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+<chapter id="passdb">
+<chapterinfo>
+ &author.jelmer;
+ &author.jht;
+ &author.jerry;
+ &author.jeremy;
+ <author>&person.gd;<contrib>LDAP updates</contrib></author>
+ <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 multiple 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>
+
+<sect1>
+<title>Features and Benefits</title>
+
+<para>
+Samba-3 provides for complete backward compatibility with Samba-2.2.x functionality
+as follows:
+<indexterm><primary>SAM backend</primary><secondary>smbpasswd</secondary></indexterm>
+<indexterm><primary>SAM backend</primary><secondary>ldapsam_compat</secondary></indexterm>
+<indexterm><primary>encrypted passwords</primary></indexterm>
+</para>
+
+<?latex \newpage ?>
+
+<sect2>
+ <title>Backward Compatibility Backends</title>
+
+<variablelist>
+ <varlistentry><term>Plain Text</term>
+ <listitem>
+ <para>
+ This option uses nothing but the UNIX/Linux <filename>/etc/passwd</filename>
+ style backend. On systems that have Pluggable Authentication Modules (PAM)
+ support, all PAM modules are supported. The behavior is just as it was with
+ Samba-2.2.x, and the protocol limitations imposed by MS Windows clients
+ apply likewise. Please refer to <link linkend="passdbtech">Technical Information</link> for more information
+ regarding the limitations of Plain Text password usage.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry><term>smbpasswd</term>
+ <listitem>
+ <para>
+ This option allows continued 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 required to
+ provide the extended controls that are needed for more comprehensive
+ inter-operation with MS Windows NT4/200x servers.
+ </para>
+
+ <para>
+ This backend should be used only for backward compatibility with older
+ versions of Samba. It may be deprecated in future releases.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry><term>ldapsam_compat (Samba-2.2 LDAP Compatibility)</term>
+ <listitem>
+ <para>
+ There is a password backend option that allows continued operation with
+ an 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. This tool will eventually
+ be deprecated.
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+
+</sect2>
+
+<para>
+Samba-3 introduces a number of new password backend capabilities.
+<indexterm><primary>SAM backend</primary><secondary>tdbsam</secondary></indexterm>
+<indexterm><primary>SAM backend</primary><secondary>ldapsam</secondary></indexterm>
+<indexterm><primary>SAM backend</primary><secondary>mysqlsam</secondary></indexterm>
+<indexterm><primary>SAM backend</primary><secondary>xmlsam</secondary></indexterm>
+</para>
+
+<sect2>
+<title>New Backends</title>
+
+<variablelist>
+ <varlistentry><term>tdbsam</term>
+ <listitem>
+ <para>
+ This backend provides a rich database backend for local servers. This
+ backend is not suitable for multiple Domain Controllers (i.e., PDC + one
+ or more BDC) installations.
+ </para>
+
+ <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 NT4/200x-based systems.
+ </para>
+
+ <para>
+ The inclusion of the <emphasis>tdbsam</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>
+ This provides a rich directory backend for distributed account installation.
+ </para>
+
+ <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 class="directory">examples/LDAP</filename> directory of the Samba distribution.
+ </para>
+
+ <para>
+ The new LDAP implementation significantly expands the control abilities that
+ were possible with prior versions of Samba. It is now possible to specify
+ <quote>per user</quote> 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 of considerable interest to sites that want to
+ leverage existing MySQL technology.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry><term>xmlsam (XML based datafile)</term>
+ <listitem>
+ <para>
+<indexterm><primary>pdbedit</primary></indexterm>
+ Allows the account and password data to be stored in an XML format
+ data file. This backend cannot be used for normal operation, it can only
+ be used in conjunction with <command>pdbedit</command>'s pdb2pdb
+ functionality. The DTD that is used might be subject to changes in the future.
+ </para>
+
+ <para>
+ The <parameter>xmlsam</parameter> option can be useful for account migration between database
+ backends or backups. Use of this tool will allow the data to be edited before migration
+ into another backend format.
+ </para>
+ </listitem>
+ </varlistentry>
+
+</variablelist>
+
+</sect2>
+
+</sect1>
+
+<sect1 id="passdbtech">
+ <title>Technical Information</title>
+
+ <para>
+ Old Windows clients send plain text passwords over the wire. Samba can check these
+ passwords by encrypting them and comparing them to the hash stored in the UNIX user database.
+ </para>
+
+ <para>
+<indexterm><primary>encrypted passwords</primary></indexterm>
+ 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. For example, workstations the user may logon from,
+ the location where the user's profile is stored, and so on. Samba retrieves and stores this
+ information using a <smbconfoption><name>passdb backend</name></smbconfoption>. Commonly available backends are LDAP, plain text
+ file, and MySQL. For more information, see the man page for &smb.conf; regarding the
+ <smbconfoption><name>passdb backend</name></smbconfoption> parameter.
+ </para>
+
+
+ <image scale="50" id="idmap-sid2uid"><imagedescription>IDMAP: Resolution of SIDs to UIDs.</imagedescription><imagefile>idmap-sid2uid</imagefile></image>
+
+ <para>
+<indexterm><primary>SID</primary></indexterm>
+ The resolution of SIDs to UIDs is fundamental to correct operation of Samba. In both cases shown, if winbindd is not running, or cannot
+ be contacted, then only local SID/UID resolution is possible. See <link linkend="idmap-sid2uid">resolution of SIDs to UIDs</link> and
+ <link linkend="idmap-uid2sid">resolution of UIDs to SIDs</link> diagrams.
+ </para>
+
+ <image scale="50" id="idmap-uid2sid"><imagedescription>IDMAP: Resolution of UIDs to SIDs.</imagedescription><imagefile>idmap-uid2sid</imagefile></image>
+
+ <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 clear-text 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 <quote>password equivalent.</quote> 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 clear-text
+ 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 network nor on disk. Unfortunately, this is not available as Samba is stuck with
+ having to be compatible with other SMB systems (Windows NT, Windows for Workgroups, Windows 9x/Me).
+ </para>
+
+ <para>
+ Windows NT 4.0 Service Pack 3 changed the default setting so plaintext passwords
+ are disabled from being sent over the wire. This mandates either the use of encrypted
+ password support or editing the Windows NT registry to re-enable plaintext passwords.
+ </para>
+
+ <para>
+ The following versions of Microsoft Windows do not support full domain security protocols,
+ although they may log onto a domain environment:
+ </para>
+
+ <itemizedlist>
+ <listitem>MS DOS Network client 3.0 with the basic network redirector installed.</listitem>
+ <listitem>Windows 95 with the network redirector update installed.</listitem>
+ <listitem>Windows 98 [Second Edition].</listitem>
+ <listitem>Windows Me.</listitem>
+ </itemizedlist>
+
+ <note>
+ <para>
+ MS Windows XP Home does not have facilities to become a Domain Member and it cannot participate in domain logons.
