Postfix
The How To is a step by step process in which teaches the user how to pull together a SMTP-AUTH to the users server. All applications and dependencies have been recommended in order to go forth with this process.
Installation
In order to install Postfix with SMTP-AUTH and TLS do the following steps:
apt-get install postfix postfix-tls libsasl2 sasl2-bin libsasl2-modules libdb3-util procmail
followed by:
dpkg-reconfigure postfix
Insert the following details when asked (replacing server1.example.com with your domain name if you have one):
- Internet Site
- NONE
- server1.example.com
- server1.example.com, localhost.example.com, localhost
- No
- 127.0.0.0/8
- 0
- +
Then run the following commands:
postconf -e 'smtpd_sasl_local_domain =' postconf -e 'smtpd_sasl_auth_enable = yes' postconf -e 'smtpd_sasl_security_options = noanonymous' postconf -e 'broken_sasl_auth_clients = yes' postconf -e 'smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject _unauth_destination' postconf -e 'inet_interfaces = all' echo 'pwcheck_method: saslauthd' >> /etc/postfix/sasl/smtpd.conf echo 'mech_list: plain login' >> /etc/postfix/sasl/smtpd.conf mkdir /etc/postfix/ssl cd /etc/postfix/ssl/ openssl genrsa -des3 -rand /etc/hosts -out smtpd.key 1024 chmod 600 smtpd.key openssl req -new -key smtpd.key -out smtpd.csr openssl x509 -req -days 3650 -in smtpd.csr -signkey smtpd.key -out smtpd.crt openssl rsa -in smtpd.key -out smtpd.key.unencrypted mv -f smtpd.key.unencrypted smtpd.key openssl req -new -x509 -extensions v3_ca -keyout cakey.pem -out cacert.pem -days 3650 postconf -e 'smtpd_tls_auth_only = no' postconf -e 'smtp_use_tls = yes' postconf -e 'smtpd_use_tls = yes' postconf -e 'smtp_tls_note_starttls_offer = yes' postconf -e 'smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key' postconf -e 'smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt' postconf -e 'smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem' postconf -e 'smtpd_tls_loglevel = 1' postconf -e 'smtpd_tls_received_header = yes' postconf -e 'smtpd_tls_session_cache_timeout = 3600s' postconf -e 'tls_random_source = dev:/dev/urandom' postconf -e 'myhostname = server1.example.com'
The file /etc/postfix/main.cf should now look like this:
# See /usr/share/postfix/main.cf.dist for a commented, more complete version smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu) biff = no # appending .domain is the MUA's job. append_dot_mydomain = no # Uncomment the next line to generate "delayed mail" warnings #delay_warning_time = 4h myhostname = server1.example.com alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases myorigin = /etc/mailname mydestination = server1.example.com, localhost.example.com, localhost relayhost = mynetworks = 127.0.0.0/8 mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all smtpd_sasl_local_domain = smtpd_sasl_auth_enable = yes smtpd_sasl_security_options = noanonymous broken_sasl_auth_clients = yes smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject _unauth_destination smtpd_tls_auth_only = no smtp_use_tls = yes smtpd_use_tls = yes smtp_tls_note_starttls_offer = yes smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem smtpd_tls_loglevel = 1 smtpd_tls_received_header = yes smtpd_tls_session_cache_timeout = 3600s tls_random_source = dev:/dev/urandom
Second Step
Restart the postfix daemon like this:
/etc/init.d/postfix restart
Authentication will be done by saslauthd. We have to change a few things to make it work properly. Because Postfix runs chrooted in /var/spool/postfix we have to do the following:
mkdir -p /var/spool/postfix/var/run/saslauthd rm -fr /var/run/saslauthd }}}
Third STEP |
Now we have to edit /etc/default/saslauthd in order to activate saslauthd. Remove # in front of START=yes and add the line PARAMS="-m /var/spool/postfix/var/run/saslauthd":
# This needs to be uncommented before saslauthd will be run automatically START=yes PARAMS="-m /var/spool/postfix/var/run/saslauthd" # You must specify the authentication mechanisms you wish to use. # This defaults to "pam" for PAM support, but may also include # "shadow" or "sasldb", like this: # MECHANISMS="pam shadow" MECHANISMS="pam"
FOURTH STEP |
Finally we have to edit /etc/init.d/saslauthd. Change the line
dir=`dpkg-statoverride --list $PWDIR`
to
#dir=`dpkg-statoverride --list $PWDIR`
FIFTH STEP |
Then change the variables PWDIR and PIDFILE and add the variable dir at the beginning of the file:
PWDIR="/var/spool/postfix/var/run/${NAME}" PIDFILE="${PWDIR}/saslauthd.pid" dir="root sasl 755 ${PWDIR}"
/etc/init.d/saslauthd should now look like this:
NAME=saslauthd DAEMON="/usr/sbin/${NAME}" DESC="SASL Authentication Daemon" DEFAULTS=/etc/default/saslauthd PWDIR="/var/spool/postfix/var/run/${NAME}" PIDFILE="${PWDIR}/saslauthd.pid" dir="root sasl 755 ${PWDIR}" createdir() { # $1 = user # $2 = group # $3 = permissions (octal) # $4 = path to directory [ -d "$4" ] || mkdir -p "$4" chown -c -h "$1:$2" "$4" chmod -c "$3" "$4" } test -f "${DAEMON}" || exit 0 # Source defaults file; edit that file to configure this script. if [ -e "${DEFAULTS}" ]; then . "${DEFAULTS}" fi # If we're not to start the daemon, simply exit if [ "${START}" != "yes" ]; then exit 0 fi # If we have no mechanisms defined if [ "x${MECHANISMS}" = "x" ]; then echo "You need to configure ${DEFAULTS} with mechanisms to be used" exit 0 fi # Add our mechanimsms with the necessary flag PARAMS="${PARAMS} -a ${MECHANISMS}" START="--start --quiet --pidfile ${PIDFILE} --startas ${DAEMON} --name ${NAME} -- ${PARAMS}" # Consider our options case "${1}" in start) echo -n "Starting ${DESC}: " #dir=`dpkg-statoverride --list $PWDIR` test -z "$dir" || createdir $dir if start-stop-daemon ${START} >/dev/null 2>&1 ; then echo "${NAME}." else if start-stop-daemon --test ${START} >/dev/null 2>&1; then echo "(failed)." exit 1 else echo "${DAEMON} already running." exit 0 fi fi ;; stop) echo -n "Stopping ${DESC}: " if start-stop-daemon --stop --quiet --pidfile "${PIDFILE}" \ --startas ${DAEMON} --retry 10 --name ${NAME} \ >/dev/null 2>&1 ; then echo "${NAME}." else if start-stop-daemon --test ${START} >/dev/null 2>&1; then echo "(not running)." exit 0 else echo "(failed)." exit 1 fi fi ;; restart|force-reload) $0 stop exec $0 start ;; *) echo "Usage: /etc/init.d/${NAME} {start|stop|restart|force-reload}" >&2 exit 1 ;; esac exit 0
SIXTH STEP |
Now start saslauthd:
/etc/init.d/saslauthd start
To see if SMTP-AUTH and TLS work properly now run the following command:
telnet localhost 25
After you have established the connection to your postfix mail server type
ehlo localhost
If you see the lines
250-STARTTLS
and
250-AUTH
everything is fine.
Type
quit
to return to the system's shell.