1074 lines
38 KiB
Groff
1074 lines
38 KiB
Groff
.Dd February 4 2015
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.Dt NTP_KEYGEN 8 User Commands
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.Os
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.\" EDIT THIS FILE WITH CAUTION (ntp-keygen-opts.mdoc)
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.\"
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.\" $FreeBSD$
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.\"
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.\" It has been AutoGen-ed February 4, 2015 at 02:44:02 AM by AutoGen 5.18.5pre4
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.\" From the definitions ntp-keygen-opts.def
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.\" and the template file agmdoc-cmd.tpl
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.Sh NAME
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.Nm ntp-keygen
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.Nd Create a NTP host key
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.Sh SYNOPSIS
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.Nm
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.\" Mixture of short (flag) options and long options
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.Op Fl flags
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.Op Fl flag Op Ar value
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.Op Fl \-option\-name Ns Oo Oo Ns "=| " Oc Ns Ar value Oc
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.Pp
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All arguments must be options.
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.Pp
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.Sh DESCRIPTION
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This program generates cryptographic data files used by the NTPv4
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authentication and identification schemes.
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It generates MD5 key files used in symmetric key cryptography.
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In addition, if the OpenSSL software library has been installed,
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it generates keys, certificate and identity files used in public key
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cryptography.
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These files are used for cookie encryption,
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digital signature and challenge/response identification algorithms
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compatible with the Internet standard security infrastructure.
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.Pp
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All files are in PEM\-encoded printable ASCII format,
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so they can be embedded as MIME attachments in mail to other sites
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and certificate authorities.
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By default, files are not encrypted.
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.Pp
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When used to generate message digest keys, the program produces a file
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containing ten pseudo\-random printable ASCII strings suitable for the
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MD5 message digest algorithm included in the distribution.
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If the OpenSSL library is installed, it produces an additional ten
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hex\-encoded random bit strings suitable for the SHA1 and other message
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digest algorithms.
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The message digest keys file must be distributed and stored
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using secure means beyond the scope of NTP itself.
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Besides the keys used for ordinary NTP associations, additional keys
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can be defined as passwords for the
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.Xr ntpq 8
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and
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.Xr ntpdc 8
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utility programs.
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.Pp
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The remaining generated files are compatible with other OpenSSL
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applications and other Public Key Infrastructure (PKI) resources.
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Certificates generated by this program are compatible with extant
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|
industry practice, although some users might find the interpretation of
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|
X509v3 extension fields somewhat liberal.
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However, the identity keys are probably not compatible with anything
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other than Autokey.
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.Pp
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Some files used by this program are encrypted using a private password.
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The
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.Fl p
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option specifies the password for local encrypted files and the
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.Fl q
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option the password for encrypted files sent to remote sites.
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If no password is specified, the host name returned by the Unix
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.Fn gethostname
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function, normally the DNS name of the host is used.
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.Pp
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The
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.Ar pw
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option of the
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.Ar crypto
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configuration command specifies the read
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password for previously encrypted local files.
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This must match the local password used by this program.
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If not specified, the host name is used.
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Thus, if files are generated by this program without password,
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they can be read back by
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.Ar ntpd
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without password but only on the same host.
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.Pp
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Normally, encrypted files for each host are generated by that host and
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used only by that host, although exceptions exist as noted later on
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this page.
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The symmetric keys file, normally called
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.Ar ntp.keys ,
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is usually installed in
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.Pa /etc .
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Other files and links are usually installed in
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.Pa /usr/local/etc ,
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which is normally in a shared filesystem in
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NFS\-mounted networks and cannot be changed by shared clients.
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The location of the keys directory can be changed by the
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.Ar keysdir
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configuration command in such cases.
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Normally, this is in
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.Pa /etc .
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.Pp
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This program directs commentary and error messages to the standard
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error stream
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.Ar stderr
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and remote files to the standard output stream
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.Ar stdout
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where they can be piped to other applications or redirected to files.
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The names used for generated files and links all begin with the
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string
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.Ar ntpkey
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and include the file type, generating host and filestamp,
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as described in the
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.Dq Cryptographic Data Files
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section below.
