captive: Group settings together and create branding section

[ipfire-2.x.git] / html / cgi-bin / captive.cgi

#!/usr/bin/perl
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2016  IPFire Team  <alexander.marx@ipfire.org>                #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

#use strict;
use HTML::Entities();
use File::Basename;

# enable only the following on debugging purpose
#use warnings;
#use CGI::Carp 'fatalsToBrowser';

require '/var/ipfire/general-functions.pl';
require "${General::swroot}/lang.pl";
require "${General::swroot}/header.pl";

my $coupons = "${General::swroot}/captive/coupons";
my %couponhash = ();

my %settings=();
my %mainsettings;
my %color;
my %cgiparams=();
my %netsettings=();
my %checked=();
my $errormessage='';
my $clients="${General::swroot}/captive/clients";
my %clientshash=();
my $settingsfile="${General::swroot}/captive/settings";
my $logopath = "/srv/web/ipfire/html/captive/logo";
unless (-e $settingsfile)	{ system("touch $settingsfile"); }

&Header::getcgihash(\%cgiparams);

&General::readhash("${General::swroot}/main/settings", \%mainsettings);
&General::readhash("/srv/web/ipfire/html/themes/".$mainsettings{'THEME'}."/include/colors.txt", \%color);
&General::readhash("$settingsfile", \%settings) if(-f $settingsfile);
&General::readhash("${General::swroot}/ethernet/settings", \%netsettings);

&Header::showhttpheaders();

#actions
if ($cgiparams{'ACTION'} eq "$Lang::tr{'save'}"){
	my $file = $cgiparams{'uploaded_file'};
	if ($file){
		#Check if extension is png
		chomp $file;
		my ($name, $path, $ext) = fileparse($file, qr/\.[^.]*$/);
		if ($ext ne ".png"){
			$errormessage=$Lang::tr{'Captive wrong ext'};
		}
	}

	$settings{'ENABLE_GREEN'}		= $cgiparams{'ENABLE_GREEN'};
	$settings{'ENABLE_BLUE'}		= $cgiparams{'ENABLE_BLUE'};
	$settings{'AUTH'}				= $cgiparams{'AUTH'};
	$settings{'TITLE'}				= $cgiparams{'TITLE'};
	$settings{'UNLIMITED'}			= $cgiparams{'UNLIMITED'};
	$settings{'COLOR'}			= $cgiparams{'COLOR'};

	if (!$errormessage){
		#Check if we need to upload a new logo
		if($file){
			#Save File
			my ($filehandle) = CGI::upload('uploaded_file');
			open (UPLOADFILE, ">$logopath/logo.png");
			binmode $filehandle;
			while ( <$filehandle> ) {
				print UPLOADFILE;
			}
			close (UPLOADFILE);

			#Open file to check if dimensions are within rang
			open (PNG , "<$logopath/logo.png");
			local $/;
			my $PNG1=<PNG>;
			close(PNG);
			my ($width,$height)=&pngsize($PNG1);
			if($width > 1920 || $height > 800 || $width < 1280 || $height < 400){
				$errormessage.="$Lang::tr{'Captive invalid logosize'} <br>Filedimensions width: $width  height: $height ";
				unlink("$logopath/logo.png");
			}
		}

		&General::writehash("$settingsfile", \%settings);

		# Save terms
		if ($cgiparams{'TERMS'}){
			$cgiparams{'TERMS'} = &Header::escape($cgiparams{'TERMS'});
			open(FH, ">:utf8", "/var/ipfire/captive/terms.txt") or die("$!");
			print FH $cgiparams{'TERMS'};
			close(FH);
			$cgiparams{'TERMS'} = "";
		}

		#execute binary to reload firewall rules
		system("/usr/local/bin/captivectrl");

		if ($cgiparams{'ENABLE_BLUE'} eq 'on'){
				system("/usr/local/bin/wirelessctrl");
		}
	}
}

if ($cgiparams{'ACTION'} eq "$Lang::tr{'Captive generate coupon'}"){
	# Generates a new coupon

