#!/bin/bash
#
# /etc/local-COMMON/postfix/postfix.sh
# Copyright 2002 Jonas Smedegaard <dr@jones.dk>
#
# $Id: postfix.sh,v 1.7 2003-01-04 02:46:14 jonas Exp $
#
# Auto-tweak plain installed postfix Debian package
#
# TODO: Check for postfix 2.0 and include improve RBL logic with new
# options reject_rhsbl_sender and default_rbl_reply
#
# TODO: Figure out a way to use chroot jail for TLS stuff.

set -e

paramdir='/etc/local-COMMON/postfix'
confdir='/etc/postfix'
sp='[[:space:]]'

function getlinesfromfile() {
	param="$1"
	echo -n "$param = "
	cat $paramdir/$param | grep -v '^#' | sed 's/#.*//' | tr '\n' ',' | sed -e 's/^[, ]*//' -e 's/[, ]\+/,/g' -e 's/,$//'
}

# Some badly configured setup use hostname instead of FQDN
if /usr/sbin/postconf myhostname | grep '.' &> /dev/null; then
	/usr/sbin/postconf -e 'smtpd_helo_required = yes'
fi
/usr/sbin/postconf -e "`getlinesfromfile permit_mx_backup_networks`"
/usr/sbin/postconf -e "`getlinesfromfile maps_rbl_domains`"
/usr/sbin/postconf -e "`getlinesfromfile smtpd_recipient_restrictions`"

# TLS breaks postfix if no SASL modules available (and doesn't make sense either)
# (change the test if using some other modules and avoid the plain ones)
if [ -f /usr/lib/postfix/tlsmgr -a -f /usr/lib/sasl/libplain.so -a -f /etc/ssl/certs/postfix.pem ]; then
	mkdir -p $confdir/sasl
	echo 'pwcheck_method: pam' >$confdir/sasl/smtpd.conf
	echo 'auto_transition: false' >>$confdir/sasl/smtpd.conf
	groups postfix | grep shadow &>/dev/null || adduser postfix shadow
	# Release TLS-related daemons from chroot jail (bringing SASL into the jail is just too messy)
	cp -a $confdir/master.cf $confdir/master.cf.old
	cat $confdir/master.cf.old | sed \
		-e "s/^\(smtp$sp\+inet\($sp\+[n-]\)\{2\}$sp\+\)[n-]\(\($sp\+-\)\{2\}$sp\+smtpd\).*/\1n\3 -o smtpd_sasl_auth_enable=yes/" \
		-e "s/^#\?\(\(smtps\|587\)$sp\+inet\($sp\+[n-]\)\{2\}$sp\+\)[n-]/\1n/" \
		-e "s/^#\(tlsmgr$sp\)/\1/" \
		> $confdir/master.cf
	cat $confdir/master.cf | egrep "^tlsmgr$sp" > /dev/null || \
		echo 'tlsmgr	  fifo	-	-	-	300	1	tlsmgr' >> $confdir/master.cf
	/usr/sbin/postconf -e 'smtpd_tls_cert_file = /etc/ssl/certs/postfix.pem'
	if [ -f /etc/ssl/private/postfix.pem ]; then
		/usr/sbin/postconf -e 'smtpd_tls_key_file = /etc/ssl/private/postfix.pem'
	fi
	/usr/sbin/postconf -e 'smtpd_tls_loglevel = 1'
	/usr/sbin/postconf -e 'smtpd_use_tls = yes'
	/usr/sbin/postconf -e 'smtpd_tls_session_cache_database = sdbm:/etc/postfix/smtpd_scache'
	/usr/sbin/postconf -e 'smtpd_tls_auth_only = yes'
	/usr/sbin/postconf -e 'smtpd_sasl_auth_enable = no'
	/usr/sbin/postconf -e 'smtpd_sasl_security_options = noanonymous'
	/usr/sbin/postconf -e 'smtpd_sasl_local_domain = $myhostname'
	/usr/sbin/postconf -e 'smtpd_tls_received_header = yes'
	/usr/sbin/postconf -e 'broken_sasl_auth_clients = yes'
	/usr/sbin/postconf -e 'tls_random_source = dev:/dev/urandom'
	/usr/sbin/postconf -e 'tls_daemon_random_source = dev:/dev/urandom'
	# Check if using a proper key exists (not just a self-signed one)
	# (it is assumed that a CA certificate is made public if used!)
	if [ -f /etc/ssl/certs/cacert.pem ]; then
		/usr/sbin/postconf -e 'smtpd_tls_CAfile = /etc/ssl/certs/cacert.pem'
		# Client side TLS only makes sense if a publicly available certificate is available
		# (and DON'T publish a self-signed certificate!)
		/usr/sbin/postconf -e 'smtp_tls_CAfile = /etc/ssl/certs/cacert.pem'
		/usr/sbin/postconf -e 'smtp_tls_cert_file = /etc/ssl/certs/postfix.pem'
		if [ -f /etc/ssl/private/postfix.pem ]; then
			/usr/sbin/postconf -e 'smtp_tls_key_file = /etc/ssl/private/postfix.pem'
		fi
		/usr/sbin/postconf -e 'smtp_tls_loglevel = 1'
		/usr/sbin/postconf -e 'smtp_use_tls = yes'
		/usr/sbin/postconf -e 'smtp_tls_CApath = /etc/ssl/certs'
		/usr/sbin/postconf -e 'smtp_tls_note_starttls_offer = no' # Enable to collect info for smtp_tls_per_site option
		/usr/sbin/postconf -e 'smtp_tls_session_cache_database = sdbm:/etc/postfix/smtp_scache'
		# This makes Netscape ask for a certificate, so make sure it IS public!
		/usr/sbin/postconf -e 'smtpd_tls_ask_ccert = yes'
	fi
else
	echo 'TLS not activated - check the script for requirements...'
fi

/etc/init.d/postfix reload

# Based on this: http://jimsun.linxnet.com/misc/postfix-anti-UCE.txt
# Support for trusted MX backup networks added
# PCRE stuff avoided, as PCRE is only optional on newest Debian packages
# RBLs replaced with those recommended by http://www.antispews.org/

# Here's a convenient overview of different blackholes:
#   http://rbls.org/

# smtpd_tls_CAfile