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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 10. User information database</title><link rel="stylesheet" href="samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.59.1"><link rel="home" href="index.html" title="SAMBA Project Documentation"><link rel="up" href="optional.html" title="Part III. Advanced Configuration"><link rel="previous" href="NetworkBrowsing.html" title="Chapter 9. Samba / MS Windows Network Browsing Guide"><link rel="next" href="unix-permissions.html" title="Chapter 11. UNIX Permission Bits and Windows NT Access Control Lists"></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 10. User information database</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="unix-permissions.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><h2 class="title"><a name="passdb"></a>Chapter 10. User information database</h2></div><div><div class="author"><h3 class="author">Jelmer R. Vernooij</h3><div class="affiliation"><span class="orgname">The Samba Team<br></span><div class="address"><p><tt><<a href="mailto:jelmer@samba.org">jelmer@samba.org</a>></tt></p></div></div></div></div><div><div class="author"><h3 class="author">Gerald (Jerry) Carter</h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt><<a href="mailto:jerry@samba.org">jerry@samba.org</a>></tt></p></div></div></div></div><div><div class="author"><h3 class="author">Jeremy Allison</h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt><<a href="mailto:jra@samba.org">jra@samba.org</a>></tt></p></div></div></div></div><div><div class="author"><h3 class="author">John H. Terpstra</h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt><<a href="mailto:jht@samba.org">jht@samba.org</a>></tt></p></div></div></div></div><div><div class="author"><h3 class="author">Olivier (lem) Lemaire</h3><div class="affiliation"><span class="orgname">IDEALX<br></span><div class="address"><p><tt><<a href="mailto:olem@IDEALX.org">olem@IDEALX.org</a>></tt></p></div></div></div></div><div><p class="pubdate">February 2003</p></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><a href="passdb.html#id2882995">Introduction</a></dt><dt><a href="passdb.html#id2883048">Important Notes About Security</a></dt><dd><dl><dt><a href="passdb.html#id2883210">Advantages of SMB Encryption</a></dt><dt><a href="passdb.html#id2883249">Advantages of non-encrypted passwords</a></dt></dl></dd><dt><a href="passdb.html#id2883283">The smbpasswd Command</a></dt><dt><a href="passdb.html#id2883464">Plain text</a></dt><dt><a href="passdb.html#id2883493">TDB</a></dt><dt><a href="passdb.html#id2883509">LDAP</a></dt><dd><dl><dt><a href="passdb.html#id2883516">Introduction</a></dt><dt><a href="passdb.html#id2883617">Encrypted Password Database</a></dt><dt><a href="passdb.html#id2883756">Supported LDAP Servers</a></dt><dt><a href="passdb.html#id2883794">Schema and Relationship to the RFC 2307 posixAccount</a></dt><dt><a href="passdb.html#id2883904">Configuring Samba with LDAP</a></dt><dt><a href="passdb.html#id2884200">Accounts and Groups management</a></dt><dt><a href="passdb.html#id2884237">Security and sambaAccount</a></dt><dt><a href="passdb.html#id2884352">LDAP specials attributes for sambaAccounts</a></dt><dt><a href="passdb.html#id2884633">Example LDIF Entries for a sambaAccount</a></dt></dl></dd><dt><a href="passdb.html#id2884689">MySQL</a></dt><dd><dl><dt><a href="passdb.html#id2884696">Creating the database</a></dt><dt><a href="passdb.html#id2884750">Configuring</a></dt><dt><a href="passdb.html#id2884895">Using plaintext passwords or encrypted password</a></dt><dt><a href="passdb.html#id2884925">Getting non-column data from the table</a></dt></dl></dd><dt><a href="passdb.html#id2884968">XML</a></dt></dl></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2882995"></a>Introduction</h2></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 only send 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>Next to a 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 his/her
profile is stored, etc.
Samba retrieves and stores this information using a "passdb backend".
Commonly
available backends are LDAP, plain text file, MySQL and nisplus.
For more information, see the documentation about the
<b>passdb backend = </b> parameter.
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2883048"></a>Important Notes About Security</h2></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 which neither requires
plain text passwords on the net or on disk. Unfortunately this
is not available as Samba is stuck with being compatible with
other SMB systems (WinNT, WfWg, Win95 etc). </p><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>Note that Windows NT 4.0 Service pack 3 changed the
default for permissible authentication so that plaintext
passwords are <span class="emphasis"><em>never</em></span> sent over the wire.
