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   2 <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 15. Unified Logons between Windows NT and UNIX using Winbind</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="CUPS-printing.html" title="Chapter 14. CUPS Printing Support"><link rel="next" href="AdvancedNetworkManagement.html" title="Chapter 16. Advanced Network Manangement"></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 15. Unified Logons between Windows NT and UNIX using Winbind</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="CUPS-printing.html">Prev</a> </td><th width="60%" align="center">Part III. Advanced Configuration</th><td width="20%" align="right"> <a accesskey="n" href="AdvancedNetworkManagement.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><h2 class="title"><a name="winbind"></a>Chapter 15. Unified Logons between Windows NT and UNIX using Winbind</h2></div><div><div class="authorgroup"><div class="author"><h3 class="author">Tim Potter</h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt>&lt;<a href="mailto:tpot@linuxcare.com.au">tpot@linuxcare.com.au</a>&gt;</tt></p></div></div></div><div class="author"><h3 class="author">Andrew Tridgell</h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt>&lt;<a href="mailto:tridge@samba.org">tridge@samba.org</a>&gt;</tt></p></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>&lt;<a href="mailto:jht@samba.org">jht@samba.org</a>&gt;</tt></p></div></div></div><div class="author"><h3 class="author">Naag Mummaneni</h3><div class="affiliation"><div class="address"><p><tt>&lt;<a href="mailto:getnag@rediffmail.com">getnag@rediffmail.com</a>&gt;</tt></p></div></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>&lt;<a href="mailto:jelmer@samba.org">jelmer@samba.org</a>&gt;</tt></p></div></div></div></div></div><div><p class="pubdate">27 June 2002</p></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><a href="winbind.html#id2891610">Abstract</a></dt><dt><a href="winbind.html#id2891639">Introduction</a></dt><dt><a href="winbind.html#id2891710">What Winbind Provides</a></dt><dd><dl><dt><a href="winbind.html#id2888972">Target Uses</a></dt></dl></dd><dt><a href="winbind.html#id2889003">How Winbind Works</a></dt><dd><dl><dt><a href="winbind.html#id2889031">Microsoft Remote Procedure Calls</a></dt><dt><a href="winbind.html#id2889066">Microsoft Active Directory Services</a></dt><dt><a href="winbind.html#id2889088">Name Service Switch</a></dt><dt><a href="winbind.html#id2892176">Pluggable Authentication Modules</a></dt><dt><a href="winbind.html#id2892248">User and Group ID Allocation</a></dt><dt><a href="winbind.html#id2892282">Result Caching</a></dt></dl></dd><dt><a href="winbind.html#id2892310">Installation and Configuration</a></dt><dd><dl><dt><a href="winbind.html#id2892338">Introduction</a></dt><dt><a href="winbind.html#id2892413">Requirements</a></dt><dt><a href="winbind.html#id2892507">Testing Things Out</a></dt></dl></dd><dt><a href="winbind.html#id2894106">Limitations</a></dt><dt><a href="winbind.html#id2894160">Conclusion</a></dt></dl></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2891610"></a>Abstract</h2></div></div><p>Integration of UNIX and Microsoft Windows NT through
   3         a unified logon has been considered a &quot;holy grail&quot; in heterogeneous
   4         computing environments for a long time. We present
   5         <span class="emphasis"><em>winbind</em></span>, a component of the Samba suite
   6         of programs as a solution to the unified logon problem. Winbind
   7         uses a UNIX implementation
   8         of Microsoft RPC calls, Pluggable Authentication Modules, and the Name
   9         Service Switch to allow Windows NT domain users to appear and operate
  10         as UNIX users on a UNIX machine. This paper describes the winbind
  11         system, explaining the functionality it provides, how it is configured,
  12         and how it works internally.</p></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2891639"></a>Introduction</h2></div></div><p>It is well known that UNIX and Microsoft Windows NT have
  13         different models for representing user and group information and
  14         use different technologies for implementing them. This fact has
  15         made it difficult to integrate the two systems in a satisfactory
  16         manner.</p><p>One common solution in use today has been to create
  17         identically named user accounts on both the UNIX and Windows systems
  18         and use the Samba suite of programs to provide file and print services
  19         between the two. This solution is far from perfect however, as
  20         adding and deleting users on both sets of machines becomes a chore
  21         and two sets of passwords are required both of which
  22         can lead to synchronization problems between the UNIX and Windows
  23         systems and confusion for users.</p><p>We divide the unified logon problem for UNIX machines into
  24         three smaller problems:</p><div class="itemizedlist"><ul type="disc"><li><p>Obtaining Windows NT user and group information
  25                 </p></li><li><p>Authenticating Windows NT users
  26                 </p></li><li><p>Password changing for Windows NT users
  27                 </p></li></ul></div><p>Ideally, a prospective solution to the unified logon problem
  28         would satisfy all the above components without duplication of
  29         information on the UNIX machines and without creating additional
  30         tasks for the system administrator when maintaining users and
  31         groups on either system. The winbind system provides a simple
  32         and elegant solution to all three components of the unified logon
  33         problem.</p></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2891710"></a>What Winbind Provides</h2></div></div><p>Winbind unifies UNIX and Windows NT account management by
