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NTP_KEYGEN(8)                        User                        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
     authentication and identification schemes.  It generates MD5 key files
     used in symmetric key cryptography.  In addition, if the OpenSSL software
     library has been installed, it generates keys, certificate and identity
     files used in public key cryptography.  These files are used for cookie
     encryption, digital signature and challenge/response identification
     algorithms compatible with the Internet standard security infrastructure.

     All files are in PEM-encoded printable ASCII format, so they can be
     embedded as MIME attachments in mail to other sites and certificate
     authorities.  By default, files are not encrypted.

     When used to generate message digest 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 the SHA1 and other message digest algorithms.
     The message digest 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 passwords for the
     ntpq(8) and ntpdc(8) utility programs.

     The remaining generated files are compatible with other OpenSSL
     applications and other Public Key Infrastructure (PKI) resources.
     Certificates generated by this program are compatible with extant
     industry practice, although 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 password for local encrypted files and the -q
     option the password for encrypted files sent to remote sites.  If no
     password is specified, the host name returned by the Unix gethostname()
     function, normally the DNS name of the host is used.

     The pw option of the crypto configuration command specifies the read
     password for previously encrypted local files.  This must match the local
     password used by this program.  If not specified, the host name is used.
     Thus, if files are generated by this program without password, they can
     be read back by ntpd without password but only on the same host.

     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.  The location of the
     keys directory can be changed by the keysdir configuration command in
     such cases.  Normally, this is in /etc.

     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
     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
     removed, use the ntp-keygen command without arguments to generate a
     default RSA host key and matching RSA-MD5 certificate with expiration
     date one year hence.  If run again without options, the program uses the
     existing keys and parameters and generates only a new certificate with
     new expiration date one year hence.

     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 descendant 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
     signatures.  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 filestamps, 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.

     The ntpd(8) configuration command crypto pw password specifies the read
     password for previously encrypted files.  The daemon expires on the spot
     if the password is missing or incorrect.  For convenience, if a file has
     been previously encrypted, the default read password is the name of the
     host running the program.  If the previous write password is specified as
     the host name, these files can be read by that host with no explicit
     password.

     File names begin with the prefix ntpkey_ and end with the postfix
     _hostname.filestamp, where hostname is the owner name, usually the string
     returned by the Unix gethostname() routine, 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 misconfiguration, the first two lines of a
     file contain the file name and generation date and time as comments.

     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
     actual location of the keys directory and each file can be overridden by
     configuration 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.
     Alternatively, files containing private values can be encrypted and these
     files permitted world readable, which simplifies maintenance in shared
     file systems.  Since uniqueness is insured by the hostname and file name
     extensions, the files for a NFS server and dependent clients can all be
     installed in the same shared directory.

     The recommended practice is to keep the file name extensions when
     installing 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 generations to be activated simply by changing the link.  If a link
     is present, ntpd 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 allows clients to verify that the file and generation times
     are always current.  The ntp-keygen program uses the same timestamp
     extension for all files generated at one time, so each generation is
     distinct and can be readily recognized in monitoring data.

   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.  When run for the first time, or if
     all ntpkey files have been removed, the program generates a RSA host key
     file and matching RSA-MD5 certificate file, 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, the program uses
     the same host key file, but generates a new certificate file and 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
     signatures.  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 MD2, MD5, SHA, SHA1, MDC2 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 certificate requests derived from them should be
     compatible with extant industry 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 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
     systems, 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 command.  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
     generating the files, but can be changed by command line options.  It is
     convenient to designate the owner name and trusted name as the subject
     and issuer 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
     actual location of the keys directory and each file can be overridden by
     configuration 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.
     Alternatively, files containing private values can be encrypted and these
     files permitted world readable, which simplifies maintenance in shared
     file systems.  Since uniqueness is insured by the hostname and file name
     extensions, the files for a NFS server and dependent clients can all be
     installed in the same shared directory.

     The recommended practice is to keep the file name extensions when
     installing 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 generations to be activated simply by changing the link.  If a link
     is present, ntpd 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 allows clients to verify that the file and generation times
     are always current.  The ntp-keygen program uses the same timestamp
     extension for all files generated at one time, so each generation is
     distinct and can be readily recognized in monitoring data.

   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.  When run for the first time, or if
     all ntpkey files have been removed, the program generates a RSA host key
     file and matching RSA-MD5 certificate file, 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, the program uses
     the same host key file, but generates a new certificate file and 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
     signatures.  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 MD2, MD5, SHA, SHA1, MDC2 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 certificate requests derived from them should be
     compatible with extant industry 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 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
     systems, 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 command.  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
     generating the files, but can be changed by command line options.  It is
     convenient to designate the owner name and trusted name as the subject
     and issuer 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.  seconds.  seconds.  s 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,
     configure 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
     authoritative 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 configuration 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 complete, 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/signature scheme than the default, run ntp-keygen with the -S type
     option, where type is either RSA or DSA.  The most often need to do this
     is when a DSA-signed certificate is used.  If it is necessary to use a
     different certificate scheme than the default, run ntp-keygen with the -c
     scheme option and selected scheme as needed.  f ntp-keygen is run again
     without these options, it generates a new certificate using the same
     scheme and sign key.

     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.  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 continue 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
     described on the "Identification Schemes" page (maybe available at
     http://www.eecis.udel.edu/%7emills/keygen.html).  These schemes are based
     on a TA, one or more trusted hosts and some number of nontrusted hosts.
     Trusted hosts prove identity using values provided by the TA, while the
     remaining hosts prove identity using values provided 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_RSAkey_alice.filestamp and trusted private certificate file
     ntpkey_RSA-MD5_cert_alice.filestamp.  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.

