#!/usr/bin/env perl

package SHA3;

use strict;
use warnings;

use Digest::SHA3 qw(sha3_256_hex);
use Digest::MD5 qw(md5_hex);
use Socket qw( inet_pton AF_INET AF_INET6 );

my @packing = qw( 
    fa13a941b76466850c2558d9ae5d969f
    e71ab0d8bb54c75b37ad23a449050121
    6736564ec6bc9bbc8ba42df565317443
    c3e088a5cf247ec0df971c5cb9ee6eec
    6cf20d548878cdd82b8f207192f58c80
    660a311b8d75d5fb28c73f7e2ec5d25e
    377f92899b81ad7c5e1d08b81ccc8904
    8e1f27dee8ae3374ae5c462adf37bba5
    ccd558ff6b9de48ca22023ead2dbd7a2
    ff228ef28ae8544155323180ba070d1b
);

print SHA3::sha3_ip('1.2.3.4'), "\n";
print SHA3::sha3_ip('1.2.3.5'), "\n";
print SHA3::sha3_ip('2001:0db8:0000:0000:0000:8a2e:0370:7334'), "\n";
print SHA3::sha3_ip('2001:0db8:0000:0000:0000:8a2e:0370:7335'), "\n";
print SHA3::sha3_bs('Mozilla'), "\n";
print SHA3::sha3_bs('Win32'), "\n";

=head 2 sha3_ip {

    Expects a dot quad or an IPv6 address and returns a 
    SHA3_256_hex string or null string for invalid input

=cut

sub sha3_ip {
    my $ip = shift;

    my $pack_format;
    if ( $ip =~ m/^\d+\.\d+\.\d+\.\d+$/ ) { 
        my $bytes = pack("H32 a4 H32", $packing[0], inet_pton( AF_INET, $ip ), $packing[7]);
        my $hash = sha3_256_hex($bytes);
        return $hash;
    }   
    elsif ( $ip =~ /^([0-9a-f]{0,4}:){0,7}([0-9a-f]{0,4})$/i ) { 
        my $bytes = pack("H32 a16 H32", $packing[0], inet_pton( AF_INET6, $ip ), $packing[7]);
        my $hash = sha3_256_hex($bytes);
        return $hash;
    }   

    warn "Invalid IP:$ip\n";
    return ''; 
}

=head 2 sha3_bs {

    Expects a browser string and returns a 
    SHA3_256_hex string or a null string for invalid input

=cut


sub sha3_bs {
    my $bs = shift;
    unless (length $bs > 4 ) { 
        warn "Insufficient data in browser string $bs";
        return ''; 
    }   
    my $bytes = pack("H32 H32 H32", $packing[1], md5_hex($bs), $packing[8]);
    my $hash = sha3_256_hex($bytes);
    return $hash;
}