Ldapsam Editposix

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(First submitted by idra (a) samba.org)

Samba and the Editposix/Trusted Ldapsam extension

The ldapsam:editposix extension is based on the ldapsam:trusted optimization. The ldapsam:trusted optimization has been developed as a performance optimization for server that uses ldap as user and group account storage. This optimization _requires_ that all samba users and group accounts store their posix account information in the ldap tree.


The ldapsam:editposix extension has been created with the aim of making it easier to configure samba for use with an ldap server, by providing means to add the posix accounts and groups on the LDAP server without the need to use external scripts.

To further help admins we introduced the net sam provision command that helps creating the basic accounts and groups need to make smbd run.

A running winbind daemon is required to use ldapsam:editposix EVEN ON A SAMBA PDC.

Using the ldap idmap backend is strongly advised too.

Basic LDAP configuration

We will not get into the specific of LDAP configuration. To use editposix you need a very basic tree.

Here it is an example base ldif to be loaded on your server to create the basic tree structure:

dn: dc=samba,dc=org
objectClass: top
objectClass: dcObject
objectClass: organization
o: samba.org
dc: samba

dn: cn=admin,dc=samba,dc=org
objectClass: simpleSecurityObject
objectClass: organizationalRole
cn: admin
description: LDAP administrator
userPassword: secret

dn: ou=users,dc=samba,dc=org
objectClass: top
objectClass: organizationalUnit
ou: users

dn: ou=groups,dc=samba,dc=org
objectClass: top
objectClass: organizationalUnit
ou: groups

dn: ou=idmap,dc=samba,dc=org
objectClass: top
objectClass: organizationalUnit
ou: idmap

dn: ou=computers,dc=samba,dc=org
objectClass: top
objectClass: organizationalUnit
ou: computers

Download it Basic_LDAP_configuration.ldif

Configuring smb.conf

you need to properly configure smb.conf before running any daemon or command.

Here is the bare minimum options to set in smb.conf:

  workgroup = MYGROUP
  encrypt passwords = true
  passdb backend = ldapsam
  ldapsam:trusted=yes
  ldapsam:editposix=yes
  ldap admin dn = cn=admin,dc=samba,dc=org
  ldap delete dn = yes
  ldap group suffix = ou=groups
  ldap machine suffix = ou=computers
  ldap user suffix = ou=users
  ldap suffix = dc=samba,dc=org


Old idmap syntax (pre 3.0.25):

  ldap idmap suffix = ou=idmap
  idmap backend = ldap:"ldap://localhost"
  idmap uid = 50000-500000
  idmap gid = 50000-500000

New idmap syntax (post 3.0.25):

  idmap domains = DEFAULT
  idmap config DEFAULT:backend = ldap
  idmap config DEFAULT:readonly = no
  idmap config DEFAULT:default = yes
  idmap config DEFAULT:ldap_base_dn = ou=idmap,dc=samba,dc=org
  idmap config DEFAULT:ldap_user_dn = cn=admin,dc=samba,dc=org
  idmap config DEFAULT:ldap_url = ldap://localhost
  idmap config DEFAULT:range = 50000-500000
  idmap alloc backend = ldap
  idmap alloc config:ldap_base_dn = ou=idmap,dc=samba,dc=org
  idmap alloc config:ldap_user_dn = cn=admin,dc=samba,dc=org
  idmap alloc config:ldap_url = ldap://localhost
  idmap alloc config:range = 50000-500000

A quick setup

Do not run any daemon until told, use a fresh install or wipe out any previously created tdb before starting.

To quickly set up and test this feature follow these steps as root:

Configure and run your ldap server, you may use the above base ldif as a starting point. Make sure the defined ldap admin works correctly.

Configure smb.conf

Add the ldap admin password to the samba secrets database:

 # smbpasswd -w secret

NOTE: If you are using the new style idmap syntax (post 3.0.25) you will need to store the password into a security store. (See man idmap_ldap)

 # net idmap secret DOMAIN <password> 
 # net idmap secret alloc <password>

Start winbindd only.

 # /etc/init.d/winbindd start

provision the tree:

 # net sam provision

Should the command returns: "Unable to allocate a new gid to create Domain Admins group" then make sure idmap is properly configured and the idmap range is large enough to hold the predicted number of unique users+groups you will have in your system life time. On a new system you should never incur into this error, in case you have to increase the idmap range in a production system, just increase the highest value, NEVER change the lowest value.

Create the default windows built-in groups to avoid this: Bug 6537.

 # net sam createbuiltingroup Administrators
 # net sam createbuiltingroup Users
 # net sam createbuiltingroup Guests

Give a password to the newly created Administrator user enabling it.

 # smbpasswd Administrator
 New SMB password:
 Retype new SMB password:

Now start also nmbd and smbd:

 # /etc/init.d/nmbd start
 # /etc/init.d/smbd start

Grant yourself some privileges:

 # net rpc rights grant Administrator SeAddUsersPrivilege -U Administrator
 # net rpc rights grant Administrator SeMachineAccountPrivilege -U Administrator

Managing your DB

At this point you will be able to connect from any windows client or use any samba tool to manage your users groups and machines with the Administrator user.