	#calculate expiredate
	my $expire;
	if ($settings{'UNLIMITED'} eq 'on'){
		$expire = $Lang::tr{'Captive nolimit'};
	}else{
		$settings{'EXPIRE'} = $cgiparams{'EXP_HOUR'}+$cgiparams{'EXP_DAY'}+$cgiparams{'EXP_WEEK'}+$cgiparams{'EXP_MONTH'};
		$expire = sub{sprintf '%02d.%02d.%04d %02d:%02d', $_[3], $_[4]+1, $_[5]+1900, $_[2], $_[1]  }->(localtime(time()+$settings{'EXPIRE'}));
    }

	#Check Expiretime
	if($cgiparams{'EXP_HOUR'}+$cgiparams{'EXP_DAY'}+$cgiparams{'EXP_WEEK'}+$cgiparams{'EXP_MONTH'} == 0 && $cgiparams{'UNLIMITED'} == ''){
		$errormessage=$Lang::tr{'Captive noexpiretime'};
	}
	#check if we already have a coupon with same code
	&General::readhasharray($coupons, \%couponhash) if (-e $coupons);
	foreach my $key (keys %couponhash) {
		if($couponhash{$key}[1] eq $cgiparams{'CODE'}){
			$errormessage=$Lang::tr{'Captive err doublevoucher'};
			last;
		}
	}

	#check valid remark
	if ($cgiparams{'REMARK'} ne '' && !&validremark($cgiparams{'REMARK'})){
		$errormessage=$Lang::tr{'fwhost err remark'};
	}

	#if no error detected, write to disk
	if (!$errormessage){
		my $date=time(); #seconds in utc

		#first get new key from hash
		my $key=&General::findhasharraykey (\%couponhash);
		#initialize all fields with ''
		foreach my $i (0 .. 3) { $couponhash{$key}[$i] = "";}
		#define fields
		$couponhash{$key}[0] = $date;
		$couponhash{$key}[1] = $cgiparams{'CODE'};
		$couponhash{$key}[2] = $settings{'EXPIRE'};
		$couponhash{$key}[3] = $cgiparams{'REMARK'};
		#write values to disk
		&General::writehasharray($coupons, \%couponhash);

		#now prepare log entry, get expiring date for voucher and decode remark for logfile
		my $expdate=localtime(time()+$couponhash{$key}[3]);
		my $rem=HTML::Entities::decode_entities($couponhash{$key}[4]);

		#write logfile entry
		&General::log("Captive", "Generated new coupon $couponhash{$key}[1] $couponhash{$key}[2] hours valid expires on $expdate remark $rem");
	}
}

if ($cgiparams{'ACTION'} eq 'delete-coupon') {
	#deletes an already generated but unused voucher

	#read all generated vouchers
	&General::readhasharray($coupons, \%couponhash) if (-e $coupons);
	foreach my $key (keys %couponhash) {
		if($cgiparams{'key'} eq $couponhash{$key}[0]){
			#write logenty with decoded remark
			my $rem=HTML::Entities::decode_entities($couponhash{$key}[4]);
			&General::log("Captive", "Delete unused coupon $couponhash{$key}[1] $couponhash{$key}[2] hours valid expires on $couponhash{$key}[3] remark $rem");
			#delete line from hash
			delete $couponhash{$key};
			last;
		}
	}
	#write back hash
	&General::writehasharray($coupons, \%couponhash);
}

if ($cgiparams{'ACTION'} eq 'delete-client') {
	#delete voucher and connection in use

	#read all active clients
	&General::readhasharray($clients, \%clientshash) if (-e $clients);
	foreach my $key (keys %clientshash) {
		if($cgiparams{'key'} eq $clientshash{$key}[0]){
			#prepare log entry with decoded remark
			my $rem=HTML::Entities::decode_entities($clientshash{$key}[7]);
			#write logentry
			&General::log("Captive", "Deleted client in use $clientshash{$key}[1] $clientshash{$key}[2] hours valid expires on $clientshash{$key}[3] remark $rem - Connection will be terminated");
			#delete line from hash
			delete $clientshash{$key};
			last;
		}
	}
	#write back hash
	&General::writehasharray("$clients", \%clientshash);
	#reload firewallrules to kill connection of client
	system("/usr/local/bin/captivectrl");
}

#open webpage, print header and open box
&Header::openpage($Lang::tr{'Captive menu'}, 1, '');
&Header::openbigbox();

#call error() to see if we have to print an errormessage on website
&error();

