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NTP_KEYGEN(8)		     System Manager's Manual		   NTP_KEYGEN(8)

NAME
     ntp-keygen -- Create a NTP host key

SYNOPSIS
     ntp-keygen [-flags] [-flag [value]] [--option-name[[=| ]value]]

		All arguments must be options.

DESCRIPTION
     This program generates cryptographic data files used by the NTPv4 authenti-
     cation  and  identification  schemes.   It can generate message digest keys
     used in symmetric key cryptography and, if the OpenSSL software library has
     been installed, it can generate host keys, signing keys, certificates,  and
     identity  keys  and  parameters  used  in	Autokey public key cryptography.
     These files are used for cookie encryption, digital  signature,  and  chal-
     lenge/response identification algorithms compatible with the Internet stan-
     dard security infrastructure.

     The  message digest symmetric keys file is generated in a format compatible
     with NTPv3.  All other files are in PEM-encoded printable ASCII format,  so
     they  can	be embedded as MIME attachments in email to other sites and cer-
     tificate authorities.  By default, files are not encrypted.

     When used to generate message digest symmetric keys, the program produces a
     file containing ten pseudo-random printable ASCII strings suitable for  the
     MD5  message digest algorithm included in the distribution.  If the OpenSSL
     library is installed, it produces an additional ten hex-encoded random  bit
     strings  suitable	for  SHA1,  AES-128-CMAC, and other message digest algo-
     rithms.  The message digest symmetric keys file  must  be	distributed  and
     stored using secure means beyond the scope of NTP itself.	Besides the keys
     used for ordinary NTP associations, additional keys can be defined as pass-
     words for the ntpq(8) and ntpdc(8) utility programs.

     The  remaining  generated	files are compatible with other OpenSSL applica-
     tions and other Public Key Infrastructure	(PKI)  resources.   Certificates
     generated by this program are compatible with extant industry practice, al-
     though  some users might find the interpretation of X509v3 extension fields
     somewhat liberal.	However, the identity keys are probably  not  compatible
     with anything other than Autokey.

     Some  files  used	by  this program are encrypted using a private password.
     The -p option specifies the read password for local encrypted files and the
     -q option the write password for encrypted files sent to remote sites.   If
     no  password  is  specified, the host name returned by the Unix hostname(1)
     command, normally the DNS name of the host, is used as the the default read
     password, for convenience.  The ntp-keygen program prompts for the password
     if it reads an encrypted file and the password is missing or incorrect.  If
     an encrypted file is read successfully and no write password is  specified,
     the read password is used as the write password by default.

     The  pw  option  of  the crypto ntpd(8) configuration command specifies the
     read password for previously encrypted local files.  This	must  match  the
     local  read password used by this program.  If not specified, the host name
     is used.  Thus, if files are generated by this program without an	explicit
     password,	they  can be read back by ntpd(8) without specifying an explicit
     password but only on the same host.  If the write password used for encryp-
     tion is specified as the host name, these files can be read  by  that  host
     with no explicit password.

     Normally, encrypted files for each host are generated by that host and used
     only  by  that host, although exceptions exist as noted later on this page.
     The symmetric keys file, normally called ntp.keys, is usually installed  in
     /etc.  Other files and links are usually installed in /usr/local/etc, which
     is  normally  in  a shared filesystem in NFS-mounted networks and cannot be
     changed by shared clients.  In these cases, NFS  clients  can  specify  the
     files  in another directory such as /etc using the keysdir ntpd(8) configu-
     ration file command.

     This program directs commentary and error messages to  the  standard  error
     stream  stderr  and remote files to the standard output stream stdout where
     they can be piped to other applications or redirected to files.  The  names
     used  for	generated  files and links all begin with the string ntpkey* and
     include the file type, generating host and filestamp, as described  in  the
     "Cryptographic Data Files" section below.

   Running the Program
     The safest way to run the ntp-keygen program is logged in directly as root.
     The  recommended  procedure  is  change  to  the  keys  directory,  usually
     /usr/local/etc, then run the program.

     To test and gain experience with Autokey  concepts,  log  in  as  root  and
     change  to  the  keys  directory, usually /usr/local/etc.	When run for the
     first time, or if all files with names beginning with ntpkey* have been re-
     moved, use the ntp-keygen command without arguments to generate  a  default
     RSA host key and matching RSA-MD5 certificate file with expiration date one
     year hence, which is all that is necessary in many cases.	The program also
     generates	soft  links  from the generic names to the respective files.  If
     run again without options, the program uses the existing keys  and  parame-
     ters and generates a new certificate file with new expiration date one year
     hence, and soft link.