  34         allowing a UNIX box to become a full member of a NT domain. Once
  35         this is done the UNIX box will see NT users and groups as if
  36         they were native UNIX users and groups, allowing the NT domain
  37         to be used in much the same manner that NIS+ is used within
  38         UNIX-only environments.</p><p>The end result is that whenever any
  39         program on the UNIX machine asks the operating system to lookup
  40         a user or group name, the query will be resolved by asking the
  41         NT domain controller for the specified domain to do the lookup.
  42         Because Winbind hooks into the operating system at a low level
  43         (via the NSS name resolution modules in the C library) this
  44         redirection to the NT domain controller is completely
  45         transparent.</p><p>Users on the UNIX machine can then use NT user and group
  46         names as they would use &quot;native&quot; UNIX names. They can chown files
  47         so that they are owned by NT domain users or even login to the
  48         UNIX machine and run a UNIX X-Window session as a domain user.</p><p>The only obvious indication that Winbind is being used is
  49         that user and group names take the form DOMAIN\user and
  50         DOMAIN\group. This is necessary as it allows Winbind to determine
  51         that redirection to a domain controller is wanted for a particular
  52         lookup and which trusted domain is being referenced.</p><p>Additionally, Winbind provides an authentication service
  53         that hooks into the Pluggable Authentication Modules (PAM) system
  54         to provide authentication via a NT domain to any PAM enabled
  55         applications. This capability solves the problem of synchronizing
  56         passwords between systems since all passwords are stored in a single
  57         location (on the domain controller).</p><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2888972"></a>Target Uses</h3></div></div><p>Winbind is targeted at organizations that have an
  58                 existing NT based domain infrastructure into which they wish
  59                 to put UNIX workstations or servers. Winbind will allow these
  60                 organizations to deploy UNIX workstations without having to
  61                 maintain a separate account infrastructure. This greatly
  62                 simplifies the administrative overhead of deploying UNIX
  63                 workstations into a NT based organization.</p><p>Another interesting way in which we expect Winbind to
  64                 be used is as a central part of UNIX based appliances. Appliances
  65                 that provide file and print services to Microsoft based networks
  66                 will be able to use Winbind to provide seamless integration of
  67                 the appliance into the domain.</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2889003"></a>How Winbind Works</h2></div></div><p>The winbind system is designed around a client/server
  68         architecture. A long running <b>winbindd</b> daemon
  69         listens on a UNIX domain socket waiting for requests
  70         to arrive. These requests are generated by the NSS and PAM
  71         clients and processed sequentially.</p><p>The technologies used to implement winbind are described
  72         in detail below.</p><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2889031"></a>Microsoft Remote Procedure Calls</h3></div></div><p>Over the last few years, efforts have been underway
  73                 by various Samba Team members to decode various aspects of
  74                 the Microsoft Remote Procedure Call (MSRPC) system. This
  75                 system is used for most network related operations between
  76                 Windows NT machines including remote management, user authentication
  77                 and print spooling. Although initially this work was done
  78                 to aid the implementation of Primary Domain Controller (PDC)
  79                 functionality in Samba, it has also yielded a body of code which
  80                 can be used for other purposes.</p><p>Winbind uses various MSRPC calls to enumerate domain users
  81                 and groups and to obtain detailed information about individual
  82                 users or groups. Other MSRPC calls can be used to authenticate
  83                 NT domain users and to change user passwords. By directly querying
  84                 a Windows PDC for user and group information, winbind maps the
  85                 NT account information onto UNIX user and group names.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2889066"></a>Microsoft Active Directory Services</h3></div></div><p>
  86                 Since late 2001, Samba has gained the ability to
  87                 interact with Microsoft Windows 2000 using its 'Native
  88                 Mode' protocols, rather than the NT4 RPC services.
  89                 Using LDAP and Kerberos, a domain member running
  90                 winbind can enumerate users and groups in exactly the
  91                 same way as a Win2k client would, and in so doing
  92                 provide a much more efficient and
  93                 effective winbind implementation.
  94                 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2889088"></a>Name Service Switch</h3></div></div><p>The Name Service Switch, or NSS, is a feature that is
  95                 present in many UNIX operating systems. It allows system
  96                 information such as hostnames, mail aliases and user information
  97                 to be resolved from different sources. For example, a standalone
  98                 UNIX workstation may resolve system information from a series of
  99                 flat files stored on the local filesystem. A networked workstation
 100                 may first attempt to resolve system information from local files,
 101                 and then consult a NIS database for user information or a DNS server
 102                 for hostname information.</p><p>The NSS application programming interface allows winbind
 103                 to present itself as a source of system information when
 104                 resolving UNIX usernames and groups.  Winbind uses this interface,
 105                 and information obtained from a Windows NT server using MSRPC
 106                 calls to provide a new source of account enumeration.  Using standard
 107                 UNIX library calls, one can enumerate the users and groups on
 108                 a UNIX machine running winbind and see all users and groups in
 109                 a NT domain plus any trusted domain as though they were local
 110                 users and groups.</p><p>The primary control file for NSS is
 111                 <tt>/etc/nsswitch.conf</tt>.
 112                 When a UNIX application makes a request to do a lookup
 113                 the C library looks in <tt>/etc/nsswitch.conf</tt>
 114                 for a line which matches the service type being requested, for
 115                 example the &quot;passwd&quot; service type is used when user or group names
 116                 are looked up. This     config line species which implementations
 117                 of that service should be tried and in what order. If the passwd
 118                 config line is:</p><p><b>passwd: files example</b></p><p>then the C library will first load a module called
 119                 <tt>/lib/libnss_files.so</tt> followed by
 120                 the module <tt>/lib/libnss_example.so</tt>. The
 121                 C library will dynamically load each of these modules in turn
 122                 and call resolver functions within the modules to try to resolve
 123                 the request. Once the request is resolved the C library returns the
 124                 result to the application.</p><p>This NSS interface provides a very easy way for Winbind
 125                 to hook into the operating system. All that needs to be done
 126                 is to put <tt>libnss_winbind.so</tt> in <tt>/lib/</tt>
 127                 then add &quot;winbind&quot; into <tt>/etc/nsswitch.conf</tt> at
 128                 the appropriate place. The C library will then call Winbind to
 129                 resolve user and group names.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2892176"></a>Pluggable Authentication Modules</h3></div></div><p>Pluggable Authentication Modules, also known as PAM,
 130                 is a system for abstracting authentication and authorization
 131                 technologies. With a PAM module it is possible to specify different
 132                 authentication methods for different system applications without
 133                 having to recompile these applications. PAM is also useful
 134                 for implementing a particular policy for authorization. For example,
 135                 a system administrator may only allow console logins from users
 136                 stored in the local password file but only allow users resolved from
 137                 a NIS database to log in over the network.</p><p>Winbind uses the authentication management and password
 138                 management PAM interface to integrate Windows NT users into a
 139                 UNIX system. This allows Windows NT users to log in to a UNIX
 140                 machine and be authenticated against a suitable Primary Domain
 141                 Controller. These users can also change their passwords and have
 142                 this change take effect directly on the Primary Domain Controller.
