##---------------------------------------------------------------------------##
## File:
## $Id: mhtxthtml.pl,v 2.31 2003/02/04 23:31:20 ehood Exp $
## Author:
## Earl Hood mhonarc@mhonarc.org
## Description:
## Library defines routine to filter text/html body parts
## for MHonArc.
## Filter routine can be registered with the following:
##
## text/html:m2h_text_html'filter:mhtxthtml.pl
##
##---------------------------------------------------------------------------##
## MHonArc -- Internet mail-to-HTML converter
## Copyright (C) 1995-2000 Earl Hood, mhonarc@mhonarc.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 2 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, write to the Free Software
## Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
##---------------------------------------------------------------------------##
package m2h_text_html;
# Beginning of URL match expression
my $Url = '(\w+://|\w+:)';
# Script related attributes
my $SAttr = q/\b(?:onload|onunload|onclick|ondblclick|/.
q/onmouse(?:down|up|over|move|out)|/.
q/onkey(?:press|down|up)|style)\b/;
# Script/questionable related elements
my $SElem = q/\b(?:applet|base|embed|form|ilayer|input|layer|link|meta|/.
q/object|option|param|select|textarea)\b/;
# Elements with auto-loaded URL attributes
my $AElem = q/\b(?:img|body|iframe|frame|object|script|input)\b/;
# URL attributes
my $UAttr = q/\b(?:action|background|cite|classid|codebase|data|datasrc|/.
q/dynsrc|for|href|longdesc|profile|src|url|usemap)\b/;
# Used to reverse the effects of CHARSETCONVERTERS
my %special_to_char = (
'lt' => '<',
'gt' => '>',
'amp' => '&',
'quot' => '"',
);
##---------------------------------------------------------------------------
## The filter must modify HTML content parts for merging into the
## final filtered HTML messages. Modification is needed so the
## resulting filtered message is valid HTML.
##
## Arguments:
##
## allowcomments Preserve any comment declarations. Normally
## Comment declarations are munged to prevent
## SSI attacks or comments that can conflict
## with MHonArc processing. Use this option
## with care.
##
## allownoncidurls Preserve URL-based attributes that are not
## cid: URLs. Normally, any URL-based attribute
## -- href, src, background, classid, data,
## longdesc -- will be stripped if it is not a
## cid: URL. This is to prevent malicious URLs
## that verify mail addresses for spam purposes,
## secretly set cookies, or gather some
## statistical data automatically with the use of
## elements that cause browsers to automatically
## fetch data: IMG, BODY, IFRAME, FRAME, OBJECT,
## SCRIPT, INPUT.
##
## allowscript Preserve any markup associated with scripting.
## This includes elements and attributes related
## to scripting. The default is to delete any
## scripting markup for security reasons.
##
## attachcheck Honor attachment disposition. By default,
## all text/html data is displayed inline on
## the message page. If attachcheck is specified
## and Content-Disposition specifies the data as
## an attachment, the data is saved to a file
## with a link to it from the message page.
##
## disablerelated Disable MHTML processing.
##
## nofont Remove tags.
##
## notitle Do not print title.
##
## subdir Place derived files in a subdirectory
##
sub filter {
my($fields, $data, $isdecode, $args) = @_;
$args = '' unless defined $args;
## Check if content-disposition should be checked
if ($args =~ /\battachcheck\b/i) {
my($disp, $nameparm, $raw) =
readmail::MAILhead_get_disposition($fields);
if ($disp =~ /\battachment\b/i) {
require 'mhexternal.pl';
return (m2h_external::filter(
$fields, $data, $isdecode,
readmail::get_filter_args('m2h_external::filter')));
}
}
local(@files) = (); # XXX: Used by resolve_cid!!!
my $base = '';
my $title = '';
my $noscript = 1;
$noscript = 0 if $args =~ /\ballowscript\b/i;
my $nofont = $args =~ /\bnofont\b/i;
my $notitle = $args =~ /\bnotitle\b/i;
my $onlycid = $args !~ /\ballownoncidurls\b/i;
my $subdir = $args =~ /\bsubdir\b/i;
my $norelate = $args =~ /\bdisablerelated\b/i;
my $atdir = $subdir ? $mhonarc::MsgPrefix.$mhonarc::MHAmsgnum : "";
my $tmp;
my $charset = $fields->{'x-mha-charset'};
my($charcnv, $real_charset_name) =
readmail::MAILload_charset_converter($charset);
if (defined($charcnv) && defined(&$charcnv)) {
$$data = &$charcnv($$data, $real_charset_name);
# translate HTML specials back
$$data =~ s/&([lg]t|amp|quot);/$special_to_char{$1}/g;
} elsif ($charcnv ne '-decode-') {
warn qq/\n/,
qq/Warning: Unrecognized character set: $charset\n/,
qq/ Message-Id: <$mhonarc::MHAmsgid>\n/,
qq/ Message Number: $mhonarc::MHAmsgnum\n/;
}
## Check comment declarations: may screw-up mhonarc processing
## and avoids someone sneaking in SSIs.
#$$data =~ s///go; # can crash perl
$$data =~ s/