<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 11. Account Information Databases</title><link rel="stylesheet" href="samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.60.1"><link rel="home" href="samba-doc.html" title="SAMBA Project Documentation"><link rel="up" href="optional.html" title="Part III. Advanced Configuration"><link rel="previous" href="NetworkBrowsing.html" title="Chapter 10. Samba / MS Windows Network Browsing Guide"><link rel="next" href="groupmapping.html" title="Chapter 12. Mapping MS Windows and UNIX Groups"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 11. Account Information Databases</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="NetworkBrowsing.html">Prev</a> </td><th width="60%" align="center">Part III. Advanced Configuration</th><td width="20%" align="right"> <a accesskey="n" href="groupmapping.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="passdb"></a>Chapter 11. Account Information Databases</h2></div><div><div class="author"><h3 class="author"><span class="firstname">Jelmer</span> <span class="othername">R.</span> <span class="surname">Vernooij</span></h3><div class="affiliation"><span class="orgname">The Samba Team<br></span><div class="address"><p><tt class="email"><<a href="mailto:jelmer@samba.org">jelmer@samba.org</a>></tt></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Gerald</span> <span class="othername">(Jerry)</span> <span class="surname">Carter</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt class="email"><<a href="mailto:jerry@samba.org">jerry@samba.org</a>></tt></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Jeremy</span> <span class="surname">Allison</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt class="email"><<a href="mailto:jra@samba.org">jra@samba.org</a>></tt></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">John</span> <span class="othername">H.</span> <span class="surname">Terpstra</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt class="email"><<a href="mailto:jht@samba.org">jht@samba.org</a>></tt></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Olivier (lem)</span> <span class="surname">Lemaire</span></h3><div class="affiliation"><span class="orgname">IDEALX<br></span><div class="address"><p><tt class="email"><<a href="mailto:olem@IDEALX.org">olem@IDEALX.org</a>></tt></p></div></div></div></div><div><p class="pubdate">May 24, 2003</p></div></div><div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><a href="passdb.html#id2898446">Features and Benefits</a></dt><dd><dl><dt><a href="passdb.html#id2898460">Backwards Compatibility Backends</a></dt><dt><a href="passdb.html#id2898561">New Backends</a></dt></dl></dd><dt><a href="passdb.html#id2898749">Technical Information</a></dt><dd><dl><dt><a href="passdb.html#id2898874">Important Notes About Security</a></dt><dt><a href="passdb.html#id2899165">Mapping User Identifiers between MS Windows and UNIX</a></dt><dt><a href="passdb.html#idmapbackend">Mapping Common UIDs/GIDs on Distributed Machines</a></dt></dl></dd><dt><a href="passdb.html#acctmgmttools">Account Management Tools</a></dt><dd><dl><dt><a href="passdb.html#id2899351">The smbpasswd Command</a></dt><dt><a href="passdb.html#id2899622">The pdbedit Command</a></dt></dl></dd><dt><a href="passdb.html#id2899860">Password Backends</a></dt><dd><dl><dt><a href="passdb.html#id2899902">Plain Text</a></dt><dt><a href="passdb.html#id2899942">smbpasswd - Encrypted Password Database</a></dt><dt><a href="passdb.html#id2900055">tdbsam</a></dt><dt><a href="passdb.html#id2900089">ldapsam</a></dt><dt><a href="passdb.html#id2901940">MySQL</a></dt><dt><a href="passdb.html#XMLpassdb">XML</a></dt></dl></dd><dt><a href="passdb.html#id2902790">Common Errors</a></dt><dd><dl><dt><a href="passdb.html#id2902796">Users can not logon</a></dt><dt><a href="passdb.html#id2902841">Users being added to wrong backend database</a></dt><dt><a href="passdb.html#id2902952">auth methods does not work</a></dt></dl></dd></dl></div><p> 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. </p><p> 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 <span class="emphasis"><em>Non UNIX Accounts (NUA)</em></span> capability. The intent was that an administrator could decide to use the <span class="emphasis"><em>tdbsam</em></span> backend and by simply specifying <a class="indexterm" name="id2898413"></a><i class="parameter"><tt>passdb backend</tt></i> = tdbsam_nua 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. </p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> Samba-3 does NOT support Non-UNIX Account (NUA) operation for user accounts. Samba-3 does support NUA operation for machine accounts. </p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2898446"></a>Features and Benefits</h2></div></div><div></div></div><p> Samba-3 provides for complete backwards compatibility with Samba-2.2.x functionality as follows: </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2898460"></a>Backwards Compatibility Backends</h3></div></div><div></div></div><div class="variablelist"><dl><dt><span class="term">Plain Text:</span></dt><dd><p> This option uses nothing but the UNIX/Linux <tt class="filename">/etc/passwd</tt> 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. </p></dd><dt><span class="term">smbpasswd:</span></dt><dd><p> This option allows continues use of the <tt class="filename">smbpasswd</tt> 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. </p><p> This backend should be used only for backwards compatibility with older versions of Samba. It may be deprecated in future releases. </p></dd><dt><span class="term">ldapsam_compat (Samba-2.2 LDAP Compatibility):</span></dt><dd><p> 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. Note that this tool will eventually be deprecated. </p></dd></dl></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2898561"></a>New Backends</h3></div></div><div></div></div><p> Samba-3 introduces the following new password backend capabilities: </p><div class="variablelist"><dl><dt><span class="term">tdbsam:</span></dt><dd><p> This backend provides a rich database backend for local servers. This backend is NOT suitable for multiple domain controller (ie: PDC + one or more BDC) installations. </p><p> The <span class="emphasis"><em>tdbsam</em></span> password backend stores the old <span class="emphasis"><em> smbpasswd</em></span> 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. </p><p> The inclusion of the <span class="emphasis"><em>tdbsam</em></span> 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. </p></dd><dt><span class="term">ldapsam:</span></dt><dd><p> This provides a rich directory backend for distributed account installation. </p><p> 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 <tt class="filename">examples/LDAP</tt> directory of the Samba distribution. </p><p> The new LDAP implementation significantly expands the control abilities that were possible with prior versions of Samba. It is now 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. </p></dd><dt><span class="term">mysqlsam (MySQL based backend):</span></dt><dd><p> 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. </p></dd><dt><span class="term">xmlsam (XML based datafile):</span></dt><dd><p> Allows the account and password data to be stored in an XML format data file. This backend can not be used for normal operation, it can only be used in conjunction with <b class="command">pdbedit</b>'s pdb2pdb functionality. The DTD that is used might be subject to changes in the future. </p><p> The xmlsam 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. </p></dd></dl></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2898749"></a>Technical Information</h2></div></div><div></div></div><p> 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. </p><p> 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. </p><p> 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. </p><p> 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 <a class="indexterm" name="id2898789"></a><i class="parameter"><tt>passdb backend</tt></i>. Commonly available backends are LDAP, plain text file, MySQL and nisplus. For more information, see the man page for <tt class="filename">smb.conf</tt> regarding the <a class="indexterm" name="id2898812"></a><i class="parameter"><tt>passdb backend</tt></i> parameter. </p><div class="figure"><a name="idmap-diag"></a><p class="title"><b>Figure 11.1. IDMAP</b></p><div class="mediaobject"><img src="projdoc/imagefiles/idmap.png" width="270" alt="IDMAP"></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2898874"></a>Important Notes About Security</h3></div></div><div></div></div><p> 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. </p><p> 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). </p><p> 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. </p><p> The following versions of MS Windows do not support full domain security protocols, although they may log onto a domain environment: </p><div class="itemizedlist"><ul type="disc"><li><p>MS DOS Network client 3.0 with the basic network redirector installed</p></li><li><p>Windows 95 with the network redirector update installed</p></li><li><p>Windows 98 [se]</p></li><li><p>Windows Me</p></li></ul></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> MS Windows XP Home does not have facilities to become a domain member and it can not participate in domain logons. </p></div><p> The following versions of MS Windows fully support domain security protocols. </p><div class="itemizedlist"><ul type="disc"><li><p>Windows NT 3.5x</p></li><li><p>Windows NT 4.0</p></li><li><p>Windows 2000 Professional</p></li><li><p>Windows 200x Server/Advanced Server</p></li><li><p>Windows XP Professional</p></li></ul></div><p> 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. </p><p> 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. <span class="emphasis"><em>USE OF ENCRYPTED PASSWORDS IS STRONGLY ADVISED.</em></span> </p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2899068"></a>Advantages of Encrypted Passwords</h4></div></div><div></div></div><div class="itemizedlist"><ul type="disc"><li><p>Plain text passwords are not passed across the network. Someone using a network sniffer cannot just record passwords going to the SMB server.</p></li><li><p>Plain text passwords are not stored anywhere in memory or on disk.</p></li><li><p>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. </p></li><li><p>Encrypted password support allows automatic share (resource) reconnects.</p></li><li><p>Encrypted passwords are essential for PDC/BDC operation.</p></li></ul></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2899128"></a>Advantages of non-encrypted passwords</h4></div></div><div></div></div><div class="itemizedlist"><ul type="disc"><li><p>Plain text passwords are not kept on disk, and are NOT cached in memory. </p></li><li><p>Uses same password file as other unix services such as login and ftp</p></li><li><p>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.</p></li></ul></div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2899165"></a>Mapping User Identifiers between MS Windows and UNIX</h3></div></div><div></div></div><p> 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. </p><p> Firstly, 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 <a class="indexterm" name="id2899188"></a><i class="parameter"><tt>add user script</tt></i> interface to add the account to the Samba host OS. In essence all accounts in the local SAM require a local user account. </p><p> The second way to affect Windows SID to UNIX UID mapping is via the <span class="emphasis"><em>idmap uid, idmap gid</em></span> parameters in <tt class="filename">smb.conf</tt>. Please refer to the man page for information about these parameters. These parameters are essential when mapping users from a remote SAM server. </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="idmapbackend"></a>Mapping Common UIDs/GIDs on Distributed Machines</h3></div></div><div></div></div><p> 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 (eg: NFS) and where users are copying files across UNIX/Linux systems using tools such as <b class="command">rsync</b>. </p><p> The special facility is enabled using a parameter called <i class="parameter"><tt>idmap backend</tt></i>. The default setting for this parameter is an empty string. Administrators should NOT set this parameter except when an LDAP based passdb backend is in use. An example of use is: </p><p> </p><div class="example"><a name="idmapbackendexample"></a><p class="title"><b>Example 11.1. </b></p><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><i class="parameter"><tt>[global]</tt></i></td></tr><tr><td><i class="parameter"><tt>idmap backend = ldapsam://ldap-server.quenya.org:636</tt></i></td></tr></table></div><p> </p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="acctmgmttools"></a>Account Management Tools</h2></div></div><div></div></div><p> Samba provides two (2) tools for management of User and machine accounts. These tools are called <b class="command">smbpasswd</b> and <b class="command">pdbedit</b>. 