
742 the loading of earlier config/rc/ini files. --no-load-opts is
743 handled early, out of order.
744 --version [{v|c|n}]
746 Output version of program and exit. The default mode is `v', a
747 simple version. The `c' mode will print copyright information
748 and `n' will print the full copyright notice.
749
751 Any option that is not marked as not presettable may be preset by load‐
752 ing values from configuration ("RC" or ".INI") file(s) and values from
753 environment variables named:
754 NTP_KEYGEN_<option-name> or NTP_KEYGEN
755 The environmental presets take precedence (are processed later than)
756 the configuration files. The homerc files are "$HOME", and ".". If
757 any of these are directories, then the file .ntprc is searched for
758 within those directories.
759
762 See OPTION PRESETS for configuration environment variables.
763
765 See OPTION PRESETS for configuration files.
766
768 One of the following exit values will be returned:
769 0 (EXIT_SUCCESS)
771 Successful program execution.
772 1 (EXIT_FAILURE)
774 The operation failed or the command syntax was not valid.
775 66 (EX_NOINPUT)
777 A specified configuration file could not be loaded.
778 70 (EX_SOFTWARE)
780 libopts had an internal operational error. Please report it to
781 autogen-users@lists.sourceforge.net. Thank you.
782
784 The University of Delaware and Network Time Foundation
785
787 Copyright (C) 1992-2017 The University of Delaware and Network Time
788 Foundation all rights reserved. This program is released under the
789 terms of the NTP license, <http://ntp.org/license>.
790
792 It can take quite a while to generate some cryptographic values.
793 Please report bugs to http://bugs.ntp.org .
795 Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
797
799 Portions of this document came from FreeBSD.
800 This manual page was AutoGen-erated from the ntp-keygen option defini‐
802 tions.
803ntp (4.2.8p13) 20 Feb 2019 ntp-keygen(8)