[Mimedefang] Wide character in print at /usr/bin/mimedefang.pl

vieri at openmailbox.org vieri at openmailbox.org
Thu Mar 12 05:49:21 EDT 2015


On 2015-03-12 08:38, Steffen Kaiser wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On Wed, 11 Mar 2015, vieri at openmailbox.org wrote:
>> On 2015-03-10 20:20, vieri at openmailbox.org wrote:
>>> Hi,
>>> 
>>> I noticed that a decade ago some users detected "Wide character in
>>> print" messages in their mimedefang logs.
>>> It was supposedly fixed by adding
> 
>>> export LC_ALL=C
> 
>>> in the mimedefang init script.
>>> 
>>> (perl unicode issue)
>>> 
>>> However, my Linux distro (Gentoo) runs the following in the 
>>> mimedefang
>>> init script:
>>> 
>>> LC_ALL=C
>>> export LC_ALL
>>> 
>>> but I'm occasionally getting the "Wide character in print" messages.
>>> 
>>> I'm running v 2.75 and Perl 5.18.2.
>>> 
>>> Any ideas?
>> 
>> Hi again,
>> 
>> Just wanted to add that I modified /usr/bin/mimedefang.pl for 
>> debugging purposes:
>> 
>> /usr/bin/mimedefang.pl:
>> 
>> sub action_notify_sender ($) {
>> [...]
>>    if (open(FILE, ">>NOTIFICATION")) {
>> <------>md_syslog('err', "action_notify_sender print FILE $msg");
>> [...]
>> 
>> If I check the logs, this is what I get (basically I have a custom 
>> filter which calls action_notify_sender with the name of each attached 
>> file):
>> 
>> action_notify_sender print FILE ComposicioÌ..pdf
>> 
>> So mimedefang and perl are choking on non-ASCII characters with "Wide 
>> character in print" messages.
>> 
>> Unfortunately the consequence of all this is that some e-mail messages 
>> aren't processed and are kept in the queue and not sent:
>> 
>> Mar 11 18:19:38 mail1 mimedefang-multiplexor[31444]: A0C4A326EB1: 
>> Slave 1 stderr: open body: Invalid argument at 
>> /usr/lib/perl5/vendor_perl/5.18.2/MIME/Entity.pm line 1878.
> 
> Could you post your filter?

It looks like the mailing list doesn't accept plain text attachments so 
I'm pasting the content of my mimedefang-filter file below (some leading 
# comments stripped out to reduce size).


$AdminAddress = 'postmaster at mydomain.org';
$AdminName = "IT";

$DaemonAddress = 'mail at mydomain.org';
$DaemonName = "MDIT";

$AddWarningsInline = 1;

md_graphdefang_log_enable('mail', 1);


$GeneralWarning = "NOTE: This e-mail has been modified automatically. 
Please follow the instructions below.\n\n";


$Stupidity{"NoMultipleInlines"} = 1;

detect_and_load_perl_modules();

sub filter_bad_filename  {
     my($entity) = @_;
     my($bad_exts, $re);

     $bad_exts = 
'(ade|adp|app|asd|asf|asx|bas|bat|chm|cmd|com|cpl|crt|dll|exe|fxp|hlp|hta|hto|inf|ini|ins|isp|jse?|lib|lnk|mdb|mde|msc|msi|msp|mst|ocx|pcd|pif|prg|reg|scr|sct|sh|shb|shs|sys|url|vb|vbe|vbs|vcs|vxd|wmd|wms|wmz|wsc|wsf|wsh|\{[^\}]+\})';