     The host key is used to encrypt the cookie when required and so must be RSA
     type.  By default, the host key is also the sign key used to encrypt signa-
     tures.   When necessary, a different sign key can be specified and this can
     be either RSA or DSA type.  By default, the message digest type is MD5, but
     any combination of sign key type and message digest type supported  by  the
     OpenSSL  library  can  be	specified, including those using the AES128CMAC,
     MD2, MD5, MDC2, SHA, SHA1 and RIPE160 message digest algorithms.	However,
     the  scheme  specified  in the certificate must be compatible with the sign
     key.  Certificates using any digest algorithm are compatible with RSA  sign
     keys;  however, only SHA and SHA1 certificates are compatible with DSA sign
     keys.

     Private/public key files and certificates are compatible with other OpenSSL
     applications and very likely other libraries as well.  Certificates or cer-
     tificate requests derived from them should be compatible with extant indus-
     try practice, although some users might find the interpretation  of  X509v3
     extension	fields	somewhat liberal.  However, the identification parameter
     files, although encoded as the other files,  are  probably  not  compatible
     with anything other than Autokey.

     Running  the program as other than root and using the Unix su(1) command to
     assume root may not work properly, since by  default  the	OpenSSL  library
     looks  for  the random seed file .rnd in the user home directory.	However,
     there should be only one .rnd, most conveniently in the root directory,  so
     it  is  convenient  to define the RANDFILE environment variable used by the
     OpenSSL library as the path to .rnd.

     Installing the keys as root might not work in NFS-mounted shared file  sys-
     tems, as NFS clients may not be able to write to the shared keys directory,
     even  as  root.  In this case, NFS clients can specify the files in another
     directory such as /etc using the keysdir ntpd(8)  configuration  file  com-
     mand.  There is no need for one client to read the keys and certificates of
     other  clients  or servers, as these data are obtained automatically by the
     Autokey protocol.

     Ordinarily, cryptographic files are generated by the host that  uses  them,
     but  it  is  possible  for a trusted agent (TA) to generate these files for
     other hosts; however, in such cases files should always be encrypted.   The
     subject  name and trusted name default to the hostname of the host generat-
     ing the files, but can be changed by command line options.   It  is  conve-
     nient  to	designate the owner name and trusted name as the subject and is-
     suer fields, respectively, of the certificate.  The owner name is also used
     for the host and sign key files, while the trusted name  is  used	for  the
     identity files.

     All  files  are  installed by default in the keys directory /usr/local/etc,
     which is normally in a shared filesystem in NFS-mounted networks.	The  ac-
     tual location of the keys directory and each file can be overridden by con-
     figuration  commands, but this is not recommended.  Normally, the files for
     each host are generated by that host and used only by that  host,	although
     exceptions exist as noted later on this page.

     Normally, files containing private values, including the host key, sign key
     and  identification  parameters,  are permitted root read/write-only; while
     others containing public values are  permitted  world  readable.	Alterna-
     tively,  files  containing  private values can be encrypted and these files
     permitted world readable, which simplifies maintenance in shared file  sys-
     tems.   Since uniqueness is insured by the hostname and filestamp file name
     extensions, the files for an NTP server and dependent clients  can  all  be
     installed in the same shared directory.

     The  recommended  practice  is  to  keep  the file name extensions when in-
     stalling a file and to install a soft link from the generic names specified
     elsewhere on this page to the generated files.  This allows new file gener-
     ations to be activated simply by changing the link.  If a link is	present,
     ntpd(8) follows it to the file name to extract the filestamp.  If a link is
     not present, ntpd(8) extracts the filestamp from the file itself.	This al-
     lows  clients  to verify that the file and generation times are always cur-
     rent.  The ntp-keygen program uses the same  filestamp  extension	for  all
     files  generated  at  one	time,  so each generation is distinct and can be
     readily recognized in monitoring data.

     Run the command on as many hosts as necessary.  Designate one  of	them  as
     the  trusted host (TH) using ntp-keygen with the -T option and configure it
     to synchronize from reliable Internet servers.  Then  configure  the  other
     hosts to synchronize to the TH directly or indirectly.  A certificate trail
     is  created when Autokey asks the immediately ascendant host towards the TH
     to sign its certificate, which is then provided to the immediately  descen-
     dant  host  on  request.	All  group hosts should have acyclic certificate
     trails ending on the TH.

     The host key is used to encrypt the cookie when required and so must be RSA
     type.  By default, the host key is also the sign key used to encrypt signa-
     tures.  A different sign key can be assigned using the -S option  and  this
     can  be  either  RSA or DSA type.	By default, the signature message digest
     type is MD5, but any combination of sign key type and message  digest  type
     supported by the OpenSSL library can be specified using the -c option.