The solution to this is either to switch to encrypted passwords
with Samba or edit the Windows NT registry to re-enable plaintext
passwords. See the document WinNT.txt for details on how to do
this.</p><p>Other Microsoft operating systems which also exhibit
this behavior includes</p><p> These versions of MS Windows do not support full domain
security protocols, although they may log onto a domain environment.
Of these Only MS Windows XP Home does NOT support domain logons.</p><table class="simplelist" border="0" summary="Simple list"><tr><td>MS DOS Network client 3.0 with
the basic network redirector installed</td></tr><tr><td>Windows 95 with the network redirector
update installed</td></tr><tr><td>Windows 98 [se]</td></tr><tr><td>Windows Me</td></tr><tr><td>Windows XP Home</td></tr></table><p> The following versions of MS Windows fully support domain
security protocols.</p><table class="simplelist" border="0" summary="Simple list"><tr><td>Windows NT 3.5x</td></tr><tr><td>Windows NT 4.0</td></tr><tr><td>Windows 2000 Professional</td></tr><tr><td>Windows 200x Server/Advanced Server</td></tr><tr><td>Windows XP Professional</td></tr></table></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><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.</p></div><p>MS Windows clients will cache the encrypted password alone.
Even when 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="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2883210"></a>Advantages of SMB Encryption</h3></div></div><table class="simplelist" border="0" summary="Simple list"><tr><td>Plain text passwords are not passed across
the network. Someone using a network sniffer cannot just
record passwords going to the SMB server.</td></tr><tr><td>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.
</td></tr><tr><td>Encrypted password support allows automatic share
(resource) reconnects.</td></tr></table></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2883249"></a>Advantages of non-encrypted passwords</h3></div></div><table class="simplelist" border="0" summary="Simple list"><tr><td>Plain text passwords are not kept
on disk, and are NOT cached in memory. </td></tr><tr><td>Uses same password file as other unix
services such as login and ftp</td></tr><tr><td>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.</td></tr></table></div></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2883283"></a>The smbpasswd Command</h2></div></div><p>The smbpasswd utility is a utility similar to the
<b>passwd</b> or <b>yppasswd</b> programs.
It maintains the two 32 byte password fields in the passdb backend. </p><p><b>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>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 you
are changing an NT Domain user's password).</p><p>To run smbpasswd as a normal user just type :</p><p><tt>$ </tt><b><tt>smbpasswd</tt></b></p><p><tt>Old SMB password: </tt><b><tt><type old value here -
or hit return if there was no old password></tt></b></p><p><tt>New SMB Password: </tt><b><tt><type new value>
</tt></b></p><p><tt>Repeat New SMB Password: </tt><b><tt><re-type new value
</tt></b></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>If invoked by an ordinary user it will only allow the user
to change his or her own Samba password.</p><p>If run by the root user smbpasswd may take an optional
argument, specifying the user name whose SMB password you wish to
change. Note that 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>smbpasswd</b> is designed to work in the same way
and be familiar to UNIX users who use the <b>passwd</b> or
<b>yppasswd</b> commands.</p><p>For more details on using <b>smbpasswd</b> refer
to the man page which will always be the definitive reference.</p></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2883464"></a>Plain text</h2></div></div><p>
Older versions of samba retrieved user information from the unix user database
and eventually some other fields from the file <tt>/etc/samba/smbpasswd</tt>
or <tt>/etc/smbpasswd</tt>. When password encryption is disabled, no
data is stored at all.
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2883493"></a>TDB</h2></div></div><p>Samba can also store the user data in a "TDB" (Trivial Database). Using this backend
doesn't require any additional configuration. This backend is recommended for new installations that
don not require LDAP.
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2883509"></a>LDAP</h2></div></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2883516"></a>Introduction</h3></div></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>
Note that <a href="http://www.ora.com/" target="_top">O'Reilly Publishing</a> is working on
a guide to LDAP for System Administrators which has a planned release date of
early summer, 2002.
</p><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><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2883617"></a>Encrypted Password Database</h3></div></div><p>
Traditionally, when configuring <a href="smb.conf.5.html#ENCRYPTPASSWORDS" target="_top">"encrypt
passwords = yes"</a> in Samba's <tt>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>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 desired to replicate a
smbpasswd file to more than one Samba server were left to use external
tools such as <b>rsync(1)</b> and <b>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
Identified (RID).
