path: root/docs/docbook/projdoc/passdb.xml

<chapter id="passdb">
<chapterinfo>
	&author.jelmer;
	&author.jerry;
	&author.jeremy;
	&author.jht;
	<author>
		<firstname>Olivier (lem)</firstname><surname>Lemaire</surname>
		<affiliation>
			<orgname>IDEALX</orgname>
			<address><email>olem@IDEALX.org</email></address>
		</affiliation>
	</author>
	
	<pubdate>May 24, 2003</pubdate>
</chapterinfo>
<title>Account Information Databases</title>

<para>
Samba-3 implements a new capability to work concurrently with mulitple account backends.
The possible new combinations of password backends allows Samba-3 a degree of flexibility
and scalability that previously could be achieved only with MS Windows Active Directory.
This chapter describes the new functionality and how to get the most out of it.
</para>

<para>
In the course of development of Samba-3 a number of requests were received to provide the
ability to migrate MS Windows NT4 SAM accounts to Samba-3 without the need to provide
matching Unix/Linux accounts. We called this the <emphasis>Non Unix Accounts (NUA)</emphasis>
capability. The intent was that an administrator could decide to use the <emphasis>tdbsam</emphasis>
backend and by simply specifying <emphasis>"passdb backedn = tdbsam_nua, guest"</emphasis>
this would allow Samba-3 to implement a solution that did not use Unix accounts per se. Late
in the development cycle the team doing this work hit upon some obstacles that prevents this
solution from being used. Given the delays with Samba-3 release a decision was made to NOT
deliver this functionality until a better method of recognising NT Group SIDs from NT User
SIDs could be found. This feature may thus return during the life cycle for the Samba-3 series.
</para>

<note><para>
Samba-3.0.0 does NOT support Non-Unix Account (NUA) operation.
</para></note>

<sect1>
<title>Features and Benefits</title>

<para>
Samba-3 provides for complete backwards compatibility with Samba-2.2.x functionality
as follows:
</para>

<variablelist>
<title>Backwards Compatibility Backends</title>
	<varlistentry><term>Plain Text:</term>
		<listitem>
			<para>
			This option uses nothing but the Unix/Linux <filename>/etc/passwd</filename>
			style back end. On systems that have PAM (Pluggable Authentication Modules)
			support all PAM modules are supported. The behaviour is just as it was with
			Samba-2.2.x, and the protocol limitations imposed by MS Windows clients
			apply likewise.
			</para>
		</listitem>
	</varlistentry>

	<varlistentry><term>smbpasswd:</term>
		<listitem>
			<para>
			This option allows continues use of the <filename>smbpasswd</filename>
			file that maintains a plain ASCII (text) layout that includes the MS Windows
			LanMan and NT encrypted passwords as well as a field that stores some
			account information. This form of password backend does NOT store any of
			the MS Windows NT/200x SAM (Security Account Manager) information needed to
			provide the extended controls that are needed for more comprehensive 
			interoperation with MS Windows NT4 / 200x servers.
			</para>
		</listitem>
	</varlistentry>

	<varlistentry><term>ldapsam_compat (Samba-2.2 LDAP Compatibilty):</term>
		<listitem>
			<para>
			There is a password backend option that allows continued operation with
			a existing OpenLDAP backend that uses the Samba-2.2.x LDAP schema extension.
			This option is provided primarily as a migration tool, although there is
			no reason to force migration at this time.
			</para>
		</listitem>
	</varlistentry>
</variablelist>

<para>
Samba-3 introduces the following new password backend capabilities:
</para>

<variablelist>
<title>New Backends</title>
	<varlistentry><term>tdbsam:</term>
		<listitem>
			<para>
			The <emphasis>tdbsam</emphasis> password backend stores the old <emphasis>
			smbpasswd</emphasis> information PLUS the extended MS Windows NT / 200x
			SAM information into a binary format TDB (trivial database) file.
			The inclusion of the extended information makes it possible for Samba-3
			to implement the same account and system access controls that are possible
			with MS Windows NT4 and MS Windows 200x based systems.
			</para>

			<para>
			The inclusion of the <emphasis>tdbssam</emphasis> capability is a direct
			response to user requests to allow simple site operation without the overhead
			of the complexities of running OpenLDAP. It is recommended to use this only
			for sites that have fewer than 250 users. For larger sites or implementations
			the use of OpenLDAP or of Active Directory integration is strongly recommended.
			</para>
		</listitem>
	</varlistentry>

	<varlistentry><term>ldapsam:</term>
		<listitem>
			<para>
			Samba-3 has a new and extended LDAP implementation that requires configuration
			of OpenLDAP with a new format samba schema. The new format schema file is
			included in the <filename>~samba/examples/LDAP</filename> directory.
			</para>

			<para>
			The new LDAP implmentation significantly expands the control abilities that
			were possible with prior versions of Samba. It is not possible to specify
			"per user" profile settings, home directories, account access controls, and
			much more. Corporate sites will see that the Samba-Team has listened to their
			requests both for capability and to allow greater scalability.
			</para>
		</listitem>
	</varlistentry>

	<varlistentry><term>mysqlsam (MySQL based backend):</term>
		<listitem>
			<para>
			It is expected that the MySQL based SAM will be very popular in some corners.
			This database backend will be on considerable interest to sites that want to
			leverage existing MySQL technology.
			</para>
		</listitem>
	</varlistentry>

	<varlistentry><term>xmlsam (XML based datafile):</term>
		<listitem>
			<para>
			Allows the account and password data to be stored in an XML format
			data file. This backend is NOT recommended for normal operation, it is
			provided for developmental and for experimental use only. We recognise
			that this will not stop some people from using it anyhow, it should work
			but is NOT officially supported at this time (and likely will not be
			at any time).
			</para>

			<para>
			The xmlsam option can be useful for account migration between database
			backends. Use of this tool will allow the data to be edited before migration
			into another backend format.
			</para>
		</listitem>
	</varlistentry>

	<varlistentry><term>nisplussam:</term>
		<listitem>
			<para>
			The  NIS+ based passdb backend. Takes name NIS domain as an
	                optional argument. Only works with Sun NIS+ servers.
			</para>
		</listitem>
	</varlistentry>