     $re = '\.' . $bad_exts . '\.*$';

     return 1 if (re_match($entity, $re));

     if (re_match($entity, '\.zip$') and
	$Features{"Archive::Zip"}) {
	my $bh = $entity->bodyhandle();
	if (defined($bh)) {
	    my $path = $bh->path();
	    if (defined($path)) {
		return re_match_in_zip_directory($path, $re);
	    }
	}
     }
     return 0;
}

sub custom_action_replace_with_warning ($;$$$) {
     my($msg, $mtype, $mext, $mname) = @_;
     return 0 if 
(!in_filter_context("custom_action_replace_with_warning"));
     $Actions{'replace_with_warning'}++;
     $Action = "replace";
     $mtype = "text/plain" unless defined($mtype);
     $mext = "txt" unless defined($mext);
     $mname = "warning" unless defined($mname);
     $ReplacementEntity = MIME::Entity->build(Type => $mtype,
					     Encoding => "-suggest",
					     Data => [ "$msg\n" ]);
     $WarningCounter++;
     $ReplacementEntity->head->mime_attr("Content-Type.name" => 
"$mname$WarningCounter.$mext");
     $ReplacementEntity->head->mime_attr("Content-Disposition" => 
"inline");
     $ReplacementEntity->head->mime_attr("Content-Disposition.filename" 
=> "$mname$WarningCounter.$mext");
     return 1;
}

sub custom_action_replace_with_file ($$;$$$$$) {
     my($entity, $nfpath, $nfname, $nftype, $nfencode, $nfdispo) = @_;
     return 0 if (!in_filter_context("custom_action_replace_with_file"));
     $Actions{'replace_with_file'}++;
     $Action = "replace";
     $nftype = "application/octet-stream" unless defined($nftype);
     $nfname = "" unless defined($nfname);
     $nfencode = "base64" unless defined($nfencode);
     $nfdispo = "attachment" unless defined($nfdispo);
     $ReplacementEntity = MIME::Entity->build(Type => $nftype,
					     Encoding => $nfencode,
					     Path => $nfpath,
					     Filename => $nfname,
					     Disposition => $nfdispo);
     copy_or_link($nfpath, $entity->bodyhandle->path) or return 0;
     return 1;
}

sub custom_action_replace_with_url ($$$$;$$$$$) {
     my($entity, $doc_root, $base_url, $msg, $mtype, $mext, $mname, 
$cd_data, $salt) = @_;
     my($ctx);
     my($path);
     my($fname, $ext, $name, $url);
     my $extension = "";

     return 0 unless in_filter_context("custom_action_replace_with_url");
     return 0 unless defined($entity->bodyhandle);
     $path = $entity->bodyhandle->path;
     return 0 unless defined($path);
     open(IN, "<$path") or return 0;

     $ctx = Digest::SHA1->new;
     $ctx->addfile(*IN);
     $ctx->add($salt) if defined($salt);
     close(IN);

     $fname = takeStabAtFilename($entity);
     $fname = "" unless defined($fname);
     $extension = $1 if ($fname =~ /(\.[^.]*)$/);

     $extension = "" unless ($extension =~ /^\.[A-Za-z0-9_]*$/);

     $name = $ctx->hexdigest . $extension;
     $fname = $doc_root . "/" . $name;
     $url = $base_url . "/" . $name;

     if (-r $fname) {
	# If file exists, then this is either a duplicate or someone
	# has defeated SHA1.  Just update the mtime on the file.
	my($now);
	$now = time;
	utime($now, $now, $fname);
     } else {
	copy_or_link($path, $fname) or return 0;
	# In case umask is whacked...
	chmod 0644, $fname;
     }

     if (defined($cd_data) and ($cd_data ne "")) {
	$hasTab = 0 unless ($hasTab = index($cd_data, "\t"));
	if ($hasTab <= 0) {
	    if ($extension eq '.xls') {
		$cd_data = "application/vnd.ms-excel\t" . $cd_data;
		}
	    elsif ($extension eq '.ppt') {
		$cd_data = "application/vnd.ms-powerpoint\t" . $cd_data;
		}
	    elsif ($extension eq '.pps') {
		$cd_data = "application/vnd.ms-powerpoint\t" . $cd_data;
		}
	    md_syslog('warning', "custom_action_replace_with_url MODIFIED 
cd_data: $cd_data - extension: $extension.");
	    }
	if (open CDF, ">$doc_root/.$name") {
	    print CDF $cd_data;
	    close CDF;
	    chmod 0644, "$doc_root/.$name";
	}
     }

     push(@custom_attachURLlist, $cd_data."\n".$url."\n");
     push(@custom_attachURLlist4html, $cd_data."\n<a 
href=\"".$url."\">".$url."</a>\n");