 143                 </p><p>PAM is configured by providing control files in the directory
 144                 <tt>/etc/pam.d/</tt> for each of the services that
 145                 require authentication. When an authentication request is made
 146                 by an application the PAM code in the C library looks up this
 147                 control file to determine what modules to load to do the
 148                 authentication check and in what order. This interface makes adding
 149                 a new authentication service for Winbind very easy, all that needs
 150                 to be done is that the <tt>pam_winbind.so</tt> module
 151                 is copied to <tt>/lib/security/</tt> and the PAM
 152                 control files for relevant services are updated to allow
 153                 authentication via winbind. See the PAM documentation
 154                 for more details.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2892248"></a>User and Group ID Allocation</h3></div></div><p>When a user or group is created under Windows NT
 155                 is it allocated a numerical relative identifier (RID). This is
 156                 slightly different to UNIX which has a range of numbers that are
 157                 used to identify users, and the same range in which to identify
 158                 groups. It is winbind's job to convert RIDs to UNIX id numbers and
 159                 vice versa.  When winbind is configured it is given part of the UNIX
 160                 user id space and a part of the UNIX group id space in which to
 161                 store Windows NT users and groups. If a Windows NT user is
 162                 resolved for the first time, it is allocated the next UNIX id from
 163                 the range. The same process applies for Windows NT groups. Over
 164                 time, winbind will have mapped all Windows NT users and groups
 165                 to UNIX user ids and group ids.</p><p>The results of this mapping are stored persistently in
 166                 an ID mapping database held in a tdb database). This ensures that
 167                 RIDs are mapped to UNIX IDs in a consistent way.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2892282"></a>Result Caching</h3></div></div><p>An active system can generate a lot of user and group
 168                 name lookups. To reduce the network cost of these lookups winbind
 169                 uses a caching scheme based on the SAM sequence number supplied
 170                 by NT domain controllers.  User or group information returned
 171                 by a PDC is cached by winbind along with a sequence number also
 172                 returned by the PDC. This sequence number is incremented by
 173                 Windows NT whenever any user or group information is modified. If
 174                 a cached entry has expired, the sequence number is requested from
 175                 the PDC and compared against the sequence number of the cached entry.
 176                 If the sequence numbers do not match, then the cached information
 177                 is discarded and up to date information is requested directly
 178                 from the PDC.</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2892310"></a>Installation and Configuration</h2></div></div><p>
 179 Many thanks to John Trostel <a href="mailto:jtrostel@snapserver.com" target="_top">jtrostel@snapserver.com</a>
 180 for providing the HOWTO for this section.
 181 </p><p>
 182 This HOWTO describes how to get winbind services up and running
 183 to control access and authenticate users on your Linux box using
 184 the winbind services which come with SAMBA 3.0.
 185 </p><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2892338"></a>Introduction</h3></div></div><p>
 186 This HOWTO describes the procedures used to get winbind up and
 187 running on my RedHat 7.1 system.  Winbind is capable of providing access
 188 and authentication control for Windows Domain users through an NT
 189 or Win2K PDC for 'regular' services, such as telnet a nd ftp, as
 190 well for SAMBA services.
 191 </p><p>
 192 This HOWTO has been written from a 'RedHat-centric' perspective, so if
 193 you are using another distribution, you may have to modify the instructions
 194 somewhat to fit the way your distribution works.
 195 </p><div class="itemizedlist"><ul type="disc"><li><p>
 196         <span class="emphasis"><em>Why should I to this?</em></span>
 197         </p><p>This allows the SAMBA administrator to rely on the
 198         authentication mechanisms on the NT/Win2K PDC for the authentication
 199         of domain members.  NT/Win2K users no longer need to have separate
 200         accounts on the SAMBA server.
 201         </p></li><li><p>
 202         <span class="emphasis"><em>Who should be reading this document?</em></span>
 203         </p><p>
 204         This HOWTO is designed for system administrators.  If you are
 205         implementing SAMBA on a file server and wish to (fairly easily)
 206         integrate existing NT/Win2K users from your PDC onto the
 207         SAMBA server, this HOWTO is for you.  That said, I am no NT or PAM
 208         expert, so you may find a better or easier way to accomplish
 209         these tasks.