#call config() to display the configuration box
&config();

sub getterms(){
	my @ret;

	open(FILE, "<:utf8", "/var/ipfire/captive/terms.txt");
	while(<FILE>) {
		push(@ret, HTML::Entities::decode_entities($_));
	}
	close(FILE);

	return join(/\n/, @ret);
}

sub config(){
	#prints the config box on the website
	&Header::openbox('100%', 'left', $Lang::tr{'Captive config'});
	print <<END
		<form method='post' action='$ENV{'SCRIPT_NAME'}' enctype="multipart/form-data">\n
		<table width='100%' border="0">
		<tr>
END
;
	#check which parameters have to be enabled (from settings file)
	$checked{'ENABLE_GREEN'}{'off'} = '';
	$checked{'ENABLE_GREEN'}{'on'} = '';
	$checked{'ENABLE_GREEN'}{$settings{'ENABLE_GREEN'}} = "checked='checked'";

	$checked{'ENABLE_BLUE'}{'off'} = '';
	$checked{'ENABLE_BLUE'}{'on'} = '';
	$checked{'ENABLE_BLUE'}{$settings{'ENABLE_BLUE'}} = "checked='checked'";

	$checked{'UNLIMITED'}{'off'} = '';
	$checked{'UNLIMITED'}{'on'} = '';
	$checked{'UNLIMITED'}{$settings{'UNLIMITED'}} = "checked='checked'";

	if ($netsettings{'GREEN_DEV'}){
		print "<td width='30%'>$Lang::tr{'Captive active on'} <font color='$Header::colourgreen'>Green</font></td><td><input type='checkbox' name='ENABLE_GREEN' $checked{'ENABLE_GREEN'}{'on'} /></td></tr>";
	}
	if ($netsettings{'BLUE_DEV'}){
		print "<td width='30%'>$Lang::tr{'Captive active on'} <font color='$Header::colourblue'>Blue</font></td><td><input type='checkbox' name='ENABLE_BLUE' $checked{'ENABLE_BLUE'}{'on'} /></td></tr>";
	}

print<<END
		</tr>
		<tr>
			<td>
				$Lang::tr{'Captive authentication'}
			</td>
			<td>
				<select name='AUTH'>
END
;
	print "<option value='TERMS' ";
	print " selected='selected'" if ($settings{'AUTH'} eq 'TERMS');
	print ">$Lang::tr{'Captive terms'}</option>";

	print "<option value='COUPON' ";
	print " selected='selected'" if ($settings{'AUTH'} eq 'COUPON');
	print ">$Lang::tr{'Captive coupon'}</option>";

	print<<END
				</select>	
			</td>
		</tr>
END
;
	if ($settings{'AUTH'} eq 'TERMS') {
		my $terms = &getterms();
		print <<END;
			<tr>
				<td></td>
				<td>
					<textarea cols="50" rows="10" name="TERMS">$terms</textarea>
				</td>
			</tr>
END
	}

	print<<END;
		<tr>
			<td colspan="2">
				<br>
				<strong>$Lang::tr{'Captive branding'}</strong>
			</td>
		</tr>
		<tr>
			<td>
				$Lang::tr{'Captive title'}
			</td>
			<td>
				<input type='text' name='TITLE' value="$settings{'TITLE'}" size='40'>
			</td>
		</tr>
		<tr>
			<td>$Lang::tr{'Captive brand color'}</td>
			<td>
				<input type="color" name="COLOR" value="$settings{'COLOR'}">
			</td>
		</tr>
END

	#Logo Upload
	print <<END;
		<tr>
			<td>
				$Lang::tr{'Captive logo_upload'}
				<br>
				$Lang::tr{'Captive logo_upload1'}
			</td>
			<td>
				<INPUT TYPE='file' NAME='uploaded_file' SIZE=30 MAXLENGTH=80>
			</td>
		</tr>
END

	#Show Logo in webinterface with 1/2 size if set
	if (-f "$logopath/logo.png"){
		print"<tr><td>$Lang::tr{'Captive logo_set'}</td>";
		print"<td><img src='/captive/logo/logo.png' alt='$logopath/logo.png' width='25%' height='25%' /></td></tr>";
	}else{
		print"<tr><td>$Lang::tr{'Captive logo_set'}</td>";
		print"<td><br>$Lang::tr{'no'}</td></tr>";
	}

	print <<END;
		<tr>
			<td></td>
			<td align='right'>
				<input type='submit' name='ACTION' value="$Lang::tr{'save'}"/>
			</td>
		</tr>
	</table></form>
END

