Net::DNS::RR::RRSIG(3)
NAME
Net::DNS::RR::RRSIG - DNS RRSIG resource record
SYNOPSIS
use Net::DNS;
$rr = Net::DNS::RR->new('name RRSIG typecovered algorithm labels
orgttl sigexpiration siginception
keytag signame signature');
use Net::DNS::SEC;
$sigrr = Net::DNS::RR::RRSIG->create( \@rrset, $keypath,
sigex => 20211231010101
sigin => 20211201010101
);
$sigrr->verify( \@rrset, $keyrr ) || die $sigrr->vrfyerrstr;
DESCRIPTION
Class for DNS digital signature (RRSIG) resource records.
In addition to the regular methods inherited from Net::DNS::RR the
class contains a method to sign RRsets using private keys (create) and
a method for verifying signatures over RRsets (verify).
The RRSIG RR is an implementation of RFC4034. See Net::DNS::RR::SIG
for an implementation of SIG0 (RFC2931).
METHODS
The available methods are those inherited from the base class augmented
by the type-specific methods defined in this package.
Use of undocumented package features or direct access to internal data
structures is discouraged and could result in program termination or
other unpredictable behaviour.
typecovered
$typecovered = $rr->typecovered;
The typecovered field identifies the type of the RRset that is covered
by this RRSIG record.
algorithm
$algorithm = $rr->algorithm;
The algorithm number field identifies the cryptographic algorithm used
to create the signature.
algorithm() may also be invoked as a class method or simple function to
perform mnemonic and numeric code translation.
labels
$labels = $rr->labels;
$rr->labels( $labels );
The labels field specifies the number of labels in the original RRSIG
RR owner name.
orgttl
$orgttl = $rr->orgttl;
$rr->orgttl( $orgttl );
The original TTL field specifies the TTL of the covered RRset as it
appears in the authoritative zone.
sigexpiration and siginception times
sigex sigin sigval
$expiration = $rr->sigexpiration;
$expiration = $rr->sigexpiration( $value );
$inception = $rr->siginception;
$inception = $rr->siginception( $value );
The signature expiration and inception fields specify a validity time
interval for the signature.
The value may be specified by a string with format 'yyyymmddhhmmss' or
a Perl time() value.
Return values are dual-valued, providing either a string value or
numerical Perl time() value.
keytag
$keytag = $rr->keytag;
$rr->keytag( $keytag );
The keytag field contains the key tag value of the DNSKEY RR that
validates this signature.
signame
$signame = $rr->signame;
$rr->signame( $signame );
The signer name field value identifies the owner name of the DNSKEY RR
that a validator is supposed to use to validate this signature.
signature
sig
$sig = $rr->sig;
$rr->sig( $sig );
The Signature field contains the cryptographic signature that covers
the RRSIG RDATA (excluding the Signature field) and the RRset specified
by the RRSIG owner name, RRSIG class, and RRSIG type covered fields.
sigbin
$sigbin = $rr->sigbin;
$rr->sigbin( $sigbin );
Binary representation of the cryptographic signature.
create
Create a signature over a RR set.
use Net::DNS::SEC;
$keypath = '/home/olaf/keys/Kbla.foo.+001+60114.private';
$sigrr = Net::DNS::RR::RRSIG->create( \@rrsetref, $keypath );
$sigrr = Net::DNS::RR::RRSIG->create( \@rrsetref, $keypath,
sigex => 20211231010101
sigin => 20211201010101
);
$sigrr->print;
# Alternatively use Net::DNS::SEC::Private
$private = Net::DNS::SEC::Private->new($keypath);
$sigrr= Net::DNS::RR::RRSIG->create( \@rrsetref, $private );
create() is an alternative constructor for a RRSIG RR object.
This method returns an RRSIG with the signature over the subject rrset
(an array of RRs) made with the private key stored in the key file.
The first argument is a reference to an array that contains the RRset
that needs to be signed.
The second argument is a string which specifies the path to a file
containing the private key as generated by dnssec-keygen.
The optional remaining arguments consist of ( name => value ) pairs as
follows:
sigex => 20211231010101, # signature expiration
sigin => 20211201010101, # signature inception
sigval => 30, # validity window (days)
ttl => 3600 # TTL
The sigin and sigex values may be specified as Perl time values or as a
string with the format 'yyyymmddhhmmss'. The default for sigin is the
time of signing.
The sigval argument specifies the signature validity window in days (
sigex = sigin + sigval ).
By default the signature is valid for 30 days.
By default the TTL matches the RRset that is presented for signing.
verify
$verify = $sigrr->verify( $rrsetref, $keyrr );
$verify = $sigrr->verify( $rrsetref, [$keyrr, $keyrr2, $keyrr3] );
$rrsetref contains a reference to an array of RR objects and the method
verifies the RRset against the signature contained in the $sigrr object
itself using the public key in $keyrr.
The second argument can either be a Net::DNS::RR::KEYRR object or a
reference to an array of such objects. Verification will return
successful as soon as one of the keys in the array leads to positive
validation.
Returns 0 on error and sets $sig->vrfyerrstr
vrfyerrstr
$verify = $sigrr->verify( $rrsetref, $keyrr );
print $sigrr->vrfyerrstr unless $verify;
$sigrr->verify( $rrsetref, $keyrr ) || die $sigrr->vrfyerrstr;
KEY GENERATION
Private key files and corresponding public DNSKEY records are most
conveniently generated using dnssec-keygen, a program that comes with
the ISC BIND distribution.
dnssec-keygen -a 10 -b 2048 -f ksk rsa.example.
dnssec-keygen -a 10 -b 1024 rsa.example.
dnssec-keygen -a 14 -f ksk ecdsa.example.
dnssec-keygen -a 14 ecdsa.example.
Do not change the name of the private key file. The create method uses
the filename as generated by dnssec-keygen to determine the keyowner,
algorithm, and the keyid (keytag).
REMARKS
The code is not optimised for speed. It is probably not suitable to be
used for signing large zones.
If this code is still around in 2100 (not a leap year) you will need to
check for proper handling of times after 28th February.
ACKNOWLEDGMENTS
Although their original code may have disappeared following redesign of
Net::DNS, Net::DNS::SEC and the OpenSSL API, the following individual
contributors deserve to be recognised for their significant influence
on the development of the RRSIG package.
Andy Vaskys (Network Associates Laboratories) supplied code for RSA.
T.J. Mather provided support for the DSA algorithm.
Dick Franks added support for elliptic curve and Edwards curve
algorithms.
Mike McCauley created the Crypt::OpenSSL::ECDSA perl extension module
specifically for this development.
COPYRIGHT
Copyright (c)2001-2005 RIPE NCC, Olaf M. Kolkman
Copyright (c)2007-2008 NLnet Labs, Olaf M. Kolkman
Portions Copyright (c)2014 Dick Franks
All rights reserved.
Package template (c)2009,2012 O.M.Kolkman and R.W.Franks.
LICENSE
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the original copyright notices appear in all copies and
that both copyright notice and this permission notice appear in
supporting documentation, and that the name of the author not be used
in advertising or publicity pertaining to distribution of the software
without specific prior written permission.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
SEE ALSO
perl(1), Net::DNS(3), Net::DNS::RR(3), Net::DNS::SEC(3), RFC4034,
Algorithm Numbers <http://www.iana.org/assignments/dns-sec-alg-numbers>
BIND 9 Administrator Reference Manual <http://www.bind9.net/manuals>
perl v5.30.3 2021-12-16 Net::DNS::RR::RRSIG(3)
net-dns 1.330.0 - Generated Fri Dec 24 13:10:18 CST 2021