	<varlistentry><term>plugin:</term>
		<listitem>
			<para>
			This option allows any external non-Samba backend to interface directly
			to the samba code. This facility will allow third part vendors to provide
			a proprietary backend to Samba-3.
			</para>
		</listitem>
	</varlistentry>
</variablelist>

</sect1>

<sect1>
	<title>Technical Information</title>

	<para>
	Old windows clients send plain text passwords over the wire. Samba can check these
	passwords by crypting them and comparing them to the hash stored in the unix user database.
	</para>
	
	<para>
	Newer windows clients send encrypted passwords (so-called Lanman and NT hashes) over 
	the wire, instead of plain text passwords. The newest clients will send only encrypted
	passwords and refuse to send plain text passwords, unless their registry is tweaked.
	</para>

	<para>
	These passwords can't be converted to unix style encrypted passwords. Because of that
	you can't use the standard unix user database, and you have to store the Lanman and NT
	hashes somewhere else.
	</para>
	
	<para>
	In addition to differently encrypted passwords, windows also stores certain data for each
	user that is not stored in a unix user database. e.g: workstations the user may logon from,
	the location where the users' profile is stored, and so on. Samba retrieves and stores this
	information using a "passdb backend".  Commonly available backends are LDAP, plain text
	file, MySQL and nisplus.  For more information, see the man page for &smb.conf; regarding the 
	<command>passdb backend = </command> parameter.
	</para>

	<sect2>
	<title>Important Notes About Security</title>
		
		<para>
		The unix and SMB password encryption techniques seem similar on the surface. This
		similarity is, however, only skin deep. The unix scheme typically sends clear text
		passwords over the network when logging in. This is bad. The SMB encryption scheme
		never sends the cleartext password over the network but it does store the 16 byte 
		hashed values on disk. This is also bad. Why? Because the 16 byte hashed values
		are a "password equivalent". You cannot derive the user's password from them, but
		they could potentially be used in a modified client to gain access to a server.
		This would require considerable technical knowledge on behalf of the attacker but
		is perfectly possible. You should thus treat the data stored in whatever passdb
		backend you use (smbpasswd file, ldap, mysql) as though it contained the cleartext
		passwords of all your users. Its contents must be kept secret, and the file should
		be protected accordingly.
		</para>
		
		<para>
		Ideally we would like a password scheme that involves neither plain text passwords
		on the net nor on disk. Unfortunately this is not available as Samba is stuck with
		having to be compatible with other SMB systems (WinNT, WfWg, Win95 etc).
		</para>

		<para>
		Windows NT 4.0 Service pack 3 changed the default setting so that plaintext passwords
		are disabled from being sent over the wire. This mandates either the use of encrypted
		password support or edit the Windows NT registry to re-enable plaintext passwords.
		</para>
		
		<para>
		The following versions of MS Windows do not support full domain security protocols,
		although they may log onto a domain environment:
		</para>

		<itemizedlist>
			<listitem><para>
			MS DOS Network client 3.0 with the basic network redirector installed
			</para></listitem>

			<listitem><para>
			Windows 95 with the network redirector update installed
			</para></listitem>

			<listitem><para>
			Windows 98 [se]
			</para></listitem>

			<listitem><para>
			Windows Me</para>
			</listitem>
		</itemizedlist>

		<note>
		<para>
 		MS Windows XP Home does not have facilities to become a domain member and it can
		not participate in domain logons.
		</para>
		</note>

		<para>
		The following versions of MS Windows fully support domain security protocols.
		</para>

		<itemizedlist>
			<listitem><para>Windows NT 3.5x</para></listitem>
			<listitem><para>Windows NT 4.0</para></listitem>
			<listitem><para>Windows 2000 Professional</para></listitem>
			<listitem><para>Windows 200x Server/Advanced Server</para></listitem>
			<listitem><para>Windows XP Professional</para></listitem>
		</itemizedlist>
			
		<para>
		All current release of Microsoft SMB/CIFS clients support authentication via the
		SMB Challenge/Response mechanism described here. Enabling clear text authentication
		does not disable the ability of the client to participate in encrypted authentication.
		Instead, it allows the client to negotiate either plain text _or_ encrypted password
		handling.
		</para>

		<para>
		MS Windows clients will cache the encrypted password alone. Where plain text passwords
		are re-enabled, through the appropriate registry change, the plain text password is NEVER
		cached. This means that in the event that a network connections should become disconnected
		(broken) only the cached (encrypted) password will be sent to the resource server to
		affect a auto-reconnect. If the resource server does not support encrypted passwords the
		auto-reconnect will fail. <emphasis>USE OF ENCRYPTED PASSWORDS IS STRONGLY ADVISED.</emphasis>
		</para>

		<sect3>
		<title>Advantages of Encrypted Passwords</title>

			<itemizedlist>
				<listitem><para>Plain text passwords are not passed across 
				the network. Someone using a network sniffer cannot just 
				record passwords going to the SMB server.</para></listitem>

				<listitem><para>Plain text passwords are not stored anywhere in
				memory or on disk.</para></listitem>
			 
				<listitem><para>WinNT doesn't like talking to a server 
				that does not support encrypted passwords. It will refuse 
				to browse the server if the server is also in user level 
				security mode. It will insist on prompting the user for the 
				password on each connection, which is very annoying. The
				only things you can do to stop this is to use SMB encryption.
				</para></listitem>

				<listitem><para>Encrypted password support allows automatic share
				(resource) reconnects.</para></listitem>

				<listitem><para>Encrypted passwords are essential for PDC/BDC
				operation.</para></listitem>
			</itemizedlist>
		</sect3>


		<sect3>
		<title>Advantages of non-encrypted passwords</title>

			<itemizedlist>
				<listitem><para>Plain text passwords are not kept 
				on disk, and are NOT cached in memory. </para></listitem>
				
				<listitem><para>Uses same password file as other unix 
				services such as login and ftp</para></listitem>
				
				<listitem><para>Use of other services (such as telnet and ftp) which
				send plain text passwords over the net, so sending them for SMB
				isn't such a big deal.</para></listitem>
			</itemizedlist>
		</sect3>
	</sect2>
</sect1>