	&Header::closebox();

	#if settings is set to use coupons, the coupon part has to be displayed
	if ($settings{'AUTH'} eq 'COUPON'){
		&coupons();
	}else{
		#otherwise we show the licensepart
		&show_license_connections();
	}
}

sub gencode(){
	#generate a random code only letters from A-Z except 'O'  and 0-9
	my @chars = ("A".."N", "P".."Z", "0".."9");
	my $randomstring;
	$randomstring .= $chars[rand @chars] for 1..8;
	return $randomstring;
}

sub coupons() {
	&Header::openbox('100%', 'left', $Lang::tr{'Captive generate coupon'});
	print "<form method='post' action='$ENV{'SCRIPT_NAME'}'>";
	print "<table border='0' width='100%'>";
	print "<tr><td width='30%'><br>$Lang::tr{'Captive vouchervalid'}</td><td width='70%'><br>";

		print "<table class='tbl' border='0' width='100%'>";
		print "<th>$Lang::tr{'hours'}</th><th>$Lang::tr{'days'}</th><th>$Lang::tr{'weeks'}</th><th>$Lang::tr{'months'}</th><th></th><th></th>";

		#print hour-dropdownbox
		my $hrs=3600;
		print "<tr height='40px'><td><select name='EXP_HOUR' style='width:8em;'>";
		print "<option value='0' ";
		print " selected='selected'" if ($settings{'EXP_HOUR'} eq '0');
		print ">--</option>";
		for (my $i = 1; $i<25; $i++){
			my $exp_sec = $i * $hrs;
			print "<option value='$exp_sec' ";
			print " selected='selected'" if ($settings{'EXP_HOUR'} eq $exp_sec);
			print ">$i</option>";
		}
		print "</td><td>";

		#print day-dropdownbox
		my $days=3600*24;
		print "<select name='EXP_DAY' style='width:8em;'>";
		print "<option value='0' ";
		print " selected='selected'" if ($settings{'EXP_DAY'} eq '0');
		print ">--</option>";
		for (my $i = 1; $i<8; $i++){
			my $exp_sec = $i * $days;
			print "<option value='$exp_sec' ";
			print " selected='selected'" if ($settings{'EXP_DAY'} eq $exp_sec);
			print ">$i</option>";
		}
		print "</td><td>";

		#print week-dropdownbox
		my $week=3600*24*7;
		print "<select name='EXP_WEEK' style='width:8em;'>";
		print "<option value='0' ";
		print " selected='selected'" if ($settings{'EXP_WEEK'} eq '0');
		print ">--</option>";
		for (my $i = 1; $i<5; $i++){
			my $exp_sec = $i * $week;
			print "<option value='$exp_sec' ";
			print " selected='selected'" if ($settings{'EXP_WEEK'} eq $exp_sec);
			print ">$i</option>";
		}
		print "</td><td>";

		#print month-dropdownbox
		my $month=3600*24*30;
		print "<select name='EXP_MONTH' style='width:8em;'>";
		print "<option value='0' ";
		print " selected='selected'" if ($settings{'EXP_MONTH'} eq '0');
		print ">--</option>";
		for (my $i = 1; $i<13; $i++){
			my $exp_sec = $i * $month;
			print "<option value='$exp_sec' ";
			print " selected='selected'" if ($settings{'EXP_MONTH'} eq $exp_sec);
			print ">$i</option>";
		}
		print "</td>";
		print "<td>&nbsp;&nbsp;&nbsp;<input type='checkbox' name='UNLIMITED' $checked{'UNLIMITED'}{'on'} /></td><td>&nbsp;<b>$Lang::tr{'Captive nolimit'}</b></td>";
		print "</tr></table>";
	print "</td></tr>";
	print "<tr><td><br>$Lang::tr{'remark'}</td><td><br><input type='text' style='width: 98%;' name='REMARK'  align='left'></td></tr>";
	print "<tr><td>&nbsp</td><td></td></tr></table><br><br>";
	$cgiparams{'CODE'} = &gencode();
	print "<div align='right'><input type='submit' name='ACTION' value='$Lang::tr{'Captive generate coupon'}'><input type='hidden' name='CODE' value='$cgiparams{'CODE'}'></form></div>";

	&Header::closebox();

