DNSSEC-KEYGEN(8)

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] [-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

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

-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 RSASHA1, NSEC3RSASHA1, 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 is specified along with the -3 option, then NSEC3RSASHA1 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 4096 bits. Diffie Hellman keys must be between 128 and 4096 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.

-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.

-d bits
    Key size in bits. For the algorithms RSASHA1, NSEC3RSASA1, RSASHA256 and RSASHA512 the key size must be in range 1024-4096. DH size is between 128 and 4096. This option is ignored for algorithms ECDSAP256SHA256, ECDSAP384SHA384, ED25519 and ED448.

-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 policy
    Create keys for a specific dnssec-policy. If a policy uses multiple keys, dnssec-keygen will generate multiple keys. This will also create 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 together with 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. 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.

-l file
    Provide 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. 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.

-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).

-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 DNSKEY or KEY record. When a zone is being signed by named or dnssec-signzone -S, DNSKEY records are included automatically. In other cases, the .key file can be inserted into a zone file manually or with a $INCLUDE statement.

    The .private file contains algorithm-specific fields. For obvious security reasons, this file does not have general read permission.

EXAMPLE

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

dnssec-keygen -a ECDSAP256SHA256 example.com

The command would print a string of the form:

Kexample.com.+013+26160

In this example, dnssec-keygen creates the files Kexample.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), BIND 9 Administrator Reference Manual, RFC 2539, RFC 2845, RFC 4034.

AUTHOR
Internet Systems Consortium

COPYRIGHT
2020, Internet Systems Consortium