 210         </p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2892413"></a>Requirements</h3></div></div><p>
 211 If you have a samba configuration file that you are currently
 212 using... <span class="emphasis"><em>BACK IT UP!</em></span>  If your system already uses PAM,
 213 <span class="emphasis"><em>back up the <tt>/etc/pam.d</tt> directory
 214 contents!</em></span> If you haven't already made a boot disk,
 215 <span class="emphasis"><em>MAKE ONE NOW!</em></span>
 216 </p><p>
 217 Messing with the pam configuration files can make it nearly impossible
 218 to log in to yourmachine. That's why you want to be able to boot back
 219 into your machine in single user mode and restore your
 220 <tt>/etc/pam.d</tt> back to the original state they were in if
 221 you get frustrated with the way things are going.  ;-)
 222 </p><p>
 223 The latest version of SAMBA (version 3.0 as of this writing), now
 224 includes a functioning winbindd daemon.  Please refer to the
 225 <a href="http://samba.org/" target="_top">main SAMBA web page</a> or,
 226 better yet, your closest SAMBA mirror site for instructions on
 227 downloading the source code.
 228 </p><p>
 229 To allow Domain users the ability to access SAMBA shares and
 230 files, as well as potentially other services provided by your
 231 SAMBA machine, PAM (pluggable authentication modules) must
 232 be setup properly on your machine.  In order to compile the
 233 winbind modules, you should have at least the pam libraries resident
 234 on your system.  For recent RedHat systems (7.1, for instance), that
 235 means <tt>pam-0.74-22</tt>.  For best results, it is helpful to also
 236 install the development packages in <tt>pam-devel-0.74-22</tt>.
 237 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><h3 class="title"><a name="id2892507"></a>Testing Things Out</h3></div></div><p>
 238 Before starting, it is probably best to kill off all the SAMBA
 239 related daemons running on your server.  Kill off all <b>smbd</b>,
 240 <b>nmbd</b>, and <b>winbindd</b> processes that may
 241 be running.  To use PAM, you will want to make sure that you have the
 242 standard PAM package (for RedHat) which supplies the <tt>/etc/pam.d</tt>
 243 directory structure, including the pam modules are used by pam-aware
 244 services, several pam libraries, and the <tt>/usr/doc</tt>
 245 and <tt>/usr/man</tt> entries for pam.  Winbind built better
 246 in SAMBA if the pam-devel package was also installed.  This package includes
 247 the header files needed to compile pam-aware applications. For instance,
 248 my RedHat system has both <tt>pam-0.74-22</tt> and
 249 <tt>pam-devel-0.74-22</tt> RPMs installed.
 250 </p><div class="sect3" lang="en"><div class="titlepage"><div><h4 class="title"><a name="id2892584"></a>Configure and compile SAMBA</h4></div></div><p>
 251 The configuration and compilation of SAMBA is pretty straightforward.
 252 The first three steps may not be necessary depending upon
 253 whether or not you have previously built the Samba binaries.
 254 </p><pre class="programlisting">
 255 <tt>root#</tt> <b>autoconf</b>
 256 <tt>root#</tt> <b>make clean</b>
 257 <tt>root#</tt> <b>rm config.cache</b>
 258 <tt>root#</tt> <b>./configure</b>
 259 <tt>root#</tt> <b>make</b>
 260 <tt>root#</tt> <b>make install</b>
 261 </pre><p>
 262 This will, by default, install SAMBA in <tt>/usr/local/samba</tt>.
 263 See the main SAMBA documentation if you want to install SAMBA somewhere else.
 264 It will also build the winbindd executable and libraries.
 265 </p></div><div class="sect3" lang="en"><div class="titlepage"><div><h4 class="title"><a name="id2892705"></a>Configure <tt>nsswitch.conf</tt> and the
 266 winbind libraries on Linux and Solaris</h4></div></div><p>
 267 The libraries needed to run the <b>winbindd</b> daemon
 268 through nsswitch need to be copied to their proper locations, so
 269 </p><p>
 270 <tt>root#</tt> <b>cp ../samba/source/nsswitch/libnss_winbind.so /lib</b>
 271 </p><p>
 272 I also found it necessary to make the following symbolic link:
 273 </p><p>
 274 <tt>root#</tt> <b>ln -s /lib/libnss_winbind.so /lib/libnss_winbind.so.2</b>
 275 </p><p>And, in the case of Sun solaris:</p><p>
 276 <tt>root#</tt> <b><tt>ln -s /usr/lib/libnss_winbind.so /usr/lib/libnss_winbind.so.1</tt></b>
 277 <tt>root#</tt> <b><tt>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.1</tt></b>
 278 <tt>root#</tt> <b><tt>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.2</tt></b>
 279 </p><p>
 280 Now, as root you need to edit <tt>/etc/nsswitch.conf</tt> to
 281 allow user and group entries to be visible from the <b>winbindd</b>
 282 daemon.  My <tt>/etc/nsswitch.conf</tt> file look like
 283 this after editing:
 284 </p><pre class="programlisting">
 285         passwd:     files winbind
 286         shadow:     files
 287         group:      files winbind
 288 </pre><p>
 289 The libraries needed by the winbind daemon will be automatically
 290 entered into the <b>ldconfig</b> cache the next time
 291 your system reboots, but it
 292 is faster (and you don't need to reboot) if you do it manually:
 293 </p><p>
 294 <tt>root#</tt> <b>/sbin/ldconfig -v | grep winbind</b>
 295 </p><p>
 296 This makes <tt>libnss_winbind</tt> available to winbindd
 297 and echos back a check to you.
 298 </p></div><div class="sect3" lang="en"><div class="titlepage"><div><h4 class="title"><a name="id2892910"></a>NSS Winbind on AIX</h4></div></div><p>(This section is only for those running AIX)</p><p>
 299 The winbind AIX identification module gets built as libnss_winbind.so in the
 300 nsswitch directory of the samba source.  This file can be copied to
 301 /usr/lib/security, and the AIX naming convention would indicate that it
 302 should be named WINBIND.  A stanza like the following:
 303 </p><pre class="programlisting">
 304 WINBIND:
 305         program = /usr/lib/security/WINBIND
 306         options = authonly
 307 </pre><p>can then be added to
 308 <tt>/usr/lib/security/methods.cfg</tt>.  This module only
 309 supports identification, but there have been success reports using the
 310 standard winbind pam module for authentication.  Use caution configuring
 311 loadable authentication modules as it is possible to make it impossible
 312 to logon to the system.  More information about the AIX authentication
 313 module API can be found at &quot;Kernel Extensions and Device Support
 314 Programming Concepts for AIX&quot;: <a href="">
 315 Chapter 18. Loadable Authentication Module Programming Interface</a>
 316 and more information on administering the  modules at <a href="">
 317 &quot;System Management Guide: Operating System and Devices&quot;</a>.