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. </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2899351"></a>The <span class="emphasis"><em>smbpasswd</em></span> Command</h3></div></div><div></div></div><p> The smbpasswd utility is a utility similar to the <b class="command">passwd</b> or <b class="command">yppasswd</b> programs. It maintains the two 32 byte password fields in the passdb backend. </p><p> <b class="command">smbpasswd</b> 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: </p><p> <b class="command">smbpasswd</b> 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). </p><p> <b class="command">smbpasswd</b> can be used to: </p><div class="itemizedlist"><ul type="disc"><li><p><span class="emphasis"><em>add</em></span> user or machine accounts</p></li><li><p><span class="emphasis"><em>delete</em></span> user or machine accounts</p></li><li><p><span class="emphasis"><em>enable</em></span> user or machine accounts</p></li><li><p><span class="emphasis"><em>disable</em></span> user or machine accounts</p></li><li><p><span class="emphasis"><em>set to NULL</em></span> user passwords</p></li><li><p><span class="emphasis"><em>manage interdomain trust accounts</em></span></p></li></ul></div><p> To run smbpasswd as a normal user just type: </p><p> </p><pre class="screen"> <tt class="prompt">$ </tt><b class="userinput"><tt>smbpasswd</tt></b> <tt class="prompt">Old SMB password: </tt><b class="userinput"><tt><i class="replaceable"><tt>secret</tt></i></tt></b> </pre><p> For <i class="replaceable"><tt>secret</tt></i> type old value here - or hit return if there was no old password </p><pre class="screen"> <tt class="prompt">New SMB Password: </tt><b class="userinput"><tt><i class="replaceable"><tt>new secret</tt></i></tt></b> <tt class="prompt">Repeat New SMB Password: </tt><b class="userinput"><tt><i class="replaceable"><tt>new secret</tt></i></tt></b> </pre><p> </p><p> 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. </p><p> When invoked by an ordinary user it will only allow change of their own SMB password. </p><p> 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. </p><p> <b class="command">smbpasswd</b> is designed to work in the way familiar to UNIX users who use the <b class="command">passwd</b> or <b class="command">yppasswd</b> commands. While designed for administrative use, this tool provides essential user level password change capabilities. </p><p> For more details on using <b class="command">smbpasswd</b> refer to the man page (the definitive reference). </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2899622"></a>The <span class="emphasis"><em>pdbedit</em></span> Command</h3></div></div><div></div></div><p> <b class="command">pdbedit</b> is a tool that can be used only by root. It is used to manage the passdb backend. <b class="command">pdbedit</b> can be used to: </p><div class="itemizedlist"><ul type="disc"><li><p>add, remove or modify user accounts</p></li><li><p>listing user accounts</p></li><li><p>migrate user accounts</p></li></ul></div><p> The <b class="command">pdbedit</b> 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. </p><p> One particularly important purpose of the <b class="command">pdbedit</b> is to allow the migration of account information from one passdb backend to another. See the <a href="passdb.html#XMLpassdb" title="XML">XML</a> password backend section of this chapter. </p><p> The following is an example of the user account information that is stored in a tdbsam password backend. This listing was produced by running: </p><pre class="screen"> <tt class="prompt">$ </tt><b class="userinput"><tt>pdbedit -Lv met</tt></b> 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 </pre><p> The <b class="command">pdbedit</b> tool allows migration of authentication (account) databases from one backend to another. For example: To migrate accounts from an old <tt class="filename">smbpasswd</tt> database to a <i class="parameter"><tt>tdbsam</tt></i> backend: </p><div class="procedure"><ol type="1"><li><p> Set the <a class="indexterm" name="id2899790"></a><i class="parameter"><tt>passdb backend</tt></i> = tdbsam, smbpasswd. </p></li><li><p> Execute: </p><pre class="screen"> <tt class="prompt">root# </tt><b class="userinput"><tt>pdbedit -i smbpassed -e tdbsam</tt></b> </pre><p> </p></li><li><p> Now remove the <i class="parameter"><tt>smbpasswd</tt></i> from the passdb backend configuration in <tt class="filename">smb.conf</tt>. </p></li></ol></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2899860"></a>Password Backends</h2></div></div><div></div></div><p> 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. </p><p> 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: </p><p> </p><table class="simplelist" border="0" summary="Simple list"><tr><td><i class="parameter"><tt>passdb backend = tdbsam:/etc/samba/passdb.tdb, tdbsam:/etc/samba/old-passdb.tdb</tt></i></td></tr></table><p> </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2899902"></a>Plain Text</h3></div></div><div></div></div><p> Older versions of Samba retrieved user information from the unix user database and eventually some other fields from the file <tt class="filename">/etc/samba/smbpasswd</tt> or <tt class="filename">/etc/smbpasswd</tt>. 