+ </para>
+ </note>
+
+ <para>
+ The following versions of MS Windows fully support domain security protocols.
+ </para>
+
+ <itemizedlist>
+ <listitem>Windows NT 3.5x.</listitem>
+ <listitem>Windows NT 4.0.</listitem>
+ <listitem>Windows 2000 Professional.</listitem>
+ <listitem>Windows 200x Server/Advanced Server.</listitem>
+ <listitem>Windows XP Professional.</listitem>
+ </itemizedlist>
+
+ <para>
+ All current releases 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
+ effect an auto-reconnect. If the resource server does not support encrypted passwords the
+ auto-reconnect will fail. Use of encrypted passwords is strongly advised.
+ </para>
+
+ <sect3>
+ <title>Advantages of Encrypted Passwords</title>
+
+ <itemizedlist>
+ <listitem><para>Plaintext 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>Plaintext passwords are not stored anywhere in
+ memory or on disk.</para></listitem>
+
+ <listitem><para>Windows NT does not 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>Plaintext 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) that
+ send plain text passwords over the network, so sending them for SMB
+ is not such a big deal.</para></listitem>
+ </itemizedlist>
+ </sect3>
+ </sect2>
+
+ <sect2>
+ <title>Mapping User Identifiers between MS Windows and UNIX</title>
+
+ <para>
+ Every operation in UNIX/Linux requires a user identifier (UID), just as in
+ MS Windows NT4/200x this requires a Security Identifier (SID). Samba provides
+ two means for mapping an MS Windows user to a UNIX/Linux UID.
+ </para>
+
+ <para>
+ First, all Samba SAM (Security Account Manager database) accounts require
+ a UNIX/Linux UID that the account will map to. As users are added to the account
+ information database, Samba will call the <smbconfoption><name>add user script</name></smbconfoption>
+ interface to add the account to the Samba host OS. In essence all accounts in
+ the local SAM require a local user account.
+ </para>
+
+ <para>
+ The second way to effect Windows SID to UNIX UID mapping is via the
+ <emphasis>idmap uid</emphasis> and <emphasis>idmap gid</emphasis> parameters in &smb.conf;.
+ Please refer to the man page for information about these parameters.
+ These parameters are essential when mapping users from a remote SAM server.
+ </para>
+
+ </sect2>
+
+ <sect2 id="idmapbackend">
+ <title>Mapping Common UIDs/GIDs on Distributed Machines</title>
+
+ <para>
+ Samba-3 has a special facility that makes it possible to maintain identical UIDs and GIDs
+ on all servers in a distributed network. A distributed network is one where there exists
+ a PDC, one or more BDCs and/or one or more Domain Member servers. Why is this important?
+ This is important if files are being shared over more than one protocol (e.g., NFS) and where
+ users are copying files across UNIX/Linux systems using tools such as <command>rsync</command>.
+ </para>
+
+ <para>
+ The special facility is enabled using a parameter called <parameter>idmap backend</parameter>.
+ The default setting for this parameter is an empty string. Technically it is possible to use
+ an LDAP based idmap backend for UIDs and GIDs, but it makes most sense when this is done for
+ network configurations that also use LDAP for the SAM backend. Following
+ <link linkend="idmapbackendexample">example</link> shows that.
+ </para>
+
+ <para>
+<indexterm><primary>SAM backend</primary><secondary>ldapsam</secondary></indexterm>
+<smbconfexample id="idmapbackendexample">
+<title>Example configuration with the LDAP idmap backend</title>
+<indexterm><primary>SAM backend</primary><secondary>xmlsam</secondary></indexterm>
+<smbconfsection>[global]</smbconfsection>
+<smbconfoption><name>idmap backend</name><value>ldap:ldap://ldap-server.quenya.org:636</value></smbconfoption>
+<smbcomment>Alternately, this could be specified as:</smbcomment>
+<smbconfoption><name>idmap backend</name><value>ldap:ldaps://ldap-server.quenya.org</value></smbconfoption>
+</smbconfexample>
+ </para>
+
+ <para>
+ A network administrator who wants to make significant use of LDAP backends will sooner or later be
+ exposed to the excellent work done by PADL Software. PADL <ulink url="http://www.padl.com"/> have
+ produced and released to open source an array of tools that might be of interest. These tools include:
+ </para>
+
+ <itemizedlist>
+ <listitem>
+ <para>
+ <emphasis>nss_ldap:</emphasis> An LDAP Name Service Switch module to provide native
+ name service support for AIX, Linux, Solaris, and other operating systems. This tool
+ can be used for centralized storage and retrieval of UIDs/GIDs.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <emphasis>pam_ldap:</emphasis> A PAM module that provides LDAP integration for UNIX/Linux
+ system access authentication.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ <emphasis>idmap_ad:</emphasis> An IDMAP backend that supports the Microsoft Services for
+ UNIX RFC 2307 schema available from their web
+ <ulink url="http://www.padl.com/download/xad_oss_plugins.tar.gz">site</ulink>.
+ </para>
+ </listitem>
+ </itemizedlist>
+
+
+ </sect2>
+</sect1>
+
+<sect1 id="acctmgmttools">
+<title>Account Management Tools</title>
+
+<para>
+<indexterm><primary>pdbedit</primary></indexterm>
+Samba provides two tools for management of user and machine accounts. These tools are
+called <command>smbpasswd</command> and <command>pdbedit</command>. 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 the Samba-3.0.1 release.
+</para>
+ <sect2>
+ <title>The <emphasis>smbpasswd</emphasis> Command</title>
+
+ <para>
+ The smbpasswd utility is 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.
+ </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:
+<indexterm><primary>User Management</primary></indexterm>
+<indexterm><primary>User Accounts</primary><secondary>Adding/Deleting</secondary></indexterm>
+
+ </para>
+
+ <itemizedlist>
+ <listitem><emphasis>add</emphasis> user or machine accounts.</listitem>
+ <listitem><emphasis>delete</emphasis> user or machine accounts.</listitem>
+ <listitem><emphasis>enable</emphasis> user or machine accounts.</listitem>
+ <listitem><emphasis>disable</emphasis> user or machine accounts.</listitem>
+ <listitem><emphasis>set to NULL</emphasis> user passwords.</listitem>
+ <listitem><emphasis>manage interdomain trust accounts.</emphasis></listitem>
+ </itemizedlist>
+
+ <para>
+ To run smbpasswd as a normal user just type:
+ </para>
+
+ <para>
+<screen>
+&prompt;<userinput>smbpasswd</userinput>
+<prompt>Old SMB password: </prompt><userinput><replaceable>secret</replaceable></userinput>
+</screen>
+ For <replaceable>secret</replaceable>, type old value here or press return if
+ there is no old password.
