DNSSEC-KEYGEN(1) BIND 9 DNSSEC-KEYGEN(1)
NAME
dnssec-keygen - DNSSEC key generation tool
SYNOPSIS
dnssec-keygen [-3] [-A date/offset] [-a algorithm] [-b keysize] [-C] [-c
class] [-D date/offset] [-d bits] [-D sync date/offset] [-E engine] [-f
flag] [-F] [-G] [-h] [-I date/offset] [-i interval] [-K directory] [-k
policy] [-L ttl] [-l file] [-n nametype] [-M tag_min:tag_max] [-P
date/offset] [-P sync date/offset] [-p protocol] [-q] [-R date/offset]
[-S key] [-s strength] [-T rrtype] [-t type] [-V] [-v level] {name}
DESCRIPTION
dnssec-keygen generates keys for DNSSEC (Secure DNS), as defined in RFC
2535 <https://datatracker.ietf.org/doc/html/rfc2535.html> and RFC 4034
<https://datatracker.ietf.org/doc/html/rfc4034.html>.
The name of the key is specified on the command line. For DNSSEC keys,
this must match the name of the zone for which the key is being gener-
ated.
OPTIONS
-3 This option uses an NSEC3-capable algorithm to generate a DNSSEC
key. If this option is used with an algorithm that has both NSEC
and NSEC3 versions, then the NSEC3 version is selected; for exam-
ple, dnssec-keygen -3 -a RSASHA1 specifies the NSEC3RSASHA1 (dep-
recated) algorithm.
-a algorithm
This option selects the cryptographic algorithm. For DNSSEC keys,
the value of algorithm must be one of RSASHA1 (deprecated),
NSEC3RSASHA1 (deprecated), RSASHA256, RSASHA512, ECDSAP256SHA256,
ECDSAP384SHA384, ED25519, or ED448.
These values are case-insensitive. In some cases, abbreviations
are supported, such as ECDSA256 for ECDSAP256SHA256 and ECDSA384
for ECDSAP384SHA384. If RSASHA1 (deprecated) is specified along
with the -3 option, NSEC3RSASHA1 (deprecated) is used instead.
This parameter must be specified except when using the -S option,
which copies the algorithm from the predecessor key.
In prior releases, HMAC algorithms could be generated for use as
TSIG keys, but that feature was removed in BIND 9.13.0. Use
tsig-keygen <#std-iscman-tsig-keygen> to generate TSIG keys.
-b keysize
This option specifies the number of bits in the key. The choice
of key size depends on the algorithm used: RSA keys must be be-
tween 1024 and 4096 bits; Diffie-Hellman keys must be between 128
and 4096 bits. Elliptic curve algorithms do not need this parame-
ter.
If the key size is not specified, some algorithms have pre-de-
fined defaults. For example, RSA keys for use as DNSSEC
zone-signing keys have a default size of 1024 bits; RSA keys for
use as key-signing keys (KSKs, generated with -f KSK) default to
2048 bits.
-C This option enables compatibility mode, which generates an
old-style key, without any timing metadata. By default,
dnssec-keygen includes the key's creation date in the metadata
stored with the private key; other dates may be set there as
well, including publication date, activation date, etc. Keys that
include this data may be incompatible with older versions of
BIND; the -C option suppresses them.
-c class
This option indicates that the DNS record containing the key
should have the specified class. If not specified, class IN is
used.
-d bits
This option specifies the key size in bits. For the algorithms
RSASHA1, NSEC3RSASA1, RSASHA256, and RSASHA512 the key size must
be between 1024 and 4096 bits; DH size is between 128 and 4096
bits. This option is ignored for algorithms ECDSAP256SHA256, ECD-
SAP384SHA384, ED25519, and ED448.
-E engine
This option specifies the cryptographic hardware to use, when ap-
plicable.
When BIND 9 is built with OpenSSL, this needs to be set to the
OpenSSL engine identifier that drives the cryptographic accelera-
tor or hardware service module (usually pkcs11).
-f flag
This option sets the specified flag in the flag field of the
KEY/DNSKEY record. The only recognized flags are ZSK (Zone-Sign-
ing Key), KSK (Key-Signing Key) and REVOKE.