 318 </p></div><div class="sect3" lang="en"><div class="titlepage"><div><h4 class="title"><a name="id2892983"></a>Configure smb.conf</h4></div></div><p>
 319 Several parameters are needed in the smb.conf file to control
 320 the behavior of <b>winbindd</b>. Configure
 321 <tt>smb.conf</tt> These are described in more detail in
 322 the <a href="winbindd.8.html">winbindd(8)</a> man page.  My
 323 <tt>smb.conf</tt> file was modified to
 324 include the following entries in the [global] section:
 325 </p><pre class="programlisting">
 326 [global]
 327      &lt;...&gt;
 328      # separate domain and username with '+', like DOMAIN+username
 329      <a href="winbindd.8.html#WINBINDSEPARATOR" target="_top">winbind separator</a> = +
 330      # use uids from 10000 to 20000 for domain users
 331      <a href="winbindd.8.html#WINBINDUID" target="_top">winbind uid</a> = 10000-20000
 332      # use gids from 10000 to 20000 for domain groups
 333      <a href="winbindd.8.html#WINBINDGID" target="_top">winbind gid</a> = 10000-20000
 334      # allow enumeration of winbind users and groups
 335      <a href="winbindd.8.html#WINBINDENUMUSERS" target="_top">winbind enum users</a> = yes
 336      <a href="winbindd.8.html#WINBINDENUMGROUP" target="_top">winbind enum groups</a> = yes
 337      # give winbind users a real shell (only needed if they have telnet access)
 338      <a href="winbindd.8.html#TEMPLATEHOMEDIR" target="_top">template homedir</a> = /home/winnt/%D/%U
 339      <a href="winbindd.8.html#TEMPLATESHELL" target="_top">template shell</a> = /bin/bash
 340 </pre></div><div class="sect3" lang="en"><div class="titlepage"><div><h4 class="title"><a name="id2893098"></a>Join the SAMBA server to the PDC domain</h4></div></div><p>
 341 Enter the following command to make the SAMBA server join the
 342 PDC domain, where <i><tt>DOMAIN</tt></i> is the name of
 343 your Windows domain and <i><tt>Administrator</tt></i> is
 344 a domain user who has administrative privileges in the domain.
 345 </p><p>
 346 <tt>root#</tt> <b>/usr/local/samba/bin/net join -S PDC -U Administrator</b>
 347 </p><p>
 348 The proper response to the command should be: &quot;Joined the domain
 349 <i><tt>DOMAIN</tt></i>&quot; where <i><tt>DOMAIN</tt></i>
 350 is your DOMAIN name.
 351 </p></div><div class="sect3" lang="en"><div class="titlepage"><div><h4 class="title"><a name="id2893155"></a>Start up the winbindd daemon and test it!</h4></div></div><p>
 352 Eventually, you will want to modify your smb startup script to
 353 automatically invoke the winbindd daemon when the other parts of
 354 SAMBA start, but it is possible to test out just the winbind
 355 portion first.  To start up winbind services, enter the following
 356 command as root:
 357 </p><p>
 358 <tt>root#</tt> <b>/usr/local/samba/bin/winbindd</b>
 359 </p><p>
 360 Winbindd can now also run in 'dual daemon mode'. This will make it
 361 run as 2 processes. The first will answer all requests from the cache,
 362 thus making responses to clients faster. The other will
 363 update the cache for the query that the first has just responded.
 364 Advantage of this is that responses stay accurate and are faster.
 365 You can enable dual daemon mode by adding '-B' to the commandline:
 366 </p><p>
 367 <tt>root#</tt> <b>/usr/local/samba/bin/winbindd -B</b>
 368 </p><p>
 369 I'm always paranoid and like to make sure the daemon
 370 is really running...
 371 </p><p>
 372 <tt>root#</tt> <b>ps -ae | grep winbindd</b>
 373 </p><p>
 374 This command should produce output like this, if the daemon is running
 375 </p><p>
 376 3025 ?        00:00:00 winbindd
 377 </p><p>
 378 Now... for the real test, try to get some information about the
 379 users on your PDC
 380 </p><p>
 381 <tt>root#</tt> <b>/usr/local/samba/bin/wbinfo -u</b>
 382 </p><p>
 383 This should echo back a list of users on your Windows users on
 384 your PDC.  For example, I get the following response:
 385 </p><pre class="programlisting">
 386         CEO+Administrator
 387         CEO+burdell
 388         CEO+Guest
 389         CEO+jt-ad
 390         CEO+krbtgt
 391         CEO+TsInternetUser
 392 </pre><p>
 393 Obviously, I have named my domain 'CEO' and my <i><tt>winbind
 394 separator</tt></i> is '+'.
 395 </p><p>
 396 You can do the same sort of thing to get group information from
 397 the PDC:
 398 </p><pre class="programlisting">
 399 <tt>root#</tt> <b>/usr/local/samba/bin/wbinfo -g</b>
 400         CEO+Domain Admins
 401         CEO+Domain Users
 402         CEO+Domain Guests
 403         CEO+Domain Computers
 404         CEO+Domain Controllers
 405         CEO+Cert Publishers
 406         CEO+Schema Admins
 407         CEO+Enterprise Admins
 408         CEO+Group Policy Creator Owners
 409 </pre><p>
 410 The function 'getent' can now be used to get unified
 411 lists of both local and PDC users and groups.