+<screen>
+<prompt>New SMB Password: </prompt><userinput><replaceable>new secret</replaceable></userinput>
+<prompt>Repeat New SMB Password: </prompt><userinput><replaceable>new secret</replaceable></userinput>
+</screen>
+ </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, the command will only allow the user to change his or her own
+ SMB password.
+ </para>
+
+ <para>
+ When run by root, <command>smbpasswd</command> may take an optional argument specifying
+ the user name whose SMB password you wish to change. When run as root, <command>smbpasswd</command>
+ 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 id="pdbeditthing">
+ <title>The <emphasis>pdbedit</emphasis> Command</title>
+
+ <para>
+<indexterm><primary>pdbedit</primary></indexterm>
+ <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:
+<indexterm><primary>User Management</primary></indexterm>
+<indexterm><primary>User Accounts</primary><secondary>Adding/Deleting</secondary></indexterm>
+
+ </para>
+
+ <itemizedlist>
+ <listitem>add, remove or modify user accounts.</listitem>
+ <listitem>list user accounts.</listitem>
+ <listitem>migrate user accounts.</listitem>
+ </itemizedlist>
+
+ <para>
+<indexterm><primary>pdbedit</primary></indexterm>
+ 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>
+<indexterm><primary>pdbedit</primary></indexterm>
+ 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>
+
+<screen>
+&prompt;<userinput>pdbedit -Lv met</userinput>
+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: &example.workgroup;
+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
+</screen>
+
+ <para>
+<indexterm><primary>pdbedit</primary></indexterm>
+ The <command>pdbedit</command> tool allows migration of authentication (account)
+ databases from one backend to another. For example: To migrate accounts from an
+ old <filename>smbpasswd</filename> database to a <parameter>tdbsam</parameter>
+ backend:
+ </para>
+
+ <procedure>
+ <step><para>
+ Set the <smbconfoption><name>passdb backend</name><value>tdbsam, smbpasswd</value></smbconfoption>.
+ </para></step>
+
+ <step><para>
+ Execute:
+<screen>
+&rootprompt;<userinput>pdbedit -i smbpasswd -e tdbsam</userinput>
+</screen>
+ </para></step>
+
+ <step><para>
+ Now remove the <parameter>smbpasswd</parameter> from the passdb backend
+ configuration in &smb.conf;.
+ </para></step>
+ </procedure>
+
+ </sect2>
+</sect1>
+
+<sect1>
+<title>Password Backends</title>
+
+<para>
+Samba 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>
+<smbconfblock>
+ <smbconfoption><name>passdb backend</name><value>tdbsam:/etc/samba/passdb.tdb \</value></smbconfoption>
+ <member><parameter>tdbsam:/etc/samba/old-passdb.tdb</parameter></member>
+</smbconfblock>
+</para>
+
+
+ <sect2>
+ <title>Plaintext</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 conducted via the way
+ that the Samba host OS will access its <filename>/etc/passwd</filename> database.
+ Linux systems For example, all operations are done via PAM.
+ </para>
+
+ </sect2>
+
+ <sect2>
+ <title>smbpasswd &smbmdash; Encrypted Password Database</title>
+
+ <para>
+<indexterm><primary>SAM backend</primary><secondary>smbpasswd</secondary></indexterm>
+ Traditionally, when configuring <smbconfoption><name>encrypt passwords</name><value>yes</value></smbconfoption> in Samba's &smb.conf; 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 large numbers of users (counted
+ in the thousands).
+ </para>
+
+ <itemizedlist>
+ <listitem><para>
+ The first problem 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 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>
+ Finally, the amount of information that is stored in an smbpasswd entry leaves
+ no room for additional attributes such as a home directory, password expiration time,
+ or even a Relative Identifier (RID).
+ </para></listitem>
+ </itemizedlist>
+
+ <para>
+ As a result of these deficiencies, 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 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>
+<indexterm><primary>SAM backend</primary><secondary>tdbsam</secondary></indexterm>
+ Samba can store user and machine account data in a <quote>TDB</quote> (Trivial Database).
+ Using this backend does not 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 does 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 implementations that require replication of the account
+ database. Clearly, for reason of scalability, the use of ldapsam should be encouraged.
+ </para>
+
+ <para>
+ The recommendation of a 250 user limit is purely based on the notion that this
+ would generally involve a site that has routed networks, possibly spread across
+ more than one physical location. The Samba Team has not at this time established
+ the performance based scalability limits of the tdbsam architecture.
+ </para>
+
+ </sect2>
+
+ <sect2>
+ <title>ldapsam</title>
+
+ <para>
+<indexterm><primary>SAM backend</primary><secondary>ldapsam</secondary></indexterm>
+ There are a few points to stress that the ldapsam does not provide. The LDAP
+ support referred to in 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
+ <ulink url="http://www.padl.com/">PADL Software</ulink>.
+ More information about the configuration of these packages may be found at
+ <ulink url="http://safari.oreilly.com/?XmlId=1-56592-491-6">
+ <emphasis>LDAP, System Administration</emphasis>; Gerald Carter by O'Reilly; Chapter 6: Replacing NIS."</ulink>
+ </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><ulink url="http://www.openldap.org/">OpenLDAP</ulink></para></listitem>
+ <listitem><para><ulink url="http://iplanet.netscape.com/directory">Sun iPlanet Directory Server</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 the process outlined in <link linkend="bugreport">Reporting Bugs</link> chapter.
+ </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 sambaSamAccount ObjectClass is given here:
+ </para>
+
+<para>
+<programlisting>
+ObjectClass (1.3.6.1.4.1.7165.2.2.6 NAME 'sambaSamAccount' SUP top AUXILIARY
+ DESC 'Samba-3.0 Auxiliary SAM Account'
+ MUST ( uid $ sambaSID )
+ MAY ( cn $ sambaLMPassword $ sambaNTPassword $ sambaPwdLastSet $
+ sambaLogonTime $ sambaLogoffTime $ sambaKickoffTime $
+ sambaPwdCanChange $ sambaPwdMustChange $ sambaAcctFlags $
+ displayName $ sambaHomePath $ sambaHomeDrive $ sambaLogonScript $
+ sambaProfilePath $ description $ sambaUserWorkstations $
+ sambaPrimaryGroupSID $ sambaDomainName ))
+</programlisting>
+</para>
+
+ <para>
+ The <filename>samba.schema</filename> file has been formatted for OpenLDAP 2.0/2.1.
+ The Samba Team owns the OID space used by the above schema and recommends its use.
