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 sync date/offset]
[-E engine]
[-f flag] [-G]
[-g generator] [-h]
[-I date/offset]
[-i interval]
[-K directory] [-k]
[-L ttl]
[-n nametype]
[-P date/offset]
[-P sync date/offset]
[-p protocol] [-q]
[-R date/offset]
[-r randomdev]
[-S key]
[-s strength]
[-t type] [-V]
[-v level] {name}
DESCRIPTION¶
dnssec-keygen generates keys for DNSSEC (Secure DNS), as
defined in RFC 2535 and RFC 4034. It can also generate keys for use with
TSIG (Transaction Signatures) as defined in RFC 2845, or TKEY (Transaction
Key) as defined in RFC 2930.
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
generated.
OPTIONS¶
-3
Use 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 will be used; for example, dnssec-keygen
-3a RSASHA1 specifies the NSEC3RSASHA1 algorithm.
-a algorithm
Selects the cryptographic algorithm. For DNSSEC keys, the
value of
algorithm must be one of RSAMD5, RSASHA1, DSA, NSEC3RSASHA1,
NSEC3DSA, RSASHA256, RSASHA512, ECCGOST, ECDSAP256SHA256, ECDSAP384SHA384,
ED25519 or ED448. For TSIG/TKEY, the value must be DH (Diffie Hellman),
HMAC-MD5, HMAC-SHA1, HMAC-SHA224, HMAC-SHA256, HMAC-SHA384, or HMAC-SHA512.
These values are case insensitive.
If no algorithm is specified, then RSASHA1 will be used by
default, unless the -3 option is specified, in which case
NSEC3RSASHA1 will be used instead. (If -3 is used and an algorithm is
specified, that algorithm will be checked for compatibility with NSEC3.)
Note 1: that for DNSSEC, RSASHA1 is a mandatory to implement
algorithm, and DSA is recommended. For TSIG, HMAC-MD5 is mandatory.
Note 2: DH, HMAC-MD5, and HMAC-SHA1 through HMAC-SHA512
automatically set the -T KEY option.
-b keysize
Specifies the number of bits in the key. The choice of
key size depends on the algorithm used. RSA keys must be between 512 and 2048
bits. Diffie Hellman keys must be between 128 and 4096 bits. DSA keys must be
between 512 and 1024 bits and an exact multiple of 64. HMAC keys must be
between 1 and 512 bits. Elliptic curve algorithms don't need this parameter.
The key size does not need to be specified if using a default
algorithm. The default key size is 1024 bits for zone signing keys (ZSKs)
and 2048 bits for key signing keys (KSKs, generated with -f KSK).
However, if an algorithm is explicitly specified with the -a, then
there is no default key size, and the -b must be used.
-C
Compatibility mode: generates an old-style key, without
any timing metadata. By default, dnssec-keygen will include the key's
creation date in the metadata stored with the private key, and other dates may
be set there as well (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
Indicates that the DNS record containing the key should
have the specified class. If not specified, class IN is used.
-E engine
Specifies the cryptographic hardware to use, when
applicable.
When BIND is built with OpenSSL PKCS#11 support, this defaults to
the string "pkcs11", which identifies an OpenSSL engine that can
drive a cryptographic accelerator or hardware service module. When BIND is
built with native PKCS#11 cryptography (--enable-native-pkcs11), it defaults
to the path of the PKCS#11 provider library specified via
"--with-pkcs11".
-f flag
Set the specified flag in the flag field of the
KEY/DNSKEY record. The only recognized flags are KSK (Key Signing Key) and
REVOKE.
-G
Generate a key, but do not publish it or sign with it.
This option is incompatible with -P and -A.
-g generator
If generating a Diffie Hellman key, use this generator.
Allowed values are 2 and 5. If no generator is specified, a known prime from
RFC 2539 will be used if possible; otherwise the default is 2.
-h
Prints a short summary of the options and arguments to
dnssec-keygen.
-K directory
Sets the directory in which the key files are to be
written.
-k
Deprecated in favor of -T KEY.
-L ttl
Sets the default TTL to use for this key when it is
converted into a DNSKEY RR. If the key is imported into a zone, this is the
TTL that will be used for it, unless there was already a DNSKEY RRset in
place, in which case the existing TTL would take precedence. If this value is
not set and there is no existing DNSKEY RRset, the TTL will default to the SOA
TTL. Setting the default TTL to 0 or none is the same as leaving it
unset.
-n nametype
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.
Defaults to ZONE for DNSKEY generation.
-p protocol
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 and
its successors.