     $msg =~ s/_URL_/$url/g;
     if (defined($mtype) and ($mtype ne "") and defined($mext) and ($mext 
ne "") and defined($mname) and ($mname ne "")) {
	custom_action_replace_with_warning($msg, $mtype, $mext, $mname);
	}
     else {
	custom_action_replace_with_warning($msg);
	}

     return 1;
}

sub custom_list_replacement_urls ($;$$) {
     my($entity, $header, $footer) = @_;
     my $plain = $header.join("\n", @custom_attachURLlist).$footer;
     my $html = $header.join("\n", @custom_attachURLlist4html).$footer;
     $html =~ s/\n/<br>\n/g;
     append_text_boilerplate($entity, $plain, 0);
     append_html_boilerplate($entity, $html, 0);
}

sub filter_begin {
     my($entity) = @_;

     @custom_attachURLlist = ();
     @custom_attachURLlist4html = ();

     if ($SuspiciousCharsInHeaders) {
         md_graphdefang_log('suspicious_chars');
	# action_quarantine_entire_message("Message quarantined because of 
suspicious characters in headers");
	# Do NOT allow message to reach recipient(s)
	return action_discard();
     }

     md_copy_orig_msg_to_work_dir_as_mbox_file();

     my($code, $category, $action) = message_contains_virus();

     $FoundVirus = ($category eq "virus");


     md_graphdefang_log('virus check', $category, $action);

     if ($FoundVirus) {
	md_graphdefang_log('virus', $VirusName, $RelayAddr);
	md_syslog('warning', "Discarding because of virus $VirusName");
	return action_discard();
     }

     my $custom_blockcontent = 0;
     if ((open(MESSAGEHEADERS,"./HEADERS")) && 
(open(MESSAGEBODY,"./INPUTMSG"))) {

	# Let's try to get unwanted HEADER content from text file:
	if (open(UNWANTED, 
"</etc/mail/custom/custom_blacklist_content_headers")) {
	while(<UNWANTED>)
	    {
	    seek MESSAGEHEADERS, 0, 0;
	    my $BANLINE = $_;
	    chomp($BANLINE);
	    # $BANLINE =~ tr/\015//d;
	    # $BANLINE =~ s/\r\n//g;
	    # $BANLINE =~ s/\n//g;
	    $BANLINE =~ s/\r//g;

	    if ((length($BANLINE) > 0) && (grep{/$BANLINE/} <MESSAGEHEADERS>)){
		$custom_blockcontent = 1;
		md_graphdefang_log('mail', "CUSTOM_BAN: Discarding because of SPAM 
marker [$BANLINE] in headers", 'ban_content');
		last;
		}
	    }

	close(UNWANTED);
	} else { # if open UNWANTED
	    md_graphdefang_log('mail', 
"CUSTOM_BAN_ERROR_NO_UNWANTED_HEADERS_DATA", 'ban_content');
	}