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 <tt class="filename">/etc/passwd</tt> database. eg: On Linux systems that is done via PAM. </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2899942"></a>smbpasswd - Encrypted Password Database</h3></div></div><div></div></div><p> Traditionally, when configuring <a class="indexterm" name="id2899952"></a><i class="parameter"><tt>encrypt passwords</tt></i> = yes in Samba's <tt class="filename">smb.conf</tt> file, user account information such as username, LM/NT password hashes, password change times, and account flags have been stored in the <tt class="filename">smbpasswd(5)</tt> file. There are several disadvantages to this approach for sites with very large numbers of users (counted in the thousands). </p><div class="itemizedlist"><ul type="disc"><li><p> 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. </p></li><li><p> 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 <b class="command">rsync(1)</b> and <b class="command">ssh(1)</b> and wrote custom, in-house scripts. </p></li><li><p> 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 Identifier (RID). </p></li></ul></div><p> 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). </p><p> 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. </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2900055"></a>tdbsam</h3></div></div><div></div></div><p>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. </p><p> 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 requires replication of the account database. Clearly, for reason of scalability, the use of ldapsam should be encouraged. </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2900089"></a>ldapsam</h3></div></div><div></div></div><p> 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: </p><div class="itemizedlist"><ul type="disc"><li><p>A means of retrieving user account information from an Windows 200x Active Directory server.</p></li><li><p>A means of replacing /etc/passwd.</p></li></ul></div><p> The second item can be accomplished by using LDAP NSS and PAM modules. LGPL versions of these libraries can be obtained from PADL Software (<a href="http://www.padl.com/" target="_top">http://www.padl.com/</a>). 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 <a href="http://safari.oreilly.com/?XmlId=1-56592-491-6" target="_top"> http://safari.oreilly.com/?XmlId=1-56592-491-6</a> for those who might wish to know more about configuration and administration of an OpenLDAP server. </p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> This section is outdated for Samba-3 schema. Samba-3 introduces a new schema that has not been documented at the time of this publication. </p></div><p> 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. </p><div class="itemizedlist"><ul type="disc"><li><p>OpenLDAP - <a href="http://www.openldap.org/" target="_top">http://www.openldap.org/</a></p></li><li><p>iPlanet Directory Server - <a href="http://iplanet.netscape.com/directory" target="_top">http://iplanet.netscape.com/directory</a></p></li></ul></div><p> Two additional Samba resources which may prove to be helpful are </p><div class="itemizedlist"><ul type="disc"><li><p>The <a href="http://www.unav.es/cti/ldap-smb/ldap-smb-3-howto.html" target="_top">Samba-PDC-LDAP-HOWTO</a> maintained by Ignacio Coupeau.</p></li><li><p>The NT migration scripts from <a href="http://samba.idealx.org/" target="_top">IDEALX</a> that are geared to manage users and group in such a Samba-LDAP Domain Controller configuration. </p></li></ul></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2900244"></a>Supported LDAP Servers</h4></div></div><div></div></div><p> 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 <a href="bugreport.html" title="Chapter 35. Reporting Bugs">Bug reporting facility</a>. </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2900270"></a>Schema and Relationship to the RFC 2307 posixAccount</h4></div></div><div></div></div><p> Samba 3.0 includes the necessary schema file for OpenLDAP 2.0 in <tt class="filename">examples/LDAP/samba.schema</tt>. The sambaSamAccount objectclass is given here: </p><p> </p><pre class="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 )) </pre><p> </p><p> The <tt class="filename">samba.schema</tt> 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 <a href="mailto:jerry@samba.org" target="_top">jerry@samba.org</a>. </p><p> Just as the smbpasswd file is meant to store information which supplements a user's <tt class="filename">/etc/passwd</tt> entry, so is the sambaSamAccount object meant to supplement the UNIX user account information. A sambaSamAccount is a <tt class="constant">STRUCTURAL</tt> 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. </p><p> In order to store all user account information (UNIX and Samba) in the directory, it is necessary to use the sambaSamAccount 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. </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2900380"></a>OpenLDAP configuration</h4></div></div><div></div></div><p> 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 <tt class="filename">examples/LDAP</tt> in the samba source distribution. </p><p> </p><pre class="screen"> <tt class="prompt">root# </tt><b class="userinput"><tt>cp samba.schema /etc/openldap/schema/</tt></b> </pre><p> </p><p> Next, include the <tt class="filename">samba.schema</tt> file in <tt class="filename">slapd.conf</tt>. The sambaSamAccount object contains two attributes which depend upon other schema files. The 'uid' attribute is defined in <tt class="filename">cosine.schema</tt> and the 'displayName' attribute is defined in the <tt class="filename">inetorgperson.schema</tt> file. Both of these must be included before the <tt class="filename">samba.schema</tt> file. </p><p> </p><pre class="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/samba.schema include /etc/openldap/schema/nis.schema .... </pre><p> </p><p> It is recommended that you maintain some indices on some of the most useful attributes, like in the following example, to speed up searches made on sambaSamAccount objectclasses (and possibly posixAccount and posixGroup as well). </p><p> </p><pre class="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 </pre><p> </p><p> Create the new index by executing: </p><p> </p><pre class="screen"> <tt class="prompt">root# </tt>./sbin/slapindex -f slapd.conf </pre><p> </p><p> Remember to restart slapd after making these changes: </p><p> </p><pre class="screen"> <tt class="prompt">root# </tt><b class="userinput"><tt>/etc/init.d/slapd restart</tt></b> </pre><p> </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2900576"></a>Initialise the LDAP database</h4></div></div><div></div></div><p> 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 (ie: Your DNS entries, etc.). </p><p> </p><pre class="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 </pre><p> </p><p> The userPassword shown above should be generated using <b class="command">slappasswd</b>. </p><p> The following command will then load the contents of the LDIF file into the LDAP database. </p><p> </p><pre class="screen"> <tt class="prompt">$ </tt><b class="userinput"><tt>slapadd -v -l initldap.dif</tt></b> </pre><p> </p><p> Do not forget to secure your LDAP server with an adequate access control list, as well as an admin password. </p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> Before Samba can access the LDAP server you need to store the LDAP admin password into the Samba-3 <tt class="filename">secrets.tdb</tt> database by: </p><pre class="screen"> <tt class="prompt">root# </tt><b class="userinput"><tt>smbpasswd -w <i class="replaceable"><tt>secret</tt></i></tt></b> </pre><p> </p></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2900704"></a>Configuring Samba</h4></div></div><div></div></div><p> 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. </p><p>LDAP related smb.conf options: <a class="indexterm" name="id2900721"></a><i class="parameter"><tt>passdb backend</tt></i> = ldapsam:url, <a class="indexterm" name="id2900737"></a><i class="parameter"><tt>ldap ssl</tt></i>, <a class="indexterm" name="id2900750"></a><i class="parameter"><tt>ldap admin dn</tt></i>, <a class="indexterm" name="id2900764"></a><i class="parameter"><tt>ldap suffix</tt></i>, <a class="indexterm" name="id2900777"></a><i class="parameter"><tt>ldap filter</tt></i>, <a class="indexterm" name="id2900791"></a><i class="parameter"><tt>ldap machine suffix</tt></i>, <a class="indexterm" name="id2900805"></a><i class="parameter"><tt>ldap user suffix</tt></i>, <a class="indexterm" name="id2900819"></a><i class="parameter"><tt>ldap delete dn</tt></i>, <a class="indexterm" name="id2900833"></a><i class="parameter"><tt>ldap passwd sync</tt></i>, <a class="indexterm" name="id2900847"></a><i class="parameter"><tt>ldap trust ids</tt></i>. </p><p> These are described in the <tt class="filename">smb.conf</tt> man page and so will not be repeated here. However, a sample smb.conf file for use with an LDAP directory could appear as </p><p> </p><div class="example"><a name="id2900879"></a><p class="title"><b>Example 11.2. Configuration with LDAP</b></p><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><i class="parameter"><tt>[global]</tt></i></td></tr><tr><td><i class="parameter"><tt>security = user</tt></i></td></tr><tr><td><i class="parameter"><tt>encrypt passwords = yes</tt></i></td></tr><tr><td><i class="parameter"><tt>netbios name = TASHTEGO</tt></i></td></tr><tr><td><i class="parameter"><tt>workgroup = NARNIA</tt></i></td></tr><tr><td># ldap related parameters</td></tr><tr><td># define the DN to use when binding to the directory servers</td></tr><tr><td># The password for this DN is not stored in smb.conf. Rather it</td></tr><tr><td># must be set by using 'smbpasswd -w <i class="replaceable"><tt>secretpw</tt></i>' to store the</td></tr><tr><td># passphrase in the secrets.tdb file. If the "ldap admin dn" values</td></tr><tr><td># change, this password will need to be reset.</td></tr><tr><td><i class="parameter"><tt>ldap admin dn = "cn=Samba Manager,ou=people,dc=samba,dc=org"</tt></i></td></tr><tr><td># Define the SSL option when connecting to the directory</td></tr><tr><td># ('off', 'start tls', or 'on' (default))</td></tr><tr><td><i class="parameter"><tt>ldap ssl = start tls</tt></i></td></tr><tr><td># syntax: passdb backend = ldapsam:ldap://server-name[:port]</td></tr><tr><td><i class="parameter"><tt>passdb backend = ldapsam:ldap://funball.samba.org</tt></i></td></tr><tr><td># smbpasswd -x delete the entire dn-entry</td></tr><tr><td><i class="parameter"><tt>ldap delete dn = no</tt></i></td></tr><tr><td># the machine and user suffix added to the base suffix</td></tr><tr><td># wrote WITHOUT quotes. NULL suffixes by default</td></tr><tr><td><i class="parameter"><tt>ldap user suffix = ou=People</tt></i></td></tr><tr><td><i class="parameter"><tt>ldap machine suffix = ou=Systems</tt></i></td></tr><tr><td># Trust unix account information in LDAP</td></tr><tr><td># (see the smb.conf manpage for details)</td></tr><tr><td><i class="parameter"><tt>ldap trust ids = Yes</tt></i></td></tr><tr><td># specify the base DN to use when searching the directory</td></tr><tr><td><i class="parameter"><tt>ldap suffix = "ou=people,dc=samba,dc=org"</tt></i></td></tr><tr><td># generally the default ldap search filter is ok</td></tr><tr><td><i class="parameter"><tt>ldap filter = "(&(uid=%u)(objectclass=sambaSamAccount))"</tt></i></td></tr></table></div><p> </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2901104"></a>Accounts and Groups management</h4></div></div><div></div></div><p> As users accounts are managed through the sambaSamAccount objectclass, you should modify your existing administration tools to deal with sambaSamAccount attributes. </p><p> Machines accounts are managed with the sambaSamAccount objectclass, just like users accounts. However, it's up to you to store those accounts in a different tree of your LDAP namespace: you should use "ou=Groups,dc=quenya,dc=org" to store groups and "ou=People,dc=quenya,dc=org" to store users. Just configure your NSS and PAM accordingly (usually, in the /etc/ldap.conf configuration file). </p><p> In Samba release 3.0, 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). </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2901140"></a>Security and sambaSamAccount</h4></div></div><div></div></div><p> There are two important points to remember when discussing the security of sambaSamAccount entries in the directory. </p><div class="itemizedlist"><ul type="disc"><li><p><span class="emphasis"><em>Never</em></span> retrieve the lmPassword or ntPassword attribute values over an unencrypted LDAP session.</p></li><li><p><span class="emphasis"><em>Never</em></span> allow non-admin users to view the lmPassword or ntPassword attribute values.