     The  rules say cryptographic media should be generated with proventic file-
     stamps, which means the host should already  be  synchronized  before  this
     program  is run.  This of course creates a chicken-and-egg problem when the
     host is started for the first time.  Accordingly, the host time  should  be
     set  by  some other means, such as eyeball-and-wristwatch, at least so that
     the certificate lifetime is within the current year.  After that  and  when
     the  host	is synchronized to a proventic source, the certificate should be
     re-generated.

     Additional information on trusted groups and identity  schemes  is  on  the
     "Autokey Public-Key Authentication" page.

     File names begin with the prefix ntpkey_ and end with the suffix _hostname.
     filestamp, where hostname is the owner name, usually the string returned by
     the  Unix	hostname(1)  command,  and filestamp is the NTP seconds when the
     file was generated, in decimal digits.  This both guarantees uniqueness and
     simplifies maintenance procedures, since all files can be	quickly  removed
     by  a  rm	ntpkey* command or all files generated at a specific time can be
     removed by a rm *filestamp command.  To further reduce the risk of  miscon-
     figuration, the first two lines of a file contain the file name and genera-
     tion date and time as comments.

   Trusted Hosts and Groups
     Each  cryptographic  configuration involves selection of a signature scheme
     and identification  scheme,  called  a  cryptotype,  as  explained  in  the
     "Authentication  Options"	section  of ntp.conf(5).  The default cryptotype
     uses RSA encryption, MD5 message digest and TC identification.  First, con-
     figure a NTP subnet including one or more low-stratum  trusted  hosts  from
     which  all  other	hosts  derive  synchronization	directly  or indirectly.
     Trusted hosts have trusted certificates; all other  hosts	have  nontrusted
     certificates.  These hosts will automatically and dynamically build author-
     itative  certificate  trails to one or more trusted hosts.  A trusted group
     is the set of all hosts that have, directly or  indirectly,  a  certificate
     trail  ending at a trusted host.  The trail is defined by static configura-
     tion file	entries  or  dynamic  means  described	on  the  "Automatic  NTP
     Configuration Options" section of ntp.conf(5).

     On  each  trusted	host as root, change to the keys directory.  To insure a
     fresh fileset, remove all ntpkey files.  Then run ntp-keygen -T to generate
     keys and a trusted certificate.  On all other hosts do the same, but  leave
     off  the  -T  flag to generate keys and nontrusted certificates.  When com-
     plete, start the NTP daemons beginning at the lowest stratum and working up
     the tree.	It may take some time for Autokey to instantiate the certificate
     trails throughout the subnet, but setting up the environment is  completely
     automatic.

     If  it  is necessary to use a different sign key or different digest/signa-
     ture scheme than the default, run ntp-keygen with the -S type option, where
     type is either RSA or DSA.  The most frequent need to do  this  is  when  a
     DSA-signed certificate is used.  If it is necessary to use a different cer-
     tificate  scheme than the default, run ntp-keygen with the -c scheme option
     and selected scheme as needed.  If ntp-keygen is run  again  without  these
     options, it generates a new certificate using the same scheme and sign key,
     and soft link.

     After  setting  up  the  environment it is advisable to update certificates
     from time to time, if only to extend the  validity  interval.   Simply  run
     ntp-keygen with the same flags as before to generate new certificates using
     existing  keys,  and  soft  links.   However,  if	the  host or sign key is
     changed, ntpd(8) should be restarted.  When ntpd(8) is restarted, it  loads
     any  new  files and restarts the protocol.  Other dependent hosts will con-
     tinue as usual until signatures are refreshed, at which time  the	protocol
     is restarted.

   Identity Schemes
     As mentioned on the Autonomous Authentication page, the default TC identity
     scheme is vulnerable to a middleman attack.  However, there are more secure
     identity  schemes available, including PC, IFF, GQ and MV schemes described
     below.  These schemes are based on a TA, one or more trusted hosts and some
     number of nontrusted hosts.  Trusted hosts prove identity using values pro-
     vided by the TA, while the remaining hosts prove identity using values pro-
     vided by a trusted host and certificate trails that end on that host.   The
     name of a trusted host is also the name of its sugroup and also the subject
     and  issuer  name	on its trusted certificate.  The TA is not necessarily a
     trusted host in this sense, but often is.

     In some schemes there are separate keys for servers and clients.  A  server
     can  also be a client of another server, but a client can never be a server
     for another client.  In general, trusted hosts and  nontrusted  hosts  that
     operate  as  both	server and client have parameter files that contain both
     server and client keys.  Hosts that operate only as clients have key  files
     that contain only client keys.

