.. 
   Copyright (C) Internet Systems Consortium, Inc. ("ISC")
   
   This Source Code Form is subject to the terms of the Mozilla Public
   License, v. 2.0. If a copy of the MPL was not distributed with this
   file, you can obtain one at https://mozilla.org/MPL/2.0/.
   
   See the COPYRIGHT file distributed with this work for additional
   information regarding copyright ownership.

..
   Copyright (C) Internet Systems Consortium, Inc. ("ISC")

   This Source Code Form is subject to the terms of the Mozilla Public
   License, v. 2.0. If a copy of the MPL was not distributed with this
   file, You can obtain one at http://mozilla.org/MPL/2.0/.

   See the COPYRIGHT file distributed with this work for additional
   information regarding copyright ownership.


.. highlight: console

.. _man_dnssec-dsfromkey:

dnssec-dsfromkey - DNSSEC DS RR generation tool
-----------------------------------------------

Synopsis
~~~~~~~~

:program:`dnssec-dsfromkey` [ **-1** | **-2** | **-a** alg ] [ **-C** ] [**-T** TTL] [**-v** level] [**-K** directory] {keyfile}

:program:`dnssec-dsfromkey` [ **-1** | **-2** | **-a** alg ] [ **-C** ] [**-T** TTL] [**-v** level] [**-c** class] [**-A**] {**-f** file} [dnsname]

:program:`dnssec-dsfromkey` [ **-1** | **-2** | **-a** alg ] [ **-C** ] [**-T** TTL] [**-v** level] [**-c** class] [**-K** directory] {**-s**} {dnsname}

:program:`dnssec-dsfromkey` [ **-h** | **-V** ]

Description
~~~~~~~~~~~

The ``dnssec-dsfromkey`` command outputs DS (Delegation Signer) resource records
(RRs), or CDS (Child DS) RRs with the ``-C`` option.

The input keys can be specified in a number of ways:

By default, ``dnssec-dsfromkey`` reads a key file named like
``Knnnn.+aaa+iiiii.key``, as generated by ``dnssec-keygen``.

With the ``-f file`` option, ``dnssec-dsfromkey`` reads keys from a zone
file or partial zone file (which can contain just the DNSKEY records).

With the ``-s`` option, ``dnssec-dsfromkey`` reads a ``keyset-`` file,
as generated by ``dnssec-keygen`` ``-C``.

Options
~~~~~~~

**-1**
   An abbreviation for ``-a SHA1``

**-2**
   An abbreviation for ``-a SHA-256``

**-a** algorithm
   Specify a digest algorithm to use when converting DNSKEY records to
   DS records. This option can be repeated, so that multiple DS records
   are created for each DNSKEY record.

   The algorithm must be one of SHA-1, SHA-256, or SHA-384. These values
   are case insensitive, and the hyphen may be omitted. If no algorithm
   is specified, the default is SHA-256.

**-A**
   Include ZSKs when generating DS records. Without this option, only
   keys which have the KSK flag set will be converted to DS records and
   printed. Useful only in ``-f`` zone file mode.

**-c** class
   Specifies the DNS class (default is IN). Useful only in ``-s`` keyset
   or ``-f`` zone file mode.

**-C**
   Generate CDS records rather than DS records.

**-f** file
   Zone file mode: ``dnssec-dsfromkey``'s final dnsname argument is the
   DNS domain name of a zone whose master file can be read from
   ``file``. If the zone name is the same as ``file``, then it may be
   omitted.

   If file is ``"-"``, then the zone data is read from the standard
   input. This makes it possible to use the output of the ``dig``
   command as input, as in:

   ``dig dnskey example.com | dnssec-dsfromkey -f - example.com``

**-h**
   Prints usage information.

**-K** directory
   Look for key files or ``keyset-`` files in ``directory``.

**-s**
   Keyset mode: ``dnssec-dsfromkey``'s final dnsname argument is the DNS
   domain name used to locate a ``keyset-`` file.

**-T** TTL
   Specifies the TTL of the DS records. By default the TTL is omitted.

**-v** level
   Sets the debugging level.

**-V**
   Prints version information.

Example
~~~~~~~

To build the SHA-256 DS RR from the ``Kexample.com.+003+26160`` keyfile
name, you can issue the following command:

``dnssec-dsfromkey -2 Kexample.com.+003+26160``

The command would print something like:

``example.com. IN DS 26160 5 2 3A1EADA7A74B8D0BA86726B0C227AA85AB8BBD2B2004F41A868A54F0C5EA0B94``

Files
~~~~~

The keyfile can be designated by the key identification
``Knnnn.+aaa+iiiii`` or the full file name ``Knnnn.+aaa+iiiii.key`` as
generated by dnssec-keygen8.

The keyset file name is built from the ``directory``, the string
``keyset-`` and the ``dnsname``.

Caveat
~~~~~~

A keyfile error can give a "file not found" even if the file exists.

See Also
~~~~~~~~

:manpage:`dnssec-keygen(8)`, :manpage:`dnssec-signzone(8)`, BIND 9 Administrator Reference Manual,
:rfc:`3658` (DS RRs), :rfc:`4509` (SHA-256 for DS RRs),
:rfc:`6605` (SHA-384 for DS RRs), :rfc:`7344` (CDS and CDNSKEY RRs).