+ 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 that provides information additional to a
+ user's <filename>/etc/passwd</filename> entry, so is the sambaSamAccount object
+ meant to supplement the UNIX user account information. A sambaSamAccount is a
+ <constant>AUXILIARY</constant> ObjectClass so it can be used to augment existing
+ user account information in the LDAP directory, thus providing information needed
+ for Samba account handling. However, there are several fields (e.g., uid) that 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 sambaSamAccount and posixAccount ObjectClass es 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 sambaSamAccount 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>
+<screen>
+&rootprompt;<userinput>cp samba.schema /etc/openldap/schema/</userinput>
+</screen>
+</para>
+
+ <para>
+ Next, include the <filename>samba.schema</filename> file in <filename>slapd.conf</filename>.
+ The sambaSamAccount object contains two attributes that depend on other schema
+ files. The <parameter>uid</parameter> attribute is defined in <filename>cosine.schema</filename> and
+ the <parameter>displayName</parameter> 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 sambaSamAccount
+include /etc/openldap/schema/cosine.schema
+include /etc/openldap/schema/inetorgperson.schema
+include /etc/openldap/schema/nis.schema
+include /etc/openldap/schema/samba.schema
+....
+</programlisting>
+</para>
+
+ <para>
+ It is recommended that you maintain some indices on some of the most useful attributes,
+ as in the following example, to speed up searches made on sambaSamAccount 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 sambaSID eq
+index sambaPrimaryGroupSID eq
+index sambaDomainName eq
+index default sub
+</programlisting>
+</para>
+
+ <para>
+ Create the new index by executing:
+ </para>
+
+<para>
+<screen>
+&rootprompt;./sbin/slapindex -f slapd.conf
+</screen>
+</para>
+
+ <para>
+ Remember to restart slapd after making these changes:
+ </para>
+
+<para>
+<screen>
+&rootprompt;<userinput>/etc/init.d/slapd restart</userinput>
+</screen>
+</para>
+
+ </sect3>
+
+ <sect3>
+ <title>Initialize the LDAP Database</title>
+
+ <para>
+ Before you can add accounts to the LDAP database you must create the account containers
+ that they will be stored in. The following LDIF file should be modified to match your
+ needs (DNS entries, and so on):
+ </para>
+
+<para>
+ <smbfile name="samba.ldif.example">
+<programlisting>
+# Organization for Samba Base
+dn: dc=quenya,dc=org
+objectclass: dcObject
+objectclass: organization
+dc: quenya
+o: Quenya Org Network
+description: The Samba-3 Network LDAP Example
+
+# Organizational Role for Directory Management
+dn: cn=Manager,dc=quenya,dc=org
+objectclass: organizationalRole
+cn: Manager
+description: Directory Manager
+
+# Setting up container for users
+dn: ou=People,dc=quenya,dc=org
+objectclass: top
+objectclass: organizationalUnit
+ou: People
+
+# Setting up admin handle for People OU
+dn: cn=admin,ou=People,dc=quenya,dc=org
+cn: admin
+objectclass: top
+objectclass: organizationalRole
+objectclass: simpleSecurityObject
+userPassword: {SSHA}c3ZM9tBaBo9autm1dL3waDS21+JSfQVz
+
+# Setting up container for groups
+dn: ou=Groups,dc=quenya,dc=org
+objectclass: top
+objectclass: organizationalUnit
+ou: Groups
+
+# Setting up admin handle for Groups OU
+dn: cn=admin,ou=Groups,dc=quenya,dc=org
+cn: admin
+objectclass: top
+objectclass: organizationalRole
+objectclass: simpleSecurityObject
+userPassword: {SSHA}c3ZM9tBaBo9autm1dL3waDS21+JSfQVz
+
+# Setting up container for computers
+dn: ou=Computers,dc=quenya,dc=org
+objectclass: top
+objectclass: organizationalUnit
+ou: Computers
+
+# Setting up admin handle for Computers OU
+dn: cn=admin,ou=Computers,dc=quenya,dc=org
+cn: admin
+objectclass: top
+objectclass: organizationalRole
+objectclass: simpleSecurityObject
+userPassword: {SSHA}c3ZM9tBaBo9autm1dL3waDS21+JSfQVz
+</programlisting>
+</smbfile>
+</para>
+
+ <para>
+ The userPassword shown above should be generated using <command>slappasswd</command>.
+ </para>
+
+ <para>
+ The following command will then load the contents of the LDIF file into the LDAP
+ database.
+ </para>
+
+<para>
+<screen>
+&prompt;<userinput>slapadd -v -l initldap.dif</userinput>
+</screen>
+</para>
+
+ <para>
+ Do not forget to secure your LDAP server with an adequate access control list
+ as well as an admin password.
+ </para>
+
+ <note>
+ <para>
+ Before Samba can access the LDAP server you need to store the LDAP admin password
+ into the Samba-3 <filename>secrets.tdb</filename> database by:
+<screen>
+&rootprompt;<userinput>smbpasswd -w <replaceable>secret</replaceable></userinput>
+</screen>
+ </para>
+ </note>
+
+ </sect3>
+
+ <sect3>
+ <title>Configuring Samba</title>
+
+ <para>
+ 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>
+
+ <para>LDAP related smb.conf options:
+ <smbconfoption><name>passdb backend</name><value>ldapsam:url</value></smbconfoption>,
+ <smbconfoption><name>ldap admin dn</name></smbconfoption>,
+ <smbconfoption><name>ldap delete dn</name></smbconfoption>,
+ <smbconfoption><name>ldap filter</name></smbconfoption>,
+ <smbconfoption><name>ldap group suffix</name></smbconfoption>,
+ <smbconfoption><name>ldap idmap suffix</name></smbconfoption>,
+ <smbconfoption><name>ldap machine suffix</name></smbconfoption>,
+ <smbconfoption><name>ldap passwd sync</name></smbconfoption>,
+ <smbconfoption><name>ldap ssl</name></smbconfoption>,
+ <smbconfoption><name>ldap suffix</name></smbconfoption>,
+ <smbconfoption><name>ldap user suffix</name></smbconfoption>,
+ </para>
+
+ <para>
+ These are described in the &smb.conf; man
+ page and so will not be repeated here. However, a <link linkend="confldapex">sample &smb.conf; file</link> for
+ use with an LDAP directory could appear as shown below.
