Megalinux

This document is to configure SMTP server on Fedora Core 4, to use it from anywhere without the necessity of opening up the relay for public use and hence subjecting yourself to the possibility of being blacklisted or ending up in other databases such as ORBS. DRAC and SMTP AUTH are two different approach which addresses this.

The Purpose of this document is to explain the process of installation and Configuration of sendmail with relay for roaming users, ie,relay based on authentication. With SMTP-AUTH client may indicate an authentication mechanism to the server, perform an authentication protocol exchange, and optionally negotiate a security layer for subsequent protocol interactions. This extension is a profile of the Cyrus Simple Authentication and Security Layer [SASL].

Platform: Fedora Core 4, Sendmail 8.13.5

Installation of sendmail with SASL support

a) Download sendmail source package from:

ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.13.5.tar.gz

This is downloaded into /usr/local/src directory.

b) tar -zxvf sendmail.8.13.5
c) cd sendmail-8.13.5
d) cd devtools/Site
e) joe site.config.m4
f) Add the following lines to it:
APPENDDEF(`confENVDEF’, `-DSASL’)
APPENDDEF(`conf_sendmail_LIBS’, `-lsasl’)

g) cd /usr/local/src/sendmail-8.13.5/cf/cf
h) create a file called linux.mc with exactly the following lines:

OSTYPE(`linux')dnl
define(`confCONNECTION_RATE_THROTTLE',40)dnl
define(`confMAX_HOP',30)dnl
define(`confMAX_MESSAGE_SIZE',10000000)dnl
define(`confPRIVACY_FLAGS',`authwarnings,needmailhelo')dnl
define(`confQUEUE_LA',5)dnl
define(`confREFUSE_LA',10)dnl
define(`confTO_CONNECT', `1m')dnl
define(`confTO_IDENT',0s)dnl
define(`confTO_QUEUEWARN', `12h')dnl
define(`confTRY_NULL_MX_LIST',true)dnl
define(`STATUS_FILE',`/etc/mail/sendmail.st')dnl
define(`ALIAS_FILE',`/etc/mail/aliases')dnl
FEATURE(`local_procmail', `/usr/bin/procmail')dnl
FEATURE(`always_add_domain')dnl
define(`confCW_FILE',` /etc/mail/local-host-names')dnl
FEATURE(`smrsh')dnl
define(`confEBINDIR',`/usr/lib/libexec')dnl
FEATURE(`use_cw_file')dnl
FEATURE(`redirect')dnl
FEATURE(`virtusertable',` hash -o /etc/mail/virtusertable')dnl
FEATURE(`access_db')dnl
FEATURE(`blacklist_recipients')dnl
TRUST_AUTH_MECH(`GSSAPI DIGEST-MD5 PLAIN LOGIN PAM')dnl
define(`confAUTH_MECHANISMS', `GSSAPI DIGEST-MD5 PLAIN LOGIN PAM')dnl
MAILER(`smtp')dnl

i) run :
m4 ../m4/cf.m4 linux.mc > sendmail.cf
j) cp sendmail.cf /etc/mail
if /etc/mail does not exist , create it and then copy
k) cd /usr/local/src/sendmail-8.13.5/
l) groupadd -g smmsp; useradd -g smmsp smmsp
m) sh Build
n) sh Build install
o) create a file called /etc/rc.d/init.d/sendmail with following lines ( the standard redhat startup-script):

#!/bin/sh
#
#This shell script takes care of starting and stopping sendmail.
#
# chkconfig: 2345 80 30
# description: Sendmail is a Mail Transport Agent, which is the program \
# that moves mail from one machine to another.
# processname: sendmail
# config: /etc/sendmail.cf
# pidfile: /var/run/sendmail.pid
# Source function library.
. /etc/rc.d/init.d/functions
# Source networking configuration.
. /etc/sysconfig/network
# Source sendmail configureation.
if [ -f /etc/sysconfig/sendmail ] ; then
. /etc/sysconfig/sendmail
else
DAEMON=yes
QUEUE=1h
fi

exit $RETVAL

********* End of start/stop sendmail script ************

0) use /etc/rc.d/init.d/sendmail start/stop to start/stop sendmail
p) cd /etc/mail
q) touch local-host-names access domaintable mailertable virtusertable
r) if not exist, create dir /var/spool/mqueue
Sendmail installation is complete

Authentication with PAM

Edit /usr/lib/sasl/Sendmail.conf. Add the following line to it:
pwcheck_method: PAM

Create /etc/pam.d/smtp with following lines:

#%PAM-1.0
auth required /lib/security/pam_pwdb.so shadow
account required /lib/security/pam_pwdb.so
session required /lib/security/pam_pwdb.so

Test your setup, by using clients like Outlook Express and relay mail through this server.

Setting up additional Yum repositories for Fedora Core 4 is the same as mentioned here. At the time of writing this article, livna was not hosting the Core 4 files and I kept getting 404 errors.

Yay ! Just completed downloading Fedora Core 4. Will install it and test it out today

There are several third-party apt and yum repositories for Fedora that provide additional software and some provide support for playing DVDs and MP3 files. Some of these are just the mirrors of Official Fedora Core 3 project site.

Let us configure 3 of such mirrors: FreshRPMS, livna and atrpms.

Since we use package verification using GPG (default setup for Yum), we need to import the GPG keys of the respective repositories. We can do that by,

#> rpm --import http://freshrpms.net/packages/RPM-GPG-KEY.txt
#> rpm --import http://rpm.livna.org/RPM-LIVNA-GPG-KEY-x86_64
#> rpm --import http://rpm.livna.org/RPM-LIVNA-GPG-KEY-i386
#> rpm --import http://atrpms.net/RPM-GPG-KEY.atrpms

Now, we need to setup the repositories for yum to download from. The repo configuration files are located in /etc/yum.repos.d.

FreshRPMS

create /etc/yum.repos.d/freshrpms.repo, with the following entries:

[freshrpms]
name=Fedora Linux $releasever - $basearch - freshrpms
baseurl=http://ayo.freshrpms.net/fedora/linux/$releasever/$basearch/freshrpms
gpgcheck=1

Livna

create /etc/yum.repos.d/livna.repo, with the following entries:

[livna-stable]
name=Livna.org Fedora Compatible Packages (stable)
baseurl=http://rpm.livna.org/fedora/$releasever/$basearch/RPMS.stable
gpgcheck=1

[livna-unstable]
name=Livna.org Fedora Compatible Packages (unstable)
baseurl=http://rpm.livna.org/fedora/$releasever/$basearch/RPMS.unstable
gpgcheck=1

[livna-testing]
name=Livna.org Fedora Compatible Packages (testing)
baseurl=http://rpm.livna.org/fedora/$releasever/$basearch/RPMS.testing
gpgcheck=1

ATRPMS

create /etc/yum.repos.d/atrpms.repo, with the following entries:

[at-stable]
name=ATrpms for Fedora Core $releasever stable
baseurl=http://apt.atrpms.net/fedora/$releasever/en/$basearch/at-stable

[at-good]
name=ATrpms for Fedora Core $releasever good
baseurl=http://apt.atrpms.net/fedora/$releasever/en/$basearch/at-good

[at-testing]
name=ATrpms for Fedora Core $releasever testing
baseurl=http://apt.atrpms.net/fedora/$releasever/en/$basearch/at-testing

[at-bleeding]
name=ATrpms for Fedora Core $releasever bleeding
baseurl=http://apt.atrpms.net/fedora/$releasever/en/$basearch/at-bleeding

Now that the entries are done, you can use yum to install/upgrade packages.