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   4 >Unified Logons between Windows NT and UNIX using Winbind</TITLE
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  15 ><DIV
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  17 ><DIV
  18 CLASS="TITLEPAGE"
  19 ><H1
  20 CLASS="TITLE"
  21 ><A
  22 NAME="WINBIND"
  23 >Unified Logons between Windows NT and UNIX using Winbind</A
  24 ></H1
  25 ><HR></DIV
  26 ><DIV
  27 CLASS="SECT1"
  28 ><H1
  29 CLASS="SECT1"
  30 ><A
  31 NAME="AEN3"
  32 >Abstract</A
  33 ></H1
  34 ><P
  35 >Integration of UNIX and Microsoft Windows NT through
  36         a unified logon has been considered a "holy grail" in heterogeneous
  37         computing environments for a long time. We present
  38         <I
  39 CLASS="EMPHASIS"
  40 >winbind</I
  41 >, a component of the Samba suite
  42         of programs as a solution to the unified logon problem. Winbind
  43         uses a UNIX implementation
  44         of Microsoft RPC calls, Pluggable Authentication Modules, and the Name
  45         Service Switch to allow Windows NT domain users to appear and operate
  46         as UNIX users on a UNIX machine. This paper describes the winbind
  47         system, explaining the functionality it provides, how it is configured,
  48         and how it works internally.</P
  49 ></DIV
  50 ><DIV
  51 CLASS="SECT1"
  52 ><HR><H1
  53 CLASS="SECT1"
  54 ><A
  55 NAME="AEN7"
  56 >Introduction</A
  57 ></H1
  58 ><P
  59 >It is well known that UNIX and Microsoft Windows NT have
  60         different models for representing user and group information and
  61         use different technologies for implementing them. This fact has
  62         made it difficult to integrate the two systems in a satisfactory
  63         manner.</P
  64 ><P
  65 >One common solution in use today has been to create
  66         identically named user accounts on both the UNIX and Windows systems
  67         and use the Samba suite of programs to provide file and print services