</p></li></ul></div><p>
As a result of these defeciencies, a more robust means of storing user attributes
used by smbd was developed. The API which defines access to user accounts
is commonly referred to as the samdb interface (previously this was called the passdb
API, and is still so named in the CVS trees).
</p><p>
There are a few points to stress about 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 2000 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".
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2883756"></a>Supported LDAP Servers</h3></div></div><p>
The LDAP samdb code in 2.2.3 (and later) has been developed and tested
using the OpenLDAP 2.0 server and client libraries.
The same code should be able to work with Netscape's Directory Server
and client SDK. However, due to lack of testing so far, there are bound
to be compile errors and bugs. These should not be hard to fix.
If you are so inclined, please be sure to forward all patches to
<a href="mailto:samba-patches@samba.org" target="_top">samba-patches@samba.org</a> and
<a href="mailto:jerry@samba.org" target="_top">jerry@samba.org</a>.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2883794"></a>Schema and Relationship to the RFC 2307 posixAccount</h3></div></div><p>
Samba 3.0 includes the necessary schema file for OpenLDAP 2.0 in
<tt>examples/LDAP/samba.schema</tt>. The sambaAccount objectclass is given here:
</p><pre class="programlisting">
objectclass ( 1.3.1.5.1.4.1.7165.2.2.2 NAME 'sambaAccount' SUP top AUXILIARY
DESC 'Samba Account'
MUST ( uid $ rid )
MAY ( cn $ lmPassword $ ntPassword $ pwdLastSet $ logonTime $
logoffTime $ kickoffTime $ pwdCanChange $ pwdMustChange $ acctFlags $
displayName $ smbHome $ homeDrive $ scriptPath $ profilePath $
description $ userWorkstations $ primaryGroupID $ domain ))
</pre><p>
The samba.schema file has been formatted for OpenLDAP 2.0. 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>/etc/passwd</tt> entry, so is the sambaAccount object
meant to supplement the UNIX user account information. A sambaAccount is a
<tt>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 sambaAccount and posixAccount objectclasses in
combination. However, smbd will still obtain the user's UNIX account
information via the standard C library calls (e.g. getpwnam(), et. al.).
This means that the Samba server must also have the LDAP NSS library installed
and functioning correctly. This division of information makes it possible to
store all Samba account information in LDAP, but still maintain UNIX account
information in NIS while the network is transitioning to a full LDAP infrastructure.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2883904"></a>Configuring Samba with LDAP</h3></div></div><div class="sect3" lang="en"><div class="titlepage"><div><h4 class="title"><a name="id2883912"></a>OpenLDAP configuration</h4></div></div><p>
To include support for the sambaAccount object in an OpenLDAP directory
server, first copy the samba.schema file to slapd's configuration directory.
</p><p>
<tt>root# </tt><b><tt>cp samba.schema /etc/openldap/schema/</tt></b>
</p><p>
Next, include the <tt>samba.schema</tt> file in <tt>slapd.conf</tt>.
The sambaAccount object contains two attributes which depend upon other schema
files. The 'uid' attribute is defined in <tt>cosine.schema</tt> and
the 'displayName' attribute is defined in the <tt>inetorgperson.schema</tt>
file. Both of these must be included before the <tt>samba.schema</tt> file.
</p><pre class="programlisting">
## /etc/openldap/slapd.conf
## schema files (core.schema is required by default)
include /etc/openldap/schema/core.schema
## needed for sambaAccount
include /etc/openldap/schema/cosine.schema
include /etc/openldap/schema/inetorgperson.schema
include /etc/openldap/schema/samba.schema
include /etc/openldap/schema/nis.schema
....
</pre><p>
It is recommended that you maintain some indices on some of the most usefull attributes,
like in the following example, to speed up searches made on sambaAccount objectclasses
(and possibly posixAccount and posixGroup as well).
</p><pre class="programlisting">
# Indices to maintain
## required by OpenLDAP 2.0
index objectclass eq
## support pb_getsampwnam()
index uid pres,eq
## support pdb_getsambapwrid()
index rid eq
## uncomment these if you are storing posixAccount and
## posixGroup entries in the directory as well
##index uidNumber eq
##index gidNumber eq
##index cn eq
##index memberUid eq
# (both fetched via ldapsearch):
index primaryGroupID eq
index displayName pres,eq
</pre></div><div class="sect3" lang="en"><div class="titlepage"><div><h4 class="title"><a name="id2884030"></a>Configuring Samba</h4></div></div><p>
The following parameters are available in smb.conf only with <i><tt>--with-ldapsam</tt></i>
was included when compiling Samba.
