path: root/postfix/anti-uce.sh

#!/bin/bash

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 postconf myhostname | grep '.' &> /dev/null; then
    postconf -e 'smtpd_helo_required = yes'
fi
postconf -e "`getlinesfromfile permit_mx_backup_networks`"
postconf -e "`getlinesfromfile maps_rbl_domains`"
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 dpkg -L libsasl-modules-plain &> /dev/null && [ -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/" \
        > $confdir/master.cf
    postconf -e 'smtpd_tls_cert_file = /etc/ssl/certs/postfix.pem'
    if [ -f /etc/ssl/private/postfix.pem ]; then
        postconf -e 'smtpd_tls_key_file = /etc/ssl/private/postfix.pem'
    fi
    postconf -e 'smtpd_tls_loglevel = 1'
    postconf -e 'smtpd_use_tls = yes'
#   postconf -e 'smtpd_tls_session_cache_database = sdbm:/etc/postfix/smtpd_scache'
    postconf -e 'smtpd_tls_auth_only = yes'
    postconf -e 'smtpd_sasl_auth_enable = no'
    postconf -e 'smtpd_sasl_security_options = noanonymous'
    postconf -e 'smtpd_sasl_local_domain = $myhostname'
    postconf -e 'broken_sasl_auth_clients = yes'
    postconf -e 'tls_random_source = dev:/dev/urandom'
    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
        postconf -e 'smtpd_tls_CAfile = /etc/ssl/certs/cacert.pem'
        postconf -e 'smtp_tls_CAfile = $smtpd_tls_CAfile'
        postconf -e 'smtp_tls_cert_file = /etc/ssl/certs/postfix.pem'
        # Client side TLS only makes sense if a publicly available certificate is available
        # (and DON'T publish a self-signed certificate!)
        if [ -f /etc/ssl/private/postfix.pem ]; then
            postconf -e 'smtp_tls_key_file = $smtpd_tls_key_file'
        fi
        postconf -e 'smtp_tls_loglevel = 1'
        postconf -e 'smtp_use_tls = yes'
        postconf -e 'smtp_tls_CApath = /etc/ssl/certs'
        postconf -e 'smtp_tls_note_starttls_offer = yes' # Useful when collecting info for smtp_tls_per_site option
#       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!
        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