<sect1>
<title>Account Management Tools</title>

<para>
Samba-3 provides two (2) tools for management of User and machine accounts. These tools are
called <filename>smbpasswd</filename> and <filename>pdbedit</filename>. A third tool is under
development but is NOT expected to ship in time for Samba-3.0.0. The new tool will be a TCL/TK
GUI tool that looks much like the MS Windows NT4 Domain User Manager - hopefully this will
be announced in time for samba-3.0.1 release timing.
</para>
	<sect2>
	<title>The <emphasis>smbpasswd</emphasis> Command</title>
	
		<para>
		The smbpasswd utility is a utility similar to the <command>passwd</command>
		or <command>yppasswd</command> programs.  It maintains the two 32 byte password
		fields in the passdb backend.
		</para>

		<para>
		<command>smbpasswd</command> works in a client-server mode where it contacts the
		local smbd to change the user's password on its behalf.This has enormous benefits
		as follows:
		</para>

		<para>
		<command>smbpasswd</command> has the capability to change passwords on Windows NT
		servers (this only works when the request is sent to the NT Primary Domain Controller
		if changing an NT Domain user's password).
		</para>

		<para>
		<command>smbpasswd</command> can be used to:
		</para>
		
		<itemizedlist>
			<listitem><para>
			<emphasis>add</emphasis> user or machine accounts
			</para></listitem>

			<listitem><para>
			<emphasis>delete</emphasis> user or machine accounts
			</para></listitem>

			<listitem><para>
			<emphasis>enable</emphasis> user or machine accounts
			</para></listitem>

			<listitem><para>
			<emphasis>disable</emphasis> user or machine accounts
			</para></listitem>

			<listitem><para>
			<emphasis>set to NULL</emphasis> user passwords
			</para></listitem>

			<listitem><para>
			<emphasis>manage interdomain trust accounts</emphasis>
			</para></listitem>
		</itemizedlist>
		
		<para>
		To run smbpasswd as a normal user just type:
		</para>
		
		<para>
		<programlisting>
		<prompt>$ </prompt><userinput>smbpasswd</userinput>
		<prompt>Old SMB password: </prompt><userinput>&lt;secret&gt;</userinput>
		</programlisting>
		For <emphasis>secret</emphasis> type old value here - or hit return if
		there was no old password
		<programlisting>
		<prompt>New SMB Password: </prompt><userinput>&lt;new secret&gt;</userinput>
		<prompt>Repeat New SMB Password: </prompt><userinput>&lt;new secret&gt;</userinput>
		</programlisting>
		</para>
		
		<para>
		If the old value does not match the current value stored for that user, or the two
		new values do not match each other, then the password will not be changed.
		</para>
		
		<para>
		When invoked by an ordinary user it will only allow change of their own
		SMB password.
		</para>
		
		<para>
		When run by root smbpasswd may take an optional argument, specifying
		the user name whose SMB password you wish to change. When run as root, smbpasswd
		does not prompt for or check the old password value, thus allowing root to set passwords 
		for users who have forgotten their passwords.
		</para>
		
		<para>
		<command>smbpasswd</command> is designed to work in the way familiar to UNIX
		users who use the <command>passwd</command> or <command>yppasswd</command> commands.
		While designed for administrative use, this tool provides essential user level
		password change capabilities.
		</para>

		<para>
		For more details on using <command>smbpasswd</command> refer to the man page (the
		definitive reference).
		</para>
	</sect2>

	<sect2>
	<title>The <emphasis>pdbedit</emphasis> Command</title>

		<para>
		<command>pdbedit</command> is a tool that can be used only by root. It is used to
		manage the passdb backend. <command>pdbedit</command> can be used to:
		</para>

		<itemizedlist>
			<listitem><para>
			add, remove or modify user accounts
			</para></listitem>

			<listitem><para>
			listing user accounts
			</para></listitem>

			<listitem><para>
			migrate user accounts
			</para></listitem>
		</itemizedlist>

		<para>
		The <command>pdbedit</command> tool is the only one that can manage the account
		security and policy settings. It is capable of all operations that smbpasswd can
		do as well as a super set of them.
		</para>

		<para>
		One particularly important purpose of the <command>pdbedit</command> is to allow
		the migration of account information from one passdb backend to another. See the
		<link linkend="XMLpassdb">XML</link> password backend section of this chapter.
		</para>

		<para>
		The following is an example of the user account information that is stored in
		a tdbsam password backend. This listing was produced by running:
		</para>

		<para>
		pdbedit -Lv met
		<programlisting>
		Unix username:        met
		NT username:
		Account Flags:        [UX         ]
		User SID:             S-1-5-21-1449123459-1407424037-3116680435-2004
		Primary Group SID:    S-1-5-21-1449123459-1407424037-3116680435-1201
		Full Name:            Melissa E Terpstra
		Home Directory:       \\frodo\met\Win9Profile
		HomeDir Drive:        H:
		Logon Script:         scripts\logon.bat
		Profile Path:         \\frodo\Profiles\met
		Domain:               MIDEARTH
		Account desc:
		Workstations:         melbelle
		Munged dial:
		Logon time:           0
		Logoff time:          Mon, 18 Jan 2038 20:14:07 GMT
		Kickoff time:         Mon, 18 Jan 2038 20:14:07 GMT
		Password last set:    Sat, 14 Dec 2002 14:37:03 GMT
		Password can change:  Sat, 14 Dec 2002 14:37:03 GMT
		Password must change: Mon, 18 Jan 2038 20:14:07 GMT
		</programlisting>
		</para>

	</sect2>
</sect1>

<sect1>
<title>Password Backends</title>

<para>
Samba-3 offers the greatest flexibility in backend account database design of any SMB/CIFS server
technology available today. The flexibility is immediately obvious as one begins to explore this
capability.
</para>

<para>
It is possible to specify not only multiple different password backends, but even multiple
backends of the same type. For example, to use two different tdbsam databases:
</para>

<para>
<programlisting>
In smb.conf [globals]
	passdb backend = tdbsam:/etc/samba/passdb.tdb, \
		tdbsam:/etc/samba/old-passdb.tdb, guest
</programlisting>
</para>


