dnssec-keygen - DNSSEC key generation tool
dnssec-keygen -a algorithm -b keysize -n nametype [ -c class ] [ -e ]
[ -g generator ] [ -h ] [ -p protocol ] [ -r randomdev ] [ -s
strength ] [ -t type ] [ -v level ] name
dnssec-keygen generates keys for DNSSEC (Secure DNS), as defined in RFC
2535. It can also generate keys for use with TSIG (Transaction Signa-
tures), as defined in RFC 2845.
Selects the cryptographic algorithm. The value of algorithm must
be one of RSAMD5 or RSA, DSA, DH (Diffie Hellman), or HMAC-MD5.
These values are case insensitive.
Note that for DNSSEC, DSA is a mandatory to implement algorithm,
and RSA is recommended. For TSIG, HMAC-MD5 is mandatory.
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-MD5 keys must be between 1 and 512 bits.
Specifies the owner type of the key. The value of nametype must
either be ZONE (for a DNSSEC zone key), HOST or ENTITY (for a
key associated with a host), or USER (for a key associated with
a user). These values are case insensitive.
Indicates that the DNS record containing the key should have the
specified class. If not specified, class IN is used.
-e If generating an RSA key, use a large exponent.
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
-h Prints a short summary of the options and arguments to dnssec-
Sets the protocol value for the generated key. The protocol is a
number between 0 and 255. The default is 2 (email) for keys of
type USER and 3 (DNSSEC) for all other key types. Other possi-
ble values for this argument are listed in RFC 2535 and its suc-
Specifies the source of randomness. If the operating system does
not provide a /dev/random or equivalent device, the default
source of randomness is keyboard input. randomdev specifies the
name of a character device or file containing random data to be
used instead of the default. The special value keyboard indi-
cates that keyboard input should be used.
Specifies the strength value of the key. The strength is a num-
ber between 0 and 15, and currently has no defined purpose in
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.
Sets the debugging level.
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. These strings can be used as argu-
ments to dnssec-makekeyset.
o nnnn is the key name.
o aaa is the numeric representation of the algorithm.
o iiiii is the key identifier (or footprint).
dnssec-keygen creates two file, 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 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 secu-
rity reasons, this file does not have general read permission.
Both .key and .private files are generated for symmetric encryption
algorithm such as HMAC-MD5, even though the public and private key are
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:
In this example, dnssec-keygen creates the files Kexam-
ple.com.+003+26160.key and Kexample.com.+003+26160.private
dnssec-makekeyset(8), dnssec-signkey(8), dnssec-signzone(8), BIND 9
Administrator Reference Manual, RFC 2535, RFC 2845, RFC 2539.
Internet Software Consortium
BIND9 June 30, 2000 DNSSEC-KEYGEN(8)