#!/usr/bin/perl

use strict;
use warnings;

my ($keyserver, $getEmails);

BEGIN {
    $keyserver = shift || 'subkeys.pgp.net:11371';  # the keyserver to use
    $getEmails = undef;                             # wether to get emails or not
}

$, = $\ = $/; # ;-)

use LWP::Simple;
use URI::Find;

use if $getEmails => 'Email::Find';
use if $getEmails => 'PGP::FindKey'; # mainly compile time death
BEGIN {
    unless (eval { require Crypt::OpenPGP::KeyServer }){ # getting ugly
        
        ## the following emulates Crypt::OpenPGP::Keyserver, in a not so pretty way.
        
        *Crypt::OpenPGP::KeyServer::new = sub { # create a new object
            my $pkg = shift;
            my %conf = @_;
            bless \$conf{Server}, $pkg; # fill it only with the keyserver setting
        };
        
        *Crypt::OpenPGP::KeyServer::find_keyblock_by_uid = sub { # fetch a key via uid - wraps around PGP::FindKey - not much fun.
            my $self = shift;
            my $str = shift;
            my $id = PGP::FindKey->new(
                keyserver   => $keyserver,
                address     => $str,
            )->result;
            
            $self->find_keyblock_by_keyid(pack("H*",$id)); # "find" they key ID. PGP::FindKey only gives back one key
        };
        
        *Crypt::OpenPGP::KeyServer::find_keyblock_by_keyid = sub { # fetch a key via it's id - constructs a simple URL
            my $self = shift;
            my $id = unpack("H*", shift);
            
            my $url = "http://" . $$self . '/pks/lookup?op=get&search=0x' . $id; # the URL we'll be fetching
            
            filter_key_blocks(LWP::Simple::get($url)); # give back an array or string of key blocks, made from the return value of the HTTP get
        };
    }
}

my $kbs = Crypt::OpenPGP::KeyServer->new(
    Server => $keyserver,
);

my @finders = ( # the general interface is the same, so we've grouped them

    URI::Find->new(sub { # to find URLS
        print filter_key_blocks(get(shift)); # get the URL using LWP::Simple, and filter key blocks out of it
        return shift;
    }),

    ($getEmails ? Email::Find->new(sub { # to find emails, if at all
        my $emails = shift;
        foreach my $email (@$emails){ print $kbs->find_keyblock_by_uid($email) || '' }; # run the list of emails through the key server object, and print the results out
        return shift;
    }) : () ),
    
);

sub get_id { # a shortcut to print a key by it's ID
    print $kbs->find_keyblock_by_keyid(pack 'H*', shift) || '';
}

sub filter_key_blocks {
    my $str = shift;
    my @blocks = $str =~ /(-----BEGIN PGP PUBLIC KEY BLOCK-----.*?-----END PGP PUBLIC KEY BLOCK-----)/sg; # get all the blocks, nothing more
    return wantarray ? @blocks : join($/, @blocks); # join if scalar context
}

while (<>){
    #study;
    foreach my $uid (/\b(?:0x)((?:[a-fA-F0-9]{8}){1,2})\b/g){ get_id($uid) }; # matches ID
    foreach my $finder (@finders) { $finder->find(\$_) }; # run the canned matches on the input
}