#!/home/ben/software/install/bin/perl
use warnings;
use strict;
use CGI;
use LWP::UserAgent;
use JSON::Parse 'parse_json';

my $secret = 'ThisIsNotARealOne';
my $gurl = 'https://www.google.com/recaptcha/api/siteverify';

my $cgi = CGI->new ();

if (! check_captcha ($cgi)) {
    # OK
}

sub check_captcha
{
    my ($icgi) = @_;
    my $ua = LWP::UserAgent->new ();
    my $response = $cgi->param ('g-recaptcha-response');
    my $remoteip = $ENV{REMOTE_ADDR};
    my $greply = $ua->post (
	$gurl,
        {
	    remoteip => $remoteip,
	    response => $response,
	    secret => $secret,
	},
    );
    if ($greply->is_success ()) {
	my $json = $greply->decoded_content ();
	my $out = parse_json ($json);
	if ($out->{success}) {
	    return undef;
	}
	return $json;
    }
    return "Connection to reCAPTCHA failed";
}