     The PC scheme supports only one trusted host in the group.  On trusted host
     alice  run  ntp-keygen -P -p password to generate the host key file ntpkey_
     RSA key_alice. filestamp  and  trusted  private  certificate  file  ntpkey_
     RSA-MD5  _  cert_alice.  filestamp, and soft links.  Copy both files to all
     group hosts; they replace the files  which  would	be  generated  in  other
     schemes.	On  each  host	bob  install  a  soft link from the generic name
     ntpkey_host_bob to the host key file and soft link ntpkey_cert_bob  to  the
     private  certificate file.  Note the generic links are on bob, but point to
     files generated by trusted host alice.  In this scheme it is  not	possible
     to  refresh  either  the  keys  or certificates without copying them to all
     other hosts in the group, and recreating the soft links.

     For the IFF scheme proceed as in the TC scheme to generate  keys  and  cer-
     tificates	for  all  group hosts, then for every trusted host in the group,
     generate the IFF parameter file.  On trusted host alice run  ntp-keygen  -T
     -I -p password to produce her parameter file ntpkey_IFFpar_alice.filestamp,
     which  includes  both  server and client keys.  Copy this file to all group
     hosts that operate as both servers and clients and install a soft link from
     the generic ntpkey_iff_alice to this file.   If  there  are  no  hosts  re-
     stricted  to  operate  only as clients, there is nothing further to do.  As
     the IFF scheme is independent of keys and certificates, these files can  be
     refreshed as needed.

     If  a rogue client has the parameter file, it could masquerade as a legiti-
     mate server and present a middleman threat.  To eliminate this threat,  the
     client keys can be extracted from the parameter file and distributed to all
     restricted  clients.   After  generating  the  parameter file, on alice run
     ntp-keygen -e and pipe the output to a file  or  email  program.	Copy  or
     email this file to all restricted clients.  On these clients install a soft
     link  from  the  generic ntpkey_iff_alice to this file.  To further protect
     the integrity of the keys, each file can be encrypted with a  secret  pass-
     word.

     For the GQ scheme proceed as in the TC scheme to generate keys and certifi-
     cates for all group hosts, then for every trusted host in the group, gener-
     ate  the IFF parameter file.  On trusted host alice run ntp-keygen -T -G -p
     password to produce her parameter file ntpkey_GQpar_alice.filestamp,  which
     includes  both  server  and client keys.  Copy this file to all group hosts
     and install a soft link from the generic ntpkey_gq_alice to this file.   In
     addition,	on  each host bob install a soft link from generic ntpkey_gq_bob
     to this file.  As the GQ scheme updates the GQ parameters file and certifi-
     cate at the same time, keys and certificates can be regenerated as needed.

     For the MV scheme, proceed as in the TC scheme to generate  keys  and  cer-
     tificates	for  all  group hosts.	For illustration assume trish is the TA,
     alice one of several trusted hosts and bob one of her clients.  On TA trish
     run ntp-keygen -V n -p password, where n is the number  of  revokable  keys
     (typically  5)  to produce the parameter file ntpkeys_MVpar_trish.filestamp
     and client key files ntpkeys_MVkeyd _ trish. filestamp where d is	the  key
     number  (0  <  d < n).  Copy the parameter file to alice and install a soft
     link from the generic ntpkey_mv_alice to this file.  Copy one of the client
     key files to alice for later distribution to her clients.	It does not mat-
     ter which client key file goes to alice, since they all work the same  way.
     Alice  copies the client key file to all of her clients.  On client bob in-
     stall a soft link from generic ntpkey_mvkey_bob to the client key file.  As
     the MV scheme is independent of keys and certificates, these files  can  be
     refreshed as needed.

   Command Line Options
     -b --imbits= modulus
	     Set the number of bits in the identity modulus for generating iden-
	     tity keys to modulus bits.  The number of bits in the identity mod-
	     ulus defaults to 256, but can be set to values from 256 to 2048 (32
	     to  256  octets).	 Use the larger moduli with caution, as this can
	     consume considerable computing resources and increases the size  of
	     authenticated packets.

     -c --certificate= scheme
	     Select certificate signature encryption/message digest scheme.  The
	     scheme  can  be  one  of the following: RSA-MD2, RSA-MD5, RSA-MDC2,
	     RSA-SHA, RSA-SHA1, RSA-RIPEMD160, DSA-SHA, or DSA-SHA1.  Note  that
	     RSA  schemes must be used with an RSA sign key and DSA schemes must
	     be used with a DSA sign key.  The default without	this  option  is
	     RSA-MD5.	If compatibility with FIPS 140-2 is required, either the
	     DSA-SHA or DSA-SHA1 scheme must be used.

