Difference between revisions of "Active Directory Integration"
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| − | In the above example, the | + | In the above example, the keyword '''NETWORK''' is to be used. Do not mistakenly substitute this with your domain name. For adding groups, prepend the '@' symbol to the group. Note that {{ic|Domain Admins}} is encapsulated in quotes so Samba correctly parses it when reading the configuration file. |
| − | == Adding a keytab file | + | == Adding a machine keytab file and activating password-free kerberized ssh to the machine == |
This explains how to generate a machine keytab file which you will need e.g. to enable password-free kerberized ssh to your machine from other machines in the domain. The scenario in mind is that you have a bunch of systems in your domain and you just added a server/workstation using the above description to your domain onto which a lot of users need to ssh in order to work - e.g. GPU workstation or an OpenMP compute node, etc. In this case you might not want to type your password every time you log in. On the other hand the key authentication used by many users in this case can not give you the necessary credentials to e.g. mount kerberized NFSv4 shares. So this will help you to enable password-free logins from your clients to the machine in question using kerberos ticket forwarding. | This explains how to generate a machine keytab file which you will need e.g. to enable password-free kerberized ssh to your machine from other machines in the domain. The scenario in mind is that you have a bunch of systems in your domain and you just added a server/workstation using the above description to your domain onto which a lot of users need to ssh in order to work - e.g. GPU workstation or an OpenMP compute node, etc. In this case you might not want to type your password every time you log in. On the other hand the key authentication used by many users in this case can not give you the necessary credentials to e.g. mount kerberized NFSv4 shares. So this will help you to enable password-free logins from your clients to the machine in question using kerberos ticket forwarding. | ||
Revision as of 11:59, 11 June 2013
A key challenge for system administrators of any datacenter is trying to coexisting in Heterogeneous environments. By this we mean the mixing of different server operating system technologies (typically Microsoft Windows & Unix/Linux). User management and authentication is by far the most difficult of these to solve. The most common way of solving this problem is to use a Directory Server. There are a number of open-source and commercial solutions for the various flavors of *NIX; however, few solve the problem of interoperating with Windows. Active Directory (AD) is a directory service created by Microsoft for Windows domain networks. It is included in most Windows Server operating systems. Server computers on which Active Directory is running are called domain controllers.
Active Directory serves as a central location for network administration and security. It is responsible for authenticating and authorizing all users and computers within a network of Windows domain type, assigning and enforcing security policies for all computers in a network and installing or updating software on network computers. For example, when a user logs into a computer that is part of a Windows domain, it is Active Directory that verifies his or her password and specifies whether he or she is a system administrator or normal user.
Active Directory uses Lightweight Directory Access Protocol (LDAP) versions 2 and 3, Kerberos and DNS. These same standards are available as linux, but piecing them together is not an easy task. Following these steps will help you configure an ArchLinux host to authenticate against an AD domain.
This guide explains how to integrate an Arch Linux host with an existing Windows Active Directory domain. Before continuing, you must have an existing Active Directory domain, and have a user with the appropriate rights within the domain to: query users and add computer accounts (Domain Join).
This document is not an intended as a complete guide to Active Directory nor Samba. Refer to the resources section for additional information.
Contents
Terminology
If you are not familiar with Active Directory, there are a few keywords that are helpful to know.
- Domain : The name used to group computers and accounts.
- SID : Each computer that joins the domain as a member must have a unique SID or System Identifier.
- SMB : Server Message Block.
- NETBIOS: Network naming protocol used as an alternative to DNS. Mostly legacy, but still used in Windows Networking.
- WINS: Windows Information Naming Service. Used for resolving Netbios names to windows hosts.
- Winbind: Protocol for windows authentication.
Configuration
Active Directory Configuration
Updating the GPO
It may be necessary to disable Digital Sign Communication (Always) in the AD group policies. Dive into:
Local policies -> Security policies -> Microsoft Network Server -> Digital sign communication (Always) -> activate define this policy and use the disable radio button.
If you use Windows Server 2008 R2, you need to modify that in GPO for Default Domain Controller Policy -> Computer Setting -> Policies -> Windows Setting -> Security Setting -> Local Policies -> Security Option -> Microsoft network client: Digitally sign communications (always)
Linux Host Configuration
The next few steps will begin the process of configuring the Host. You will need root or sudo access to complete these steps.