Note that ZSK is not a physical flag in the DNSKEY record, it is
merely used to explicitly tell that you want to create a ZSK.
Setting -f in conjunction with -k will result in generating keys
that only match the given role set with this option.
-F This options turns on FIPS (US Federal Information Processing
Standards) mode if the underlying crytographic library supports
running in FIPS mode.
-G This option generates a key, but does not publish it or sign with
it. This option is incompatible with -P and -A.
-h This option prints a short summary of the options and arguments
to dnssec-keygen.
-K directory
This option sets the directory in which the key files are to be
written.
-k policy
This option creates keys for a specific dnssec-policy. If a pol-
icy uses multiple keys, dnssec-keygen generates multiple keys.
This also creates a ".state" file to keep track of the key state.
This option creates keys according to the dnssec-policy configu-
ration, hence it cannot be used at the same time as many of the
other options that dnssec-keygen provides.
-L ttl This option sets the default TTL to use for this key when it is
converted into a DNSKEY RR. This is the TTL used when the key is
imported into a zone, unless there was already a DNSKEY RRset in
place, in which case the existing TTL takes precedence. If this
value is not set and there is no existing DNSKEY RRset, the TTL
defaults to the SOA TTL. Setting the default TTL to 0 or none is
the same as leaving it unset.
-l file
This option provides a configuration file that contains a
dnssec-policy statement (matching the policy set with -k).
-M tag_min:tag_max
This option sets the range of acceptable key tag values that
dnssec-keygen will produce. If the key tag of the new key or the
key tag of the revoked version of the new key is outside this
range, the new key will be rejected and another new key will be
generated. This is designed to be used when generating keys in a
multi-signer scenario, where each operator is given a range of
key tags to prevent collisions among different operators. The
valid values for tag_min and tag_max are [0..65535]. The default
allows all key tag values to be produced. This option is ignored
when -k policy is specified.
-n nametype
This option specifies the owner type of the key. The value of
nametype must either be ZONE (for a DNSSEC zone key
(KEY/DNSKEY)), HOST or ENTITY (for a key associated with a host
(KEY)), USER (for a key associated with a user (KEY)), or OTHER
(DNSKEY). These values are case-insensitive. The default is ZONE
for DNSKEY generation.
-p protocol
This option sets the protocol value for the generated key, for
use with -T KEY. The protocol is a number between 0 and 255. The
default is 3 (DNSSEC). Other possible values for this argument
are listed in RFC 2535 <https://datatracker.ietf.org/doc/html/
rfc2535.html> and its successors.
-q This option sets quiet mode, which suppresses unnecessary output,
including progress indication. Without this option, when
dnssec-keygen is run interactively to generate an RSA or DSA key
pair, it prints a string of symbols to stderr indicating the
progress of the key generation. A . indicates that a random num-
ber has been found which passed an initial sieve test; + means a
number has passed a single round of the Miller-Rabin primality
test; and a space ( ) means that the number has passed all the
tests and is a satisfactory key.
-S key This option creates a new key which is an explicit successor to
an existing key. The name, algorithm, size, and type of the key
are set to match the existing key. The activation date of the new
key is set to the inactivation date of the existing one. The pub-
lication date is set to the activation date minus the prepublica-
tion interval, which defaults to 30 days.
-s strength
This option specifies the strength value of the key. The strength
is a number between 0 and 15, and currently has no defined pur-
pose in DNSSEC.
-T rrtype
This option specifies the resource record type to use for the
key. rrtype must be either DNSKEY or KEY. The default is DNSKEY
when using a DNSSEC algorithm, but it can be overridden to KEY
for use with SIG(0).
-t type
This option indicates the type of the key for use with -T KEY.
type must be one of AUTHCONF, NOAUTHCONF, NOAUTH, or NOCONF. The
default is AUTHCONF. AUTH refers to the ability to authenticate
data, and CONF to the ability to encrypt data.
-V This option prints version information.
-v level
This option sets the debugging level.
TIMING OPTIONS
Dates can be expressed in the format YYYYMMDD or YYYYMMDDHHMMSS (which
is the format used inside key files), or 'Day Mon DD HH:MM:SS YYYY' (as
printed by dnssec-settime -p), or UNIX epoch time (as printed by
dnssec-settime -up), or the literal now.