</p></li></ul></div><p> 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 <a href="passdb.html" title="Chapter 11. Account Information Databases">Account Information Database</a> section of this chapter. </p><p> To remedy the first security issue, the <a class="indexterm" name="id2901200"></a><i class="parameter"><tt>ldap ssl</tt></i> <tt class="filename">smb.conf</tt> parameter defaults to require an encrypted session (<a class="indexterm" name="id2901222"></a><i class="parameter"><tt>ldap ssl</tt></i> = on) using the default port of <tt class="constant">636</tt> 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 (<a class="indexterm" name="id2901244"></a><i class="parameter"><tt>ldap ssl</tt></i> = off). </p><p> 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. </p><p> 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 <tt class="filename">slapd.conf</tt>: </p><p> </p><pre class="programlisting"> ## allow the "ldap admin dn" access, but deny everyone else access to attrs=lmPassword,ntPassword by dn="cn=Samba Admin,ou=people,dc=quenya,dc=org" write by * none </pre><p> </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2901300"></a>LDAP special attributes for sambaSamAccounts</h4></div></div><div></div></div><p> The sambaSamAccount objectclass is composed of the following attributes: </p><p> </p><div class="table"><a name="id2901317"></a><p class="title"><b>Table 11.1. Attributes in the sambaSamAccount objectclass (LDAP)</b></p><table summary="Attributes in the sambaSamAccount objectclass (LDAP)" border="1"><colgroup><col align="left"><col align="justify"></colgroup><tbody><tr><td align="left"><tt class="constant">sambaLMPassword</tt></td><td align="justify">the LANMAN password 16-byte hash stored as a character representation of a hexadecimal string.</td></tr><tr><td align="left"><tt class="constant">sambaNTPassword</tt></td><td align="justify">the NT password hash 16-byte stored as a character representation of a hexadecimal string.</td></tr><tr><td align="left"><tt class="constant">sambaPwdLastSet</tt></td><td align="justify">The integer time in seconds since 1970 when the <tt class="constant">sambaLMPassword</tt> and <tt class="constant">sambaNTPassword</tt> attributes were last set. </td></tr><tr><td align="left"><tt class="constant">sambaAcctFlags</tt></td><td align="justify">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).</td></tr><tr><td align="left"><tt class="constant">sambaLogonTime</tt></td><td align="justify">Integer value currently unused</td></tr><tr><td align="left"><tt class="constant">sambaLogoffTime</tt></td><td align="justify">Integer value currently unused</td></tr><tr><td align="left"><tt class="constant">sambaKickoffTime</tt></td><td align="justify">Integer value currently unused</td></tr><tr><td align="left"><tt class="constant">sambaPwdCanChange</tt></td><td align="justify">Integer value currently unused</td></tr><tr><td align="left"><tt class="constant">sambaPwdMustChange</tt></td><td align="justify">Integer value currently unused</td></tr><tr><td align="left"><tt class="constant">sambaHomeDrive</tt></td><td align="justify">specifies the drive letter to which to map the UNC path specified by sambaHomePath. 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.</td></tr><tr><td align="left"><tt class="constant">sambaLogonScript</tt></td><td align="justify">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 <a class="indexterm" name="id2901492"></a><i class="parameter"><tt>logon script</tt></i> parameter in the <tt class="filename">smb.conf</tt> man page for more information.</td></tr><tr><td align="left"><tt class="constant">sambaProfilePath</tt></td><td align="justify">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 <a class="indexterm" name="id2901527"></a><i class="parameter"><tt>logon path</tt></i> parameter in the <tt class="filename">smb.conf</tt> man page for more information.</td></tr><tr><td align="left"><tt class="constant">sambaHomePath</tt></td><td align="justify">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 <tt class="filename">\\server\share\directory</tt>. This value can be a null string. Refer to the <b class="command">logon home</b> parameter in the <tt class="filename">smb.conf</tt> man page for more information. </td></tr><tr><td align="left"><tt class="constant">sambaUserWorkstations</tt></td><td align="justify">character string value currently unused. </td></tr><tr><td align="left"><tt class="constant">sambaSID</tt></td><td align="justify">The security identifier(SID) of the user. The windows equivalent of unix uid's.</td></tr><tr><td align="left"><tt class="constant">sambaPrimaryGroupSID</tt></td><td align="justify">the relative identifier (RID) of the primary group of the user.</td></tr><tr><td align="left"><tt class="constant">sambaDomainName</tt></td><td align="justify">domain the user is part of.</td></tr></tbody></table></div><p> </p><p> The majority of these parameters are only used when Samba is acting as a PDC of a domain (refer to the <a href="samba-pdc.html" title="Chapter 5. Domain Control">Samba as a primary domain controller</a> chapter 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: </p><div class="itemizedlist"><ul type="disc"><li><p>sambaHomePath</p></li><li><p>sambaLogonScript</p></li><li><p>sambaProfilePath</p></li><li><p>sambaHomeDrive</p></li></ul></div><p> These attributes are only stored with the sambaSamAccount entry if the values are non-default values. For example, assume TASHTEGO has now been configured as a PDC and that <a class="indexterm" name="id2901683"></a><i class="parameter"><tt>logon home</tt></i> = \\%L\%u was defined in its <tt class="filename">smb.conf</tt> file. When a user named "becky" logons to the domain, the <a class="indexterm" name="id2901708"></a><i class="parameter"><tt>logon home</tt></i> 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 <a class="indexterm" name="id2901732"></a><i class="parameter"><tt>logon home</tt></i> 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. <tt class="filename">\\MOBY\becky</tt>). </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2901758"></a>Example LDIF Entries for a sambaSamAccount</h4></div></div><div></div></div><p> The following is a working LDIF with the inclusion of the posixAccount objectclass: </p><p> </p><pre class="programlisting"> dn: uid=guest2, ou=people,dc=quenya,dc=org sambaNTPassword: 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 </pre><p> </p><p> The following is an LDIF entry for using both the sambaSamAccount and posixAccount objectclasses: </p><p> </p><pre class="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/tashtego/gcarter sambaPwdCanChange: 0 sambaPwdMustChange: 2147483647 sambaNTPassword: 878D8014606CDA29677A44EFA1353FC7 </pre><p> </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2901824"></a>Password synchronisation</h4></div></div><div></div></div><p> 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. </p><p>The <a class="indexterm" name="id2901842"></a><i class="parameter"><tt>ldap passwd sync</tt></i> options can have the following values:</p><div class="variablelist"><dl><dt><span class="term">yes</span></dt><dd><p>When the user changes his password, update <tt class="constant">ntPassword</tt>, <tt class="constant">lmPassword</tt> and the <tt class="constant">password</tt> fields.