Installation
Install the following packages:
- samba
- pam-krb5AUR ---- AUR
- pam_pwcheck
- openntpd (or) ntp
Updating DNS
Active Directory is heavily dependent upon DNS. You will need to update /etc/resolv.conf to use one or more of the Active Directory domain controllers:
/etc/resolv.conf
nameserver <IP1> nameserver <IP2>
Replacing <IP1> and <IP2> with valid IP addresses for the AD servers. If your AD domains do not permit DNS forwarding or recursion, you may need to add additional resolvers.
Configuring NTP
Read NTPd or OpenNTPD to configure a NTP service. Note that OpenNTPD is no longer maintained.
On the configuration, use the IP addresses for the AD servers. Alternatively, you can use other known NTP servers provided the Active directory servers sync to the same stratum. However, AD servers typically run NTP as a service.
Ensure the daemon is configured to sync automatically on startup.
Kerberos
Let's assume that your AD is named example.com. Let's further assume your AD is ruled by two domain controllers, the primary and secondary one, which are named PDC and BDC, pdc.example.com and bdc.example.com respectively. Their IP adresses will be 192.168.1.2 and 192.168.1.3 in this example. Take care to watch your syntax; upper-case is very important here.
/etc/krb5.conf
[libdefaults]
default_realm = EXAMPLE.COM
clockskew = 300
ticket_lifetime = 1d
forwardable = true
proxiable = true
dns_lookup_realm = true
dns_lookup_kdc = true
[realms]
EXAMPLE.COM = {
kdc = PDC.EXAMPLE.COM
admin_server = PDC.EXAMPLE.COM
default_domain = EXAMPLE.COM
}
[domain_realm]
.kerberos.server = EXAMPLE.COM
.example.com = EXAMPLE.COM
example.com = EXAMPLE.COM
example = EXAMPLE.COM
[appdefaults]
pam = {
ticket_lifetime = 1d
renew_lifetime = 1d
forwardable = true
proxiable = false
retain_after_close = false
minimum_uid = 0
debug = false
}
[logging]
default = FILE:/var/log/krb5libs.log
kdc = FILE:/var/log/kdc.log
admin_server = FILE:/var/log/kadmind.log
allow_weak_crypto = trueto the
[libdefaults] section.Creating a Kerberos Ticket
Now you can query the AD domain controllers and request a kerberos ticket (uppercase is necessary):
kinit administrator@EXAMPLE.COM
You can use any username that has rights as a Domain Administrator.
Validating the Ticket
Run klist to verify you did receive the token. You should see something similar to:
# klist
Ticket cache: FILE:/tmp/krb5cc_0
Default principal: administrator@EXAMPLE.COM
Valid starting Expires Service principal
02/04/12 21:27:47 02/05/12 07:27:42 krbtgt/EXAMPLE.COM@EXAMPLE.COM
renew until 02/05/12 21:27:47
Samba
Samba is a free software re-implementation of the SMB/CIFS networking protocol. It also includes tools for Linux machines to act as Windows networking servers and clients.
In this section, we will focus on getting Authentication to work first by editing the 'Global' section first. Later, we will go back and add shares.
/etc/samba/smb.conf
[Global] netbios name = MYARCHLINUX workgroup = EXAMPLE realm = EXAMPLE.COM server string = %h ArchLinux Host security = ads encrypt passwords = yes password server = pdc.example.com idmap uid = 10000-20000 idmap gid = 10000-20000 #idmap backend = rid winbind use default domain = Yes winbind enum users = Yes winbind enum groups = Yes winbind nested groups = Yes winbind separator = + winbind refresh tickets = yes winbind gid = 10000-20000 template shell = /bin/bash template homedir = /home/%D/%U preferred master = no dns proxy = no wins server = pdc.example.com wins proxy = no inherit acls = Yes map acl inherit = Yes acl group control = yes load printers = no debug level = 3 use sendfile = no
We shall now explain to Samba that it shall use the PDC´s database for authentication queries. Again, we use winbindd which is a part of the samba package. Winbind maps the UID and GID of the AD to our Linux-machine. Winbind uses a Unix-implementation of RPC-calls, Pluggable Authentication Modules (aka PAM) and Name Service Switch (NSS) to allow Windows AD and users accessing and to grant permissions on the Linux-machine. The best part of winbindd is, that you don´t have to define the mapping yourself, but only define a range of UID and GID. That´s what we defined in smb.conf.
Update the samba configuration file to enable the winbind daemon
/etc/conf.d/samba
##### /etc/conf.d/samba ##### #SAMBA_DAEMONS=(smbd nmbd) SAMBA_DAEMONS=(smbd nmbd winbindd)
Next, configure samba to startup at boot. Read Daemons for more details.