 412 Try the following command:
 413 </p><p>
 414 <tt>root#</tt> <b>getent passwd</b>
 415 </p><p>
 416 You should get a list that looks like your <tt>/etc/passwd</tt>
 417 list followed by the domain users with their new uids, gids, home
 418 directories and default shells.
 419 </p><p>
 420 The same thing can be done for groups with the command
 421 </p><p>
 422 <tt>root#</tt> <b>getent group</b>
 423 </p></div><div class="sect3" lang="en"><div class="titlepage"><div><h4 class="title"><a name="id2893399"></a>Fix the init.d startup scripts</h4></div></div><div class="sect4" lang="en"><div class="titlepage"><div><h5 class="title"><a name="id2893407"></a>Linux</h5></div></div><p>
 424 The <b>winbindd</b> daemon needs to start up after the
 425 <b>smbd</b> and <b>nmbd</b> daemons are running.
 426 To accomplish this task, you need to modify the startup scripts of your system.
 427 They are located at <tt>/etc/init.d/smb</tt> in RedHat and
 428 <tt>/etc/init.d/samba</tt> in Debian.
 429 script to add commands to invoke this daemon in the proper sequence.  My
 430 startup script starts up <b>smbd</b>,
 431 <b>nmbd</b>, and <b>winbindd</b> from the
 432 <tt>/usr/local/samba/bin</tt> directory directly.  The 'start'
 433 function in the script looks like this:
 434 </p><pre class="programlisting">
 435 start() {
 436         KIND=&quot;SMB&quot;
 437         echo -n $&quot;Starting $KIND services: &quot;
 438         daemon /usr/local/samba/bin/smbd $SMBDOPTIONS
 439         RETVAL=$?
 440         echo
 441         KIND=&quot;NMB&quot;
 442         echo -n $&quot;Starting $KIND services: &quot;
 443         daemon /usr/local/samba/bin/nmbd $NMBDOPTIONS
 444         RETVAL2=$?
 445         echo
 446         KIND=&quot;Winbind&quot;
 447         echo -n $&quot;Starting $KIND services: &quot;
 448         daemon /usr/local/samba/bin/winbindd
 449         RETVAL3=$?
 450         echo
 451         [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] &amp;&amp; \
 452                 touch /var/lock/subsys/smb || RETVAL=1
 453         return $RETVAL
 454 }
 455 </pre><p>If you would like to run winbindd in dual daemon mode, replace
 456 the line
 457 </p><pre class="programlisting">
 458         daemon /usr/local/samba/bin/winbindd
 459 </pre><p>
 460
 461 in the example above with:
 462
 463 </p><pre class="programlisting">
 464         daemon /usr/local/samba/bin/winbindd -B
 465 </pre><p>.
 466 </p><p>
 467 The 'stop' function has a corresponding entry to shut down the
 468 services and looks like this:
 469 </p><pre class="programlisting">
 470 stop() {
 471         KIND=&quot;SMB&quot;
 472         echo -n $&quot;Shutting down $KIND services: &quot;
 473         killproc smbd
 474         RETVAL=$?
 475         echo
 476         KIND=&quot;NMB&quot;
 477         echo -n $&quot;Shutting down $KIND services: &quot;
 478         killproc nmbd
 479         RETVAL2=$?
 480         echo
 481         KIND=&quot;Winbind&quot;
 482         echo -n $&quot;Shutting down $KIND services: &quot;
 483         killproc winbindd
 484         RETVAL3=$?
 485         [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] &amp;&amp; \
 486                  rm -f /var/lock/subsys/smb
 487         echo &quot;&quot;
 488         return $RETVAL
 489 }
 490 </pre></div><div class="sect4" lang="en"><div class="titlepage"><div><h5 class="title"><a name="id2893544"></a>Solaris</h5></div></div><p>Winbind doesn't work on solaris 9, see the <a href="Portability.html#winbind-solaris9" title="Winbind on Solaris 9">Portability</a> chapter for details.</p><p>On solaris, you need to modify the
 491 <tt>/etc/init.d/samba.server</tt> startup script. It usually
 492 only starts smbd and nmbd but should now start winbindd too. If you
 493 have samba installed in <tt>/usr/local/samba/bin</tt>,
 494 the file could contains something like this:
 495 </p><pre class="programlisting">
 496         ##
 497         ## samba.server
 498         ##
 499
 500         if [ ! -d /usr/bin ]
 501         then                    # /usr not mounted
 502                 exit
 503         fi
 504
 505         killproc() {            # kill the named process(es)
 506                 pid=`/usr/bin/ps -e |
 507                      /usr/bin/grep -w $1 |
 508                      /usr/bin/sed -e 's/^  *//' -e 's/ .*//'`
 509                 [ &quot;$pid&quot; != &quot;&quot; ] &amp;&amp; kill $pid
 510         }
 511
 512         # Start/stop processes required for samba server
 513
 514         case &quot;$1&quot; in
 515
 516         'start')
 517         #
 518         # Edit these lines to suit your installation (paths, workgroup, host)
 519         #
 520         echo Starting SMBD
 521            /usr/local/samba/bin/smbd -D -s \
 522                 /usr/local/samba/smb.conf
 523
 524         echo Starting NMBD
 525            /usr/local/samba/bin/nmbd -D -l \
 526                 /usr/local/samba/var/log -s /usr/local/samba/smb.conf
 527
 528         echo Starting Winbind Daemon
 529            /usr/local/samba/bin/winbindd
 530            ;;
 531
 532         'stop')
 533            killproc nmbd
 534            killproc smbd
 535            killproc winbindd
 536            ;;
 537
 538         *)
 539            echo &quot;Usage: /etc/init.d/samba.server { start | stop }&quot;
 540            ;;
 541         esac
 542 </pre><p>
 543 Again, if you would like to run samba in dual daemon mode, replace
 544 </p><pre class="programlisting">
 545         /usr/local/samba/bin/winbindd
 546 </pre><p>
 547
 548 in the script above with:
 549
 550 </p><pre class="programlisting">
 551         /usr/local/samba/bin/winbindd -B
 552 </pre><p>
 553 </p></div><div class="sect4" lang="en"><div class="titlepage"><div><h5 class="title"><a name="id2893644"></a>Restarting</h5></div></div><p>
 554 If you restart the <b>smbd</b>, <b>nmbd</b>,
 555 and <b>winbindd</b> daemons at this point, you
 556 should be able to connect to the samba server as a domain member just as
 557 if you were a local user.