	# Let's try to get unwanted BODY content from text file:
	if (($custom_blockcontent == 0) && (open(UNWANTED, 
"</etc/mail/custom/custom_blacklist_content_body"))) {
	while(<UNWANTED>)
	    {
	    seek MESSAGEBODY, 0, 0;
	    my $BANLINE = $_;
	    chomp($BANLINE);
	    $BANLINE =~ s/\r//g;

	    if ((length($BANLINE) > 0) && (grep{/$BANLINE/} <MESSAGEBODY>)){
		$custom_blockcontent = 1;
		md_graphdefang_log('mail', "CUSTOM_BAN: Discarding because of SPAM 
marker [$BANLINE] in body", 'ban_content');
		last;
		}
	    }

	close(UNWANTED);
	} else { # if open UNWANTED
	    md_graphdefang_log('mail', 
"CUSTOM_BAN_ERROR_NO_UNWANTED_BODY_DATA_OR_ALREADY_BANNED", 
'ban_content');
	}

	# Let's try to get suspicious HEADER and BODY content from text file:
	if (($custom_blockcontent == 0) && (open(UNWANTED, 
"</etc/mail/custom/custom_alertlist_content"))) {
	while(<UNWANTED>)
	    {
	    seek MESSAGEHEADERS, 0, 0;
	    seek MESSAGEBODY, 0, 0;
	    my $BANLINE = $_;
	    chomp($BANLINE);
	    $BANLINE =~ s/\r//g;

	    if ((length($BANLINE) > 0) && ((grep{/$BANLINE/} <MESSAGEHEADERS>) 
|| (grep{/$BANLINE/} <MESSAGEBODY>))){
		md_graphdefang_log('mail', "CUSTOM_ALERT: Alerting because of 
SUSPICIOUS marker [$BANLINE] in message", 'alert_content');
		last;
		}
	    }

	close(UNWANTED);
	} else { # if open UNWANTED
	    md_graphdefang_log('mail', 
"CUSTOM_ALERT_ERROR_NO_UNWANTED_DATA_OR_ALREADY_BANNED", 
'alert_content');
	}

	close(MESSAGEHEADERS);
	close(MESSAGEBODY);

	} else { # if open MESSAGEHEADERS and MESSAGEBODY
	    md_graphdefang_log('mail', "CUSTOM_BAN_ERROR_NO_MESSAGE_DATA", 
'ban_content');
	}

     return action_discard() if ($custom_blockcontent);

     if ($action eq "tempfail") {
	md_syslog('warning', "Problem running virus scanner: code=$code, 
category=$category, action=$action");
     }

     action_add_header("X-FHM-Filter", "Message from $Sender was filtered 
by FHM.");
}

sub filter {
     my($entity, $fname, $ext, $type) = @_;

     return if message_rejected(); # Avoid unnecessary work

     $NotifySenderSubject = "AVISO correo";

     if (lc($type) eq "message/partial") {
         md_graphdefang_log('message/partial');
	action_bounce("MIME type message/partial not accepted here");
	return action_discard();
     }

     if ( ($Sender eq '<>') && ($fname ne '') ) {
         md_graphdefang_log('mail', 'CUSTOM_UNKNOWN_SENDER', $fname);
	return action_drop_with_warning("Attachment removed due to unknown 
sender: $fname\n");
     }

     my($custom_applyfilter) = 1;

     my($custom_applysecurefilter) = 0;

     if ( (index($Sender, '@myotherdomain.org>') == -1) && 
(index($Sender, '@mydomain.org>') == -1) ) {
	$custom_applyfilter = 0;
	return action_accept();
	}

     if ($custom_applysecurefilter eq 1) {
	if ($fname ne '') {
     	    #action_notify_sender("Processed file: $fname.\n\n");
     	    return 
custom_action_replace_with_url($entity,"/var/www/localhost/htdocs/securedownloads/dkduueeksdfuh3447373","https://securedownloads.myotherdomain.org/securedownloads/dkduueeksdfuh3447373","You 
can download the file from here:<br>\n<br>\n<a 
href='_URL_'>_URL_</a><br>\n<br>\nWARNING: the attached file $fname will 
be available for a period of 30 
days.<br>\n","text/html","html","attachment",$fname);
	    } else {
	    return custom_action_replace_with_warning("My Org\n\n");
	    #return 1;
	    }
     }


