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Server installation of Kerberos
The server installation basically consists of just two packages
apt-get install krb5-{admin-server,kdc} Default Kerberos version 5 realm? STUDENT.LAB
Does DNS contain pointers to your realm's Kerberos Servers? No
Add locations of default Kerberos servers to /etc/krb5.conf? Yes
Create the Kerberos KDC configuration automatically? Yes
Should the data be purged as well as the package files? No
Run the Kerberos V5 administration daemon (kadmind)? Yes
Kerberos servers for your realm: vm14.student.lab
Administrative server for your Kerberos realm: vm14.atudent.lab
Create the Kerberos KDC configuration automatically? Yes
To create the Kerberos realm, invoke Debian-specific command krb5_newrealm.
krb5_newrealm
Enter your master password for kerberos. PASSWORD
Kerberos Configuration
Next need to edit the Kerberos config file, /etc/krb5.conf. That file also needs to be the same on all Kerberos servers and clients belonging to the same realm. /etc/krb5.conf is split into sections; you should search for section ”[domain_realm]” and append your definition:
.student.lab = STUDENT.LAB student.lab = STUDENT.LAB At the bottom of the file add the logging section: [logging]
kdc = FILE:/var/log/kerberos/krb5kdc.log admin_server = FILE:/var/log/kerberos/kadmin.log default = FILE:/var/log/kerberos/krb5lib.log
After editing /etc/krb5.conf use scp to copy it to vm15 and vm16
next we need to edit the ”[libdefaults]” in /etc/krb5.conf (usually at the top of the file) and append the following definition:
allow_weak_crypto = false
Now we need to apply the changes we made.
invoke-rc.d krb5-admin-server restart
invoke-rc.d krb5-kdc restart
Next we need to test the changes.
kadmin.local
Authenticating as principal root/admin@STUDENT.LAB with password.
kadmin.local: listprincs
K/M@STUDENT.LAB kadmin/admin@STUDENT.LAB kadmin/changepw@STUDENT.LAB kadmin/history@STUDENT.LAB kadmin/krb1.STUDENT.LAB@STUDENT.LAB krbtgt/STUDENT.LAB@STUDENT.LAB
kadmin.local: quit
vi /etc/krb5kdc/kadm5.acl
Check to make sure is has the line below
*/admin *
next we need to restart the krb5-admin-server
invoke-rc.d krb5-admin-server restart
Next we need to create four basic policies:
kadmin.local
Authenticating as principal root/admin@STUDENT.LAB with password.
kadmin.local: add_policy -minlength 8 -minclasses 3
Kadmin kadmin.local: add_policy -minlength 8 -minclasses 4 host
kadmin.local: add_policy -minlength 8 -minclasses 4 service
kadmin.local: add_policy -minlength 8 -minclasses 2 user
kadmin.local: quit
Principal creation
Next we need to create the principal for the root kadmin.local Authenticating as principal root/admin@STUDENT.LAB with password.
kadmin.local: addprinc -policy admin root/admin
Enter password for principal “root/admin@STUDENT.LAB”: PASSWORD Re-enter password for principal “root/admin@STUDENT.LAB”: PASSWORD Principal “root/admin@STUDENT.LAB” created.
kadmin.local: quit
Creating first unprivileged principal
Next we need add an unprivileged account.
kadmin -p root/admin
Authenticating as principal root/admin@STUDENT.LAB with password.
Password for root/admin@STUDENT.LAB: PASSWORD
kadmin: addprinc -policy user mirko
Enter password for principal “mirko@STUDENT.LAB”: PASSWORD
Re-enter password for principal “mirko@STUDENT.LAB”: PASSWORD
Principal “mirko@STUDENT.LAB” created.
kadmin: quit
let check our tickets: klist -5f
klist: No credentials cache found (ticket cache FILE:/tmp/krb5cc_0)
kinit
Password for mirko@STUDENT.LAB: PASSWORD klist -5f
Ticket cache: FILE:/tmp/krb5cc_1000
Default principal: mirko@STUDENT.LAB
Valid starting Expires Service principal 04/12/2010 08:30:33 04/13/2010 08:30:33 krbtgt/STUDENT.LAB@STUDENT.LAB
renew until 04/13/2010 22:30:34, Flags: FPRIA
kdestroy This thows away the ticket
Installing krb5-rsh-server
Next we need to install the krb5-rsh-server.
apt-get install openbsd-inetd
apt-get install krb5-rsh-server
update-rc.d -f openbsd-inetd remove
update-rc.d openbsd-inetd defaults
update-inetd –enable kshell update-inetd –enable eklogin
invoke-rc.d openbsd-inetd restart
we need to export the key to a keytab file
kadmin -p root/admin
Authenticating as principal root/admin@STUDENT.LAB with password.