	<sect2>
	<title>Plain Text</title>

		<para>
		Older versions of samba retrieved user information from the unix user database 
		and eventually some other fields from the file <filename>/etc/samba/smbpasswd</filename>
		or <filename>/etc/smbpasswd</filename>. When password encryption is disabled, no 
		SMB specific data is stored at all. Instead all operations are conduected via the way
		that the samba host OS will access it's <filename>/etc/passwd</filename> database.
		eg: On Linux systems that is done via PAM.
		</para>

	</sect2>

	<sect2>
	<title>smbpasswd - Encrypted Password Database</title>

		<para>
		Traditionally, when configuring <ulink url="smb.conf.5.html#ENCRYPTPASSWORDS">"encrypt
		passwords = yes"</ulink> in Samba's <filename>smb.conf</filename> file, user account
		information such as username, LM/NT password hashes, password change times, and account
		flags have been stored in the <filename>smbpasswd(5)</filename> file.  There are several
		disadvantages to this approach for sites with very large numbers of users (counted
		in the thousands).
		</para>

		<itemizedlist>
		<listitem><para>
		The first is that all lookups must be performed sequentially.  Given that
		there are approximately two lookups per domain logon (one for a normal
		session connection such as when mapping a network drive or printer), this
		is a performance bottleneck for large sites.  What is needed is an indexed approach
		such as is used in databases.
		</para></listitem>

		<listitem><para>
		The second problem is that administrators who desire to replicate a smbpasswd file
		to more than one Samba server were left to use external tools such as
		<command>rsync(1)</command> and <command>ssh(1)</command> and wrote custom,
		in-house scripts.
		</para></listitem>

		<listitem><para>
		And finally, the amount of information which is stored in an smbpasswd entry leaves
		no room for additional attributes such as a home directory, password expiration time,
		or even a Relative Identified (RID).
		</para></listitem>
		</itemizedlist>

		<para>
		As a result of these defeciencies, a more robust means of storing user attributes
		used by smbd was developed.  The API which defines access to user accounts
		is commonly referred to as the samdb interface (previously this was called the passdb
		API, and is still so named in the Samba CVS trees). 
		</para>

		<para>
		Samba-3 provides an enhanced set of passdb backends that overcome the deficiencies
		of the smbpasswd plain text database. These are tdbsam, ldapsam, and xmlsam.
		Of these ldapsam will be of most interest to large corporate or enterprise sites.
		</para>

	</sect2>

	<sect2>
	<title>tdbsam</title>

		<para>Samba can store user and machine account data in a "TDB" (Trivial Database).
		Using this backend doesn't require any additional configuration. This backend is
		recommended for new installations that do not require LDAP.
		</para>

		<para>
		As a general guide the Samba-Team do NOT recommend using the tdbsam backend for sites
		that have 250 or more users. Additionally, tdbsam is not capable of scaling for use
		in sites that require PDB/BDC implmentations that requires replication of the account
		database. Clearly, for reason of scalability the use of ldapsam should be encouraged.
		</para>

	</sect2>

	<sect2>
	<title>ldapsam</title>

		<para>
		There are a few points to stress that the ldapsam does not provide. The LDAP
		support referred to in the this documentation does not include:
		</para>

		<itemizedlist>
			<listitem><para>A means of retrieving user account information from
			an Windows 200x Active Directory server.</para></listitem>
			<listitem><para>A means of replacing /etc/passwd.</para></listitem>
		</itemizedlist>

		<para>
		The second item can be accomplished by using LDAP NSS and PAM modules.  LGPL
		versions of these libraries can be obtained from PADL Software
		(<ulink url="http://www.padl.com/">http://www.padl.com/</ulink>). More
		information about the configuration of these packages may be found at "LDAP,
		System Administration; Gerald Carter, O'Reilly; Chapter 6: Replacing NIS".
		Refer to <ulink url="http://safari.oreilly.com/?XmlId=1-56592-491-6">
		http://safari.oreilly.com/?XmlId=1-56592-491-6</ulink> for those who might wish to know
                more about configuration and adminstration of an OpenLDAP server.
		</para>

		<para>
		This document describes how to use an LDAP directory for storing Samba user
		account information traditionally stored in the smbpasswd(5) file.  It is
		assumed that the reader already has a basic understanding of LDAP concepts
		and has a working directory server already installed.  For more information
		on LDAP architectures and Directories, please refer to the following sites.
		</para>

		<itemizedlist>
			<listitem><para>OpenLDAP - <ulink url="http://www.openldap.org/">http://www.openldap.org/</ulink></para></listitem>
			<listitem><para>iPlanet Directory Server -
			 <ulink url="http://iplanet.netscape.com/directory">http://iplanet.netscape.com/directory</ulink></para></listitem>
		</itemizedlist>

		<para>
		Two additional Samba resources which may prove to be helpful are
		</para>

		<itemizedlist>
			<listitem><para>The <ulink url="http://www.unav.es/cti/ldap-smb/ldap-smb-3-howto.html">Samba-PDC-LDAP-HOWTO</ulink>
			maintained by Ignacio Coupeau.</para></listitem>

			<listitem><para>The NT migration scripts from <ulink url="http://samba.idealx.org/">IDEALX</ulink> that are
			geared to manage users and group in such a Samba-LDAP Domain Controller configuration.
			</para></listitem>
		</itemizedlist>

		<sect3>
		<title>Supported LDAP Servers</title>

			<para>
			The LDAP ldapsam code has been developed and tested using the OpenLDAP 2.0 and 2.1 server and
			client libraries.  The same code should work with Netscape's Directory Server and client SDK.
			However, there are bound to be compile errors and bugs. These should not be hard to fix.
			Please submit fixes via <link linkend="bugreport">Bug reporting facility</link>.
			</para>

		</sect3>

		<sect3>
		<title>Schema and Relationship to the RFC 2307 posixAccount</title>


			<para>
			Samba 3.0 includes the necessary schema file for OpenLDAP 2.0 in
			<filename>examples/LDAP/samba.schema</filename>.  The sambaAccount objectclass is given here:
			</para>