Starting and testing services
Starting Samba
Hopefully, you have not rebooted yet! Fine. If you are in an X-session, quit it, so you can test login into another console, while you are still logged in.
Start Samba (including smbd, nmbd and winbindd):
If you check the processes, you'll see that winbind did not actually start. A quick review of the logs shows that the SID for this host could be obtained from the domain:
# tail /var/log/samba/log.winbindd
[2012/02/05 21:51:30.085574, 0] winbindd/winbindd_cache.c:3147(initialize_winbindd_cache) initialize_winbindd_cache: clearing cache and re-creating with version number 2 [2012/02/05 21:51:30.086137, 2] winbindd/winbindd_util.c:233(add_trusted_domain) Added domain BUILTIN S-1-5-32 [2012/02/05 21:51:30.086223, 2] winbindd/winbindd_util.c:233(add_trusted_domain) Added domain MYARCHLINUX S-1-5-21-3777857242-3272519233-2385508432 [2012/02/05 21:51:30.086254, 0] winbindd/winbindd_util.c:635(init_domain_list) Could not fetch our SID - did we join? [2012/02/05 21:51:30.086408, 0] winbindd/winbindd.c:1105(winbindd_register_handlers) unable to initialize domain list
Join the Domain
You need an AD Administrator account to do this. Let's assume this is named Administrator. The command is 'net ads join'
# net ads join -U Administrator
Administrator's password: xxx Using short domain name -- EXAMPLE Joined 'MYARCHLINUX' to realm 'EXAMPLE.COM'
See screenshot of Active Directory Users and Computers [[1]]
![[1]](http://en.wikipedia.org/wiki/File:Ads_myarchlinux_computer_account.png){kind=link}
Restart Samba
winbindd failed to start on the first try because we were not yet a domain.
Restart the Samba service and winbind should fire up as well.
NSSwitch tells the Linux host how to retrieve information from various sources and in which order to do so. In this case, we are appending Active Directory as additional sources for Users, Groups, and Hosts.
/etc/nsswitch.conf
passwd: files winbind shadow: files winbind group: files winbind hosts: files dns wins
Testing Winbind
Let's check if winbind is able to query the AD. The following command should return a list of AD users:
# wbinfo -u
administrator guest krbtgt test.user
- Note we created an Active Directory user called 'test.user' on the domain controller
We can do the same for AD groups:
# wbinfo -g
domain computers domain controllers schema admins enterprise admins cert publishers domain admins domain users domain guests group policy creator owners ras and ias servers allowed rodc password replication group denied rodc password replication group read-only domain controllers enterprise read-only domain controllers dnsadmins dnsupdateproxy
Testing nsswitch
To ensure that our host is able to query the domain for users and groups, we test nsswitch settings by issuing the 'getent' command. The following output shows what a stock ArchLinux install looks like:
# getent passwd
root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/bin/false daemon:x:2:2:daemon:/sbin:/bin/false mail:x:8:12:mail:/var/spool/mail:/bin/false ftp:x:14:11:ftp:/srv/ftp:/bin/false http:x:33:33:http:/srv/http:/bin/false nobody:x:99:99:nobody:/:/bin/false dbus:x:81:81:System message bus:/:/bin/false ntp:x:87:87:Network Time Protocol:/var/empty:/bin/false avahi:x:84:84:avahi:/:/bin/false administrator:*:10001:10006:Administrator:/home/EXAMPLE/administrator:/bin/bash guest:*:10002:10007:Guest:/home/EXAMPLE/guest:/bin/bash krbtgt:*:10003:10006:krbtgt:/home/EXAMPLE/krbtgt:/bin/bash test.user:*:10000:10006:Test User:/home/EXAMPLE/test.user:/bin/bash
And for groups:
# getent group
root:x:0:root bin:x:1:root,bin,daemon daemon:x:2:root,bin,daemon sys:x:3:root,bin adm:x:4:root,daemon tty:x:5: disk:x:6:root lp:x:7:daemon mem:x:8: kmem:x:9: wheel:x:10:root ftp:x:11: mail:x:12: uucp:x:14: log:x:19:root utmp:x:20: locate:x:21: rfkill:x:24: smmsp:x:25: http:x:33: games:x:50: network:x:90: video:x:91: audio:x:92: optical:x:93: floppy:x:94: storage:x:95: scanner:x:96: power:x:98: nobody:x:99: users:x:100: dbus:x:81: ntp:x:87: avahi:x:84: domain computers:x:10008: domain controllers:x:10009: schema admins:x:10010:administrator enterprise admins:x:10011:administrator cert publishers:x:10012: domain admins:x:10013:test.user,administrator domain users:x:10006: domain guests:x:10007: group policy creator owners:x:10014:administrator ras and ias servers:x:10015: allowed rodc password replication group:x:10016: denied rodc password replication group:x:10017:krbtgt read-only domain controllers:x:10018: enterprise read-only domain controllers:x:10019: dnsadmins:x:10020: dnsupdateproxy:x:10021:
Testing Samba commands
Try out some net commands to see if Samba can communicate with AD:
# net ads info
[2012/02/05 20:21:36.473559, 0] param/loadparm.c:7599(lp_do_parameter) Ignoring unknown parameter "idmapd backend" LDAP server: 192.168.1.2 LDAP server name: PDC.example.com Realm: EXAMPLE.COM Bind Path: dc=EXAMPLE,dc=COM LDAP port: 389 Server time: Sun, 05 Feb 2012 20:21:33 CST KDC server: 192.168.1.2 Server time offset: -3
# net ads lookup
[2012/02/05 20:22:39.298823, 0] param/loadparm.c:7599(lp_do_parameter)
Ignoring unknown parameter "idmapd backend"
Information for Domain Controller: 192.168.1.2
Response Type: LOGON_SAM_LOGON_RESPONSE_EX
GUID: 2a098512-4c9f-4fe4-ac22-8f9231fabbad
Flags:
Is a PDC: yes
Is a GC of the forest: yes
Is an LDAP server: yes
Supports DS: yes
Is running a KDC: yes
Is running time services: yes
Is the closest DC: yes
Is writable: yes
Has a hardware clock: yes
Is a non-domain NC serviced by LDAP server: no
Is NT6 DC that has some secrets: no
Is NT6 DC that has all secrets: yes
Forest: example.com
Domain: example.com
Domain Controller: PDC.example.com
Pre-Win2k Domain: EXAMPLE
Pre-Win2k Hostname: PDC
Server Site Name : Office
Client Site Name : Office
NT Version: 5
LMNT Token: ffff
LM20 Token: ffff
# net ads status -U administrator | less
objectClass: top objectClass: person objectClass: organizationalPerson objectClass: user objectClass: computer cn: myarchlinux distinguishedName: CN=myarchlinux,CN=Computers,DC=leafscale,DC=inc instanceType: 4 whenCreated: 20120206043413.0Z whenChanged: 20120206043414.0Z uSNCreated: 16556 uSNChanged: 16563 name: myarchlinux objectGUID: 2c24029c-8422-42b2-83b3-a255b9cb41b3 userAccountControl: 69632 badPwdCount: 0 codePage: 0 countryCode: 0 badPasswordTime: 0 lastLogoff: 0 lastLogon: 129729780312632000 localPolicyFlags: 0 pwdLastSet: 129729764538848000 primaryGroupID: 515 objectSid: S-1-5-21-719106045-3766251393-3909931865-1105 ...<snip>...
Configuring PAM
Now we will change various rules in PAM to allow Active Directory users to use the system for things like login and sudo access. When changing the rules, note the order of these items and whether they are marked as required or sufficient is critical to things working as expected. You should not deviate from these rules unless you know how to write PAM rules.
In case of logins, PAM should first ask for AD accounts, and for local accounts if no matching AD account was found. Therefore, we add entries to include pam_winbindd.so into the authentication process. Furthermore, we include pam_mkhomedir.so. If an AD user logs in, /home/example/user will be created automatically.