     For the IFF scheme proceed as in the TC scheme to generate keys and
     certificates 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 restricted 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
     legitimate 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 mail
     program.  Copy or mail 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 password.

     For the GQ scheme proceed as in the TC scheme to generate keys and
     certificates 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 -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 certificate 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
     certificates 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 doesn't matter which client
     key file goes to alice, since they all work the same way.  Alice copies
     the client key file to all of her cliens.  On client bob install 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
     -c scheme
             Select certificate message digest/signature encryption scheme.
             The scheme can be one of the following: RSA-MD2, RSA-MD5,
             RSA-SHA, RSA-SHA1, RSA-MDC2, RSA-RIPEMD160, DSA-SHA, or DSA-SHA1.
             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.

     -d      Enable debugging.  This option displays the cryptographic data
             produced in eye-friendly billboards.

     -e      Write the IFF client keys to the standard output.  This is
             intended for automatic key distribution by mail.

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

     -g      Generate keys for the GQ identification scheme using the existing
             GQ parameters.  If the GQ parameters do not yet exist, create
             them first.

     -H      Generate new host keys, obsoleting any that may exist.

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

     -i name
             Set the suject name to name.  This is used as the subject field
             in certificates and in the file name for host and sign keys.

     -M      Generate MD5 keys, obsoleting any that may exist.

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

     -p password
             Encrypt generated files containing private data with password and
             the DES-CBC algorithm.

     -q      Set the password for reading files to password.

     -S [RSA | 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.

     -s name
             Set the issuer name to name.  This is used for the issuer field
             in certificates and in the file name for identity files.

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

     -V nkeys
             Generate parameters and keys for the Mu-Varadharajan (MV)
             identification scheme.

   Random Seed File
     All cryptographically sound key generation schemes must have means to
     randomize the entropy seed used to initialize the internal pseudo-random
     number 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
     generation, for otherwise the random number sequence would be
     predictable.  Various 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,
     usually 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 specified 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 directory.  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 other file formats begin with two lines.  The first contains the file
     name, including the generated host name and filestamp.  The second
     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.  Cryptographic values are encoded first using ASN.1
     rules, then encrypted if necessary, and finally written PEM-encoded
     printable ASCII format preceded and followed by MIME content identifier
     lines.

     The format of the symmetric keys file is somewhat different than the
     other files in the interest of backward compatibility.  Since DES-CBC is
     deprecated in NTPv4, the only key format of interest is MD5 alphanumeric
     strings.  Following hte heard the keys are entered one per line in the
     format
           keyno type key
     where keyno is a positive integer in the range 1-65,535, type is the
     string MD5 defining the key format and key is the key itself, which is a
     printable ASCII string 16 characters or less in length.  Each character
     is chosen from the 93 printable characters in the range 0x21 through 0x7f
     excluding space and the `#' character.

     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 MD5 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
                 256.

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

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

                 Select the certificate message digest/signature encryption
                 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 "@code{-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
                 unlimited 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 argument.


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

                 Write the IFF or GQ client keys to the standard output.  This
                 is intended for automatic key distribution by mail.

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

                 Generate parameters and keys for the GQ identification
                 scheme, obsoleting 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/--subject-name following an '@' character, is also a
                 part of the self-signed host certificate's subject and issuer
                 names in the form host@group and should match the 'crypto
                 ident' or 'server ident' configuration in ntpd's
                 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, --md5key
                 generate MD5 keys.

                 Generate MD5 keys, obsoleting any that may exist.

     -m modulus, --modulus=modulus
                 modulus.  This option takes an integer number as its
                 argument.  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.

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

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

     -p passwd, --pvt-passwd=passwd
                 output private password.

                 Encrypt generated files containing private data with the
                 specified password and the cipher selected with -C/--cipher.

     -q passwd, --get-pvt-passwd=passwd
                 input private password.

                 Set the password for reading files to the specified password.

     -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.

     -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's subject and issuer fields.  Specifying '-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 parameter files.

     -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)
                 identification 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
                 configuration file listed in the OPTION PRESETS section,
                 below.  The command 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
     environment 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 "$HOME", and ".".  If any of these are directories, then
     the file .ntprc is searched for within those directories.
     cvt_prog='/usr/local/gnu/share/autogen/texi2mdoc' cvt_prog=`cd `dirname
     "$cvt_prog"` >/dev/null && pwd
              `/`basename "$cvt_prog"` cd $tmp_dir test -x "$cvt_prog" || die
     "'$cvt_prog' is not executable" {
         list='synopsis description options option-presets'
         for f in $list ; do cat $f ; echo ; done
         rm -f $list name
         list='implementation-notes environment files examples exit-status
     errors
             compatibility see-also conforming-to history authors copyright
     bugs
             notes'
         for f in $list ; do cat $f ; echo ; done > .end-doc
         rm -f $list
         list=`ls -1 *`' .end-doc'
         for f in $list ; do cat $f ; echo ; done
         rm -f $list } 1>.doc 2>/dev/null sed -f .cmds .doc |
     /usr/local/gnu/bin/grep -E -v '^[  ]*$' | $cvt_prog

USAGE
     The -p password option specifies the write password and -q password
     option the read password for previously encrypted files.  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.

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 autogen-users@lists.sourceforge.net.
                         Thank you.

AUTHORS
     The University of Delaware

COPYRIGHT
     Copyright (C) 1970-2013 The University of Delaware 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, from one
     to several minutes with modern architectures such as UltraSPARC and up to
     tens of minutes to an hour with older architectures such as SPARC IPC.

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

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

NOTES
     This document corresponds to version 4.2.7p404 of NTP.  Portions of this
     document came from FreeBSD.

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

SunOS 5.10                     December 24 2013                     SunOS 5.10