-q
Quiet mode: Suppresses unnecessary output, including
progress indication. Without this option, when dnssec-keygen is run
interactively to generate an RSA or DSA key pair, it will print a string of
symbols to stderr indicating the progress of the key generation. A '.'
indicates that a random number has been found which passed an initial sieve
test; '+' means a number has passed a single round of the Miller-Rabin
primality test; a space means that the number has passed all the tests and is
a satisfactory key.
-r randomdev
Specifies a source of randomness. Normally, when
generating DNSSEC keys, this option has no effect; the random number
generation function provided by the cryptographic library will be used.
If that behavior is disabled at compile time, however, the
specified file will be used as entropy source for key generation. randomdev
is the name of a character device or file containing random data to be used.
The special value keyboard indicates that keyboard input should be used.
The default is /dev/random if the operating system provides it or
an equivalent device; if not, the default source of randomness is keyboard
input.
-S key
Create a new key which is an explicit successor to an
existing key. The name, algorithm, size, and type of the key will be set to
match the existing key. The activation date of the new key will be set to the
inactivation date of the existing one. The publication date will be set to the
activation date minus the prepublication interval, which defaults to 30
days.
-s strength
Specifies the strength value of the key. The strength is
a number between 0 and 15, and currently has no defined purpose in
DNSSEC.
-T rrtype
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). Using
any TSIG algorithm (HMAC-* or DH) forces this option to KEY.
-t type
Indicates the use 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
the ability to encrypt data.
-V
Prints version information.
-v level
Sets the debugging level.
TIMING OPTIONS¶
Dates can be expressed in the format YYYYMMDD or YYYYMMDDHHMMSS.
If the argument begins with a '+' or '-', it is interpreted as an offset
from the present time. For convenience, if such an offset is followed by one
of the suffixes 'y', 'mo', 'w', 'd', 'h', or 'mi', then the offset 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, respectively.
Without a suffix, the offset is computed in seconds. To explicitly prevent a
date from being set, use 'none' or 'never'.
-P date/offset
Sets the date on which a key is to be published to the
zone. After that date, the key will be included in the zone but will not be
used to sign it. If not set, and if the -G option has not been used, the
default is "now".
-P sync date/offset
Sets the date on which CDS and CDNSKEY records that match
this key are to be published to the zone.
-A date/offset
Sets the date on which the key is to be activated. After
that date, the key will be included in the zone and used to sign it. If not
set, and if the -G option has not been used, the default is "now".
If set, if and -P is not set, then the publication date will be set to the
activation date minus the prepublication interval.
-R date/offset
Sets the date on which the key is to be revoked. After
that date, the key will be flagged as revoked. It will be included in the zone
and will be used to sign it.
-I date/offset
Sets the date on which the key is to be retired. After
that date, the key will still be included in the zone, but it will not be used
to sign it.
-D date/offset
Sets the date on which the key is to be deleted. After
that date, the key will no longer be included in the zone. (It may remain in
the key repository, however.)
-D sync date/offset
Sets the date on which the CDS and CDNSKEY records that
match this key are to be deleted.
-i interval
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 isn't, then
the publication date will default to this much time before the activation
date; conversely, if the publication date is specified but activation date
isn't, then activation will be 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; otherwise it is
zero.
As with date offsets, if the argument is followed by one of the
suffixes 'y', 'mo', 'w', 'd', 'h', or 'mi', then 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.private contains the private key.
The .key file contains a DNS KEY record that can be inserted into
a zone file (directly or with a $INCLUDE statement).
The .private file contains algorithm-specific fields. For obvious
security reasons, this file does not have general read permission.
Both .key and .private files are generated for symmetric
cryptography algorithms such as HMAC-MD5, even though the public and private
key are equivalent.
EXAMPLE¶
To generate a 768-bit DSA key for the domain example.com,
the following command would be issued:
dnssec-keygen -a DSA -b 768 -n ZONE example.com
The command would print a string of the form:
Kexample.com.+003+26160
In this example, dnssec-keygen creates the files
Kexample.com.+003+26160.key and Kexample.com.+003+26160.private.
To generate a matching key-signing key, issue the command:
dnssec-keygen -a DSA -b 768 -n ZONE -f KSK example.com
SEE ALSO¶
dnssec-signzone(8), BIND 9 Administrator Reference Manual,
RFC 2539, RFC 2845, RFC 4034.
AUTHOR¶
Internet Systems Consortium, Inc.
COPYRIGHT¶
Copyright © 2000-2005, 2007-2012, 2014-2021 Internet
Systems Consortium, Inc. ("ISC")