/etc/pam.d/login
#%PAM-1.0 auth required pam_securetty.so auth requisite pam_nologin.so auth sufficient pam_unix.so nullok auth required pam_winbind.so use_first_pass use_authtok auth required pam_tally.so onerr=succeed file=/var/log/faillog # use this to lockout accounts for 10 minutes after 3 failed attempts #auth required pam_tally.so deny=2 unlock_time=600 onerr=succeed file=/var/log/faillog account required pam_access.so account required pam_time.so account sufficient pam_unix.so account sufficient pam_winbind.so use_first_pass use_authtok password required pam_pwcheck.so password sufficient pam_unix.so password sufficient pam_winbind.so use_first_pass use_authtok #password required pam_cracklib.so difok=2 minlen=8 dcredit=2 ocredit=2 retry=3 #password required pam_unix.so sha512 shadow use_authtok session required pam_mkhomedir.so skel=/etc/skel/ umask=0022 session sufficient pam_unix.so session sufficient pam_winbind.so use_first_pass use_authtok session required pam_env.so session required pam_motd.so session required pam_limits.so session optional pam_mail.so dir=/var/spool/mail standard session optional pam_lastlog.so session optional pam_loginuid.so -session optional pam_ck_connector.so nox11 -session optional pam_systemd.so
Testing login
Now, start a new console session (or ssh) and try to login using the AD credentials. The domain name is optional, as this was set in the Winbind configuration as 'default realm'. Please note that in the case of ssh, you will need to modify the /etc/ssh/sshd_config file to allow kerberos authentication (KerberosAuthentication yes).
test.user EXAMPLE+test.user
Both should work. You should notice that /home/example/test.user will be automatically created. Again, if you are using ssh, you need to add the pam_mkhomedir.so line mentioned above to the /etc/pam.d/sshd file.
Log into another session using an linux account. Check that you still be able to log in as root - but keep in mind to be logged in as root in at least one session!
/etc/pam.d/gdm
TODO
Sudo
Another thing to get working is 'sudo'. First add the 'test.user' to /etc/sudoers. You can tweak this later, for now lets test things are working:
/etc/sudoers
If you were to attempt a sudo now, it would fail.
Adjust the sudo file to mark pam_unix as sufficient and add the line for winbind as shown:
/etc/pam.d/sudo
#%PAM-1.0 auth sufficient pam_unix.so auth required pam_winbind.so use_first_pass use_authtok auth required pam_nologin.so
Earlier we skipped configuration of the shares. Now that things are working, go back to /etc/smb.conf, and add the exports for the host that you want available on the windows network.
/etc/smb.conf
[MyShare] comment = Example Share path = /srv/exports/myshare read only = no browseable = yes valid users = @NETWORK+"Domain Admins" NETWORK+test.user
In the above example, the keyword NETWORK is to be used. Do not mistakenly substitute this with your domain name. For adding groups, prepend the '@' symbol to the group. Note that Domain Admins is encapsulated in quotes so Samba correctly parses it when reading the configuration file.
Adding a machine keytab file and activating password-free kerberized ssh to the machine
This explains how to generate a machine keytab file which you will need e.g. to enable password-free kerberized ssh to your machine from other machines in the domain. The scenario in mind is that you have a bunch of systems in your domain and you just added a server/workstation using the above description to your domain onto which a lot of users need to ssh in order to work - e.g. GPU workstation or an OpenMP compute node, etc. In this case you might not want to type your password every time you log in. On the other hand the key authentication used by many users in this case can not give you the necessary credentials to e.g. mount kerberized NFSv4 shares. So this will help you to enable password-free logins from your clients to the machine in question using kerberos ticket forwarding.
Creating a machine key tab file
run 'net ads keytab create -U administrator' as root to create a machine keytab file in /etc/krb5.keytab. It will promt you with a warning that we need to enable keytab authentication in our configuration file, so we will do that in the next step. In my case it had problems when a key tab file is already in place - the command just did not come back it hang ... In that case you should rename the existing /etc/krb5.keytab and run the command again - it should work now.
# net ads keytab create -U administrator
verify the content of your keytab by running:
# klist -k /etc/krb5.keytab
Keytab name: FILE:/etc/krb5.keytab KVNO Principal ---- -------------------------------------------------------------------------- 4 host/myarchlinux.example.com@EXAMPLE.COM 4 host/myarchlinux.example.com@EXAMPLE.COM 4 host/myarchlinux.example.com@EXAMPLE.COM 4 host/myarchlinux.example.com@EXAMPLE.COM 4 host/myarchlinux.example.com@EXAMPLE.COM 4 host/MYARCHLINUX@EXAMPLE.COM 4 host/MYARCHLINUX@EXAMPLE.COM 4 host/MYARCHLINUX@EXAMPLE.COM 4 host/MYARCHLINUX@EXAMPLE.COM 4 host/MYARCHLINUX@EXAMPLE.COM 4 MYARCHLINUX$@EXAMPLE.COM 4 MYARCHLINUX$@EXAMPLE.COM 4 MYARCHLINUX$@EXAMPLE.COM 4 MYARCHLINUX$@EXAMPLE.COM 4 MYARCHLINUX$@EXAMPLE.COM
Enabeling keytab authentication
Now you need to tell winbind to use the file by adding this line to the /etc/samba/smb.conf:
use kerberos keytab = true
It should look sth. like this:
/etc/samba/smb.conf
[Global] netbios name = MYARCHLINUX workgroup = EXAMPLE realm = EXAMPLE.COM server string = %h ArchLinux Host security = ads encrypt passwords = yes password server = pdc.example.com use kerberos keytab = true idmap uid = 10000-20000 idmap gid = 10000-20000 #idmap backend = rid winbind use default domain = Yes winbind enum users = Yes winbind enum groups = Yes winbind nested groups = Yes winbind separator = + winbind refresh tickets = yes winbind gid = 10000-20000 template shell = /bin/bash template homedir = /home/%D/%U preferred master = no dns proxy = no wins server = pdc.example.com wins proxy = no inherit acls = Yes map acl inherit = Yes acl group control = yes load printers = no debug level = 3 use sendfile = no
Restart the winbind.service using 'systemctl restart winbind.service' with root privileges.