</p><div class="itemizedlist"><ul type="disc"><li><p><a href="smb.conf.5.html#PASSDBBACKEND" target="_top">passdb backend [ldapsam|ldapsam_nua]:url</a></p></li><li><p><a href="smb.conf.5.html#LDAPSSL" target="_top">ldap ssl</a></p></li><li><p><a href="smb.conf.5.html#LDAPADMINDN" target="_top">ldap admin dn</a></p></li><li><p><a href="smb.conf.5.html#LDAPSUFFIX" target="_top">ldap suffix</a></p></li><li><p><a href="smb.conf.5.html#LDAPFILTER" target="_top">ldap filter</a></p></li><li><p><a href="smb.conf.5.html#LDAPPORT" target="_top">ldap port</a></p></li><li><p><a href="smb.conf.5.html#LDAPMACHINSUFFIX" target="_top">ldap machine suffix</a></p></li><li><p><a href="smb.conf.5.html#LDAPUSERSUFFIX" target="_top">ldap user suffix</a></p></li><li><p><a href="smb.conf.5.html#LDAPDELETEDN" target="_top">ldap delete dn</a></p></li></ul></div><p>
These are described in the <a href="smb.conf.5.html" target="_top">smb.conf(5)</a> 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><pre class="programlisting">
## /usr/local/samba/lib/smb.conf
[global]
security = user
encrypt passwords = yes
netbios name = TASHTEGO
workgroup = NARNIA
# ldap related parameters
# define the DN to use when binding to the directory servers
# The password for this DN is not stored in smb.conf. Rather it
# must be set by using 'smbpasswd -w <i><tt>secretpw</tt></i>' to store the
# passphrase in the secrets.tdb file. If the "ldap admin dn" values
# change, this password will need to be reset.
ldap admin dn = "cn=Samba Manager,ou=people,dc=samba,dc=org"
# Define the SSL option when connecting to the directory
# ('off', 'start tls', or 'on' (default))
ldap ssl = start tls
passdb backend ldapsam:ldap://ahab.samba.org
# smbpasswd -x delete the entire dn-entry
ldap delete dn = no
# the machine and user suffix added to the base suffix
# wrote WITHOUT quotes. NULL siffixes by default
ldap user suffix = ou=People
ldap machine suffix = ou=Systems
# define the port to use in the LDAP session (defaults to 636 when
# "ldap ssl = on")
ldap port = 389
# specify the base DN to use when searching the directory
ldap suffix = "ou=people,dc=samba,dc=org"
# generally the default ldap search filter is ok
# ldap filter = "(&(uid=%u)(objectclass=sambaAccount))"
</pre></div></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2884200"></a>Accounts and Groups management</h3></div></div><p>
As users accounts are managed thru the sambaAccount objectclass, you should
modify your existing administration tools to deal with sambaAccount attributes.
</p><p>
Machines accounts are managed with the sambaAccount objectclass, just
like users accounts. However, it's up to you to store thoses accounts
in a different tree of you LDAP namespace: you should use
"ou=Groups,dc=plainjoe,dc=org" to store groups and
"ou=People,dc=plainjoe,dc=org" to store users. Just configure your
NSS and PAM accordingly (usually, in the /etc/ldap.conf configuration
file).
</p><p>
In Samba release 3.0, the group management system is based on posix
groups. This means that Samba makes usage of the posixGroup objectclass.
For now, there is no NT-like group system management (global and local
groups).
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2884237"></a>Security and sambaAccount</h3></div></div><p>
There are two important points to remember when discussing the security
of sambaAccount 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 10. User information database">User Database</a> of the Samba-HOWTO-Collection.
</p><p>
To remedy the first security issue, the "ldap ssl" smb.conf parameter defaults
to require an encrypted session (<b>ldap ssl = on</b>) using
the default port of 636
when contacting the directory server. When using an OpenLDAP 2.0 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
(<b>ldap ssl = off</b>).