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.Ss Running the Program
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To test and gain experience with Autokey concepts, log in as root and
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change to the keys directory, usually
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.Pa /usr/local/etc
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When run for the first time, or if all files with names beginning with
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.Ar ntpkey
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have been removed, use the
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.Nm
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command without arguments to generate a
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default RSA host key and matching RSA\-MD5 certificate with expiration
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date one year hence.
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If run again without options, the program uses the
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existing keys and parameters and generates only a new certificate with
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new expiration date one year hence.
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.Pp
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Run the command on as many hosts as necessary.
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Designate one of them as the trusted host (TH) using
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.Nm
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with the
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.Fl T
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option and configure it to synchronize from reliable Internet servers.
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Then configure the other hosts to synchronize to the TH directly or
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indirectly.
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A certificate trail is created when Autokey asks the immediately
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ascendant host towards the TH to sign its certificate, which is then
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provided to the immediately descendant host on request.
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All group hosts should have acyclic certificate trails ending on the TH.
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.Pp
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The host key is used to encrypt the cookie when required and so must be
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RSA type.
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By default, the host key is also the sign key used to encrypt
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signatures.
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A different sign key can be assigned using the
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.Fl S
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option and this can be either RSA or DSA type.
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By default, the signature
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message digest type is MD5, but any combination of sign key type and
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message digest type supported by the OpenSSL library can be specified
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using the
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.Fl c
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option.
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The rules say cryptographic media should be generated with proventic
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filestamps, which means the host should already be synchronized before
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this program is run.
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This of course creates a chicken\-and\-egg problem
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when the host is started for the first time.
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Accordingly, the host time
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should be set by some other means, such as eyeball\-and\-wristwatch, at
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least so that the certificate lifetime is within the current year.
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After that and when the host is synchronized to a proventic source, the
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certificate should be re\-generated.
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.Pp
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Additional information on trusted groups and identity schemes is on the
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.Dq Autokey Public\-Key Authentication
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page.
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.Pp
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The
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.Xr ntpd 8
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configuration command
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.Ic crypto pw Ar password
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specifies the read password for previously encrypted files.
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The daemon expires on the spot if the password is missing
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or incorrect.
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For convenience, if a file has been previously encrypted,
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the default read password is the name of the host running
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the program.
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If the previous write password is specified as the host name,
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these files can be read by that host with no explicit password.
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.Pp
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File names begin with the prefix
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.Cm ntpkey_
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and end with the postfix
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.Ar _hostname.filestamp ,
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where
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.Ar hostname
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is the owner name, usually the string returned
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by the Unix gethostname() routine, and
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.Ar filestamp
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is the NTP seconds when the file was generated, in decimal digits.
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This both guarantees uniqueness and simplifies maintenance
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procedures, since all files can be quickly removed
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by a
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.Ic rm ntpkey\&*
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command or all files generated
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at a specific time can be removed by a
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.Ic rm
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.Ar \&*filestamp
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command.
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|
To further reduce the risk of misconfiguration,
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the first two lines of a file contain the file name
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and generation date and time as comments.
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.Pp
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|
All files are installed by default in the keys directory
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.Pa /usr/local/etc ,
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|
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.
|
|
.Pp
|
|
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.
|
|
.Pp
|
|
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,
|
|
.Xr ntpd 8
|
|
extracts the filestamp from the file itself.
|
|
This allows clients to verify that the file and generation times
|
|
are always current.
|
|
The
|
|
.Nm
|
|
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.
|
|
.Ss Running the program
|
|
The safest way to run the
|
|
.Nm
|
|
program is logged in directly as root.
|
|
The recommended procedure is change to the keys directory,
|
|
usually
|
|
.Pa /usr/local/etc ,
|
|
then run the program.
|
|
When run for the first time,
|
|
or if all
|
|
.Cm 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.
|
|
.Pp
|
|
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.
|
|
.Pp
|
|
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.
|
|
.Pp
|
|
Running the program as other than root and using the Unix
|
|
.Ic su
|
|
command
|
|
to assume root may not work properly, since by default the OpenSSL library
|
|
looks for the random seed file
|
|
.Cm .rnd
|
|
in the user home directory.
