## Name

dnssec-keygen — DNSSEC key generation tool

## Synopsis

`dnssec-keygen` [`-a `algorithm``] [`-b `keysize``] [`-n `nametype``] [`-3`] [`-A `date/offset``] [`-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``] [`-P `date/offset``] [`-P sync `date/offset``] [`-p `protocol``] [`-q`] [`-R `date/offset``] [`-S `key``] [`-s `strength``] [`-t `type``] [`-V`] [`-v `level``] [`-z`] {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.

The dnssec-keymgr command acts as a wrapper around dnssec-keygen, generating and updating keys as needed to enforce defined security policies such as key rollover scheduling. Using dnssec-keymgr may be preferable to direct use of dnssec-keygen.

## OPTIONS

-a `algorithm`

  Selects the cryptographic algorithm. For DNSSEC keys, the value of `algorithm` must be one of RSAMD5, RSASHA1, DSA, NSEC3RSASHA1, NSEC3DSA, RSASHA256, RSASHA512, ECDSAP256SHA256, ECDSAP384SHA384, ED25519 or ED448. For TKEY, the value must be DH (Diffie Hellman); specifying his value will automatically set the `-T KEY` option as well.

  These values are case insensitive. In some cases, abbreviations are supported, such as ECDSA256 for ECDSAP256SHA256 and ECDSA384 for ECDSAP384SHA384. If RSASHA1 or DSA is specified along with the `-3` option, then NSEC3RSASHA1 or NSEC3DSA will be 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 has been removed as of BIND 9.13.0. Use tsig-keygen to generate TSIG keys.

-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 1024 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.

  If the key size is not specified, some algorithms have pre-defined 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.

-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.

-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.

-C

  Compatibility mode: generates an old-style key, without any 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.

-p `protocol`

  Sets the protocol value for the generated 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.

-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).

  Specifying any TSIG algorithm (HMAC-* or DH) with `-a` forces this option to KEY.

-t `type`

  Indicates the use of the 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 `level`

  Sets the debugging level.

-V

  Prints version information.

## 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`.

## SEE ALSO

dnssec-signzone(8) , BIND 9 Administrator Reference Manual, RFC 2539, RFC 2845, RFC 4034.