Provided by: libnet-dns-perl_1.34-1_all 
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, Net::DNS, Net::DNS::RR, Net::DNS::SEC, RFC4034
Algorithm Numbers <http://www.iana.org/assignments/dns-sec-alg-numbers>
BIND Administrator Reference Manual <http://bind.isc.org/>