|
|
However, there should be only one
|
|
.Cm .rnd ,
|
|
most conveniently
|
|
in the root directory, so it is convenient to define the
|
|
.Cm $RANDFILE
|
|
environment variable used by the OpenSSL library as the path to
|
|
.Cm /.rnd .
|
|
.Pp
|
|
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
|
|
.Pa /etc
|
|
using the
|
|
.Ic 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.
|
|
.Pp
|
|
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.
|
|
.Pp
|
|
All files are installed by default in the keys directory
|
|
.Pa /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.
|
|
.Pp
|
|
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.
|
|
.Pp
|
|
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,
|
|
.Xr ntpd 8
|
|
extracts the filestamp from the file itself.
|
|
This allows clients to verify that the file and generation times
|
|
are always current.
|
|
The
|
|
.Nm
|
|
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.
|
|
.Ss Running the program
|
|
The safest way to run the
|
|
.Nm
|
|
program is logged in directly as root.
|
|
The recommended procedure is change to the keys directory,
|
|
usually
|
|
.Pa /usr/local/etc ,
|
|
then run the program.
|
|
When run for the first time,
|
|
or if all
|
|
.Cm 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.
|
|
.Pp
|
|
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.
|
|
.Pp
|
|
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.
|
|
.Pp
|
|
Running the program as other than root and using the Unix
|
|
.Ic su
|
|
command
|
|
to assume root may not work properly, since by default the OpenSSL library
|
|
looks for the random seed file
|
|
.Cm .rnd
|
|
in the user home directory.
|
|
However, there should be only one
|
|
.Cm .rnd ,
|
|
most conveniently
|
|
in the root directory, so it is convenient to define the
|
|
.Cm $RANDFILE
|
|
environment variable used by the OpenSSL library as the path to
|
|
.Cm /.rnd .
|
|
.Pp
|
|
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
|
|
.Pa /etc
|
|
using the
|
|
.Ic 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.
|
|
.Pp
|
|
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
|
|
.Sx Authentication Options
|
|
section of
|
|
.Xr 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
|
|
.Sx Automatic NTP Configuration Options
|
|
section of
|
|
.Xr ntp.conf 5 .
|
|
.Pp
|
|
On each trusted host as root, change to the keys directory.
|
|
To insure a fresh fileset, remove all
|
|
.Cm ntpkey
|
|
files.
|
|
Then run
|
|
.Nm
|
|
.Fl T
|
|
to generate keys and a trusted certificate.
|
|
On all other hosts do the same, but leave off the
|
|
.Fl 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.
|
|
.Pp
|
|
If it is necessary to use a different sign key or different digest/signature
|
|
scheme than the default, run
|
|
.Nm
|
|
with the
|
|
.Fl S Ar type
|
|
option, where
|
|
.Ar type
|
|
is either
|
|
.Cm RSA
|
|
or
|
|
.Cm 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
|
|
.Nm
|
|
with the
|
|
.Fl c Ar scheme
|
|
option and selected
|
|
.Ar scheme
|
|
as needed.
|
|
f
|
|
.Nm
|
|
is run again without these options, it generates a new certificate
|
|
using the same scheme and sign key.
|
|
.Pp
|
|
After setting up the environment it is advisable to update certificates
|
|
from time to time, if only to extend the validity interval.
|
|
Simply run
|
|
.Nm
|
|
with the same flags as before to generate new certificates
|
|
using existing keys.
|
|
However, if the host or sign key is changed,
|
|
.Xr ntpd 8
|
|
should be restarted.
|
|
When
|
|
.Xr 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.
|
|
.Ss 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
|
|
.Qq Identification Schemes
|
|
page
|
|
(maybe available at
|
|
.Li 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.
|
|
.Pp
|
|
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.
|
|
.Pp
|
|
The PC scheme supports only one trusted host in the group.
|
|
On trusted host alice run
|
|
.Nm
|
|
.Fl P
|
|
.Fl p Ar password
|
|
to generate the host key file
|
|
.Pa ntpkey_RSAkey_ Ns Ar alice.filestamp
|
|
and trusted private certificate file
|
|
.Pa ntpkey_RSA\-MD5_cert_ Ns Ar 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
|
|
.Pa ntpkey_host_ Ns Ar bob
|
|
to the host key file and soft link
|
|
.Pa ntpkey_cert_ Ns Ar 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.
