One Hat Cyber Team

Your IP : 216.73.216.115

Server IP : 194.44.31.54

Server : Linux zen.imath.kiev.ua 4.18.0-553.77.1.el8_10.x86_64 #1 SMP Fri Oct 3 14:30:23 UTC 2025 x86_64

Server Software : Apache/2.4.37 (Rocky Linux) OpenSSL/1.1.1k

PHP Version : 5.6.40

Buat File | Buat Folder

Dir : ~/etc/postfix/

View File Name : filter.sh

#!/bin/bash
# Simple shell-based filter. It is meant to be invoked as follows:
#       /path/to/script -f sender recipients...

# Localize these. The -G option does nothing before Postfix 2.3.
INSPECT_DIR=/var/spool/filter
SENDMAIL="/usr/sbin/sendmail -G -i" # NEVER NEVER NEVER use "-t" here.

# Exit codes from <sysexits.h>
EX_TEMPFAIL=75
EX_UNAVAILABLE=69

# Clean up when done or when aborting.
trap "rm -f in.$$" 0 1 2 3 15

filter() {
    tzone=`date +%z`
    while read line; do 
	# Nothing interesting more 
	if [[ "$line" =~ 'Content-Type' ]]; then break; fi
	
	# Is this nosc mail?
	if [[ "$line" =~ 'Return-Path: <nosc@imath.kiev.ua>' ]]; then  
	    nosc=1
	fi

	# Markers to check: wrong timezone, missing 'for <blah-blah@some>', hostname webmail.imath.kiev.ua or imath.kiev.ua, presence of X-Sender
    
	# Timezone
	if [[ "$line" =~  ^Date: ]]; then  
	    messagetz=`echo $line |cut -d' ' -f 7|tr -d "\r"`
	fi
    
	# Check hostname
	if [[ "$line" =~ 'Received: from' ]] && [[ "$line" =~ '(localhost [127.0.0.1])' ]]; then  
	    mailhost=`echo $line |cut -d' ' -f 3`
	    read
	    read line
	    if [[ "$line" =~ ^for ]]; then
		withdest=1
	    fi
	fi
	if [[ "$line" =~ ^X-Sender ]]; then  
	    xsender=1
	fi
    done

    if [[  $tzone != $messagetz ]]; then 
	wrongtz=1; 
	#echo "Wrong timezome"
    fi
    #echo "Current tz .$tzone."
    #echo "Message tz .$messagetz."
    #echo "nosc $nosc"
    #echo "Mailhost .$mailhost."
    #echo "With destination $withdest"
    #echo "X-Sender $xsender"
    
    # We inspect only one user
    if [[ ! $nosc ]]; then return 0; fi

    # We discard unconditionally wrong timezone
    if [[ $wrongtz ]]; then return 1; fi
    # We accept imath.kiev.ua without X-sender (mail from NO site)
    if [[ "$mailhost" == "imath.kiev.ua" ]] && [[ !$xsender ]]; then return 0 ; fi
    # We accept webmail with destination address in Received:
    if [[ "$mailhost" == "webmail.imath.kiev.ua" ]] && [[ $withdest ]]; then return 0 ; fi

    return 1
}

# Start processing.
cd $INSPECT_DIR || {
    echo $INSPECT_DIR does not exist; exit $EX_TEMPFAIL; }

cat >in.$$ || { 
    echo Cannot save mail to file; exit $EX_TEMPFAIL; }

# Specify your content filter here.
filter <in.$$ || {
   echo Message content rejected; exit $EX_UNAVAILABLE; }

$SENDMAIL "$@" <in.$$

exit $?