Configuring Heimdal
Config files
/etc/heimdal/*
Configuration Information
Master KDC Server Configuration
Create the Kerberos configuration file with the following command:
install -d /etc/heimdal &&
cat > /etc/heimdal/krb5.conf << "EOF"
# Begin /etc/heimdal/krb5.conf
[libdefaults]
default_realm = [LFS.ORG]
encrypt = true
[realms]
[LFS.ORG] = {
kdc = [belgarath.lfs.org]
admin_server = [belgarath.lfs.org]
kpasswd_server = [belgarath.lfs.org]
}
[domain_realm]
.[lfs.org] = [LFS.ORG]
[logging]
kdc = FILE:/var/log/kdc.log
admin_server = FILE:/var/log/kadmin.log
default = FILE:/var/log/krb.log
# End /etc/heimdal/krb5.conf
EOF
You will need to substitute your domain and proper hostname for the
occurances of the belgarath and lfs.org names.
default_realm should be the name of your domain changed to ALL CAPS.
This isn't required, but both Heimdal and MIT
recommend it.
encrypt = true provides encryption of all traffic between kerberized
clients and servers. It's not necessary and can be left off. If you
leave it off, you can encrypt all traffic from the client to the server
using a switch on the client program instead.
The [realms] parameters tell the client programs where to look for the
KDC authentication services.
The [domain_realm] section maps a domain to a realm.
Store the master password in a key file using the following commands:
install -d -m 755 /var/lib/heimdal &&
kstash
Create the KDC database:
kadmin -l
Choose the defaults for now. You can go in later and change the
defaults, should you feel the need. At the
kadmin> prompt, issue the following statement:
init [LFS.ORG]
Now we need to populate the database with principles (users). For now,
just use your regular login name or root.
add [loginname]
The KDC server and any machine running kerberized
server daemons must have a host key installed:
add --random-key host/[belgarath.lfs.org]
After choosing the defaults when prompted, you will have to export the
data to a keytab file:
ext host/[belgarath.lfs.org]
This should have created two files in
/etc/heimdal;
krb5.keytab (Kerberos 5) and
srvtab (Kerberos 4). Both files should have 600
(root rw only) permissions. Keeping the keytab files from public access
is crucial to the overall security of the Kerberos installation.
Eventually, you'll want to add server daemon principles to the database
and extract them to the keytab file. You do this in the same way you
created the host principles. Below is an example:
add --random-key ftp/[belgarath.lfs.org]
(choose the defaults)
ext ftp/[belgarath.lfs.org]
Exit the kadmin program (use quit
or exit) and return back to the shell prompt. Start
the KDC daemon manually, just to test out the
installation:
/usr/sbin/kdc &
Attempt to get a TGT (ticket granting ticket) with the
following command:
kinit [loginname]
You will be prompted for the password you created. After you get your
ticket, you should list it with the following command:
klist
Information about the ticket should be displayed on the screen.
To test the functionality of the keytab file, issue the following
command:
ktutil list
This should dump a list of the host principals, along with the encryption
methods used to access the principals.
At this point, if everything has been successful so far, you can feel
fairly confident in the installation and configuration of the package.
To automate the running of Kerberos server and
kpasswdd daemon, use the following command to create
the init.d script:
cat >etc/rc.d/init.d/heimdal << "EOF"
#!/bin/sh
# Begin $rc_base/init.d/heimdal
# Based on sysklogd script from LFS-3.1 and earlier.
# Rewritten by Gerard Beekmans - gerard@linuxfromscratch.org
# Heimdal bootscript submitted by Randy McMurchy <LFS-User_at_mcmurchy_dot_com>
. /etc/sysconfig/rc
. $rc_functions
case "$1" in
start)
echo "Starting KDC Server Daemon..."
if test -f "/var/run/kdc.pid"
then
print_status warning running
else
/usr/sbin/kdc &
sleep 1
if test -f "/var/run/kdc.pid"
then
print_status success
else
print_status failure
fi
fi
echo "Starting KDC kpasswdd Daemon..."
if test -f "/var/run/kpasswdd.pid"
then
print_status warning running
else
/usr/sbin/kpasswdd &
sleep 1
if test -f "/var/run/kpasswdd.pid"
then
print_status success
else
print_status failure
fi
fi
;;
stop)
echo "Stopping KDC kpasswdd Daemon..."
killproc /usr/sbin/kpasswdd
echo "Stopping KDC Server Daemon..."
killproc /usr/sbin/kdc
;;
restart)
$0 stop
sleep 1
$0 start
;;
status)
statusproc /usr/sbin/kdc
statusproc /usr/sbin/kpasswdd
;;
*)
echo "Usage: $0 {start|stop|restart|status}"
exit 1
;;
esac
# End $rc_base/init.d/heimdal
EOF
chmod 754 /etc/rc.d/init.d/heimdal
Create the symbolic links to this file in the relevant rc.d directory with the following commands:
cd /etc/rc.d/init.d &&
ln -sf ../init.d/heimdal ../rc0.d/K42heimdal &&
ln -sf ../init.d/heimdal ../rc1.d/K42heimdal &&
ln -sf ../init.d/heimdal ../rc2.d/K42heimdal &&
ln -sf ../init.d/heimdal ../rc3.d/S28heimdal &&
ln -sf ../init.d/heimdal ../rc4.d/S28heimdal &&
ln -sf ../init.d/heimdal ../rc5.d/S28heimdal &&
ln -sf ../init.d/heimdal ../rc6.d/K42heimdal
Using Kerberized Client Programs
To use the kerberized client programs (telnet,
ftp, rsh,
rxterm, rxtelnet,
rcp, xnlock), you first must get
a TGT. Use the kinit program to
get the ticket. After you've acquired the ticket, you can use the
kerberized programs to connect to any kerberized server on the network.
You will not be prompted for authentication until your ticket expires
(default is one day), unless you specify a different user as a command
line argument to the program.
The kerberized programs will connect to non kerberized daemons, warning
you that authentication is not encrypted. As mentioned earlier, only the
ftp program gives any trouble connecting to non
kerberized daemons.
For additional information consult the
Heimdal hint on which the above instructions are based.