|
|
.Pp
|
|
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
|
|
.Nm
|
|
.Fl T
|
|
.Fl I
|
|
.Fl p Ar password
|
|
to produce her parameter file
|
|
.Pa ntpkey_IFFpar_ Ns Ar 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
|
|
.Pa ntpkey_iff_ Ns Ar 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.
|
|
.Pp
|
|
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
|
|
.Nm
|
|
.Fl 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
|
|
.Pa ntpkey_iff_ Ns Ar alice
|
|
to this file.
|
|
To further protect the integrity of the keys,
|
|
each file can be encrypted with a secret password.
|
|
.Pp
|
|
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
|
|
.Nm
|
|
.Fl T
|
|
.Fl G
|
|
.Fl p Ar password
|
|
to produce her parameter file
|
|
.Pa ntpkey_GQpar_ Ns Ar alice.filestamp ,
|
|
which includes both server and client keys.
|
|
Copy this file to all group hosts and install a soft link
|
|
from the generic
|
|
.Pa ntpkey_gq_ Ns Ar alice
|
|
to this file.
|
|
In addition, on each host bob install a soft link
|
|
from generic
|
|
.Pa ntpkey_gq_ Ns Ar 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.
|
|
.Pp
|
|
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
|
|
.Nm
|
|
.Fl V Ar n
|
|
.Fl p Ar password ,
|
|
where
|
|
.Ar n
|
|
is the number of revokable keys (typically 5) to produce
|
|
the parameter file
|
|
.Pa ntpkeys_MVpar_ Ns Ar trish.filestamp
|
|
and client key files
|
|
.Pa ntpkeys_MVkeyd_ Ns Ar trish.filestamp
|
|
where
|
|
.Ar d
|
|
is the key number (0 \&<
|
|
.Ar d
|
|
\&<
|
|
.Ar n ) .
|
|
Copy the parameter file to alice and install a soft link
|
|
from the generic
|
|
.Pa ntpkey_mv_ Ns Ar 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
|
|
.Pa ntpkey_mvkey_ Ns Ar bob
|
|
to the client key file.
|
|
As the MV scheme is independent of keys and certificates,
|
|
these files can be refreshed as needed.
|
|
.Ss Command Line Options
|
|
.Bl -tag -width indent
|
|
.It Fl c Ar scheme
|
|
Select certificate message digest/signature encryption scheme.
|
|
The
|
|
.Ar scheme
|
|
can be one of the following:
|
|
. Cm RSA\-MD2 , RSA\-MD5 , RSA\-SHA , RSA\-SHA1 , RSA\-MDC2 , RSA\-RIPEMD160 , DSA\-SHA ,
|
|
or
|
|
.Cm 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
|
|
.Cm RSA\-MD5 .
|
|
.It Fl d
|
|
Enable debugging.
|
|
This option displays the cryptographic data produced in eye\-friendly billboards.
|
|
.It Fl e
|
|
Write the IFF client keys to the standard output.
|
|
This is intended for automatic key distribution by mail.
|
|
.It Fl G
|
|
Generate parameters and keys for the GQ identification scheme,
|
|
obsoleting any that may exist.
|
|
.It Fl g
|
|
Generate keys for the GQ identification scheme
|
|
using the existing GQ parameters.
|
|
If the GQ parameters do not yet exist, create them first.
|
|
.It Fl H
|
|
Generate new host keys, obsoleting any that may exist.
|
|
.It Fl I
|
|
Generate parameters for the IFF identification scheme,
|
|
obsoleting any that may exist.
|
|
.It Fl i Ar name
|
|
Set the suject name to
|
|
.Ar name .
|
|
This is used as the subject field in certificates
|
|
and in the file name for host and sign keys.
|
|
.It Fl M
|
|
Generate MD5 keys, obsoleting any that may exist.
|
|
.It Fl P
|
|
Generate a private certificate.
|
|
By default, the program generates public certificates.