     open(VIPUSERS, "</etc/mail/custom/custom_whitelist_senders");
     while(<VIPUSERS>)
     {
     my($VIPLINE) = $_;
     chomp($VIPLINE);
     $VIPLINE =~ s/\r//g;
     if ( $Sender =~ /<$VIPLINE@/i ) {
	$custom_applyfilter = 0;
	md_graphdefang_log('mail', 'CUSTOM_NOFILTER_SENDER_AUTO', 
'priv_senders');
     }
     }

     if ( ($fname eq '') || ($Sender eq '<>') ) {
	$custom_applyfilter = 0;
	md_graphdefang_log('mail', 'CUSTOM_NOFILTER_UNSPEC', 
'unspecified_fname_or_sender');
     	}


     my($custom_size, $custom_bandwidth);
     my($custom_size_max, $custom_bandwidth_max);
     my($custom_size_max2, $custom_bandwidth_max2);
     $custom_bandwidth = (stat("./INPUTMSG"))[7]*scalar(@Recipients);
     md_graphdefang_log('mail', 'CUSTOM_BANDWIDTH', $custom_bandwidth);
     $custom_size = (stat($entity->bodyhandle->path))[7];
     md_graphdefang_log('mail', 'CUSTOM_MSG_PART_SIZE', $custom_size);
     $custom_size_max = 4*1024*1024;
     $custom_bandwidth_max = 8*1024*1024;
     $custom_size_max2 = 40*1024*1024;
     $custom_bandwidth_max2 = 150*1024*1024;
     if ( ($custom_size > $custom_size_max2) || ($custom_bandwidth > 
$custom_bandwidth_max2) ) {
     	$custom_applyfilter = 1;
	}

     if ($custom_applyfilter eq 1) {

	# If it's not a compressed file then zip it, if possible
	my($comp_exts, $re);
	$comp_exts = '(zip|gz|tgz|bz2|Z|\{[^\}]+\})';
	$re = '\.' . $comp_exts . '\.*$';
	my $zipped;

	# Dec. 2010: do NOT create ZIP files because some recipients don't have 
uncompression software...
	#if ( ($Features{"Archive::Zip"}) && (!re_match($entity, $re)) ) {
	#    md_graphdefang_log('mail', 'CUSTOM_COMPRESS', $fname);
	#    my $zip = Archive::Zip->new();
	#    my $member;
	#    $member = $zip->addFile($entity->bodyhandle->path, $fname);
	#    # compress (DEFLATED) or not (STORED)
	#    $member->desiredCompressionMethod( COMPRESSION_DEFLATED );
	#    $member->desiredCompressionLevel( 
COMPRESSION_LEVEL_BEST_COMPRESSION );
	#    $member->setLastModFileDateTimeFromUnix( 318211200 );
	#    $fname = "$fname.zip" unless $fname =~ s/\.[^.]*$/\.zip/;
	#    $zip->writeToFileNamed("./Work/CUSTOM_$fname");
	#    custom_action_replace_with_file($entity, "./Work/CUSTOM_$fname", 
$fname);
	#    $zipped = 1;
	#}

	if ( ($custom_size > $custom_size_max) || ($custom_bandwidth > 
$custom_bandwidth_max) ) {
     	    action_notify_sender("The file $fname has been sent to the 
recipient as a web link.\n");
     	    return 
custom_action_replace_with_url($entity,"/var/www/localhost/htdocs/downloads/sdsfd67sf6dsfdsfd78","http://downloads.myotherdomain.org/downloads/sdsfd67sf6dsfdsfd78","<i>You 
can download the attached file from here:</i><br>\n<br>\n<a 
href='_URL_'>_URL_</a><br>\n<br>\nNOTE: the file ($fname - $custom_size 
bytes) will be available for a period of 30 
days.\n","text/html","html","attachment",$fname);
	}

	if ($zipped) {
	    return 1;
	}

     }

     return action_accept();
}

sub filter_multipart {
     my($entity, $fname, $ext, $type) = @_;

