This page describes the current (2019) Active Directory configuration at UCC.

The Active Directory (AD) domain at UCC is ad.ucc.gu.uwa.edu.au with the NETBIOS domain name UCCDOMAYNE. The primary Domain Controller (DC) samson.ucc.gu.uwa.edu.au which also serves authoritative DNS for ad.ucc.gu.uwa.edu.au.

For some background on why the Standard Operating Environment does what it does, see NewActiveDirectory. For outdated documentation and some info about the migration from the old LDAP domain, see OldActiveDirectory.

This page describes how to configure Linux systems to connect to an Active Directory domain as the database for users and groups.

Windows

Assumed you are using Windows 10.

1. Open File Explorer, right click on My PC and select Properties. You might need to click the rename (advanced) option on the rightmost pane of the window.

2. Under the Computer Name tab, select Change... and enter ad.ucc.gu.uwa.edu.au as the domain. Make sure the computer name is also correct, change it if necessary (Windows 10 generates a random name when you install it).

3. When you click OK, enter a UCC wheel username/password (aka someone who has domain admin permissions). Restart the computer at your convenience.
4. Congratulations, you have joined a computer to the domain.

   • If user encountered profile loading failure and run into a temp profile, it's likely to be their user profile folder get deleted incorrectly. A fix is removing the corresponding SID under  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\ProfileList 

Linux

Configuring SSSD

Full section and alternative client configurations: https://wiki.ucc.asn.au/NewActiveDirectory/LinuxClients

There is a very informative Red Hat article about configuring sssd manually. The following instructions are a functional adaptation. For a more detailed understanding of what these config files and options mean, please start by reading the manpages for sssd, sssd-ad, sssd-krb5, sssd-ldap, sssd.conf, krb5.conf and smb.conf and the above article.

These instructions are confirmed working on Linux Mint 19.1 (Tara), using sssd version 1.16.1 and samba-common-bin package version 4.7.6.

1. Install the necessary packages and uninstall any conflicting ones:

   apt -y install samba-common-bin samba-dsdb-modules sssd sssd-ad sssd-krb5 sssd-ldap sssd-tools krb5-user krb5-doc libpam-sss libnss-sss adcli libsasl2-modules-gssapi-mit
   apt -y purge winbind realmd libpam-krb5 libpam-ldap libpam-winbind libnss-ldap libnss-winbind

2. Remove any configuration files if they exist and stop services:

   mv /etc/samba/smb.conf /etc/samba/smb.conf.old
   mv /etc/nsswitch.conf /etc/nsswitch.conf.old
   rm /etc/krb5.conf /etc/krb5.keytab /etc/sssd/sssd.conf
   systemctl stop sssd winbind samba-ad-dc smbd nmbd

3. Install the configs semi-automatically:

   wget -O /tmp/ucc-ad-config.tar.gz https://www.ucc.asn.au/ucc-ad-config.tar.gz && tar -C / -xvzf /tmp/ucc-ad-config.tar.gz

4. Run pam-auth-update and check that SSS authentication is enabled and that winbind authentication (if present) is disabled.

5. Create the machine account in AD and produce a keytab for sssd containing the machine account credentials. If using a user other than Administrator, ensure they have sufficient privileges to join a machine to the domain.

   rm /etc/krb5.keytab
   kinit <wheel username here>
   net ads join --no-dns-updates -k
   # verify the machine account credentials are in the keytab:
   klist -k

6. Start the necessary services:

   systemctl restart sssd

7. Verify that you can see the correct user and group info using getent passwd and getent group respectively. The output format is equivalent to the /etc/passwd and /etc/group files.

Diagnostics

Sometimes group memberships don't seem to be updated, this can often be fixed by clearing the cache:

• sss_cache -E if using sssd

• net cache flush if using winbind

• Or if the above fails to have an effect, try rejoining to the domain using the instructions below.

You can edit things with

• kinit; ldapvi -b dc=ad,dc=ucc,dc=gu,dc=uwa,dc=edu,dc=au --host AD.UCC.GU.UWA.EDU.AU -Y GSSAPI

or more easily with

• samba-tool user edit <username>

Config file examples

These should be the same as in the config package (https://www.ucc.asn.au/ucc-ad-config.tar.gz but here they are in case something gets broken or that archive goes missing.

• /etc/sssd/sssd.conf

  [sssd]
  config_file_version = 2
  domains = ad.ucc.gu.uwa.edu.au
  services = nss, pam, pac
  
  # domain configuration: see manpages sssd.conf, sssd-ldap, sssd-krb5 and sssd-ad
  # see https://access.redhat.com/articles/3023951
  # needs correct configution for: /etc/nsswitch.conf /etc/samba/smb.conf /etc/resolv.conf `pam-auth-update`
  [domain/AD.UCC.GU.UWA.EDU.AU]
  enumerate = true
  id_provider = ad
  auth_provider = ad
  chpass_provider = ad
  access_provider = ad
  ldap_id_mapping = false
  
  cache_credentials = true
  # if you want to use a custom CA certificate for AD
  #ldap_tls_cacert = /etc/sssd/ucc-ad-ca.cer
  # or just allow invalid (self-signed) certificates
  ldap_tls_reqcert = allow
  
  # allow local users to be included in AD groups
  ldap_rfc2307_fallback_to_local_users = true

• /etc/nsswitch.conf

  # /etc/nsswitch.conf
  
  passwd:         compat systemd sss
  group:          compat systemd sss
  shadow:         compat sss
  gshadow:        files
  
  hosts:          files mdns4_minimal [NOTFOUND=return] dns myhostname
  networks:       files
  
  protocols:      db files
  services:       db files sss
  ethers:         db files
  rpc:            db files
  
  netgroup:       nis sss

• /etc/krb5.conf

  [libdefaults]
      default_realm = AD.UCC.GU.UWA.EDU.AU
      dns_lookup_realm = true
      dns_lookup_kdc = true
      rdns = false
      ticket_lifetime = 24h
      renew_lifetime = 7d
      forwardable = yes

• /etc/samba/smb.conf

  [global]
          realm = AD.UCC.GU.UWA.EDU.AU
          workgroup = UCCDOMAYNE
          security = ads
          client signing = mandatory
          client use spnego = yes
          tls enabled = yes
          kerberos method = secrets and keytab
          dedicated keytab file = /etc/krb5.keytab
          log file = /var/log/samba/%m.log

OpenLDAP

If for some reason you need to authenticate using our AD over OpenLDAP (e.g. OpenVPN or Octoprint), you will need two things to actually talk LDAP to samson.

The UCC-CA certificate, and a custom OpenLDAP config file.

The cert is available from the main website at the top, or from /etc/ssl/certs on most of the main servers.

• /etc/ldap/ldap.conf

          URI ldaps://samson.ad.ucc.gu.uwa.edu.au
          BASE dc=ad,dc=ucc,dc=gu,dc=uwa,dc=edu,dc=au
  
          SSL on
          TLS_REQCERT allow
          TLS_CACERT /etc/ssl/certs/UCC-CA.crt

Once you have both of these, both ldapsearch and actual LDAP calls will actually contact samson properly.

Also use ldaps://ad.ucc.gu.uwa.edu.au to talk to it.

Hints and Tricks

Updating windows login name

To update the name displayed when logging into windows (while keeping finger output the same), use samba-tool user edit USERNAME and update displayName