|
|
.It Fl p Ar password
|
|
Encrypt generated files containing private data with
|
|
.Ar password
|
|
and the DES\-CBC algorithm.
|
|
.It Fl q
|
|
Set the password for reading files to password.
|
|
.It Fl S Oo Cm RSA | DSA Oc
|
|
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.
|
|
.It Fl s Ar name
|
|
Set the issuer name to
|
|
.Ar name .
|
|
This is used for the issuer field in certificates
|
|
and in the file name for identity files.
|
|
.It Fl T
|
|
Generate a trusted certificate.
|
|
By default, the program generates a non\-trusted certificate.
|
|
.It Fl V Ar nkeys
|
|
Generate parameters and keys for the Mu\-Varadharajan (MV) identification scheme.
|
|
.El
|
|
.Ss 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
|
|
.Nm
|
|
program.
|
|
If a site supports OpenSSL or its companion OpenSSH,
|
|
it is very likely that means to do this are already available.
|
|
.Pp
|
|
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.
|
|
.Pp
|
|
The entropy seed used by the OpenSSL library is contained in a file,
|
|
usually called
|
|
.Cm .rnd ,
|
|
which must be available when starting the NTP daemon
|
|
or the
|
|
.Nm
|
|
program.
|
|
The NTP daemon will first look for the file
|
|
using the path specified by the
|
|
.Ic randfile
|
|
subcommand of the
|
|
.Ic crypto
|
|
configuration command.
|
|
If not specified in this way, or when starting the
|
|
.Nm
|
|
program,
|
|
the OpenSSL library will look for the file using the path specified
|
|
by the
|
|
.Ev RANDFILE
|
|
environment variable in the user home directory,
|
|
whether root or some other user.
|
|
If the
|
|
.Ev RANDFILE
|
|
environment variable is not present,
|
|
the library will look for the
|
|
.Cm .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.
|
|
.Ss 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
|
|
.Nm
|
|
program and
|
|
.Xr 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.
|
|
.Pp
|
|
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
|
|
.D1 Ar keyno type key
|
|
where
|
|
.Ar keyno
|
|
is a positive integer in the range 1\-65,535,
|
|
.Ar type
|
|
is the string MD5 defining the key format and
|
|
.Ar 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
|
|
.Ql #
|
|
character.
|
|
.Pp
|
|
Note that the keys used by the
|
|
.Xr ntpq 8
|
|
and
|
|
.Xr 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.
|
|
.Pp
|
|
The
|
|
.Nm
|
|
program generates a MD5 symmetric keys file
|
|
.Pa ntpkey_MD5key_ Ns Ar 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
|
|
.Pa ntp.keys ,
|
|
so
|
|
.Nm
|
|
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
|
|
.Xr ntpq 8
|
|
and
|
|
.Xr ntpdc 8
|
|
utilities.
|
|
.Sh "OPTIONS"
|
|
.Bl -tag
|
|
.It Fl b Ar imbits , Fl \-imbits Ns = Ns Ar imbits
|
|
identity modulus bits.
|
|
This option takes an integer number as its argument.
|
|
The value of
|
|
.Ar imbits
|
|
is constrained to being:
|
|
.in +4
|
|
.nf
|
|
.na
|
|
in the range 256 through 2048
|
|
.fi
|
|
.in -4
|
|
.sp
|
|
The number of bits in the identity modulus. The default is 256.
|
|
.It Fl c Ar scheme , Fl \-certificate Ns = Ns Ar scheme
|
|
certificate scheme.
|
|
.sp
|
|
scheme is one of
|
|
RSA\-MD2, RSA\-MD5, RSA\-SHA, RSA\-SHA1, RSA\-MDC2, RSA\-RIPEMD160,
|
|
DSA\-SHA, or DSA\-SHA1.
|
|
.sp
|
|
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.
|
|
.It Fl C Ar cipher , Fl \-cipher Ns = Ns Ar cipher
|
|
privatekey cipher.
|
|
.sp
|
|
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 "\fBopenssl \-h\fP" output.
|
|
.It Fl d , Fl \-debug\-level
|
|
Increase debug verbosity level.
|
|
This option may appear an unlimited number of times.