</p></dd><dt><span class="term">no</span></dt><dd><p>Only update <tt class="constant">ntPassword</tt> and <tt class="constant">lmPassword</tt>.</p></dd><dt><span class="term">only</span></dt><dd><p>Only update the LDAP password and let the LDAP server worry about the other fields. This option is only available on some LDAP servers. <sup>[<a name="id2901925" href="#ftn.id2901925">3</a>]</sup></p></dd></dl></div><p>More information can be found in the smb.conf manpage. </p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2901940"></a>MySQL</h3></div></div><div></div></div><p> Every so often someone will come along with a great new idea. Storing of user accounts in an 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 can not attempt to document every nitty 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. </p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2901962"></a>Creating the database</h4></div></div><div></div></div><p> 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 <tt class="filename">examples/pdb/mysql/mysql.dump</tt> contains the correct queries to create the required tables. Use the command : </p><pre class="screen"> <tt class="prompt">$ </tt><b class="userinput"><tt>mysql -u<i class="replaceable"><tt>username</tt></i> -h<i class="replaceable"><tt>hostname</tt></i> -p<i class="replaceable"><tt>password</tt></i> \ <i class="replaceable"><tt>databasename</tt></i> < <tt class="filename">/path/to/samba/examples/pdb/mysql/mysql.dump</tt></tt></b> </pre><p> </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2902030"></a>Configuring</h4></div></div><div></div></div><p>This plugin lacks some good documentation, but here is some short info:</p><p>Add a the following to the <a class="indexterm" name="id2902046"></a><i class="parameter"><tt>passdb backend</tt></i> variable in your <tt class="filename">smb.conf</tt>: </p><table class="simplelist" border="0" summary="Simple list"><tr><td><i class="parameter"><tt>passdb backend = [other-plugins] mysql:identifier [other-plugins]</tt></i></td></tr></table><p> </p><p>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 <a class="indexterm" name="id2902089"></a><i class="parameter"><tt>passdb backend</tt></i>, you also need to use different identifiers! </p><p> Additional options can be given through the <tt class="filename">smb.conf</tt> file in the <i class="parameter"><tt>[global]</tt></i> section. </p><p> </p><div class="table"><a name="id2902128"></a><p class="title"><b>Table 11.2. Basic smb.conf options for MySQL passdb backend</b></p><table summary="Basic smb.conf options for MySQL passdb backend" border="1"><colgroup><col align="left"><col align="justify"></colgroup><thead><tr><th align="left">Field</th><th align="justify">Contents</th></tr></thead><tbody><tr><td align="left">mysql host</td><td align="justify">host name, defaults to 'localhost'</td></tr><tr><td align="left">mysql password</td><td align="justify"> </td></tr><tr><td align="left">mysql user</td><td align="justify">defaults to 'samba'</td></tr><tr><td align="left">mysql database</td><td align="justify">defaults to 'samba'</td></tr><tr><td align="left">mysql port</td><td align="justify">defaults to 3306</td></tr><tr><td align="left">table</td><td align="justify">Name of the table containing users</td></tr></tbody></table></div><p> </p><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p> Since the password for the MySQL user is stored in the <tt class="filename">smb.conf</tt> file, you should make the <tt class="filename">smb.conf</tt> file readable only to the user that runs Samba This is considered a security bug and will be fixed soon. </p></div><p>Names of the columns in this table (I've added column types those columns should have first):</p><p> </p><div class="table"><a name="id2902260"></a><p class="title"><b>Table 11.3. MySQL field names for MySQL passdb backend</b></p><table summary="MySQL field names for MySQL passdb backend" border="1"><colgroup><col align="left"><col align="left"><col align="justify"></colgroup><thead><tr><th align="left">Field</th><th align="left">Type</th><th align="justify">Contents</th></tr></thead><tbody><tr><td align="left">logon time column</td><td align="left">int(9)</td><td align="justify"> </td></tr><tr><td align="left">logoff time column</td><td align="left">int(9)</td><td align="justify"> </td></tr><tr><td align="left">kickoff time column</td><td align="left">int(9)</td><td align="justify"> </td></tr><tr><td align="left">pass last set time column</td><td align="left">int(9)</td><td align="justify"> </td></tr><tr><td align="left">pass can change time column</td><td align="left">int(9)</td><td align="justify"> </td></tr><tr><td align="left">pass must change time column</td><td align="left">int(9)</td><td align="justify"> </td></tr><tr><td align="left">username column</td><td align="left">varchar(255)</td><td align="justify">unix username</td></tr><tr><td align="left">domain column</td><td align="left">varchar(255)</td><td align="justify">NT domain user is part of</td></tr><tr><td align="left">nt username column</td><td align="left">varchar(255)</td><td align="justify">NT username</td></tr><tr><td align="left">fullname column</td><td align="left">varchar(255)</td><td align="justify">Full name of user</td></tr><tr><td align="left">home dir column</td><td align="left">varchar(255)</td><td align="justify">UNIX homedir path</td></tr><tr><td align="left">dir drive column</td><td align="left">varchar(2)</td><td align="justify">Directory drive path (eg: 'H:')</td></tr><tr><td align="left">logon script column</td><td align="left">varchar(255)</td><td align="justify">Batch file to run on client side when logging on</td></tr><tr><td align="left">profile path column</td><td align="left">varchar(255)</td><td align="justify">Path of profile</td></tr><tr><td align="left">acct desc column</td><td align="left">varchar(255)</td><td align="justify">Some ASCII NT user data</td></tr><tr><td align="left">workstations column</td><td align="left">varchar(255)</td><td align="justify">Workstations user can logon to (or NULL for all)</td></tr><tr><td align="left">unknown string column</td><td align="left">varchar(255)</td><td align="justify">unknown string</td></tr><tr><td align="left">munged dial column</td><td align="left">varchar(255)</td><td align="justify">?