NAME

       Net::DNS::RR::TSIG - DNS TSIG resource record

SYNOPSIS

           use Net::DNS;
           $tsig = create Net::DNS::RR::TSIG( $keyfile );

           $tsig = create Net::DNS::RR::TSIG( $keyfile,
                                               fudge => 300
                                               );

DESCRIPTION

       Class for DNS Transaction Signature (TSIG) resource records.

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.

   algorithm
           $algorithm = $rr->algorithm;
           $rr->algorithm( $algorithm );

       A domain name which specifies the name of the algorithm.

   key
           $rr->key( $key );

       Base64 representation of the key material.

   keybin
           $rr->keybin( $keybin );

       Binary representation of the key material.

   time_signed
           $time_signed = $rr->time_signed;
           $rr->time_signed( $time_signed );

       Signing time as the number of seconds since 1 Jan 1970 00:00:00 UTC.  The default signing
       time is the current time.

   fudge
           $fudge = $rr->fudge;
           $rr->fudge( $fudge );

       "fudge" represents the permitted error in the signing time.  The default fudge is 300
       seconds.

   mac
           $mac = $rr->mac;

       Returns the message authentication code (MAC) as a string of hex characters.  The
       programmer must call the Net::DNS::Packet data() object method before this will return
       anything meaningful.

   macbin
           $macbin = $rr->macbin;
           $rr->macbin( $macbin );

       Binary message authentication code (MAC).

   prior_mac
           $prior_mac = $rr->prior_mac;
           $rr->prior_mac( $prior_mac );

       Prior message authentication code (MAC).

   prior_macbin
           $prior_macbin = $rr->prior_macbin;
           $rr->prior_macbin( $prior_macbin );

       Binary prior message authentication code.

   request_mac
           $request_mac = $rr->request_mac;
           $rr->request_mac( $request_mac );

       Request message authentication code (MAC).

   request_macbin
           $request_macbin = $rr->request_macbin;
           $rr->request_macbin( $request_macbin );

       Binary request message authentication code.

   original_id
           $original_id = $rr->original_id;
           $rr->original_id( $original_id );

       The message ID from the header of the original packet.

   error
   vrfyerrstr
            $rcode = $tsig->error;

       Returns the RCODE covering TSIG processing.  Common values are NOERROR, BADSIG, BADKEY,
       and BADTIME.  See RFC 2845 for details.

   other
            $other = $tsig->other;

       This field should be empty unless the error is BADTIME, in which case it will contain the
       server time as the number of seconds since 1 Jan 1970 00:00:00 UTC.

   sig_function
           sub signing_function {
               my ( $keybin, $data ) = @_;

               my $hmac = new Digest::HMAC( $keybin, 'Digest::MD5' );
               $hmac->add( $data );
               return $hmac->digest;
           }

           $tsig->sig_function( \&signing_function );

       This sets the signing function to be used for this TSIG record.  The default signing
       function is HMAC-MD5.

   sig_data
            $sigdata = $tsig->sig_data($packet);

       Returns the packet packed according to RFC2845 in a form for signing. This is only needed
       if you want to supply an external signing function, such as is needed for TSIG-GSS.

   create
           $tsig = create Net::DNS::RR::TSIG( $keyfile );

           $tsig = create Net::DNS::RR::TSIG( $keyfile,
                                               fudge => 300
                                               );

       Returns a TSIG RR constructed using the parameters in the specified key file, which is
       assumed to have been generated by dnssec-keygen.

           $tsig = create Net::DNS::RR::TSIG( $keyname, $key );

       The two argument form is supported for backward compatibility.

   verify
           $verify = $tsig->verify( $data );
           $verify = $tsig->verify( $packet );

           $verify = $tsig->verify( $reply,  $query );

           $verify = $tsig->verify( $packet, $prior );

       The boolean verify method will return true if the hash over the packet data conforms to
       the data in the TSIG itself

TSIG Keys

       TSIG keys are symmetric keys generated using dnssec-keygen:

               $ dnssec-keygen -a HMAC-SHA1 -b 160 -n HOST <keyname>

               The key will be stored as a private and public keyfile pair
               K<keyname>+161+<keyid>.private and K<keyname>+161+<keyid>.key

           where
               <keyname> is the DNS name of the key.

               <keyid> is the (generated) numerical identifier used to
               distinguish this key.

       Other algorithms may be substituted for HMAC-SHA1 in the above example.

       It is recommended that the keyname be globally unique and incorporate the fully qualified
       domain names of the resolver and nameserver in that order. It should be possible for more
       than one key to be in use simultaneously between any such pair of hosts.

       Although the formats differ, the private and public keys are identical and both should be
       stored and handled as secret data.

Configuring BIND Nameserver

       The following lines must be added to the /etc/named.conf file:

           key <keyname> {
               algorithm HMAC-SHA1;
               secret "<keydata>";
           };

       <keyname> is the name of the key chosen when the key was generated.

       <keydata> is the key string extracted from the generated key file.

ACKNOWLEDGMENT

       Most of the code in the Net::DNS::RR::TSIG module was contributed by Chris Turbeville.

       Support for external signing functions was added by Andrew Tridgell.

       TSIG verification, BIND keyfile handling and support for HMAC-SHA1, HMAC-SHA224,
       HMAC-SHA256, HMAC-SHA384 and HMAC-SHA512 functions was added by Dick Franks.

BUGS

       A 32-bit representation of time is used, contrary to RFC2845 which demands 48 bits.  This
       design decision will need to be reviewed before the code stops working on 7 February 2106.

COPYRIGHT

       Copyright (c)2000,2001 Michael Fuhr.

       Portions Copyright (c)2002,2003 Chris Reinhardt.

       Portions Copyright (c)2013 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 above copyright notice
       appear in all copies and that both that 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, RFC2845, RFC4635

       TSIG Algorithm Names <http://www.iana.org/assignments/tsig-algorithm-names>