dnssec-keygen Command

Purpose

Domain name system security extensions (DNSSEC) key generation tool.

Syntax

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] [-G] [-g generator] [-h] [-I date/offset] [-i interval] [-K directory] [-k policy] [-L ttl] [-l file] [-n nametype] [-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

The dnssec-keygen command generates keys for DNSSEC (Secure DNS), as defined in RFC 2535 and RFC 4034. It can also generate keys to use with Transaction Signatures (TSIG) as defined in RFC 2845, or Transaction Key (TKEY) as defined in RFC 2930.

start of change 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. end of change

start of change The dnssec-keymgr command acts as a wrapper around dnssec-keygen command, 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. end of change

Flags

Item	Description
-3	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 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 `RSASHA1`, `NSEC3RSASHA1`, `RSASHA256`, `RSASHA512`, `ECDSAP256SHA256`, `ECDSAP384SHA384`, `ED25519`, or `ED448`. For `TKEY`, the value must be DH (Diffie-Hellman); specifying this value automatically sets 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` is specified along with the -3 option, `NSEC3RSASHA1` 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 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 4096 bits; Diffie-Hellman keys must be between 128 and 4096 bits. Elliptic curve algorithms do not 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.
-C	Enables compatibility mode, which generates an old-style key, without any timing metadata. By default, dnssec-keygen command 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`	Indicates that the Domain Name Server (DNS) record that contains the key must have the specified class. If not specified, class IN is used.
-d `bite`	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`, `ECDSAP384SHA384`, `ED25519`, and `ED448`.
-E `engine`	Specifies the cryptographic hardware to use, when applicable. When BIND 9 is built with OpenSSL, this needs to be set to the OpenSSL engine identifier that drives the cryptographic accelerator or hardware service module (usually pkcs11). 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`	Sets the specified flag in the `flag` field of the KEY or the DNSKEY record. The only recognized flag is KSK (Key Signing Key) DNSKEY.
-G	Generates a key, but does not publish it or sign with it. This option is incompatible with -P and -A.
-g `generator`	Indicates the generator to use if generating a Diffie-Hellman key. Allowed values are 2 and 5. If no generator is specified, a known prime from RFC 2539 is used if possible; otherwise the default is 2.
-h	Prints a short summary of the options and arguments to dnssec-keyfromlabel.
-K directory	Sets the directory in which the key files are to be written.
-k `policy`	Creates keys for a specific dnssec-policy. If a policy 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 configuration, hence it cannot be used at the same time as many of the other options that dnssec-keygen provides.
-L `ttl`	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 would take precedence. Setting the default TTL to `0` or `none` removes it.
-l `file`	This option provides a configuration file that contains a dnssec-policy statement (matching the policy set with -k).
-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. The default is `ZONE` for DNSKEY generation.
-p `protocol`	Sets the protocol value for the generated key. The protocol is a number 0 - 255. The default is 3 (DNSSEC). Other possible values for this argument are listed in RFC 2535 and its successors.
-q	Sets quiet mode, which suppresses unnecessary output, including progress indication. Without this option, when dnssec-keygen command 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 number 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`	The activation date of the new key is set to the inactivation date of the existing one. The publication date is set to the activation date minus the pre-publication 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. The `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`	Indicates the use of the key. The `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.

Timings flags

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.

Item	Description
-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.
-P 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 default is the current date. If set, and -P is not set, the publication date is set to the activation date minus the pre-publication interval.
-R `date/offset`	This option sets the date on which the key is to be revoked. After 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. After 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. After that date, the key is no longer included in the zone. (However, it may remain in the key repository.)
-D 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 pre-publication 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 publication 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 pre-publication 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`, the interval is measured in years, months, weeks, days, hours, or minutes, respectively. Without a suffix, the interval is measured in seconds.

Parameters

Item	Description
name	The name of the key that is specified on the command line. For DNSSEC keys, this name must match the name of the zone for which the key is being generated.

Generated Keys

When the dnssec-keygen command completes successfully, it prints a string of the form Knnnn.+aaa+iiiii to the standard output. It is an identification string for the key that it generated.

nnnn is the key name.
aaa is the numeric representation of the algorithm.
iiiii is the key identifier (or footprint).

The dnssec-keygen command 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 DNSKEY record that can be inserted into a zone file (directly or with a $INCLUDE statement). The .private file contains algorithm-specific fields. For security reasons, this file does not have general read permission. Both the .key and .private files are generated for symmetric encryption algorithm such as HMAC-MD5, even though the public key and the private key are equivalent.

Examples

To generate an ECDSAP256SHA256 zone-signing key for the zone example.com, type the following command:

dnssec-keygen -a ECDSAP256SHA256 example.com

The command prints a string of the form:

Kexample.com.+013+26160

In this example, dnssec-keygen command creates the files Kexample.com.+013+26160.key and Kexample.com.+013+26160.private.

To generate a matching key-signing key, type the following command:

dnssec-keygen -a ECDSAP256SHA256 -f KSK example.com