+ </para>
+
+<para>
+<smbconfexample id="confldapex">
+<title>Configuration with LDAP</title>
+<smbconfsection>[global]</smbconfsection>
+<smbconfoption><name>security</name><value>user</value></smbconfoption>
+<smbconfoption><name>encrypt passwords</name><value>yes</value></smbconfoption>
+<smbconfoption><name>netbios name</name><value>MORIA</value></smbconfoption>
+<smbconfoption><name>workgroup</name><value>NOLDOR</value></smbconfoption>
+
+<smbconfcomment>ldap related parameters</smbconfcomment>
+
+<smbconfcomment>define the DN to use when binding to the directory servers</smbconfcomment>
+<smbconfcomment>The password for this DN is not stored in smb.conf. Rather it</smbconfcomment>
+<smbconfcomment>must be set by using 'smbpasswd -w <replaceable>secretpw</replaceable>' to store the</smbconfcomment>
+<smbconfcomment>passphrase in the secrets.tdb file. If the "ldap admin dn" values</smbconfcomment>
+<smbconfcomment>change, this password will need to be reset.</smbconfcomment>
+<smbconfoption><name>ldap admin dn</name><value>"cn=Manager,dc=quenya,dc=org"</value></smbconfoption>
+
+<smbconfcomment>Define the SSL option when connecting to the directory</smbconfcomment>
+<smbconfcomment>('off', 'start tls', or 'on' (default))</smbconfcomment>
+<smbconfoption><name>ldap ssl</name><value>start tls</value></smbconfoption>
+
+<smbconfcomment>syntax: passdb backend = ldapsam:ldap://server-name[:port]</smbconfcomment>
+<smbconfoption><name>passdb backend</name><value>ldapsam:ldap://frodo.quenya.org</value></smbconfoption>
+
+<smbconfcomment>smbpasswd -x delete the entire dn-entry</smbconfcomment>
+<smbconfoption><name>ldap delete dn</name><value>no</value></smbconfoption>
+
+<smbconfcomment>the machine and user suffix added to the base suffix</smbconfcomment>
+<smbconfcomment>wrote WITHOUT quotes. NULL suffixes by default</smbconfcomment>
+<smbconfoption><name>ldap user suffix</name><value>ou=People</value></smbconfoption>
+<smbconfoption><name>ldap group suffix</name><value>ou=Groups</value></smbconfoption>
+<smbconfoption><name>ldap machine suffix</name><value>ou=Computers</value></smbconfoption>
+
+<smbconfcomment>Trust UNIX account information in LDAP</smbconfcomment>
+<smbconfcomment> (see the smb.conf man page for details)</smbconfcomment>
+
+<smbconfcomment> specify the base DN to use when searching the directory</smbconfcomment>
+<smbconfoption><name>ldap suffix</name><value>dc=quenya,dc=org</value></smbconfoption>
+
+<smbconfcomment> generally the default ldap search filter is ok</smbconfcomment>
+<smbconfoption><name>ldap filter</name><value>(&amp;(uid=%u)(objectclass=sambaSamAccount))</value></smbconfoption>
+</smbconfexample>
+</para>
+
+ </sect3>
+
+ <sect3>
+ <title>Accounts and Groups Management</title>
+
+ <para>
+<indexterm><primary>User Management</primary></indexterm>
+<indexterm><primary>User Accounts</primary><secondary>Adding/Deleting</secondary></indexterm>
+
+ As user accounts are managed through the sambaSamAccount objectclass, you should
+ modify your existing administration tools to deal with sambaSamAccount attributes.
+ </para>
+
+ <para>
+ Machine accounts are managed with the sambaSamAccount objectclass, just
+ like users accounts. However, it is up to you to store those accounts
+ in a different tree of your LDAP namespace. You should use
+ <quote>ou=Groups,dc=quenya,dc=org</quote> to store groups and
+ <quote>ou=People,dc=quenya,dc=org</quote> to store users. Just configure your
+ NSS and PAM accordingly (usually, in the <filename>/etc/openldap/sldap.conf</filename>
+ configuration file).
+ </para>
+
+ <para>
+ In Samba-3, the group management system is based on POSIX
+ groups. This means that Samba makes use of the posixGroup objectclass.
+ For now, there is no NT-like group system management (global and local
+ groups). Samba-3 knows only about <constant>Domain Groups</constant>
+ and, unlike MS Windows 2000 and Active Directory, Samba-3 does not
+ support nested groups.
+ </para>
+
+ </sect3>
+
+ <sect3>
+ <title>Security and sambaSamAccount</title>
+
+
+ <para>
+ There are two important points to remember when discussing the security
+ of sambaSamAccount entries in the directory.
+ </para>
+
+ <itemizedlist>
+ <listitem><para><emphasis>Never</emphasis> retrieve the SambaLMPassword or
+ SambaNTPassword attribute values over an unencrypted LDAP session.</para></listitem>
+ <listitem><para><emphasis>Never</emphasis> allow non-admin users to
+ view the SambaLMPassword or SambaNTPassword 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 <smbconfoption><name>ldap ssl</name></smbconfoption> &smb.conf; parameter defaults
+ to require an encrypted session (<smbconfoption><name>ldap ssl</name><value>on</value></smbconfoption>) using
+ the default port of <constant>636</constant>
+ 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
+ (<smbconfoption><name>ldap ssl</name><value>off</value></smbconfoption>).
+ </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=SambaLMPassword,SambaNTPassword
+ by dn="cn=Samba Admin,ou=People,dc=quenya,dc=org" write
+ by * none
+</programlisting>
+</para>
+
+ </sect3>
+
+ <sect3>
+ <title>LDAP Special Attributes for sambaSamAccounts</title>
+
+ <para> The sambaSamAccount objectclass is composed of the attributes shown in next tables: <link
+ linkend="attribobjclPartA">Part A</link>, and <link linkend="attribobjclPartB">Part B</link>.
+ </para>
+
+ <para>
+ <table frame="all" id="attribobjclPartA">
+ <title>Attributes in the sambaSamAccount objectclass (LDAP) &smbmdash; Part A</title>
+ <tgroup cols="2" align="justify">
+ <colspec align="left"/>
+ <colspec align="justify" colwidth="1*"/>
+ <tbody>
+ <row><entry><constant>sambaLMPassword</constant></entry><entry>The LANMAN password 16-byte hash stored as a character
+ representation of a hexadecimal string.</entry></row>
+ <row><entry><constant>sambaNTPassword</constant></entry><entry>The NT password hash 16-byte stored as a character
+ representation of a hexadecimal string.</entry></row>
+ <row><entry><constant>sambaPwdLastSet</constant></entry><entry>The integer time in seconds since 1970 when the
+ <constant>sambaLMPassword</constant> and <constant>sambaNTPassword</constant> attributes were last set.
+ </entry></row>
+
+ <row><entry><constant>sambaAcctFlags</constant></entry><entry>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).</entry></row>
+
+ <row><entry><constant>sambaLogonTime</constant></entry><entry>Integer value currently unused</entry></row>
+
+ <row><entry><constant>sambaLogoffTime</constant></entry><entry>Integer value currently unused</entry></row>
+
+ <row><entry><constant>sambaKickoffTime</constant></entry><entry>Specifies the time (UNIX time format) when the user
+ will be locked down and cannot login any longer. If this attribute is omitted, then the account will never expire.