<para>
<programlisting>
objectclass ( 1.3.6.1.4.1.7165.2.2.3 NAME 'sambaAccount' SUP top AUXILIARY
    DESC 'Samba Auxilary Account'
    MUST ( uid $ rid )
    MAY  ( cn $ lmPassword $ ntPassword $ pwdLastSet $ logonTime $
           logoffTime $ kickoffTime $ pwdCanChange $ pwdMustChange $ acctFlags $
           displayName $ smbHome $ homeDrive $ scriptPath $ profilePath $
           description $ userWorkstations $ primaryGroupID $ domain ))
</programlisting>
</para>

			<para>
			The <filename>samba.schema</filename> file has been formatted for OpenLDAP 2.0/2.1.
			The OID's are owned by the Samba Team and as such is legal to be openly published.
			If you translate the schema to be used with Netscape DS, please
			submit the modified schema file as a patch to
			<ulink url="mailto:jerry@samba.org">jerry@samba.org</ulink>.
			</para>

			<para>
			Just as the smbpasswd file is meant to store information which supplements a
			user's <filename>/etc/passwd</filename> entry, so is the sambaAccount object
			meant to supplement the UNIX user account information.  A sambaAccount is a
			<constant>STRUCTURAL</constant> objectclass so it can be stored individually
			in the directory.  However, there are several fields (e.g. uid) which overlap
			with the posixAccount objectclass outlined in RFC2307.  This is by design.
			</para>

			<!--olem: we should perhaps have a note about shadowAccounts too as many
			systems use them, isn'it ? -->

			<para>
			In order to store all user account information (UNIX and Samba) in the directory,
			it is necessary to use the sambaAccount and posixAccount objectclasses in
			combination.  However, smbd will still obtain the user's UNIX account
			information via the standard C library calls (e.g. getpwnam(), et. al.).
			This means that the Samba server must also have the LDAP NSS library installed
			and functioning correctly.  This division of information makes it possible to
			store all Samba account information in LDAP, but still maintain UNIX account
			information in NIS while the network is transitioning to a full LDAP infrastructure.
			</para>
		</sect3>

		<sect3>
		<title>OpenLDAP configuration</title>

			<para>
			To include support for the sambaAccount object in an OpenLDAP directory
			server, first copy the samba.schema file to slapd's configuration directory.
			The samba.schema file can be found in the directory <filename>examples/LDAP</filename>
			in the samba source distribution.
			</para>

<para>
<programlisting>
<prompt>root# </prompt><userinput>cp samba.schema /etc/openldap/schema/</userinput>
</programlisting>
</para>

			<para>
			Next, include the <filename>samba.schema</filename> file in <filename>slapd.conf</filename>.
			The sambaAccount object contains two attributes which depend upon other schema
			files.  The 'uid' attribute is defined in <filename>cosine.schema</filename> and
			the 'displayName' attribute is defined in the <filename>inetorgperson.schema</filename>
			file.  Both of these must be included before the <filename>samba.schema</filename> file.
			</para>

<para>
<programlisting>
## /etc/openldap/slapd.conf

## schema files (core.schema is required by default)
include	           /etc/openldap/schema/core.schema

## needed for sambaAccount
include            /etc/openldap/schema/cosine.schema
include            /etc/openldap/schema/inetorgperson.schema
include            /etc/openldap/schema/samba.schema
include            /etc/openldap/schema/nis.schema
....
</programlisting>
</para>

		<para>
		It is recommended that you maintain some indices on some of the most usefull attributes,
		like in the following example, to speed up searches made on sambaAccount objectclasses
		(and possibly posixAccount and posixGroup as well).
		</para>

<para>
<programlisting>
# Indices to maintain
## required by OpenLDAP
index objectclass             eq

index cn                      pres,sub,eq
index sn                      pres,sub,eq
## required to support pdb_getsampwnam
index uid                     pres,sub,eq
## required to support pdb_getsambapwrid()
index displayName             pres,sub,eq

## uncomment these if you are storing posixAccount and
## posixGroup entries in the directory as well
##index uidNumber               eq
##index gidNumber               eq
##index memberUid               eq

index   rid                   eq
index   sambaSID              eq
index   sambaPrimaryGroupSID  eq
index   sambaDomainName       eq
index   default               sub
</programlisting>
</para>

		<para>
		Create the new index by executing:
		</para>

<para>
<programlisting>
./sbin/slapindex -f slapd.conf
</programlisting>
</para>

		<para>
		Remember to restart slapd after making these changes:
		</para>

<para>
<programlisting>
<prompt>root# </prompt><userinput>/etc/init.d/slapd restart</userinput>
</programlisting>
</para>

		</sect3>

		<sect3>
		<title>Configuring Samba</title>

			<para>
			The following parameters are available in smb.conf only with <parameter>--with-ldapsam</parameter>
			was included when compiling Samba. The following parameters are available in smb.conf only if your
			version of samba was built with LDAP support. Samba automatically builds with LDAP support if the
			LDAP libraries are found.
			</para>

		<itemizedlist>
			<listitem><para><ulink url="smb.conf.5.html#PASSDBBACKEND">passdb backend ldapsam:url</ulink></para></listitem>
			<listitem><para><ulink url="smb.conf.5.html#LDAPSSL">ldap ssl</ulink></para></listitem>
			<listitem><para><ulink url="smb.conf.5.html#LDAPADMINDN">ldap admin dn</ulink></para></listitem>
			<listitem><para><ulink url="smb.conf.5.html#LDAPSUFFIX">ldap suffix</ulink></para></listitem>
			<listitem><para><ulink url="smb.conf.5.html#LDAPFILTER">ldap filter</ulink></para></listitem>
			<listitem><para><ulink url="smb.conf.5.html#LDAPMACHINSUFFIX">ldap machine suffix</ulink></para></listitem>
			<listitem><para><ulink url="smb.conf.5.html#LDAPUSERSUFFIX">ldap user suffix</ulink></para></listitem>
			<listitem><para><ulink url="smb.conf.5.html#LDAPDELETEDN">ldap delete dn</ulink></para></listitem>
			<listitem><para><ulink url="smb.conf.5.html#LDAPPASSWDSYNC">ldap passwd sync</ulink></para></listitem>
			<listitem><para><ulink url="smb.conf.5.html#LDAPTRUSTIDS">ldap trust ids</ulink></para></listitem>

		</itemizedlist>

			<para>
			These are described in the &smb.conf; man
			page and so will not be repeated here.  However, a sample smb.conf file for
			use with an LDAP directory could appear as
			</para>