	# Show all coupons if exist
	if (! -z $coupons) {
		&show_coupons();
	}

	if (! -z $clients) {
		&show_clients();
	}
}

sub show_license_connections(){
	#if there are active clients, show the box with active connections
	return if ( -z $clients || ! -f $clients );
	my $count=0;
	my $col;
	&Header::openbox('100%', 'left', $Lang::tr{'Captive voactive'});
print<<END
		<center><table class='tbl'>
		<tr>
			<th align='center' width='15%'>$Lang::tr{'Captive coupon'}</th><th th align='center' width='15%'>$Lang::tr{'Captive activated'}</th><th th align='center' width='15%'>$Lang::tr{'Captive expire'}</th><th align='center' width='50%'><font size='1'>$Lang::tr{'Captive mac'}</th><th th align='center' width='5%'>$Lang::tr{'delete'}</th></tr>
END
;
	#read all clients from hash and show table
	&General::readhasharray($clients, \%clientshash) if (-e $clients);
	foreach my $key (keys %clientshash){
		my $starttime = sub{sprintf '%02d.%02d.%04d %02d:%02d', $_[3], $_[4]+1, $_[5]+1900, $_[2], $_[1]  }->(localtime($clientshash{$key}[2]));
		my $endtime;
		if ($clientshash{$key}[3] eq '0'){
			$endtime=$Lang::tr{'Captive nolimit'};
		}else{
			$endtime=sub{sprintf '%02d.%02d.%04d %02d:%02d', $_[3], $_[4]+1, $_[5]+1900, $_[2], $_[1]  }->(localtime($clientshash{$key}[2]+$clientshash{$key}[3]));
		}

		if ($count % 2){
			print" <tr>";
			$col="bgcolor='$color{'color20'}'";
		}else{
			$col="bgcolor='$color{'color22'}'";
			print" <tr>";
		}
		print "<td $col><center>$clientshash{$key}[4]</td><td $col><center>$starttime ";
		print "</center></td><td $col><center>$endtime ";
		print "</td><td $col><center>$clientshash{$key}[0]</td><td $col><form method='post'><center><input type='image' src='/images/delete.gif' align='middle' alt='$Lang::tr{'delete'}' title='$Lang::tr{'delete'}' /><form method='post'><input type='hidden' name='ACTION' value='delete-client' /><input type='hidden' name='key' value='$clientshash{$key}[0]' /></form></tr>";
		$count++;
	}
	
	print "</table>";
	&Header::closebox();
}

sub show_coupons() {
	#if there are already generated but unsused coupons, print a table
	my $count=0;
	my $col;
	&Header::openbox('100%', 'left', $Lang::tr{'Captive vout'});
	print<<END
		<center><table class='tbl' border='0'>
		<tr>
			<th align='center' width='15%'>$Lang::tr{'Captive coupon'}</th><th align='center' width='15%'>$Lang::tr{'date'}</th><th th align='center' width='15%'>$Lang::tr{'Captive expire'}</th><th align='center' width='60%'>$Lang::tr{'remark'}</th><th align='center' width='5%'>$Lang::tr{'delete'}</th></tr>
END
;
	&General::readhasharray($coupons, \%couponhash) if (-e $coupons);
	foreach my $key (keys %couponhash)
	{
		my $starttime = sub{sprintf '%02d.%02d.%04d %02d:%02d', $_[3], $_[4]+1, $_[5]+1900, $_[2], $_[1]  }->(localtime($couponhash{$key}[0]));
		my $endtime;
		if ($couponhash{$key}[2] eq '0'){
			$endtime=$Lang::tr{'Captive nolimit'};
		}else{
			$endtime=sub{sprintf '%02d.%02d.%04d %02d:%02d', $_[3], $_[4]+1, $_[5]+1900, $_[2], $_[1]  }->(localtime(time()+$couponhash{$key}[2]));
		}

		if ($count % 2){
			print" <tr>";
			$col="bgcolor='$color{'color20'}'";
		}else{
			$col="bgcolor='$color{'color22'}'";
			print" <tr>";
		}

		print "<td $col><center><b>$couponhash{$key}[1]</b></td>";
		print "<td $col><center>$starttime</td>";
		print "<td $col><center>$endtime</td>";
		print "<td $col align='center'>$couponhash{$key}[3]</td>";
		print "<td $col><form method='post'><center><input type='image' src='/images/delete.gif' align='middle' alt='$Lang::tr{'delete'}' title='$Lang::tr{'delete'}' /><form method='post'><input type='hidden' name='ACTION' value='delete-coupon' /><input type='hidden' name='key' value='$couponhash{$key}[0]' /></form></tr>";
		$count++;
	}