+ If you use this attribute together with `shadowExpire' of the `shadowAccount' objectClass, will enable accounts to
+ expire completely on an exact date.</entry></row>
+
+ <row><entry><constant>sambaPwdCanChange</constant></entry><entry>Specifies the time (UNIX time format) from which on the user is allowed to
+ change his password. If attribute is not set, the user will be free to change his password whenever he wants.</entry></row>
+
+ <row><entry><constant>sambaPwdMustChange</constant></entry><entry>Specifies the time (UNIX time format) since when the user is
+ forced to change his password. If this value is set to `0', the user will have to change his password at first login.
+ If this attribute is not set, then the password will never expire.</entry></row>
+
+ <row><entry><constant>sambaHomeDrive</constant></entry><entry>Specifies the drive letter to which to map the
+ UNC path specified by sambaHomePath. The drive letter must be specified in the form <quote>X:</quote>
+ where X is the letter of the drive to map. Refer to the <quote>logon drive</quote> parameter in the
+ smb.conf(5) man page for more information.</entry></row>
+
+ <row><entry><constant>sambaLogonScript</constant></entry><entry>The sambaLogonScript 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 <smbconfoption><name>logon script</name></smbconfoption> parameter in the
+ &smb.conf; man page for more information.</entry></row>
+
+ <row><entry><constant>sambaProfilePath</constant></entry><entry>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
+ <smbconfoption><name>logon path</name></smbconfoption> parameter in the &smb.conf; man page for more information.</entry></row>
+
+ <row><entry><constant>sambaHomePath</constant></entry><entry>The sambaHomePath property specifies the path of
+ the home directory for the user. The string can be null. If sambaHomeDrive is set and specifies
+ a drive letter, sambaHomePath 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.
+ </entry></row>
+ </tbody>
+ </tgroup></table>
+ </para>
+ <para>
+ <table frame="all" id="attribobjclPartB">
+ <title>Attributes in the sambaSamAccount objectclass (LDAP) &smbmdash; Part B</title>
+ <tgroup cols="2" align="justify">
+ <colspec align="left"/>
+ <colspec align="justify" colwidth="1*"/>
+ <tbody>
+ <row><entry><constant>sambaUserWorkstations</constant></entry><entry>Here you can give a comma-separated list of machines
+ on which the user is allowed to login. You may observe problems when you try to connect to an Samba Domain Member.
+ Because Domain Members are not in this list, the Domain Controllers will reject them. Where this attribute is omitted,
+ the default implies no restrictions.
+ </entry></row>
+
+ <row><entry><constant>sambaSID</constant></entry><entry>The security identifier(SID) of the user.
+ The Windows equivalent of UNIX UIDs.</entry></row>
+
+ <row><entry><constant>sambaPrimaryGroupSID</constant></entry><entry>The Security IDentifier (SID) of the primary group
+ of the user.</entry></row>
+
+ <row><entry><constant>sambaDomainName</constant></entry><entry>Domain the user is part of.</entry></row>
+ </tbody>
+ </tgroup></table>
+ </para>
+
+ <para>
+ The majority of these parameters are only used when Samba is acting as a PDC of
+ a domain (refer to <link linkend="samba-pdc">Domain Control</link>, for details on
+ how to configure Samba as a Primary Domain Controller). The following four attributes
+ are only stored with the sambaSamAccount entry if the values are non-default values:
+ </para>
+
+ <itemizedlist>
+ <listitem>sambaHomePath</listitem>
+ <listitem>sambaLogonScript</listitem>
+ <listitem>sambaProfilePath</listitem>
+ <listitem>sambaHomeDrive</listitem>
+ </itemizedlist>
+
+ <para>
+ These attributes are only stored with the sambaSamAccount entry if
+ the values are non-default values. For example, assume MORIA has now been
+ configured as a PDC and that <smbconfoption><name>logon home</name><value>\\%L\%u</value></smbconfoption> was defined in
+ its &smb.conf; file. When a user named <quote>becky</quote> logons to the domain,
+ the <smbconfoption><name>logon home</name></smbconfoption> string is expanded to \\MORIA\becky.
+ If the smbHome attribute exists in the entry <quote>uid=becky,ou=People,dc=samba,dc=org</quote>,
+ this value is used. However, if this attribute does not exist, then the value
+ of the <smbconfoption><name>logon home</name></smbconfoption> 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 sambaSamAccount</title>
+
+ <para>
+ The following is a working LDIF that demonstrates the use of the SambaSamAccount objectclass:
+ </para>
+
+ <para>
+ <smbfile name="samba.ldif.example2">
+ <programlisting>
+ dn: uid=guest2, ou=People,dc=quenya,dc=org
+ sambaLMPassword: 878D8014606CDA29677A44EFA1353FC7
+ sambaPwdMustChange: 2147483647
+ sambaPrimaryGroupSID: S-1-5-21-2447931902-1787058256-3961074038-513
+ sambaNTPassword: 552902031BEDE9EFAAD3B435B51404EE
+ sambaPwdLastSet: 1010179124
+ sambaLogonTime: 0
+ objectClass: sambaSamAccount
+ uid: guest2
+ sambaKickoffTime: 2147483647
+ sambaAcctFlags: [UX ]
+ sambaLogoffTime: 2147483647
+ sambaSID: S-1-5-21-2447931902-1787058256-3961074038-5006
+ sambaPwdCanChange: 0
+</programlisting>
+</smbfile>
+ </para>
+
+ <para>
+ The following is an LDIF entry for using both the sambaSamAccount and
+ posixAccount objectclasses:
+ </para>
+
+ <para>
+ <smbfile name="samba.ldif.example3">
+ <programlisting>
+ dn: uid=gcarter, ou=People,dc=quenya,dc=org
+ sambaLogonTime: 0
+ displayName: Gerald Carter
+ sambaLMPassword: 552902031BEDE9EFAAD3B435B51404EE
+ sambaPrimaryGroupSID: S-1-5-21-2447931902-1787058256-3961074038-1201
+ objectClass: posixAccount
+ objectClass: sambaSamAccount
+ sambaAcctFlags: [UX ]
+ userPassword: {crypt}BpM2ej8Rkzogo
+ uid: gcarter
+ uidNumber: 9000
+ cn: Gerald Carter
+ loginShell: /bin/bash
+ logoffTime: 2147483647
+ gidNumber: 100
+ sambaKickoffTime: 2147483647
+ sambaPwdLastSet: 1010179230
+ sambaSID: S-1-5-21-2447931902-1787058256-3961074038-5004
+ homeDirectory: /home/moria/gcarter
+ sambaPwdCanChange: 0
+ sambaPwdMustChange: 2147483647
+ sambaNTPassword: 878D8014606CDA29677A44EFA1353FC7
+</programlisting>
+</smbfile>
+ </para>
+
+ </sect3>
+
+ <sect3>
+ <title>Password Synchronization</title>
+
+ <para>
+ Samba-3 and later 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 <smbconfoption><name>ldap passwd sync</name></smbconfoption> options can have the values shown in
+ <link linkend="ldappwsync">the next table</link>.</para>
+
+ <table iframe="all" id="ldappwsync">
+ <title>Possible <emphasis>ldap passwd sync</emphasis> values</title>
+ <tgroup cols="2">
+ <colspec align="left" width="1*"/>
+ <colspec align="justify" width="4*"/>
+ <thead>
+ <row><entry align="left">Value</entry><entry align="center">Description</entry></row>
+ </thead>
+ <tbody>
+ <row><entry>yes</entry><entry><para>When the user changes his password, update
+ <constant>SambaNTPassword</constant>, <constant>SambaLMPassword</constant>
+ and the <constant>password</constant> fields.</para></entry></row>
+
+ <row><entry>no</entry><entry><para>Only update <constant>SambaNTPassword</constant> and <constant>SambaLMPassword</constant>.</para></entry></row>
+
+ <row><entry>only</entry><entry><para>Only update the LDAP password and let the LDAP server worry about the other fields.