 558 </p></div></div><div class="sect3" lang="en"><div class="titlepage"><div><h4 class="title"><a name="id2893681"></a>Configure Winbind and PAM</h4></div></div><p>
 559 If you have made it this far, you know that winbindd and samba are working
 560 together.  If you want to use winbind to provide authentication for other
 561 services, keep reading.  The pam configuration files need to be altered in
 562 this step.  (Did you remember to make backups of your original
 563 <tt>/etc/pam.d</tt> files? If not, do it now.)
 564 </p><p>
 565 You will need a pam module to use winbindd with these other services.  This
 566 module will be compiled in the <tt>../source/nsswitch</tt> directory
 567 by invoking the command
 568 </p><p>
 569 <tt>root#</tt> <b>make nsswitch/pam_winbind.so</b>
 570 </p><p>
 571 from the <tt>../source</tt> directory.  The
 572 <tt>pam_winbind.so</tt> file should be copied to the location of
 573 your other pam security modules.  On my RedHat system, this was the
 574 <tt>/lib/security</tt> directory. On Solaris, the pam security
 575 modules reside in <tt>/usr/lib/security</tt>.
 576 </p><p>
 577 <tt>root#</tt> <b>cp ../samba/source/nsswitch/pam_winbind.so /lib/security</b>
 578 </p><div class="sect4" lang="en"><div class="titlepage"><div><h5 class="title"><a name="id2893790"></a>Linux/FreeBSD-specific PAM configuration</h5></div></div><p>
 579 The <tt>/etc/pam.d/samba</tt> file does not need to be changed. I
 580 just left this fileas it was:
 581 </p><pre class="programlisting">
 582         auth    required        /lib/security/pam_stack.so service=system-auth
 583         account required        /lib/security/pam_stack.so service=system-auth
 584 </pre><p>
 585 The other services that I modified to allow the use of winbind
 586 as an authentication service were the normal login on the console (or a terminal
 587 session), telnet logins, and ftp service.  In order to enable these
 588 services, you may first need to change the entries in
 589 <tt>/etc/xinetd.d</tt> (or <tt>/etc/inetd.conf</tt>).
 590 RedHat 7.1 uses the new xinetd.d structure, in this case you need
 591 to change the lines in <tt>/etc/xinetd.d/telnet</tt>
 592 and <tt>/etc/xinetd.d/wu-ftp</tt> from
 593 </p><pre class="programlisting">
 594         enable = no
 595 </pre><p>
 596 to
 597 </p><pre class="programlisting">
 598         enable = yes
 599 </pre><p>
 600 For ftp services to work properly, you will also need to either
 601 have individual directories for the domain users already present on
 602 the server, or change the home directory template to a general
 603 directory for all domain users.  These can be easily set using
 604 the <tt>smb.conf</tt> global entry
 605 <b>template homedir</b>.
 606 </p><p>
 607 The <tt>/etc/pam.d/ftp</tt> file can be changed
 608 to allow winbind ftp access in a manner similar to the
 609 samba file.  My <tt>/etc/pam.d/ftp</tt> file was
 610 changed to look like this:
 611 </p><pre class="programlisting">
 612         auth       required     /lib/security/pam_listfile.so item=user sense=deny \
 613                  file=/etc/ftpusers onerr=succeed
 614         auth       sufficient   /lib/security/pam_winbind.so
 615         auth       required     /lib/security/pam_stack.so service=system-auth
 616         auth       required     /lib/security/pam_shells.so
 617         account    sufficient   /lib/security/pam_winbind.so
 618         account    required     /lib/security/pam_stack.so service=system-auth
 619         session    required     /lib/security/pam_stack.so service=system-auth
 620 </pre><p>
 621 The <tt>/etc/pam.d/login</tt> file can be changed nearly the
 622 same way.  It now looks like this:
 623 </p><pre class="programlisting">
 624         auth       required     /lib/security/pam_securetty.so
 625         auth       sufficient   /lib/security/pam_winbind.so
 626         auth       sufficient   /lib/security/pam_unix.so use_first_pass
 627         auth       required     /lib/security/pam_stack.so service=system-auth
 628         auth       required     /lib/security/pam_nologin.so
 629         account    sufficient   /lib/security/pam_winbind.so
 630         account    required     /lib/security/pam_stack.so service=system-auth
 631         password   required     /lib/security/pam_stack.so service=system-auth
 632         session    required     /lib/security/pam_stack.so service=system-auth
 633         session    optional     /lib/security/pam_console.so
 634 </pre><p>
 635 In this case, I added the <b>auth sufficient /lib/security/pam_winbind.so</b>
 636 lines as before, but also added the <b>required pam_securetty.so</b>
 637 above it, to disallow root logins over the network.  I also added a
 638 <b>sufficient /lib/security/pam_unix.so use_first_pass</b>
 639 line after the <b>winbind.so</b> line to get rid of annoying
 640 double prompts for passwords.