     -C --cipher= cipher
	     Select the OpenSSL cipher to encrypt the files  containing  private
	     keys.   The  default without this option is three-key triple DES in
	     CBC mode, des-ede3-cbc.   The  openssl  -h  command  provided  with
	     OpenSSL displays available ciphers.

     -d --debug-level
	     Increase debugging verbosity level.  This option displays the cryp-
	     tographic data produced in eye-friendly billboards.

     -D --set-debug-level= level
	     Set  the  debugging  verbosity  to level.	This option displays the
	     cryptographic data produced in eye-friendly billboards.

     -e --id-key
	     Write the IFF or GQ public parameters  from  the  IFFkey  or  GQkey
	     client  keys  file  previously specified as unencrypted data to the
	     standard output stream stdout.  This is intended for automatic  key
	     distribution by email.

     -G --gq-params
	     Generate  a  new encrypted GQ parameters and key file for the Guil-
	     lou-Quisquater (GQ) identity scheme.  This option is  mutually  ex-
	     clusive with the -I and -V options.

     -H --host-key
	     Generate a new encrypted RSA public/private host key file.

     -I --iffkey
	     Generate  a  new encrypted IFF key file for the Schnorr (IFF) iden-
	     tity scheme.  This option is mutually exclusive with the -G and  Fl
	     V options.

     -i --ident= group
	     Set  the optional Autokey group name to group.  This is used in the
	     identity scheme parameter file names of IFF, GQ, and MV client  pa-
	     rameters  files.	In that role, the default is the host name if no
	     group is provided.  The group name, if specified  using  -i  or  -s
	     following an `@' character, is also used in certificate subject and
	     issuer  names  in	the form host @ group and should match the group
	     specified via crypto ident or server ident in the	ntpd  configura-
	     tion file.

     -l --lifetime= days
	     Set  the  lifetime for certificate expiration to days.  The default
	     lifetime is one year (365 days).

     -m --modulus= bits
	     Set the number of bits in the prime modulus for generating files to
	     bits.  The modulus defaults to 512, but can be set from 256 to 2048
	     (32 to 256 octets).  Use the larger moduli with  caution,	as  this
	     can consume considerable computing resources and increases the size
	     of authenticated packets.

     -M --md5key
	     Generate  a  new symmetric keys file containing 10 MD5 keys, and if
	     OpenSSL is available, 10 SHA keys.  An MD5 key is a  string  of  20
	     random  printable	ASCII characters, while a SHA key is a string of
	     40 random hex digits.  The file can be edited using a  text  editor
	     to change the key type or key content.  This option is mutually ex-
	     clusive with all other options.

     -p --password= passwd
	     Set the password for reading and writing encrypted files to passwd.
	     These  include  the host, sign and identify key files.  By default,
	     the password is the string returned by the Unix hostname command.

     -P --pvt-cert
	     Generate a new private certificate used by the PC identity  scheme.
	     By  default,  the program generates public certificates.  Note: the
	     PC identity scheme is not recommended for new installations.

     -q --export-passwd= passwd
	     Set the password for writing encrypted  IFF,  GQ  and  MV	identity
	     files  redirected	to stdout to passwd.  In effect, these files are
	     decrypted with the -p password, then encrypted with  the  -q  pass-
	     word.   By default, the password is the string returned by the Unix
	     hostname command.

     -s --subject-key= file ... [host] [@ group]
	     Specify the Autokey host name, where host is the optional host name
	     and group is the optional group name.  The host name, and	if  pro-
	     vided, group name are used in host @ group form as certificate sub-
	     ject and issuer.  Specifying -s -@ group is allowed, and results in
	     leaving the host name unchanged, as with -i group.  The group name,
	     or if no group is provided, the host name are also used in the file
	     names  of	IFF,  GQ, and MV identity scheme client parameter files.
	     If host is not specified, the default host name is the  string  re-
	     turned by the Unix hostname command.

     -S --sign-key= [RSA | DSA]
	     Generate a new encrypted public/private sign key file of the speci-
	     fied  type.   By  default, the sign key is the host key and has the
	     same type.  If compatibility with FIPS 140-2 is required, the  sign
	     key type must be DSA.

     -T --trusted-cert
	     Generate  a trusted certificate.  By default, the program generates
	     a non-trusted certificate.

     -V --mv-params nkeys
	     Generate  nkeys  encrypted  server  keys  and  parameters	for  the
	     Mu-Varadharajan  (MV) identity scheme.  This option is mutually ex-
	     clusive with the -I and -G options.  Note: support for this  option
	     should be considered a work in progress.