The argument can be followed by + or - and an offset from the given
time. The literal now can be omitted before an offset. The offset can be
followed by one of the suffixes y, mo, w, d, h, or mi, so that it is
computed in years (defined as 365 24-hour days, ignoring leap years),
months (defined as 30 24-hour days), weeks, days, hours, or minutes, re-
spectively. Without a suffix, the offset is computed in seconds.
To unset a date, use none, never, or unset.
-P date/offset
This option sets the date on which a key is to be published to
the zone. After that date, the key is included in the zone but is
not used to sign it. If not set, and if the -G option has not
been used, the default is the current date.
sync date/offset
This option sets the date on which CDS and CDNSKEY records
that match this key are to be published to the zone.
-A date/offset
This option sets the date on which the key is to be activated.
After that date, the key is included in the zone and used to sign
it. If not set, and if the -G option has not been used, the de-
fault is the current date. If set, and -P is not set, the publi-
cation date is set to the activation date minus the prepublica-
tion interval.
-R date/offset
This option sets the date on which the key is to be revoked. Af-
ter that date, the key is flagged as revoked. It is included in
the zone and is used to sign it.
-I date/offset
This option sets the date on which the key is to be retired. Af-
ter that date, the key is still included in the zone, but it is
not used to sign it.
-D date/offset
This option sets the date on which the key is to be deleted. Af-
ter that date, the key is no longer included in the zone. (How-
ever, it may remain in the key repository.)
sync date/offset
This option sets the date on which the CDS and CDNSKEY
records that match this key are to be deleted.
-i interval
This option sets the prepublication interval for a key. If set,
then the publication and activation dates must be separated by at
least this much time. If the activation date is specified but the
publication date is not, the publication date defaults to this
much time before the activation date; conversely, if the publica-
tion date is specified but not the activation date, activation is
set to this much time after publication.
If the key is being created as an explicit successor to another
key, then the default prepublication interval is 30 days; other-
wise it is zero.
As with date offsets, if the argument is followed by one of the
suffixes y, mo, w, d, h, or mi, the interval is measured in
years, months, weeks, days, hours, or minutes, respectively.
Without a suffix, the interval is measured in seconds.
GENERATED KEYS
When dnssec-keygen completes successfully, it prints a string of the
form Knnnn.+aaa+iiiii to the standard output. This is an identification
string for the key it has generated.
• nnnn is the key name.
• aaa is the numeric representation of the algorithm.
• iiiii is the key identifier (or footprint).
dnssec-keygen creates two files, with names based on the printed string.
Knnnn.+aaa+iiiii.key contains the public key, and Knnnn.+aaa+iiiii.pri-
vate contains the private key.
The .key file contains a DNSKEY or KEY record. When a zone is being
signed by named <#std-iscman-named> or dnssec-signzone -S <#
cmdoption-dnssec-signzone-S>, DNSKEY records are included automatically.
In other cases, the .key file can be inserted into a zone file manually
or with an $INCLUDE statement.
The .private file contains algorithm-specific fields. For obvious secu-
rity reasons, this file does not have general read permission.
EXAMPLE
To generate an ECDSAP256SHA256 zone-signing key for the zone exam-
ple.com, issue the command:
dnssec-keygen -a ECDSAP256SHA256 example.com
The command prints a string of the form:
Kexample.com.+013+26160
In this example, dnssec-keygen creates the files Kexam-
ple.com.+013+26160.key and Kexample.com.+013+26160.private.
To generate a matching key-signing key, issue the command:
dnssec-keygen -a ECDSAP256SHA256 -f KSK example.com
SEE ALSO
dnssec-signzone(8) <#std-iscman-dnssec-signzone>, BIND 9 Administrator
Reference Manual, RFC 2539 <https://datatracker.ietf.org/doc/html/
rfc2539.html>, RFC 2845 <https://datatracker.ietf.org/doc/html/rfc2845
.html>, RFC 4034 <https://datatracker.ietf.org/doc/html/rfc4034.html>.
Author
Internet Systems Consortium
Copyright
2026, Internet Systems Consortium
9.20.21-1~deb13u1-Debian 2026-03-13 DNSSEC-KEYGEN(1)
Generated by dwww version 1.16 on Mon Mar 30 02:32:22 CEST 2026.