+ This option is only available on some LDAP servers. Only when the LDAP server
+ supports LDAP_EXOP_X_MODIFY_PASSWD.</para></entry></row>
+ </tbody>
+ </tgroup>
+ </table>
+
+
+ <para>More information can be found in the &smb.conf; man page.</para>
+
+ </sect3>
+
+ </sect2>
+
+ <sect2>
+ <title>MySQL</title>
+
+ <para>
+<indexterm><primary>SAM backend</primary><secondary>mysqlsam</secondary></indexterm>
+ Every so often someone will come along with a great new idea. Storing user accounts in a
+ SQL backend is one of them. Those who want to do this are in the best position to know what the
+ specific benefits are to them. This may sound like a cop-out, but in truth we cannot attempt
+ to document every little detail why certain things of marginal utility to the bulk of
+ Samba users might make sense to the rest. In any case, the following instructions should help
+ the determined SQL user to implement a working system.
+ </para>
+
+ <sect3>
+ <title>Creating the Database</title>
+
+ <para>
+ You 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:
+
+<screen>
+&prompt;<userinput>mysql -u<replaceable>username</replaceable> -h<replaceable>hostname</replaceable> -p<replaceable>password</replaceable> \
+ <replaceable>databasename</replaceable> &lt; <filename>/path/to/samba/examples/pdb/mysql/mysql.dump</filename></userinput>
+</screen>
+ </para>
+ </sect3>
+
+ <sect3>
+ <title>Configuring</title>
+
+ <para>This plug-in lacks some good documentation, but here is some brief information. Add the following to the
+ <smbconfoption><name>passdb backend</name></smbconfoption> variable in your &smb.conf;:
+<smbconfblock>
+<smbconfoption><name>passdb backend</name><value>[other-plugins] mysql:identifier [other-plugins]</value></smbconfoption>
+</smbconfblock>
+ </para>
+
+ <para>The identifier can be any string you like, as long as it does not collide with
+ the identifiers of other plugins or other instances of pdb_mysql. If you
+ specify multiple pdb_mysql.so entries in <smbconfoption><name>passdb backend</name></smbconfoption>, you also need to
+ use different identifiers.
+ </para>
+
+ <para>
+ Additional options can be given through the &smb.conf; file in the <smbconfsection>[global]</smbconfsection> section.
+ Refer to <link linkend="mysqlpbe">the following table</link>.
+ </para>
+
+ <table frame="all" id="mysqlpbe">
+ <title>Basic smb.conf options for MySQL passdb backend</title>
+ <tgroup cols="2">
+ <colspec align="left"/>
+ <colspec align="justify" colwidth="1*"/>
+ <thead>
+ <row><entry>Field</entry><entry>Contents</entry></row>
+ </thead>
+ <tbody>
+ <row><entry>mysql host</entry><entry>Host name, defaults to `localhost'</entry></row>
+ <row><entry>mysql password</entry><entry></entry></row>
+ <row><entry>mysql user</entry><entry>Defaults to `samba'</entry></row>
+ <row><entry>mysql database</entry><entry>Defaults to `samba'</entry></row>
+ <row><entry>mysql port</entry><entry>Defaults to 3306</entry></row>
+ <row><entry>table</entry><entry>Name of the table containing the users</entry></row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <warning>
+ <para>
+ Since the password for the MySQL user is stored in the &smb.conf; file, you should make the &smb.conf; file
+ readable only to the user who runs Samba. This is considered a security bug and will soon be fixed.
+ </para>
+ </warning>
+
+ <para>Names of the columns are given in <link linkend="moremysqlpdbe">the next table</link>.
+ The default column names can be found in the example table dump.
+ </para>
+
+ <para>
+ <table frame="all" id="moremysqlpdbe">
+ <title>MySQL field names for MySQL passdb backend</title>
+ <tgroup cols="3" align="justify">
+ <colspec align="left"/>
+ <colspec align="left"/>
+ <colspec align="justify" colwidth="1*"/>
+ <thead>
+ <row><entry>Field</entry><entry>Type</entry><entry>Contents</entry></row>
+ </thead>
+ <tbody>
+ <row><entry>logon time column</entry><entry>int(9)</entry><entry>UNIX time stamp of last logon of user</entry></row>
+ <row><entry>logoff time column</entry><entry>int(9)</entry><entry>UNIX time stamp of last logoff of user</entry></row>
+ <row><entry>kickoff time column</entry><entry>int(9)</entry><entry>UNIX time stamp of moment user should be kicked off workstation (not enforced)</entry></row>
+ <row><entry>pass last set time column</entry><entry>int(9)</entry><entry>UNIX time stamp of moment password was last set</entry></row>
+ <row><entry>pass can change time column</entry><entry>int(9)</entry><entry>UNIX time stamp of moment from which password can be changed</entry></row>
+ <row><entry>pass must change time column</entry><entry>int(9)</entry><entry>UNIX time stamp of moment on which password must be changed</entry></row>
+ <row><entry>username column</entry><entry>varchar(255)</entry><entry>UNIX username</entry></row>
+ <row><entry>domain column</entry><entry>varchar(255)</entry><entry>NT domain user belongs to</entry></row>
+ <row><entry>nt username column</entry><entry>varchar(255)</entry><entry>NT username</entry></row>
+ <row><entry>fullname column</entry><entry>varchar(255)</entry><entry>Full name of user</entry></row>
+ <row><entry>home dir column</entry><entry>varchar(255)</entry><entry>UNIX homedir path (equivalent of the <smbconfoption><name>logon home</name></smbconfoption> parameter.</entry></row>
+ <row><entry>dir drive column</entry><entry>varchar(2)</entry><entry>Directory drive path (e.g., <quote>H:</quote>)</entry></row>
+ <row><entry>logon script column</entry><entry>varchar(255)</entry><entry>Batch file to run on client side when logging on</entry></row>
+ <row><entry>profile path column</entry><entry>varchar(255)</entry><entry>Path of profile</entry></row>
+ <row><entry>acct desc column</entry><entry>varchar(255)</entry><entry>Some ASCII NT user data</entry></row>
+ <row><entry>workstations column</entry><entry>varchar(255)</entry><entry>Workstations user can logon to (or NULL for all)</entry></row>
