Moving …

Hello for whoever read this,

My new post will be in blog.mochtar.net , see you in my new blog site.

Using HAPROXY Against Zimbra MTA Services, reveal origin IP

We often use HAProxy when deploying zimbra in large environment for load balancing traffic espesially in MTA services  port 25, 465 and 587. but using default configuration  in haproxy and zimbra  affecting sender IP will be read as HAProxy server’s IP, so we cannot trace email by it’s origin IP. this is a big issue when dealing with spammer either from outside or internal.

Luckily there are option in postfix for read original IP from traffic that was sent by haproxy. the configuration are postscreen_upstream_proxy_protocol (if using postscreen as it’s a default in smtp port 25 since zimbra 8.7) and smtpd_upstream_proxy_protocol then from haproxy side by adding send-proxy option.

So here’s the steps for configuring it:

[ClearOS_6] Make ldap service listen to all IP

In ClearOS We can set Ldap service listen to all interface by setting Publish Policy option to All Networks, but maybe for security concern the service was not for ldap but ldaps (SSL ldap protocol) which listen in port 636.

Because there is an application that will be using ClearOS ldap as authentication backend cannot using ldaps (as it’s been hardcoded from  vendor) so we need to force ldap (port 389) service to listen in all IP.

So here’s the steps.

• Edit init service for slapd

vi /etc/init.d/slapd

• Go to line number 72 then add following lines.

for ip in $AUTOMAGIC_LANIPS; do
      harg="$harg ldap://$ip"
done

• Save and exit, then restart slapd service to apply the changes

service slapd restart

• Make sure the modified file will not replaced if there is update for package openldap-servers (do as your own risk)

vi /etc/yum.conf

• Under section [main] add following line

exclude=openldap-servers

• make sure ldap service port are listening to all available IP.

netstat -tnap | grep LISTEN | grep 389

 

[ZIMBRA] Prevent User Customizing “FROM” header

Background

Some of our Zimbra customers are complaining for authenticated user can customizing FROM header which can lead to fraud email. this issue can be reproduce by using thunderbird once compose an email as following picture.

or by using this script, change variables username, password, fake_from and to_addr based on your environment.

Solution

I created customized milter engine using python milter library for my workaroud with following features:

Getting all Zimbra Task Through SOAP

For example you want to fetch all task list which has branch in it as this picture.

You can fetch them using soap call Search for filter recursively task folder from root dir (/) and GetFolder for fetch task detail, here’s the example script of using mentioned soap call.

Installing pgAdmin4 (desktop mode) in Ubuntu

First install development package for compiling latest pscyopg2 package.

Note: make sure the version of postgresql server that will be remote using pgAdmin4 is 9.0 above.

sudo apt-get install python-dev postgresql-server-dev-9.5

Zimbra Weak Password Scanner

Sometime our customer that use Zimbra has frequent issue in internal spammer because weakness in user password so i created a script to scanning it then we can push the user to use the hard one. maybe it’s quite similar as my previous post

Mailman3 Easy Installation

I made script to make mailman3 installation easy (automated) based on my experience installing it manually.  for installation guide and prerequisite condition you can see in it’s repository here https://github.com/iomarmochtar/mailman3_ei

Here’s the post installation topics that may you need:

Using Django Template Outside Project

if you have similar needs for using django template outside django project then this snipped will be useful.

	import django
	from django.template import Template, Context
	from django.conf import settings
	# optional if you just render str instead of template file
	from django.template.loader import get_template
	settings.configure(TEMPLATES=[{
	'BACKEND': 'django.template.backends.django.DjangoTemplates',
	# if you want to render using template file
	'DIRS': ['/tmp/template_dirs']
	}])
	django.setup()
	# variables that will be passed to template
	vars = {'name':'mochtar'}
	print Template("Using string = {{name}}").render(Context(vars))
	# file say_hello.tmpl located in folder /tmp/template_dirs as it's configured above
	print get_template("say_hello.tmpl").render(vars)

view raw using_django_template_outside.py hosted with ❤ by GitHub

ClearOS 6 weak password scanner

As my previous post about enhancing password policy in ClearOS i mentioned about create simple PHP script for detecting user which using weak password. so i’d like to share it.