	print "</table>";
	&Header::closebox();
}

sub show_clients() {
	#if there are active clients which use coupons show table
	return if ( -z $clients || ! -f $clients );
	my $count=0;
	my $col;
	&Header::openbox('100%', 'left', $Lang::tr{'Captive voactive'});
print<<END
	<center><table class='tbl' width='100%'>
		<tr>
			<th align='center' width='15%'>$Lang::tr{'Captive coupon'}</th><th th align='center' width='15%'>$Lang::tr{'Captive activated'}</th><th align='center' width='15%'>$Lang::tr{'Captive expire'}</th><th align='center' width='10%'>$Lang::tr{'Captive mac'}</th><th align='center' width='43%'>$Lang::tr{'remark'}</th><th th align='center' width='5%'>$Lang::tr{'delete'}</th></tr>
END
;
	&General::readhasharray($clients, \%clientshash) if (-e $clients);
	foreach my $key (keys %clientshash)
	{
		#calculate time from clientshash (starttime)
		my $starttime = sub{sprintf '%02d.%02d.%04d %02d:%02d', $_[3], $_[4]+1, $_[5]+1900, $_[2], $_[1]  }->(localtime($clientshash{$key}[2]));
		#calculate endtime from clientshash
		my $endtime;
		if ($clientshash{$key}[3] eq '0'){
			$endtime=$Lang::tr{'Captive nolimit'};
		}else{
			$endtime = sub{sprintf '%02d.%02d.%04d %02d:%02d', $_[3], $_[4]+1, $_[5]+1900, $_[2], $_[1]  }->(localtime($clientshash{$key}[2]+$clientshash{$key}[3]));
		}

			if ($count % 2){
				print" <tr>";
				$col="bgcolor='$color{'color20'}'";
			}else{
				$col="bgcolor='$color{'color22'}'";
				print" <tr>";
			}

			print "<td $col><center><b>$clientshash{$key}[4]</b></td><td $col><center>$starttime ";
			print "</center></td><td $col><center>$endtime</center></td><td $col><center>$clientshash{$key}[0]</td><td $col><center>$clientshash{$key}[5]</center>";
			print "</td><td $col><form method='post'><center><input type='image' src='/images/delete.gif' align='middle' alt='$Lang::tr{'delete'}' title='$Lang::tr{'delete'}' /><form method='post'><input type='hidden' name='ACTION' value='delete-client' /><input type='hidden' name='key' value='$clientshash{$key}[0]' /></form></tr>";
			$count++;
	}

	print "</table>";
	&Header::closebox();
}

sub validremark
{
	# Checks a hostname against RFC1035
        my $remark = $_[0];
	# Each part should be at least two characters in length
	# but no more than 63 characters
	if (length ($remark) < 1 || length ($remark) > 255) {
		return 0;}
	# Only valid characters are a-z, A-Z, 0-9 and -
	if ($remark !~ /^[a-zäöüA-ZÖÄÜ0-9-.:;\|_()\/\s]*$/) {
		return 0;}
	# First character can only be a letter or a digit
	if (substr ($remark, 0, 1) !~ /^[a-zäöüA-ZÖÄÜ0-9]*$/) {
		return 0;}
	# Last character can only be a letter or a digit
	if (substr ($remark, -1, 1) !~ /^[a-zöäüA-ZÖÄÜ0-9.:;_)]*$/) {
		return 0;}
	return 1;
}

sub pngsize {
	my $Buffer = shift;
	my ($width,$height) = ( undef, undef );

	if ($Buffer =~ /IHDR(.{8})/) {
		my $PNG = $1;
		($width,$height) = unpack( "NN", $PNG );
	} else {
		$width="invalid";
		$height= "invalid";
	};
	return ($width,$height);
}

sub error{
	#if an errormessage exits, show a box with errormessage
	if ($errormessage) {
		&Header::openbox('100%', 'left', $Lang::tr{'error messages'});
		print "<class name='base'>$errormessage\n";
		print "&nbsp;</class>\n";
		&Header::closebox();
	}
}

&Header::closebigbox();
&Header::closepage();