# systemctl restart winbind.service
Check if everything works by getting a machine ticket for your system by running
# kinit MYARCHLINUX$ -kt /etc/krb5.keytab
This should not give you any feedback but running 'klist' should show you sth like:
# klist
Ticket cache: FILE:/tmp/krb5cc_0
Default principal: MYARCHLINUX$@EXAMPLE.COM
Valid starting Expires Service principal
02/04/12 21:27:47 02/05/12 07:27:42 krbtgt/EXAMPLE.COM@EXAMPLE.COM
renew until 02/05/12 21:27:47
Some common mistakes here are a) forgetting the trailing $ or b) ignoring case sensitivity - it needs to look exactly like the entry in the keytab (usually you cannot to much wrong with all capital)
Preparing sshd on server
All we need to do is add some options to our sshd_config and restart the sshd.service.
Edit /etc/ssh/sshd_config to look like this in the appropriate places:
# /etc/ssh/sshd_config
... # Change to no to disable s/key passwords ChallengeResponseAuthentication no # Kerberos options KerberosAuthentication yes #KerberosOrLocalPasswd yes KerberosTicketCleanup yes KerberosGetAFSToken yes # GSSAPI options GSSAPIAuthentication yes GSSAPICleanupCredentials yes ...
Restart the sshd.service using:
# systemctl restart sshd.service
Adding necessary options on client
First we need to make sure that the tickets on our client are forwardable. This is usually standard but we better check anyways. You have to look for the forwardable option and set it to 'true'
forwardable = true
Secondly we need to add the options
GSSAPIAuthentication yes GSSAPIDelegateCredentials yes
to our .ssh/config file to tell ssh to use this options - alternatively they can be invoked using the -o options directly in the ssh command (see 'man ssh' for help).
Testing the setup
On Client:
make sure you have a valid ticket - if in doubt run 'kinit'
then use ssh to connect to you machine
ssh myarchlinux.example.com
you should get connected without needing to enter your password.
if you have key authentication additionally activated then you should perform
ssh -v myarchlinux.example.com
to see which authentication method it actually uses.
For debugging you can enable DEBUG3 on the server and look into the journal using journalctl
Nifty fine-tunig for complete password-free kerberos handling.
In case your clients are not using domain accounts on their local machines (for whatever reason) it can be hard to actually teach them to kinit before ssh to the workstation. Therefore I came up with a nice workaround:
Generating user Keytabs which are accepted by AD
On a system run
ktutil addent -password -p username@EXAMPLE.COM -k 1 -e RC4-HMAC - enter password for username - wkt username.keytab q
Now test the file by invoking:
kinit -kt username.keytab
It should not promt you to give your password nor should it give any other feedback. If it worked you are basically done - just put the line above into your ~./bashrc - you can now get kerberos tickets without typing a password and with that you can connect to your workstation without typing a password while being completely kerberized and able to authenticate against NFSv4 and CIFS via tickets - pretty neat.
Nice to know
The file 'username.keytab' is not machinespecific and can therefore be copied around. E.g. we created the files on a linux machine and copied them to our Mac clients as the commands on Macs are different ...
See also
- Wikipedia: Active Directory
- Wikipedia: Samba
- Wikipedia: Kerberos
- Samba: Documentation
- Samba Wiki: Samba & Active Directory
- Samba Man Page: smb.conf
Commercial Solutions
- Centrify
- Likewise