   Random Seed File
     All  cryptographically sound key generation schemes must have means to ran-
     domize the entropy seed used to initialize the internal pseudo-random  num-
     ber  generator  used  by  the library routines.  The OpenSSL library uses a
     designated random seed file for this purpose.  The file must  be  available
     when  starting  the  NTP daemon and ntp-keygen program.  If a site supports
     OpenSSL or its companion OpenSSH, it is very likely that means to	do  this
     are already available.

     It is important to understand that entropy must be evolved for each genera-
     tion, for otherwise the random number sequence would be predictable.  Vari-
     ous means dependent on external events, such as keystroke intervals, can be
     used  to  do this and some systems have built-in entropy sources.	Suitable
     means are described in the OpenSSL software documentation, but are  outside
     the scope of this page.

     The  entropy  seed used by the OpenSSL library is contained in a file, usu-
     ally called .rnd, which must be available when starting the NTP  daemon  or
     the  ntp-keygen program.  The NTP daemon will first look for the file using
     the path specified by the randfile subcommand of the  crypto  configuration
     command.	If  not  specified  in this way, or when starting the ntp-keygen
     program, the OpenSSL library will look for the file using the  path  speci-
     fied  by  the  RANDFILE  environment  variable  in the user home directory,
     whether root or some other user.  If the RANDFILE environment  variable  is
     not  present,  the library will look for the .rnd file in the user home di-
     rectory.  Since both the ntp-keygen program and ntpd(8) daemon must run  as
     root, the logical place to put this file is in /.rnd or /root/.rnd.  If the
     file is not available or cannot be written, the daemon exits with a message
     to the system log and the program exits with a suitable error message.

   Cryptographic Data Files
     All  file	formats  begin with two nonencrypted lines.  The first line con-
     tains the file name, including the generated host name  and  filestamp,  in
     the  format ntpkey_key _ name. filestamp, where key is the key or parameter
     type, name is the host or group name and filestamp is  the  filestamp  (NTP
     seconds)  when the file was created.  By convention, key names in generated
     file names include both upper and lower case characters, while key names in
     generated link names include only lower case characters.  The filestamp  is
     not  used	in generated link names.  The second line contains the datestamp
     in conventional Unix date format.	Lines beginning with `#' are  considered
     comments and ignored by the ntp-keygen program and ntpd(8) daemon.

     The  remainder of the file contains cryptographic data, encoded first using
     ASN.1 rules, then encrypted if necessary, and finally  written  in  PEM-en-
     coded  printable  ASCII text, preceded and followed by MIME content identi-
     fier lines.

     The format of the symmetric keys file, ordinarily named ntp.keys, is  some-
     what different than the other files in the interest of backward compatibil-
     ity.  Ordinarily, the file is generated by this program, but it can be con-
     structed and edited using an ordinary text editor.

			# ntpkey_MD5key_bk.ntp.org.3595864945
			# Thu Dec 12 19:22:25 2013
			1  MD5 L";Nw<`.I<f4U0)247"i  # MD5 key
			2  MD5 &>l0%XXK9O'51VwV<xq~  # MD5 key
			3  MD5 lb4zLW~d^!K:]RsD'qb6  # MD5 key
			4  MD5 Yue:tL[+vR)M`n~bY,'?  # MD5 key
			5  MD5 B;fx'Kgr/&4ZTbL6=RxA  # MD5 key
			6  MD5 4eYwa`o}3i@@V@..R9!l  # MD5 key
			7  MD5 `A.([h+;wTQ|xfi%Sn_!  # MD5 key
			8  MD5 45:V,r4]l6y^JH6"Sh?F  # MD5 key
			9  MD5 3-5vcn*6l29DS?Xdsg)*  # MD5 key
			10 MD5 2late4Me 	     # MD5 key
			11 SHA1 a27872d3030a9025b8446c751b4551a7629af65c  # SHA1 key
			12 SHA1 21bc3b4865dbb9e920902abdccb3e04ff97a5e74  # SHA1 key
			13 SHA1 2b7736fe24fef5ba85ae11594132ab5d6f6daba9  # SHA1 key
			14 SHA	a5332809c8878dd3a5b918819108a111509aeceb  # SHA  key
			15 MD2	2fe16c88c760ff2f16d4267e36c1aa6c926e6964  # MD2  key
			16 MD4	b2691811dc19cfc0e2f9bcacd74213f29812183d  # MD4  key
			17 MD5	e4d6735b8bdad58ec5ffcb087300a17f7fef1f7c  # MD5  key
			18 MDC2 a8d5e2315c025bf3a79174c87fbd10477de2eabc  # MDC2 key
			19 RIPEMD160 77ca332cafb30e3cafb174dcd5b80ded7ba9b3d2  # RIPEMD160 key
			20 AES128CMAC f92ff73eee86c1e7dc638d6489a04e4e555af878	# AES128CMAC key
	   Figure 1. Typical Symmetric Key File