|
|
.sp
|
|
.It Fl D Ar number , Fl \-set\-debug\-level Ns = Ns Ar number
|
|
Set the debug verbosity level.
|
|
This option may appear an unlimited number of times.
|
|
This option takes an integer number as its argument.
|
|
.sp
|
|
.It Fl e , Fl \-id\-key
|
|
Write IFF or GQ identity keys.
|
|
.sp
|
|
Write the IFF or GQ client keys to the standard output. This is
|
|
intended for automatic key distribution by mail.
|
|
.It Fl G , Fl \-gq\-params
|
|
Generate GQ parameters and keys.
|
|
.sp
|
|
Generate parameters and keys for the GQ identification scheme,
|
|
obsoleting any that may exist.
|
|
.It Fl H , Fl \-host\-key
|
|
generate RSA host key.
|
|
.sp
|
|
Generate new host keys, obsoleting any that may exist.
|
|
.It Fl I , Fl \-iffkey
|
|
generate IFF parameters.
|
|
.sp
|
|
Generate parameters for the IFF identification scheme, obsoleting
|
|
any that may exist.
|
|
.It Fl i Ar group , Fl \-ident Ns = Ns Ar group
|
|
set Autokey group name.
|
|
.sp
|
|
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 \fB\-i/\-\-ident\fP or
|
|
using \fB\-s/\-\-subject\-name\fP following an '\fB@\fP' character,
|
|
is also a part of the self\-signed host certificate's subject and
|
|
issuer names in the form \fBhost@group\fP and should match the
|
|
\'\fBcrypto ident\fP' or '\fBserver ident\fP' configuration in
|
|
\fBntpd\fP's configuration file.
|
|
.It Fl l Ar lifetime , Fl \-lifetime Ns = Ns Ar lifetime
|
|
set certificate lifetime.
|
|
This option takes an integer number as its argument.
|
|
.sp
|
|
Set the certificate expiration to lifetime days from now.
|
|
.It Fl M , Fl \-md5key
|
|
generate MD5 keys.
|
|
.sp
|
|
Generate MD5 keys, obsoleting any that may exist.
|
|
.It Fl m Ar modulus , Fl \-modulus Ns = Ns Ar modulus
|
|
modulus.
|
|
This option takes an integer number as its argument.
|
|
The value of
|
|
.Ar modulus
|
|
is constrained to being:
|
|
.in +4
|
|
.nf
|
|
.na
|
|
in the range 256 through 2048
|
|
.fi
|
|
.in -4
|
|
.sp
|
|
The number of bits in the prime modulus. The default is 512.
|
|
.It Fl P , Fl \-pvt\-cert
|
|
generate PC private certificate.
|
|
.sp
|
|
Generate a private certificate. By default, the program generates
|
|
public certificates.
|
|
.It Fl p Ar passwd , Fl \-password Ns = Ns Ar passwd
|
|
local private password.
|
|
.sp
|
|
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"
|
|
configuration command. The default password is the local
|
|
hostname.
|
|
.It Fl q Ar passwd , Fl \-export\-passwd Ns = Ns Ar passwd
|
|
export IFF or GQ group keys with password.
|
|
.sp
|
|
Export IFF or GQ identity group keys to the standard output,
|
|
encrypted 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.
|
|
.It Fl S Ar sign , Fl \-sign\-key Ns = Ns Ar sign
|
|
generate sign key (RSA or DSA).
|
|
.sp
|
|
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.
|
|
.It Fl s Ar host@group , Fl \-subject\-name Ns = Ns Ar host@group
|
|
set host and optionally group name.
|
|
.sp
|
|
Set the Autokey host name, and optionally, group name specified
|
|
following an '\fB@\fP' 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 \fBhost@group\fP form for the host certificate's subject and issuer
|
|
fields. Specifying '\fB\-s @group\fP' is allowed, and results in
|
|
leaving the host name unchanged while appending \fB@group\fP to the
|
|
subject and issuer fields, as with \fB\-i group\fP. 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.
|
|
.It Fl T , Fl \-trusted\-cert
|
|
trusted certificate (TC scheme).