</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>slapd.conf</tt>:
</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=plainjoe,dc=org" write
by * none
</pre></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2884352"></a>LDAP specials attributes for sambaAccounts</h3></div></div><p>
The sambaAccount objectclass is composed of the following attributes:
</p><div class="itemizedlist"><ul type="disc"><li><p><tt>lmPassword</tt>: the LANMAN password 16-byte hash stored as a character
representation of a hexidecimal string.</p></li><li><p><tt>ntPassword</tt>: the NT password hash 16-byte stored as a character
representation of a hexidecimal string.</p></li><li><p><tt>pwdLastSet</tt>: The integer time in seconds since 1970 when the
<tt>lmPassword</tt> and <tt>ntPassword</tt> attributes were last set.
</p></li><li><p><tt>acctFlags</tt>: string of 11 characters surrounded by square brackets []
representing account flags such as U (user), W(workstation), X(no password expiration), and
D(disabled).</p></li><li><p><tt>logonTime</tt>: Integer value currently unused</p></li><li><p><tt>logoffTime</tt>: Integer value currently unused</p></li><li><p><tt>kickoffTime</tt>: Integer value currently unused</p></li><li><p><tt>pwdCanChange</tt>: Integer value currently unused</p></li><li><p><tt>pwdMustChange</tt>: Integer value currently unused</p></li><li><p><tt>homeDrive</tt>: specifies the drive letter to which to map the
UNC path specified by homeDirectory. The drive letter must be specified in the form "X:"
where X is the letter of the drive to map. Refer to the "logon drive" parameter in the
smb.conf(5) man page for more information.</p></li><li><p><tt>scriptPath</tt>: The scriptPath property specifies the path of
the user's logon script, .CMD, .EXE, or .BAT file. The string can be null. The path
is relative to the netlogon share. Refer to the "logon script" parameter in the
smb.conf(5) man page for more information.</p></li><li><p><tt>profilePath</tt>: specifies a path to the user's profile.
This value can be a null string, a local absolute path, or a UNC path. Refer to the
"logon path" parameter in the smb.conf(5) man page for more information.</p></li><li><p><tt>smbHome</tt>: The homeDirectory property specifies the path of
the home directory for the user. The string can be null. If homeDrive is set and specifies
a drive letter, homeDirectory should be a UNC path. The path must be a network
UNC path of the form \\server\share\directory. This value can be a null string.
Refer to the "logon home" parameter in the smb.conf(5) man page for more information.
</p></li><li><p><tt>userWorkstation</tt>: character string value currently unused.
</p></li><li><p><tt>rid</tt>: the integer representation of the user's relative identifier
(RID).</p></li><li><p><tt>primaryGroupID</tt>: the relative identifier (RID) of the primary group
of the user.</p></li></ul></div><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-HOWTO.html" target="_top">Samba-PDC-HOWTO</a> for details on
how to configure Samba as a Primary Domain Controller). The following four attributes
are only stored with the sambaAccount entry if the values are non-default values:
</p><div class="itemizedlist"><ul type="disc"><li><p>smbHome</p></li><li><p>scriptPath</p></li><li><p>logonPath</p></li><li><p>homeDrive</p></li></ul></div><p>
These attributes are only stored with the sambaAccount entry if
the values are non-default values. For example, assume TASHTEGO has now been
configured as a PDC and that <b>logon home = \\%L\%u</b> was defined in
its <tt>smb.conf</tt> file. When a user named "becky" logons to the domain,
the <i><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 <i><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. \\MOBY\becky).