	<para>
	<programlisting>
	## /usr/local/samba/lib/smb.conf
	[global]
	     security = user
	     encrypt passwords = yes

	     netbios name = TASHTEGO
	     workgroup = NARNIA

	     # ldap related parameters

	     # define the DN to use when binding to the directory servers
	     # The password for this DN is not stored in smb.conf.  Rather it
	     # must be set by using 'smbpasswd -w <replaceable>secretpw</replaceable>' to store the
	     # passphrase in the secrets.tdb file.  If the "ldap admin dn" values
	     # change, this password will need to be reset.
	     ldap admin dn = "cn=Samba Manager,ou=people,dc=samba,dc=org"

	     # Define the SSL option when connecting to the directory
	     # ('off', 'start tls', or 'on' (default))
	     ldap ssl = start tls

	     # syntax: passdb backend = ldapsam:ldap://server-name[:port]
	     passdb backend ldapsam:ldap://funball.samba.org

	     # smbpasswd -x delete the entire dn-entry
	     ldap delete dn = no

	     # the machine and user suffix added to the base suffix
	     # wrote WITHOUT quotes. NULL siffixes by default
	     ldap user suffix = ou=People
	     ldap machine suffix = ou=Systems

	     # Trust unix account information in LDAP
	     #  (see the smb.conf manpage for details)
	     ldap trust ids = Yes

	     # specify the base DN to use when searching the directory
	     ldap suffix = "ou=people,dc=samba,dc=org"

	     # generally the default ldap search filter is ok
	     # ldap filter = "(&amp;(uid=%u)(objectclass=sambaAccount))"
	</programlisting>
	</para>

		</sect3>

		<sect3>
		<title>Accounts and Groups management</title>

			<para>
			As users accounts are managed thru the sambaAccount objectclass, you should
			modify your existing administration tools to deal with sambaAccount attributes.
			</para>

			<para>
			Machines accounts are managed with the sambaAccount objectclass, just
			like users accounts. However, it's up to you to store thoses accounts
			in a different tree of you LDAP namespace: you should use
			"ou=Groups,dc=plainjoe,dc=org" to store groups and
			"ou=People,dc=plainjoe,dc=org" to store users. Just configure your
			NSS and PAM accordingly (usually, in the /etc/ldap.conf configuration
			file).
			</para>

			<para>
			In Samba release 3.0, the group management system is based on posix
			groups. This means that Samba makes usage of the posixGroup objectclass.
			For now, there is no NT-like group system management (global and local
			groups).
			</para>

		</sect3>

		<sect3>
		<title>Security and sambaAccount</title>


			<para>
			There are two important points to remember when discussing the security
			of sambaAccount entries in the directory.
			</para>

			<itemizedlist>
				<listitem><para><emphasis>Never</emphasis> retrieve the lmPassword or
				ntPassword attribute values over an unencrypted LDAP session.</para></listitem>
				<listitem><para><emphasis>Never</emphasis> allow non-admin users to
				view the lmPassword or ntPassword attribute values.</para></listitem>
			</itemizedlist>

			<para>
			These password hashes are clear text equivalents and can be used to impersonate
			the user without deriving the original clear text strings.  For more information
			on the details of LM/NT password hashes, refer to the
			<link linkend="passdb">Account Information Database</link> section of this chapter.
			</para>

			<para>
			To remedy the first security issue, the "ldap ssl" smb.conf parameter defaults
			to require an encrypted session (<command>ldap ssl = on</command>) using
			the default port of 636
			when contacting the directory server.  When using an OpenLDAP server, it
			is possible to use the use the StartTLS LDAP extended  operation in the place of
			LDAPS.  In either case, you are strongly discouraged to disable this security
			(<command>ldap ssl = off</command>).
			</para>

			<para>
			Note that the LDAPS protocol is deprecated in favor of the LDAPv3 StartTLS
			extended operation.  However, the OpenLDAP library still provides support for
			the older method of securing communication between clients and servers.
			</para>

			<para>
			The second security precaution is to prevent non-administrative users from
			harvesting password hashes from the directory.  This can be done using the
			following ACL in <filename>slapd.conf</filename>:
			</para>

	<para>
	<programlisting>
	## allow the "ldap admin dn" access, but deny everyone else
	access to attrs=lmPassword,ntPassword
	     by dn="cn=Samba Admin,ou=people,dc=plainjoe,dc=org" write
	     by * none
	</programlisting>
	</para>

		</sect3>

		<sect3>
		<title>LDAP special attributes for sambaAccounts</title>

			<para>
			The sambaAccount objectclass is composed of the following attributes:
			</para>

			<itemizedlist>
				<listitem><para><constant>lmPassword</constant>: the LANMAN password 16-byte hash stored as a character
				representation of a hexidecimal string.</para></listitem>

				<listitem><para><constant>ntPassword</constant>: the NT password hash 16-byte stored as a character
				representation of a hexidecimal string.</para></listitem>

				<listitem><para><constant>pwdLastSet</constant>: The integer time in seconds since 1970 when the
				<constant>lmPassword</constant> and <constant>ntPassword</constant> attributes were last set.
				</para></listitem>

				<listitem><para><constant>acctFlags</constant>: string of 11 characters surrounded by square brackets []
						representing account flags such as U (user), W(workstation), X(no password expiration),
						I(Domain trust account), H(Home dir required), S(Server trust account),
						and D(disabled).</para></listitem>

				<listitem><para><constant>logonTime</constant>: Integer value currently unused</para></listitem>

				<listitem><para><constant>logoffTime</constant>: Integer value currently unused</para></listitem>

				<listitem><para><constant>kickoffTime</constant>: Integer value currently unused</para></listitem>

				<listitem><para><constant>pwdCanChange</constant>: Integer value currently unused</para></listitem>

				<listitem><para><constant>pwdMustChange</constant>: Integer value currently unused</para></listitem>

				<listitem><para><constant>homeDrive</constant>: specifies the drive letter to which to map the
				UNC path specified by homeDirectory. The drive letter must be specified in the form "X:"
				where X is the letter of the drive to map. Refer to the "logon drive" parameter in the
				smb.conf(5) man page for more information.</para></listitem>