 641 </p></div><div class="sect4" lang="en"><div class="titlepage"><div><h5 class="title"><a name="id2894014"></a>Solaris-specific configuration</h5></div></div><p>
 642 The /etc/pam.conf needs to be changed. I changed this file so that my Domain
 643 users can logon both locally as well as telnet.The following are the changes
 644 that I made.You can customize the pam.conf file as per your requirements,but
 645 be sure of those changes because in the worst case it will leave your system
 646 nearly impossible to boot.
 647 </p><pre class="programlisting">
 648         #
 649         #ident  &quot;@(#)pam.conf      1.14    99/09/16 SMI&quot;
 650         #
 651         # Copyright (c) 1996-1999, Sun Microsystems, Inc.
 652         # All Rights Reserved.
 653         #
 654         # PAM configuration
 655         #
 656         # Authentication management
 657         #
 658         login   auth required   /usr/lib/security/pam_winbind.so
 659         login   auth required   /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
 660         login   auth required   /usr/lib/security/$ISA/pam_dial_auth.so.1 try_first_pass
 661         #
 662         rlogin  auth sufficient /usr/lib/security/pam_winbind.so
 663         rlogin  auth sufficient /usr/lib/security/$ISA/pam_rhosts_auth.so.1
 664         rlogin  auth required   /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
 665         #
 666         dtlogin auth sufficient /usr/lib/security/pam_winbind.so
 667         dtlogin auth required   /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
 668         #
 669         rsh     auth required   /usr/lib/security/$ISA/pam_rhosts_auth.so.1
 670         other   auth sufficient /usr/lib/security/pam_winbind.so
 671         other   auth required   /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
 672         #
 673         # Account management
 674         #
 675         login   account sufficient      /usr/lib/security/pam_winbind.so
 676         login   account requisite       /usr/lib/security/$ISA/pam_roles.so.1
 677         login   account required        /usr/lib/security/$ISA/pam_unix.so.1
 678         #
 679         dtlogin account sufficient      /usr/lib/security/pam_winbind.so
 680         dtlogin account requisite       /usr/lib/security/$ISA/pam_roles.so.1
 681         dtlogin account required        /usr/lib/security/$ISA/pam_unix.so.1
 682         #
 683         other   account sufficient      /usr/lib/security/pam_winbind.so
 684         other   account requisite       /usr/lib/security/$ISA/pam_roles.so.1
 685         other   account required        /usr/lib/security/$ISA/pam_unix.so.1
 686         #
 687         # Session management
 688         #
 689         other   session required        /usr/lib/security/$ISA/pam_unix.so.1
 690         #
 691         # Password management
 692         #
 693         #other   password sufficient     /usr/lib/security/pam_winbind.so
 694         other   password required       /usr/lib/security/$ISA/pam_unix.so.1
 695         dtsession auth required /usr/lib/security/$ISA/pam_unix.so.1
 696         #
 697         # Support for Kerberos V5 authentication (uncomment to use Kerberos)
 698         #
 699         #rlogin auth optional   /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
 700         #login  auth optional   /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
 701         #dtlogin        auth optional   /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
 702         #other  auth optional   /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
 703         #dtlogin        account optional /usr/lib/security/$ISA/pam_krb5.so.1
 704         #other  account optional /usr/lib/security/$ISA/pam_krb5.so.1
 705         #other  session optional /usr/lib/security/$ISA/pam_krb5.so.1
 706         #other  password optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
 707 </pre><p>
 708 I also added a try_first_pass line after the winbind.so line to get rid of
 709 annoying double prompts for passwords.
 710 </p><p>
 711 Now restart your Samba and try connecting through your application that you
 712 configured in the pam.conf.
 713 </p></div></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2894106"></a>Limitations</h2></div></div><p>Winbind has a number of limitations in its current
 714         released version that we hope to overcome in future
 715         releases:</p><div class="itemizedlist"><ul type="disc"><li><p>Winbind is currently only available for
 716                 the Linux, Solaris and IRIX operating systems, although ports to other operating
 717                 systems are certainly possible. For such ports to be feasible,
 718                 we require the C library of the target operating system to
 719                 support the Name Service Switch and Pluggable Authentication
 720                 Modules systems. This is becoming more common as NSS and
 721                 PAM gain        support among UNIX vendors.</p></li><li><p>The mappings of Windows NT RIDs to UNIX ids
 722                 is not made algorithmically and depends on the order in which
 723                 unmapped users or groups are seen by winbind. It may be difficult
 724                 to recover the mappings of rid to UNIX id mapping if the file
 725                 containing this information is corrupted or destroyed.</p></li><li><p>Currently the winbind PAM module does not take
 726                 into account possible workstation and logon time restrictions
 727                 that may be been set for Windows NT users, this is
 728                 instead up to the PDC to enforce.</p></li></ul></div></div><div class="sect1" lang="en"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="id2894160"></a>Conclusion</h2></div></div><p>The winbind system, through the use of the Name Service
 729         Switch, Pluggable Authentication Modules, and appropriate
 730         Microsoft RPC calls have allowed us to provide seamless
 731         integration of Microsoft Windows NT domain users on a
 732         UNIX system. The result is a great reduction in the administrative
 733         cost of running a mixed UNIX and NT network.</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="CUPS-printing.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="AdvancedNetworkManagement.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 14. CUPS Printing Support </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 16. Advanced Network Manangement</td></tr></table></div></body></html>