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2884633"></a>Example LDIF Entries for a sambaAccount</h3></div></div><p>
The following is a working LDIF with the inclusion of the posixAccount objectclass:
</p><pre class="programlisting">
dn: uid=guest2, ou=people,dc=plainjoe,dc=org
ntPassword: 878D8014606CDA29677A44EFA1353FC7
pwdMustChange: 2147483647
primaryGroupID: 1201
lmPassword: 552902031BEDE9EFAAD3B435B51404EE
pwdLastSet: 1010179124
logonTime: 0
objectClass: sambaAccount
uid: guest2
kickoffTime: 2147483647
acctFlags: [UX ]
logoffTime: 2147483647
rid: 19006
pwdCanChange: 0
</pre><p>
The following is an LDIF entry for using both the sambaAccount and
posixAccount objectclasses:
</p><pre class="programlisting">
dn: uid=gcarter, ou=people,dc=plainjoe,dc=org
logonTime: 0
displayName: Gerald Carter
lmPassword: 552902031BEDE9EFAAD3B435B51404EE
primaryGroupID: 1201
objectClass: posixAccount
objectClass: sambaAccount
acctFlags: [UX ]
userPassword: {crypt}BpM2ej8Rkzogo
uid: gcarter
uidNumber: 9000
cn: Gerald Carter
loginShell: /bin/bash
logoffTime: 2147483647
gidNumber: 100
kickoffTime: 2147483647
pwdLastSet: 1010179230
rid: 19000
homeDirectory: /home/tashtego/gcarter
pwdCanChange: 0
pwdMustChange: 2147483647
ntPassword: 878D8014606CDA29677A44EFA1353FC7
</pre></div></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2884689"></a>MySQL</h2></div></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2884696"></a>Creating the database</h3></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>examples/pdb/mysql/mysql.dump</tt>
contains the correct queries to create the required tables. Use the command :
<b>mysql -u<i><tt>username</tt></i> -h<i><tt>hostname</tt></i> -p<i><tt>password</tt></i> <i><tt>databasename</tt></i> > <tt>/path/to/samba/examples/pdb/mysql/mysql.dump</tt></b>
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2884750"></a>Configuring</h3></div></div><p>This plugin lacks some good documentation, but here is some short info:</p><p>Add a the following to the <b>passdb backend</b> variable in your <tt>smb.conf</tt>:
</p><pre class="programlisting">
passdb backend = [other-plugins] mysql:identifier [other-plugins]
</pre><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 'passdb backend', you also need to
use different identifiers!
</p><p>
Additional options can be given thru the smb.conf file in the [global] section.
</p><pre class="programlisting">
identifier:mysql host - host name, defaults to 'localhost'
identifier:mysql password
identifier:mysql user - defaults to 'samba'
identifier:mysql database - defaults to 'samba'
identifier:mysql port - defaults to 3306
identifier:table - Name of the table containing users
</pre><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
smb.conf file, you should make the the smb.conf file
readable only to the user that runs samba. This is considered a security
bug and will be fixed soon.
</p></div><p>Names of the columns in this table(I've added column types those columns should have first):</p><pre class="programlisting">
identifier:logon time column - int(9)
identifier:logoff time column - int(9)
identifier:kickoff time column - int(9)
identifier:pass last set time column - int(9)
identifier:pass can change time column - int(9)
identifier:pass must change time column - int(9)
identifier:username column - varchar(255) - unix username
identifier:domain column - varchar(255) - NT domain user is part of
identifier:nt username column - varchar(255) - NT username
identifier:fullname column - varchar(255) - Full name of user
identifier:home dir column - varchar(255) - Unix homedir path
identifier:dir drive column - varchar(2) - Directory drive path (eg: 'H:')
identifier:logon script column - varchar(255)
- Batch file to run on client side when logging on
identifier:profile path column - varchar(255) - Path of profile
identifier:acct desc column - varchar(255) - Some ASCII NT user data
identifier:workstations column - varchar(255)
- Workstations user can logon to (or NULL for all)
identifier:unknown string column - varchar(255) - unknown string
identifier:munged dial column - varchar(255) - ?
identifier:user sid column - varchar(255) - NT user SID
identifier:group sid column - varchar(255) - NT group ID
identifier:lanman pass column - varchar(255) - encrypted lanman password
identifier:nt pass column - varchar(255) - encrypted nt passwd
identifier:plain pass column - varchar(255) - plaintext password
identifier:acct control column - int(9) - nt user data
identifier:unknown 3 column - int(9) - unknown
identifier:logon divs column - int(9) - ?
identifier:hours len column - int(9) - ?
identifier:unknown 5 column - int(9) - unknown
identifier:unknown 6 column - int(9) - unknown
</pre><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="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2884895"></a>Using plaintext passwords or encrypted password</h3></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="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2884925"></a>Getting non-column data from the table</h3></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>CONCAT(First_name,' ',Sur_name)</b>
</p><p>
Or, set 'identifier:workstations column' to :
<b>NULL</b></p><p>See the MySQL documentation for more language constructs.</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2884968"></a>XML</h2></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>
<b><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:
<b><tt>pdbedit -i xml:filename -e current-pdb</tt></b>
</p><p>
Where filename is the name to read the data from and current-pdb to put it in.
</p></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="unix-permissions.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 9. Samba / MS Windows Network Browsing Guide </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 11. UNIX Permission Bits and Windows NT Access Control Lists</td></tr></table></div></body></html>
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