</td></tr><tr><td align="left">user sid column</td><td align="left">varchar(255)</td><td align="justify">NT user SID</td></tr><tr><td align="left">group sid column</td><td align="left">varchar(255)</td><td align="justify">NT group ID</td></tr><tr><td align="left">lanman pass column</td><td align="left">varchar(255)</td><td align="justify">encrypted lanman password</td></tr><tr><td align="left">nt pass column</td><td align="left">varchar(255)</td><td align="justify">encrypted nt passwd</td></tr><tr><td align="left">plain pass column</td><td align="left">varchar(255)</td><td align="justify">plaintext password</td></tr><tr><td align="left">acct control column</td><td align="left">int(9)</td><td align="justify">nt user data</td></tr><tr><td align="left">unknown 3 column</td><td align="left">int(9)</td><td align="justify">unknown</td></tr><tr><td align="left">logon divs column</td><td align="left">int(9)</td><td align="justify">?</td></tr><tr><td align="left">hours len column</td><td align="left">int(9)</td><td align="justify">?</td></tr><tr><td align="left">unknown 5 column</td><td align="left">int(9)</td><td align="justify">unknown</td></tr><tr><td align="left">unknown 6 column</td><td align="left">int(9)</td><td align="justify">unknown</td></tr></tbody></table></div><p> </p><p> 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. </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2902649"></a>Using plaintext passwords or encrypted password</h4></div></div><div></div></div><p> I strongly discourage the use of plaintext passwords, however, you can use them: </p><p> 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. </p><p> If you use encrypted passwords, set the 'identifier:plain pass column' to 'NULL' (without the quotes). This is the default. </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2902679"></a>Getting non-column data from the table</h4></div></div><div></div></div><p> It is possible to have not all data in the database and making some 'constant'. </p><p> For example, you can set 'identifier:fullname column' to : <b class="command">CONCAT(First_name,' ',Sur_name)</b> </p><p> Or, set 'identifier:workstations column' to : <b class="command">NULL</b></p><p>See the MySQL documentation for more language constructs.</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="XMLpassdb"></a>XML</h3></div></div><div></div></div><p>This module requires libxml2 to be installed.</p><p>The usage of pdb_xml is pretty straightforward. To export data, use: </p><p> <tt class="prompt">$ </tt> <b class="userinput"><tt>pdbedit -e xml:filename</tt></b> </p><p> (where filename is the name of the file to put the data in) </p><p> To import data, use: <tt class="prompt">$ </tt> <b class="userinput"><tt>pdbedit -i xml:filename</tt></b> </p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2902790"></a>Common Errors</h2></div></div><div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2902796"></a>Users can not logon</h3></div></div><div></div></div><p>“<span class="quote">I've installed samba, but now I can't log on with my unix account!</span>”</p><p>Make sure your user has been added to the current samba <a class="indexterm" name="id2902813"></a><i class="parameter"><tt>passdb backend</tt></i>. Read the section <a href="passdb.html#acctmgmttools" title="Account Management Tools">Account Management Tools</a> for details.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2902841"></a>Users being added to wrong backend database</h3></div></div><div></div></div><p> A few complaints have been received from users that just moved to Samba-3. The following <tt class="filename">smb.conf</tt> file entries were causing problems, new accounts were being added to the old smbpasswd file, not to the tdbsam passdb.tdb file: </p><p> </p><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><i class="parameter"><tt>[global]</tt></i></td></tr><tr><td>...</td></tr><tr><td><i class="parameter"><tt>passdb backend = smbpasswd, tdbsam</tt></i></td></tr><tr><td>...</td></tr></table><p> </p><p> Samba will add new accounts to the first entry in the <span class="emphasis"><em>passdb backend</em></span> parameter entry. If you want to update to the tdbsam, then change the entry to: </p><p> </p><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><i class="parameter"><tt>[globals]</tt></i></td></tr><tr><td>...</td></tr><tr><td><i class="parameter"><tt>passdb backend = tdbsam, smbpasswd</tt></i></td></tr><tr><td>...</td></tr></table><p> </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2902952"></a>auth methods does not work</h3></div></div><div></div></div><p> If you explicitly set an <a class="indexterm" name="id2902963"></a><i class="parameter"><tt>auth methods</tt></i> parameter, guest must be specified as the first entry on the line. Eg: <a class="indexterm" name="id2902979"></a><i class="parameter"><tt>auth methods</tt></i> = guest sam. </p><p> This is the exact opposite of the requirement for the <a class="indexterm" name="id2902998"></a><i class="parameter"><tt>passdb backend</tt></i> option, where it must be the <span class="emphasis"><em>LAST</em></span> parameter on the line. </p></div></div><div class="footnotes"><br><hr width="100" align="left"><div class="footnote"><p><sup>[<a name="ftn.id2901925" href="#id2901925">3</a>] </sup>Only when the LDAP server supports LDAP_EXOP_X_MODIFY_PASSWD</p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="NetworkBrowsing.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="optional.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="groupmapping.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 10. 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