Password for root/admin@STUDENT.LAB: PASSWORD
kadmin: addprinc -policy service -randkey host/vm15.STUDENT.LAB Principal “host/vm15.STUDENT.LAB@STUDENT.LAB” created.
kadmin: addprinc -policy service -randkey host/vm16.STUDENT.LAB Principal “host/vm16.STUDENT.LAB@STUDENT.LAB” created.
kadmin: ktadd -k /etc/krb5.keytab -norandkey host/vm15.STUDENT.LAB
Entry for principal host/vm15.STUDENT.LAB@STUDENT.LAB with kvno 3, encryption type AES-256 CTS mode with 96-bit SHA-1 HMAC added to keytab WRFILE:/etc/krb5.keytab.
Entry for principal host/vm15.STUDENT.LAB@STUDENT.LAB with kvno 3, encryption type ArcFour cbc mode with HMAC/md5 added to keytab WRFILE:/etc/krb5.keytab.
Entry for principal host/vm15.monarch.STUDENT.LAB@STUDENT.LAB with kvno 3, encryption type Triple DES cbc mode with HMAC/sha1 added to keytab WRFILE:/etc/krb5.keytab.
Entry for principal host/vm15.STUDENT.LAB@STUDENT.LAB with kvno 3, encryption type DES cbc mode with CRC-32 added to keytab WRFILE:/etc/krb5.keytab.
kadmin: ktadd -k /etc/krb5.keytab -norandkey host/vm16.STUDENT.LAB
Entry for principal host/vm16.STUDENT.LAB@STUDENT.LAB with kvno 3, encryption type AES-256 CTS mode with 96-bit SHA-1 HMAC added to keytab WRFILE:/etc/krb5.keytab.
Entry for principal host/vm16.STUDENT.LAB@STUDENT.LAB with kvno 3, encryption type ArcFour cbc mode with HMAC/md5 added to keytab WRFILE:/etc/krb5.keytab.
Entry for principal host/vm16.monarch.STUDENT.LAB@STUDENT.LAB with kvno 3, encryption type Triple DES cbc mode with HMAC/sha1 added to keytab WRFILE:/etc/krb5.keytab.
Entry for principal host/vm16.STUDENT.LAB@STUDENT.LAB with kvno 3, encryption type DES cbc mode with CRC-32 added to keytab WRFILE:/etc/krb5.keytab.
kadmin: quit
Installing krb5-clients
Let's install kerberized versions of the basic client programs: apt-get install krb5-clients
Obtain Kerberos ticket:
kinit
Password for USERNAME@STUDENT.LAB: PASSWORD Connect:
krb5-rsh -x -PN VM14.STUDENT.LAB
Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. You have new mail.
Pam files Configuration
cd /etc
cp -a pam.d pam.d,orig
enter the below command as a safety net.
cp -a pam.d,orig/* pam.d/
We need to make sure that only the following lines are active in each of the indicated files.
vi /etc/pam.d/common-account
account sufficient pam_unix.so
account sufficient pam_krb5.so
account required pam_deny.so
vi /etc/pam.d/common-auth
auth sufficient pam_unix.so nullok_secure
auth sufficient pam_krb5.so use_first_pass
auth required pam_deny.so
vi /etc/pam.d/common-password
password sufficient pam_unix.so nullok obscure md5
password sufficient pam_krb5.so use_first_pass
password required pam_deny.so
vi /etc/pam.d/common-session
session required pam_limits.so
session optional pam_krb5.so
session optional pam_unix.so
restart vm14.student.lab If everything is working
Configuration of client systems
log on to vm15 and vm16. Enter:
apt-get install libpam-krb5
apt-get install krb5-user
once this is done log back in to vm14.student.lab and do
scp /etc/pam.d/common* root@vm16.student.lab
scp /etc/pam.d/common* root@vm15.student.lab
Reference