|
|
.sp
|
|
Generate a trusted certificate. By default, the program generates
|
|
a non\-trusted certificate.
|
|
.It Fl V Ar num , Fl \-mv\-params Ns = Ns Ar num
|
|
generate <num> MV parameters.
|
|
This option takes an integer number as its argument.
|
|
.sp
|
|
Generate parameters and keys for the Mu\-Varadharajan (MV)
|
|
identification scheme.
|
|
.It Fl v Ar num , Fl \-mv\-keys Ns = Ns Ar num
|
|
update <num> MV keys.
|
|
This option takes an integer number as its argument.
|
|
.sp
|
|
This option has not been fully documented.
|
|
.It Fl \&? , Fl \-help
|
|
Display usage information and exit.
|
|
.It Fl \&! , Fl \-more\-help
|
|
Pass the extended usage information through a pager.
|
|
.It Fl > Oo Ar cfgfile Oc , Fl \-save\-opts Oo Ns = Ns Ar cfgfile Oc
|
|
Save the option state to \fIcfgfile\fP. The default is the \fIlast\fP
|
|
configuration file listed in the \fBOPTION PRESETS\fP section, below.
|
|
The command will exit after updating the config file.
|
|
.It Fl < Ar cfgfile , Fl \-load\-opts Ns = Ns Ar cfgfile , Fl \-no\-load\-opts
|
|
Load options from \fIcfgfile\fP.
|
|
The \fIno\-load\-opts\fP form will disable the loading
|
|
of earlier config/rc/ini files. \fI\-\-no\-load\-opts\fP is handled early,
|
|
out of order.
|
|
.It Fl \-version Op Brq Ar 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.
|
|
.El
|
|
.Sh "OPTION PRESETS"
|
|
Any option that is not marked as \fInot presettable\fP may be preset
|
|
by loading values from configuration ("RC" or ".INI") file(s) and values from
|
|
environment variables named:
|
|
.nf
|
|
\fBNTP_KEYGEN_<option\-name>\fP or \fBNTP_KEYGEN\fP
|
|
.fi
|
|
.ad
|
|
The environmental presets take precedence (are processed later than)
|
|
the configuration files.
|
|
The \fIhomerc\fP files are "\fI$HOME\fP", and "\fI.\fP".
|
|
If any of these are directories, then the file \fI.ntprc\fP
|
|
is searched for within those directories.
|
|
.Sh USAGE
|
|
The
|
|
.Fl p Ar password
|
|
option specifies the write password and
|
|
.Fl q Ar password
|
|
option the read password for previously encrypted files.
|
|
The
|
|
.Nm
|
|
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.
|
|
.Sh "ENVIRONMENT"
|
|
See \fBOPTION PRESETS\fP for configuration environment variables.
|
|
.Sh "FILES"
|
|
See \fBOPTION PRESETS\fP for configuration files.
|
|
.Sh "EXIT STATUS"
|
|
One of the following exit values will be returned:
|
|
.Bl -tag
|
|
.It 0 " (EXIT_SUCCESS)"
|
|
Successful program execution.
|
|
.It 1 " (EXIT_FAILURE)"
|
|
The operation failed or the command syntax was not valid.
|
|
.It 66 " (EX_NOINPUT)"
|
|
A specified configuration file could not be loaded.
|
|
.It 70 " (EX_SOFTWARE)"
|
|
libopts had an internal operational error. Please report
|
|
it to autogen\-users@lists.sourceforge.net. Thank you.
|
|
.El
|
|
.Sh "AUTHORS"
|
|
The University of Delaware and Network Time Foundation
|
|
.Sh "COPYRIGHT"
|
|
Copyright (C) 1992\-2015 The University of Delaware and Network Time Foundation all rights reserved.
|
|
This program is released under the terms of the NTP license, <http://ntp.org/license>.
|
|
.Sh 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.
|
|
.Pp
|
|
Please report bugs to http://bugs.ntp.org .
|
|
.Pp
|
|
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
|
|
.Sh NOTES
|
|
Portions of this document came from FreeBSD.
|
|
.Pp
|
|
This manual page was \fIAutoGen\fP\-erated from the \fBntp\-keygen\fP
|
|
option definitions.
|