				<listitem><para><constant>scriptPath</constant>: The scriptPath property specifies the path of
				the user's logon script, .CMD, .EXE, or .BAT file. The string can be null. The path
				is relative to the netlogon share.  Refer to the "logon script" parameter in the
				smb.conf(5) man page for more information.</para></listitem>

				<listitem><para><constant>profilePath</constant>: specifies a path to the user's profile.
				This value can be a null string, a local absolute path, or a UNC path.  Refer to the
				"logon path" parameter in the smb.conf(5) man page for more information.</para></listitem>

				<listitem><para><constant>smbHome</constant>: The homeDirectory property specifies the path of
				the home directory for the user. The string can be null. If homeDrive is set and specifies
				a drive letter, homeDirectory should be a UNC path. The path must be a network
				UNC path of the form <filename>\\server\share\directory</filename>. This value can be a null string.
				Refer to the <command>logon home</command> parameter in the &smb.conf; man page for more information.
				</para></listitem>

				<listitem><para><constant>userWorkstation</constant>: character string value currently unused.
				</para></listitem>

				<listitem><para><constant>rid</constant>: the integer representation of the user's relative identifier
				(RID).</para></listitem>

				<listitem><para><constant>primaryGroupID</constant>: the relative identifier (RID) of the primary group
				of the user.</para></listitem>

				<listitem><para><constant>domain</constant>: domain the user is part of.</para></listitem>
			</itemizedlist>

			<para>
			The majority of these parameters are only used when Samba is acting as a PDC of
			a domain (refer to the <link linkend="samba-pdc">Samba as a primary domain controller</link> chapter for details on
			how to configure Samba as a Primary Domain Controller). The following four attributes
			are only stored with the sambaAccount entry if the values are non-default values:
			</para>

			<itemizedlist>
				<listitem><para>smbHome</para></listitem>
				<listitem><para>scriptPath</para></listitem>
				<listitem><para>logonPath</para></listitem>
				<listitem><para>homeDrive</para></listitem>
			</itemizedlist>

			<para>
			These attributes are only stored with the sambaAccount entry if
			the values are non-default values.  For example, assume TASHTEGO has now been
			configured as a PDC and that <command>logon home = \\%L\%u</command> was defined in
			its <filename>smb.conf</filename> file. When a user named "becky" logons to the domain,
			the <parameter>logon home</parameter> string is expanded to \\TASHTEGO\becky.
			If the smbHome attribute exists in the entry "uid=becky,ou=people,dc=samba,dc=org",
			this value is used.  However, if this attribute does not exist, then the value
			of the <parameter>logon home</parameter> parameter is used in its place.  Samba
			will only write the attribute value to the directory entry if the value is
			something other than the default (e.g. <filename>\\MOBY\becky</filename>).
			</para>

		</sect3>

		<sect3>
		<title>Example LDIF Entries for a sambaAccount</title>

			<para>
			The following is a working LDIF with the inclusion of the posixAccount objectclass:
			</para>

	<para>
	<programlisting>
	dn: uid=guest2, ou=people,dc=plainjoe,dc=org
	ntPassword: 878D8014606CDA29677A44EFA1353FC7
	pwdMustChange: 2147483647
	primaryGroupID: 1201
	lmPassword: 552902031BEDE9EFAAD3B435B51404EE
	pwdLastSet: 1010179124
	logonTime: 0
	objectClass: sambaAccount
	uid: guest2
	kickoffTime: 2147483647
	acctFlags: [UX         ]
	logoffTime: 2147483647
	rid: 19006
	pwdCanChange: 0
	</programlisting>
	</para>

			<para>
			The following is an LDIF entry for using both the sambaAccount and
			posixAccount objectclasses:
			</para>

	<para>
	<programlisting>
	dn: uid=gcarter, ou=people,dc=plainjoe,dc=org
	logonTime: 0
	displayName: Gerald Carter
	lmPassword: 552902031BEDE9EFAAD3B435B51404EE
	primaryGroupID: 1201
	objectClass: posixAccount
	objectClass: sambaAccount
	acctFlags: [UX         ]
	userPassword: {crypt}BpM2ej8Rkzogo
	uid: gcarter
	uidNumber: 9000
	cn: Gerald Carter
	loginShell: /bin/bash
	logoffTime: 2147483647
	gidNumber: 100
	kickoffTime: 2147483647
	pwdLastSet: 1010179230
	rid: 19000
	homeDirectory: /home/tashtego/gcarter
	pwdCanChange: 0
	pwdMustChange: 2147483647
	ntPassword: 878D8014606CDA29677A44EFA1353FC7
	</programlisting>
	</para>

		</sect3>

		<sect3>
		<title>Password synchronisation</title>

		<para>
		Since version 3.0 samba can update the non-samba (LDAP) password stored with an account. When
		using pam_ldap, this allows changing both unix and windows passwords at once.
		</para>

		<para>The <command>ldap passwd sync</command> options can have the following values:</para>

		<variablelist>
		       <varlistentry>
			       <term>yes</term>
			       <listitem><para>When the user changes his password, update
					       <constant>ntPassword</constant>, <constant>lmPassword</constant>
					       and the <constant>password</constant> fields.</para></listitem>
		       </varlistentry>

		       <varlistentry>
			       <term>no</term>
			       <listitem><para>Only update <constant>ntPassword</constant> and <constant>lmPassword</constant>.</para></listitem>
		       </varlistentry>

		       <varlistentry>
			       <term>only</term>
			       <listitem><para>Only update the LDAP password and let the LDAP server worry
					       about the other fields. This option is only available when
					       the LDAP library supports LDAP_EXOP_X_MODIFY_PASSWD. </para></listitem>
		       </varlistentry>
		</variablelist>

		<para>More information can be found in the <ulink url="smb.conf.5.html#LDAPPASSWDSYNC">smb.conf</ulink> manpage.
		</para>

		</sect3>

		<sect3>
		<title>ldap trust ids</title>

		<para>
		LDAP Performance can be improved by using the <command>ldap trust ids</command> parameter.
		See the <ulink url="smb.conf.5.html#LDAPTRUSTIDS">smb.conf</ulink> manpage for details.
		</para>

