tinyDNS deconstruct.

[0xdeadbad]

Could somebody lend a hand with deconstructing tinydns CAA records please.

"\000\005issueentrust.net"   > "CAA   IN  0       issue entrust.net"
                                          [flag]  [tag] [issuer]

The first octal is the Flag ( 000 )
The second octal ( 005 ) is the taglength and used to deduce the tag and issuer from the ascii string.

If I could just get "\000\005issueentrust.net" translated to "0,5,issueentrust.net" that would be a great help. I've been looking at pack and unpack but cannot work it out as I'm not a real programmer.

many thanks

[AnomalousMonk]

... just get "\000\005issueentrust.net" translated to "0,5,issueentrust.net" ...

Try:

c:\@Work\Perl\monks>perl -wMstrict -le
"my $s = qq{\000\005issueentrust.net};
 $s =~ s{ \A (.) (.) }{ sprintf '%d,%d,', ord($1), ord($2) }xmse;
 print qq{'$s'};
"
'0,5,issueentrust.net'

Update 1: But this sounds like an XY Problem; it that really all you want?

Update 2: Here's an unpack approach:

c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le
"my $s = qq{\000\005issueentrust.net};
 my ($flag, $tag, $issuer) = unpack 'C C/a a*', $s;
 dd $flag, $tag, $issuer;
 my $t = sprintf '%-6s %s %s', $flag, $tag, $issuer;
 print qq{'$t'};
"
(0, "issue", "entrust.net")

'0      issue entrust.net'

(Update: Changed  $remainder to  $issuer in this code example because this naming corresponds better to terminology used in the OP.)

[0xdeadbad]

Great,many thanks. Your unpack template was just what I needed.

[atcroft]

I know you may have your reasons for looking at the record in a particular way, but why not use a module that is made for doing this, Net::DNS?

Below was a quick example of using Net::DNS to retrieve similar information:

Read more... (2 kB)

Hope that helps.