     Figure  1	shows a typical symmetric keys file used by the reference imple-
     mentation.  Following the header the keys are entered one per line  in  the
     format
	   keyno type key
     where  keyno  is  a  positive integer in the range 1-65535; type is the key
     type for the message digest algorithm, which in the absence of the  OpenSSL
     library  must  be MD5 to designate the MD5 message digest algorithm; if the
     OpenSSL library is installed, the key type can be any message digest  algo-
     rithm  supported by that library; however, if compatibility with FIPS 140-2
     is required, the key type must be either SHA or SHA1; key is  the	key  it-
     self,  which  is  a printable ASCII string 20 characters or less in length:
     each character is chosen from the 93 printable characters in the range 0x21
     through 0x7e ( `'!  through `~' ) excluding space and  the  `#'  character,
     and  terminated  by whitespace or a `#' character.  An OpenSSL key consists
     of a hex-encoded ASCII string of 40 characters, which is truncated as  nec-
     essary.

     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 human readable ASCII format.

     The    ntp-keygen	  program    generates	  a    symmetric    keys    file
     ntpkey_MD5key_hostname.filestamp.	Since the file contains  private  shared
     keys,  it should be visible only to root and distributed by secure means to
     other subnet hosts.  The NTP daemon loads the file ntp.keys, so  ntp-keygen
     installs  a  soft link from this name to the generated file.  Subsequently,
     similar soft links must be installed by manual or automated  means  on  the
     other subnet hosts.  While this file is not used with the Autokey Version 2
     protocol,	it  is needed to authenticate some remote configuration commands
     used by the ntpq(8) and ntpdc(8) utilities.

OPTIONS
     -b imbits, --imbits=imbits
	     identity modulus bits.  This option takes an integer number as  its
	     argument.	The value of imbits is constrained to being:
		 in the range  256 through 2048

	     The number of bits in the identity modulus.  The default is 512.

     -c scheme, --certificate=scheme
	     certificate scheme.

	     scheme is one of RSA-MD2, RSA-MD5, RSA-MDC2, RSA-SHA, RSA-SHA1,
	     RSA-RIPEMD160, DSA-SHA, or DSA-SHA1.

	     Select the certificate signature encryption/message digest scheme.
	     Note that RSA schemes must be used with a RSA sign key and DSA
	     schemes must be used with a DSA sign key.	The default without this
	     option is RSA-MD5.

     -C cipher, --cipher=cipher
	     privatekey cipher.

	     Select the cipher which is used to encrypt the files containing
	     private keys.  The default is three-key triple DES in CBC mode,
	     equivalent to "-C des-ede3-cbc".  The openssl tool lists ciphers
	     available in "openssl -h" output.

     -d, --debug-level
	     Increase debug verbosity level.  This option may appear an unlim-
	     ited number of times.

     -D number, --set-debug-level=number
	     Set the debug verbosity level.  This option may appear an unlimited
	     number of times.  This option takes an integer number as its argu-
	     ment.

     -e, --id-key
	     Write IFF or GQ identity keys.

	     Write the public parameters from the IFF or GQ client keys to the
	     standard output.  This is intended for automatic key distribution
	     by email.

     -G, --gq-params
	     Generate GQ parameters and keys.

	     Generate parameters and keys for the GQ identification scheme, ob-
	     soleting any that may exist.

     -H, --host-key
	     generate RSA host key.

	     Generate new host keys, obsoleting any that may exist.

     -I, --iffkey
	     generate IFF parameters.

	     Generate parameters for the IFF identification scheme, obsoleting
	     any that may exist.

     -i group, --ident=group
	     set Autokey group name.

	     Set the optional Autokey group name to name.  This is used in the
	     file name of IFF, GQ, and MV client parameters files.  In that
	     role, the default is the host name if this option is not provided.
	     The group name, if specified using -i/--ident or using -s/--sub-
	     ject-name following an '@' character, is also a part of the
	     self-signed host certificate subject and issuer names in the form
	     host@group and should match the 'crypto ident' or 'server ident'
	     configuration in the ntpd configuration file.

     -l lifetime, --lifetime=lifetime
	     set certificate lifetime.	This option takes an integer number as
	     its argument.

	     Set the certificate expiration to lifetime days from now.

     -m modulus, --modulus=modulus
	     prime modulus.  This option takes an integer number as its argu-
	     ment.  The value of modulus is constrained to being:
		 in the range  256 through 2048

	     The number of bits in the prime modulus.  The default is 512.

     -M, --md5key
	     generate symmetric keys.

	     Generate symmetric keys, obsoleting any that may exist.