		</sect3>

	</sect2>

	<sect2>
	<title>MySQL</title>

	<para>
	Stuff goes here!
	</para>

		<sect3>
		<title>Creating the database</title>

			<para>
			You either can set up your own table and specify the field names to pdb_mysql (see below
			for the column names) or use the default table. The file <filename>examples/pdb/mysql/mysql.dump</filename> 
			contains the correct queries to create the required tables. Use the command :

			<command>mysql -u<replaceable>username</replaceable> -h<replaceable>hostname</replaceable> -p<replaceable>password</replaceable> <replaceable>databasename</replaceable> &gt; <filename>/path/to/samba/examples/pdb/mysql/mysql.dump</filename></command>
			</para>
		</sect3>

		<sect3>
		<title>Configuring</title>

			<para>This plugin lacks some good documentation, but here is some short info:</para>

			<para>Add a the following to the <command>passdb backend</command> variable in your <filename>smb.conf</filename>:
			<programlisting>
			passdb backend = [other-plugins] mysql:identifier [other-plugins]
			</programlisting>
			</para>

			<para>The identifier can be any string you like, as long as it doesn't collide with 
			the identifiers of other plugins or other instances of pdb_mysql. If you 
			specify multiple pdb_mysql.so entries in 'passdb backend', you also need to 
			use different identifiers!
			</para>

			<para>
				Additional options can be given thru the &smb.conf; file in the <command>[global]</command> section.
			</para>

	<para>
	<programlisting>
	identifier:mysql host                     - host name, defaults to 'localhost'
	identifier:mysql password
	identifier:mysql user                     - defaults to 'samba'
	identifier:mysql database                 - defaults to 'samba'
	identifier:mysql port                     - defaults to 3306
	identifier:table                          - Name of the table containing users
	</programlisting>
	</para>

			<warning>
			<para>
			Since the password for the mysql user is stored in the 
			&smb.conf; file, you should make the the &smb.conf; file 
			readable only to the user that runs samba. This is considered a security 
			bug and will be fixed soon.
			</para>
			</warning>

			<para>Names of the columns in this table(I've added column types those columns should have first):</para>

	<para>
	<programlisting>
	identifier:logon time column             - int(9)
	identifier:logoff time column            - int(9)
	identifier:kickoff time column           - int(9)
	identifier:pass last set time column     - int(9)
	identifier:pass can change time column   - int(9)
	identifier:pass must change time column  - int(9)
	identifier:username column               - varchar(255) - unix username
	identifier:domain column                 - varchar(255) - NT domain user is part of
	identifier:nt username column            - varchar(255) - NT username
	identifier:fullname column               - varchar(255) - Full name of user
	identifier:home dir column               - varchar(255) - Unix homedir path
	identifier:dir drive column              - varchar(2)   - Directory drive path (eg: 'H:')
	identifier:logon script column           - varchar(255)
						 - Batch file to run on client side when logging on
	identifier:profile path column           - varchar(255) - Path of profile
	identifier:acct desc column              - varchar(255) - Some ASCII NT user data
	identifier:workstations column           - varchar(255)
						 - Workstations user can logon to (or NULL for all)
	identifier:unknown string column         - varchar(255) - unknown string
	identifier:munged dial column            - varchar(255) - ?
	identifier:user sid column               - varchar(255) - NT user SID
	identifier:group sid column              - varchar(255) - NT group ID
	identifier:lanman pass column            - varchar(255) - encrypted lanman password
	identifier:nt pass column                - varchar(255) - encrypted nt passwd
	identifier:plain pass column             - varchar(255) - plaintext password
	identifier:acct control column           - int(9) - nt user data
	identifier:unknown 3 column              - int(9) - unknown
	identifier:logon divs column             - int(9) - ?
	identifier:hours len column              - int(9) - ?
	identifier:unknown 5 column              - int(9) - unknown
	identifier:unknown 6 column              - int(9) - unknown
	</programlisting>
	</para>

			<para>
			Eventually, you can put a colon (:) after the name of each column, which 
			should specify the column to update when updating the table. You can also
			specify nothing behind the colon - then the data from the field will not be 
			updated. 
			</para>

		</sect3>

		<sect3>
		<title>Using plaintext passwords or encrypted password</title>

			<para>
			I strongly discourage the use of plaintext passwords, however, you can use them:
			</para>

			<para>
			If you would like to use plaintext passwords, set
			'identifier:lanman pass column' and 'identifier:nt pass column' to
			'NULL' (without the quotes) and 'identifier:plain pass column' to the
			name of the column containing the plaintext passwords. 
			</para>

			<para>
			If you use encrypted passwords, set the 'identifier:plain pass
			column' to 'NULL' (without the quotes). This is the default.
			</para>

		</sect3>

		<sect3>
		<title>Getting non-column data from the table</title>

			<para>
			It is possible to have not all data in the database and making some 'constant'.
			</para>

			<para>
			For example, you can set 'identifier:fullname column' to : 
			<command>CONCAT(First_name,' ',Sur_name)</command>
			</para>

			<para>
			Or, set 'identifier:workstations column' to :
			<command>NULL</command></para>

			<para>See the MySQL documentation for more language constructs.</para>

		</sect3>
	</sect2>

	<sect2 id="XMLpassdb">
	<title>XML</title>

		<para>This module requires libxml2 to be installed.</para>

		<para>The usage of pdb_xml is pretty straightforward. To export data, use:
		</para>

		<para>
			<userinput>pdbedit -e xml:filename</userinput>
		</para>

		<para>
		(where filename is the name of the file to put the data in)
		</para>

		<para>
		To import data, use:
		<userinput>pdbedit -i xml:filename -e current-pdb</userinput>
		</para>

		<para>
		Where filename is the name to read the data from and current-pdb to put it in.
		</para>

		<para>
		For example: To migrate (copy) the smbpasswd database into a tdbsam database:
		</para>

		<para>
		<programlisting>
		then execute (as root):
			pdbedit -i smbpasswd -e tdbsam
		</programlisting>
		</para>
	</sect2>
</sect1>

<sect1>
<title>Common Errors</title>

<para>
Put stuff here
- People forget to put their users in their backend and then complain samba 
  won't authorize them
</para>

</sect1>
</chapter>