+ <row><entry>unknown string column</entry><entry>varchar(255)</entry><entry>Unknown string</entry></row>
+ <row><entry>munged dial column</entry><entry>varchar(255)</entry><entry>Unknown</entry></row>
+ <row><entry>user sid column</entry><entry>varchar(255)</entry><entry>NT user SID</entry></row>
+ <row><entry>group sid column</entry><entry>varchar(255)</entry><entry>NT group SID</entry></row>
+ <row><entry>lanman pass column</entry><entry>varchar(255)</entry><entry>Encrypted lanman password</entry></row>
+ <row><entry>nt pass column</entry><entry>varchar(255)</entry><entry>Encrypted nt passwd</entry></row>
+ <row><entry>plain pass column</entry><entry>varchar(255)</entry><entry>Plaintext password</entry></row>
+ <row><entry>acct ctrl column</entry><entry>int(9)</entry><entry>NT user data</entry></row>
+ <row><entry>unknown 3 column</entry><entry>int(9)</entry><entry>Unknown</entry></row>
+ <row><entry>logon divs column</entry><entry>int(9)</entry><entry>Unknown</entry></row>
+ <row><entry>hours len column</entry><entry>int(9)</entry><entry>Unknown</entry></row>
+ <row><entry>bad password count column</entry><entry>int(5)</entry><entry>Number of failed password tries before disabling an account</entry></row>
+ <row><entry>logon count column</entry><entry>int(5)</entry><entry>Number of logon attempts</entry></row>
+ <row><entry>unknown 6 column</entry><entry>int(9)</entry><entry>Unknown</entry></row>
+ </tbody></tgroup>
+ </table>
+ </para>
+
+ <para>
+ 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 field data will not be updated. Setting a column name to <parameter>NULL</parameter> means the field should not be used.
+ </para>
+
+ <para><link linkend="mysqlsam">An example configuration</link> looks like:
+ </para>
+
+ <smbconfexample id="mysqlsam">
+ <title>Example configuration for the MySQL passdb backend</title>
+ <smbconfsection>[global]</smbconfsection>
+ <smbconfoption><name>passdb backend</name><value>mysql:foo</value></smbconfoption>
+ <smbconfoption><name>foo:mysql user</name><value>samba</value></smbconfoption>
+ <smbconfoption><name>foo:mysql password</name><value>abmas</value></smbconfoption>
+ <smbconfoption><name>foo:mysql database</name><value>samba</value></smbconfoption>
+ <smbconfcomment>domain name is static and can't be changed</smbconfcomment>
+ <smbconfoption><name>foo:domain column</name><value>'MYWORKGROUP':</value></smbconfoption>
+ <smbconfcomment>The fullname column comes from several other columns</smbconfcomment>
+ <smbconfoption><name>foo:fullname column</name><value>CONCAT(firstname,' ',surname):</value></smbconfoption>
+ <smbconfcomment>Samba should never write to the password columns</smbconfcomment>
+ <smbconfoption><name>foo:lanman pass column</name><value>lm_pass:</value></smbconfoption>
+ <smbconfoption><name>foo:nt pass column</name><value>nt_pass:</value></smbconfoption>
+ <smbconfcomment>The unknown 3 column is not stored</smbconfcomment>
+ <smbconfoption><name>foo:unknown 3 column</name><value>NULL</value></smbconfoption>
+ </smbconfexample>
+ </sect3>
+
+ <sect3>
+ <title>Using Plaintext Passwords or Encrypted Password</title>
+
+ <para>
+<indexterm><primary>encrypted passwords</primary></indexterm>
+ 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 by making some `constant'.
+ </para>
+
+ <para>
+ For example, you can set `identifier:fullname column' to
+ something like <?latex \linebreak ?><command>CONCAT(Firstname,' ',Surname)</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>
+<indexterm><primary>SAM backend</primary><secondary>xmlsam</secondary></indexterm>
+ This module requires libxml2 to be installed.</para>
+
+ <para>The usage of pdb_xml is fairly straightforward. To export data, use:
+ </para>
+
+ <para>
+<indexterm><primary>pdbedit</primary></indexterm>
+ <prompt>$ </prompt> <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:
+ <prompt>$ </prompt> <userinput>pdbedit -i xml:filename</userinput>
+ </para>
+ </sect2>
+</sect1>
+
+<sect1>
+<title>Common Errors</title>
+
+ <sect2>
+ <title>Users Cannot Logon</title>
+
+ <para><quote>I've installed Samba, but now I can't log on with my UNIX account! </quote></para>
+
+ <para>Make sure your user has been added to the current Samba <smbconfoption><name>passdb backend</name></smbconfoption>.
+ Read the section <link linkend="acctmgmttools">Account Management Tools</link> for details.</para>
+
+ </sect2>
+
+ <sect2>
+ <title>Users Being Added to the Wrong Backend Database</title>
+
+ <para>
+ A few complaints have been received from users that just moved to Samba-3. The following
+ &smb.conf; file entries were causing problems, new accounts were being added to the old
+ smbpasswd file, not to the tdbsam passdb.tdb file:
+ </para>
+
+ <para>
+ <smbconfblock>
+ <smbconfsection>[global]</smbconfsection>
+ <member>...</member>
+ <smbconfoption><name>passdb backend</name><value>smbpasswd, tdbsam</value></smbconfoption>
+ <member>...</member>
+ </smbconfblock>
+ </para>
+
+ <para>
+ Samba will add new accounts to the first entry in the <emphasis>passdb backend</emphasis>
+ parameter entry. If you want to update to the tdbsam, then change the entry to:
+ </para>
+
+ <para>
+<smbconfblock>
+[globals]
+...
+<smbconfoption><name>passdb backend</name><value>tdbsam, smbpasswd</value></smbconfoption>
+...
+</smbconfblock>
+ </para>
+
+ </sect2>
+
+ <sect2>
+ <title>Configuration of <parameter>auth methods</parameter></title>
+
+ <para>
+ When explicitly setting an <smbconfoption><name>auth methods</name></smbconfoption> parameter,
+ <parameter>guest</parameter> must be specified as the first entry on the line,
+ for example, <smbconfoption><name>auth methods</name><value>guest sam</value></smbconfoption>.
+ </para>
+
+ <para>
+ This is the exact opposite of the requirement for the <smbconfoption><name>passdb backend</name></smbconfoption>
+ option, where it must be the <emphasis>LAST</emphasis> parameter on the line.
+ </para>
+
+ </sect2>
+
+</sect1>
+
+</chapter>