     return if message_rejected(); # Avoid unnecessary work

     md_graphdefang_log('CUSTOM_MULTIPART_DATA', $fname, $type);

     if (filter_bad_filename($entity)) {
         md_graphdefang_log('bad_filename', $fname, $type);
	action_notify_administrator("A MULTIPART attachment of type $type, 
named $fname was dropped.\n");
	return action_drop_with_warning("An attachment of type $type, named 
$fname was removed from this document as it\nconstituted a security 
hazard.  If you require this document, please contact\nthe sender and 
arrange an alternate means of receiving it.\n");
     }

     if (lc($type) eq "message/partial") {
         md_graphdefang_log('message/partial');
	action_bounce("MIME type message/partial not accepted here");
	return;
     }

     return action_accept();
}


sub defang_warning {
     my($oldfname, $fname) = @_;
     return
	"The attached file '$oldfname' was converted to '$fname'.\n" .
	"To restore it, right-click and Save As\n" .
	"'$oldfname'\n";
}

sub filter_end {
     my($entity) = @_;



     return if message_rejected();

     if ($Features{"SpamAssassin"}) {
	if (-s "./INPUTMSG" < 100*1024) {
	    # Only scan messages smaller than 100kB.  Larger messages
	    # are extremely unlikely to be spam, and SpamAssassin is
	    # dreadfully slow on very large messages.
	    my($hits, $req, $names, $report) = spam_assassin_check();
	    my($score);
	    if ($hits < 40) {
		$score = "*" x int($hits);
	    } else {
		$score = "*" x 40;
	    }
     	    md_graphdefang_log('CUSTOM_LOG_INFO_SPAM_HITS_SCORE', $hits, 
$score);
	    # We add a header which looks like this:
	    # X-Spam-Score: 6.8 (******) NAME_OF_TEST,NAME_OF_TEST
	    # The number of asterisks in parens is the integer part
	    # of the spam score clamped to a maximum of 40.
	    # MUA filters can easily be written to trigger on a
	    # minimum number of asterisks...
	    if ($hits >= $req) {
		action_change_header("X-Spam-Score", "$hits ($score) $names");
                 md_graphdefang_log('spam', $hits, $RelayAddr);

		action_change_header('Subject', "**MYORG-SPAM** $Subject");
		# If you find the SA report useful, add it, I guess...
		#action_add_part($entity, "text/plain", "-suggest",
		#                "$report\n",
		#		"SpamReport.txt", "inline");
	    } else {
		# Delete any existing X-Spam-Score header?
		action_delete_header("X-Spam-Score");
	    }
	}
     }



     md_graphdefang_log('mail_in');

     if (@custom_attachURLlist > 0) {
	&custom_list_replacement_urls($entity,"\n\n============================\n\nPlease 
click on each link to download.\n\n","\nData available during a period 
of 30 days.\n\n------- ------\n=== END MESSAGE ===\n")
     }

     if ($Sender eq '<>') {
	append_text_boilerplate($entity, "\n------\nPlease do not send the 
message again. Message ID $MessageID.", 0);
	my($custom_msgid) = $MessageID;
	$custom_msgid =~ s/\@/-/g;
	my($custom_okchars) = '-a-zA-Z0-9_.';
	$custom_msgid =~ s/[^$custom_okchars]//g;
	my($custom_recip) = $Recipients[0];
	$custom_recip =~ s/\@/-/g;
	$custom_recip =~ s/[^$custom_okchars]//g;
	$custom_recip = substr($custom_recip, 0, 30);
	my($custom_bkfname) = 
"/SAMBA/Trouble_email/msg_".$custom_msgid."_".$custom_recip."_".time()."_".int(rand(100)).".eml";
	copy_or_link("./INPUTMSG", $custom_bkfname);
	chmod 0666, $custom_bkfname;
     }



}

1;




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