## Name

dnssec-dsfromkey — DNSSEC DS RR generation tool

## Synopsis

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

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

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

`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 SHA-1`. (Note: The SHA-1 algorithm is no longer recommended for use when generating new DS and CDS records.)

-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. (Note: The SHA-1 algorithm is no longer recommended for use when generating new DS and CDS records.)

-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-keygen(8).

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

dnssec-keygen(8) , 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).