     -P, --pvt-cert
	     generate PC private certificate.

	     Generate a private certificate.  By default, the program generates
	     public certificates.

     -p passwd, --password=passwd
	     local private password.

	     Local files containing private data are encrypted with the DES-CBC
	     algorithm and the specified password.  The same password must be
	     specified to the local ntpd via the "crypto pw password" configura-
	     tion command.  The default password is the local hostname.

     -q passwd, --export-passwd=passwd
	     export IFF or GQ group keys with password.

	     Export IFF or GQ identity group keys to the standard output, en-
	     crypted with the DES-CBC algorithm and the specified password.  The
	     same password must be specified to the remote ntpd via the "crypto
	     pw password" configuration command.  See also the option --id-key
	     (-e) for unencrypted exports.

     -s host@group, --subject-name=host@group
	     set host and optionally group name.

	     Set the Autokey host name, and optionally, group name specified
	     following an '@' character.  The host name is used in the file name
	     of generated host and signing certificates, without the group name.
	     The host name, and if provided, group name are used in host@group
	     form for the host certificate subject and issuer fields.  Specify-
	     ing '-s @group' is allowed, and results in leaving the host name
	     unchanged while appending @group to the subject and issuer fields,
	     as with -i group.	The group name, or if not provided, the host
	     name are also used in the file names of IFF, GQ, and MV client pa-
	     rameter files.

     -S sign, --sign-key=sign
	     generate sign key (RSA or DSA).

	     Generate a new sign key of the designated type, obsoleting any that
	     may exist.  By default, the program uses the host key as the sign
	     key.

     -T, --trusted-cert
	     trusted certificate (TC scheme).

	     Generate a trusted certificate.  By default, the program generates
	     a non-trusted certificate.

     -V num, --mv-params=num
	     generate <num> MV parameters.  This option takes an integer number
	     as its argument.

	     Generate parameters and keys for the Mu-Varadharajan (MV) identifi-
	     cation scheme.

     -v num, --mv-keys=num
	     update <num> MV keys.  This option takes an integer number as its
	     argument.

	     This option has not been fully documented.

     -?, --help
	     Display usage information and exit.

     -!, --more-help
	     Pass the extended usage information through a pager.

     -> [cfgfile], --save-opts [=cfgfile]
	     Save the option state to cfgfile.	The default is the last configu-
	     ration file listed in the OPTION PRESETS section, below.  The com-
	     mand will exit after updating the config file.

     -< cfgfile, --load-opts=cfgfile, --no-load-opts
	     Load options from cfgfile.  The no-load-opts form will disable the
	     loading of earlier config/rc/ini files.  --no-load-opts is handled
	     early, out of order.

     --version [{v|c|n}]
	     Output version of program and exit.  The default mode is `v', a
	     simple version.  The `c' mode will print copyright information and
	     `n' will print the full copyright notice.

OPTION PRESETS
     Any  option  that is not marked as not presettable may be preset by loading
     values from configuration ("RC" or ".INI") file(s) and values from environ-
     ment variables named:
       NTP_KEYGEN_<option-name> or NTP_KEYGEN
     The environmental presets take precedence (are processed  later  than)  the
     configuration  files.   The  homerc  files are "$HOME", and ".".  If any of
     these are directories, then the file .ntprc is searched  for  within  those
     directories.

USAGE
ENVIRONMENT
     See OPTION PRESETS for configuration environment variables.

FILES
     See OPTION PRESETS for configuration files.

EXIT STATUS
     One of the following exit values will be returned:

     0	(EXIT_SUCCESS)
	     Successful program execution.

     1	(EXIT_FAILURE)
	     The operation failed or the command syntax was not valid.

     66  (EX_NOINPUT)
	     A specified configuration file could not be loaded.

     70  (EX_SOFTWARE)
	     libopts had an internal operational error.  Please report it to au-
	     togen-users@lists.sourceforge.net.  Thank you.

AUTHORS
     The University of Delaware and Network Time Foundation

COPYRIGHT
     Copyright (C) 1992-2024 The University of Delaware and Network Time Founda-
     tion  all rights reserved.  This program is released under the terms of the
     NTP license, <http://ntp.org/license>.

BUGS
     It can take quite a while to generate some cryptographic values.

     Please report bugs to http://bugs.ntp.org .

     Please send bug reports to: https://bugs.ntp.org, bugs@ntp.org

NOTES
     Portions of this document came from FreeBSD.

     This manual page was AutoGen-erated from the ntp-keygen option definitions.

FreeBSD ports 15.quarterly	   May 25 2024			   NTP_KEYGEN(8)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=ntp-keygen&sektion=8&manpath=FreeBSD+Ports+15.1.quarterly>

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