  68         between the two. This solution is far from perfect however, as
  69         adding and deleting users on both sets of machines becomes a chore
  70         and two sets of passwords are required both of which
  71         can lead to synchronization problems between the UNIX and Windows
  72         systems and confusion for users.</P
  73 ><P
  74 >We divide the unified logon problem for UNIX machines into
  75         three smaller problems:</P
  76 ><P
  77 ></P
  78 ><UL
  79 ><LI
  80 ><P
  81 >Obtaining Windows NT user and group information
  82                 </P
  83 ></LI
  84 ><LI
  85 ><P
  86 >Authenticating Windows NT users
  87                 </P
  88 ></LI
  89 ><LI
  90 ><P
  91 >Password changing for Windows NT users
  92                 </P
  93 ></LI
  94 ></UL
  95 ><P
  96 >Ideally, a prospective solution to the unified logon problem
  97         would satisfy all the above components without duplication of
  98         information on the UNIX machines and without creating additional
  99         tasks for the system administrator when maintaining users and
 100         groups on either system. The winbind system provides a simple
 101         and elegant solution to all three components of the unified logon
 102         problem.</P
 103 ></DIV
 104 ><DIV
 105 CLASS="SECT1"
 106 ><HR><H1
 107 CLASS="SECT1"
 108 ><A
 109 NAME="AEN20"
 110 >What Winbind Provides</A
 111 ></H1
 112 ><P
 113 >Winbind unifies UNIX and Windows NT account management by
 114         allowing a UNIX box to become a full member of a NT domain. Once
 115         this is done the UNIX box will see NT users and groups as if
 116         they were native UNIX users and groups, allowing the NT domain
 117         to be used in much the same manner that NIS+ is used within
 118         UNIX-only environments.</P
 119 ><P
 120 >The end result is that whenever any
 121         program on the UNIX machine asks the operating system to lookup
 122         a user or group name, the query will be resolved by asking the
 123         NT domain controller for the specified domain to do the lookup.
 124         Because Winbind hooks into the operating system at a low level
 125         (via the NSS name resolution modules in the C library) this
 126         redirection to the NT domain controller is completely
 127         transparent.</P
 128 ><P
 129 >Users on the UNIX machine can then use NT user and group
 130         names as they would use "native" UNIX names. They can chown files
 131         so that they are owned by NT domain users or even login to the
 132         UNIX machine and run a UNIX X-Window session as a domain user.</P
 133 ><P
 134 >The only obvious indication that Winbind is being used is
 135         that user and group names take the form DOMAIN\user and
 136         DOMAIN\group. This is necessary as it allows Winbind to determine
 137         that redirection to a domain controller is wanted for a particular
 138         lookup and which trusted domain is being referenced.</P
 139 ><P
 140 >Additionally, Winbind provides an authentication service
 141         that hooks into the Pluggable Authentication Modules (PAM) system
 142         to provide authentication via a NT domain to any PAM enabled
 143         applications. This capability solves the problem of synchronizing
 144         passwords between systems since all passwords are stored in a single
 145         location (on the domain controller).</P
 146 ><DIV
 147 CLASS="SECT2"
 148 ><HR><H2
 149 CLASS="SECT2"
 150 ><A
 151 NAME="AEN27"
 152 >Target Uses</A
 153 ></H2
 154 ><P
 155 >Winbind is targeted at organizations that have an
 156                 existing NT based domain infrastructure into which they wish
 157                 to put UNIX workstations or servers. Winbind will allow these
 158                 organizations to deploy UNIX workstations without having to
 159                 maintain a separate account infrastructure. This greatly
 160                 simplifies the administrative overhead of deploying UNIX
 161                 workstations into a NT based organization.</P
 162 ><P
 163 >Another interesting way in which we expect Winbind to
 164                 be used is as a central part of UNIX based appliances. Appliances
 165                 that provide file and print services to Microsoft based networks
 166                 will be able to use Winbind to provide seamless integration of
 167                 the appliance into the domain.</P
 168 ></DIV
 169 ></DIV
 170 ><DIV
 171 CLASS="SECT1"
 172 ><HR><H1
 173 CLASS="SECT1"
 174 ><A
 175 NAME="AEN31"
 176 >How Winbind Works</A
 177 ></H1
 178 ><P
 179 >The winbind system is designed around a client/server
 180         architecture. A long running <B
 181 CLASS="COMMAND"
 182 >winbindd</B
 183 > daemon
 184         listens on a UNIX domain socket waiting for requests
 185         to arrive. These requests are generated by the NSS and PAM
 186         clients and processed sequentially.</P
 187 ><P
 188 >The technologies used to implement winbind are described
 189         in detail below.</P
 190 ><DIV
 191 CLASS="SECT2"
 192 ><HR><H2
 193 CLASS="SECT2"
 194 ><A
 195 NAME="AEN36"
 196 >Microsoft Remote Procedure Calls</A
 197 ></H2
 198 ><P
 199 >Over the last two years, efforts have been underway
 200                 by various Samba Team members to decode various aspects of
 201                 the Microsoft Remote Procedure Call (MSRPC) system. This
 202                 system is used for most network related operations between
 203                 Windows NT machines including remote management, user authentication
 204                 and print spooling. Although initially this work was done
 205                 to aid the implementation of Primary Domain Controller (PDC)
 206                 functionality in Samba, it has also yielded a body of code which
 207                 can be used for other purposes.</P
 208 ><P
 209 >Winbind uses various MSRPC calls to enumerate domain users
 210                 and groups and to obtain detailed information about individual
 211                 users or groups. Other MSRPC calls can be used to authenticate
 212                 NT domain users and to change user passwords. By directly querying
 213                 a Windows PDC for user and group information, winbind maps the
 214                 NT account information onto UNIX user and group names.</P
 215 ></DIV
 216 ><DIV
 217 CLASS="SECT2"
 218 ><HR><H2
 219 CLASS="SECT2"
 220 ><A
 221 NAME="AEN40"
 222 >Name Service Switch</A
 223 ></H2
 224 ><P
 225 >The Name Service Switch, or NSS, is a feature that is
 226                 present in many UNIX operating systems. It allows system
 227                 information such as hostnames, mail aliases and user information
 228                 to be resolved from different sources. For example, a standalone
 229                 UNIX workstation may resolve system information from a series of
 230                 flat files stored on the local filesystem. A networked workstation
 231                 may first attempt to resolve system information from local files,
 232                 and then consult a NIS database for user information or a DNS server
 233                 for hostname information.</P
 234 ><P
 235 >The NSS application programming interface allows winbind
 236                 to present itself as a source of system information when
 237                 resolving UNIX usernames and groups.  Winbind uses this interface,
 238                 and information obtained from a Windows NT server using MSRPC
 239                 calls to provide a new source of account enumeration.  Using standard
 240                 UNIX library calls, one can enumerate the users and groups on
 241                 a UNIX machine running winbind and see all users and groups in
 242                 a NT domain plus any trusted domain as though they were local
 243                 users and groups.</P
 244 ><P
 245 >The primary control file for NSS is
 246                 <TT
 247 CLASS="FILENAME"
 248 >/etc/nsswitch.conf</TT
 249 >.
 250                 When a UNIX application makes a request to do a lookup
 251                 the C library looks in <TT
 252 CLASS="FILENAME"
 253 >/etc/nsswitch.conf</TT
 254 >
 255                 for a line which matches the service type being requested, for
 256                 example the "passwd" service type is used when user or group names
 257                 are looked up. This     config line species which implementations
 258                 of that service should be tried and in what order. If the passwd
 259                 config line is:</P
 260 ><P
 261 ><B
 262 CLASS="COMMAND"
 263 >passwd: files example</B
 264 ></P
 265 ><P
 266 >then the C library will first load a module called
 267                 <TT
 268 CLASS="FILENAME"
 269 >/lib/libnss_files.so</TT
 270 > followed by
 271                 the module <TT
 272 CLASS="FILENAME"
 273 >/lib/libnss_example.so</TT
 274 >. The
 275                 C library will dynamically load each of these modules in turn
 276                 and call resolver functions within the modules to try to resolve
 277                 the request. Once the request is resolved the C library returns the
 278                 result to the application.</P
 279 ><P
 280 >This NSS interface provides a very easy way for Winbind
 281                 to hook into the operating system. All that needs to be done
 282                 is to put <TT
 283 CLASS="FILENAME"
 284 >libnss_winbind.so</TT
 285 > in <TT
 286 CLASS="FILENAME"
 287 >/lib/</TT
 288 >
 289                 then add "winbind" into <TT
 290 CLASS="FILENAME"
 291 >/etc/nsswitch.conf</TT
 292 > at
 293                 the appropriate place. The C library will then call Winbind to
 294                 resolve user and group names.</P
 295 ></DIV
 296 ><DIV
 297 CLASS="SECT2"
 298 ><HR><H2
 299 CLASS="SECT2"
 300 ><A
 301 NAME="AEN56"
 302 >Pluggable Authentication Modules</A
 303 ></H2
 304 ><P
 305 >Pluggable Authentication Modules, also known as PAM,
 306                 is a system for abstracting authentication and authorization
 307                 technologies. With a PAM module it is possible to specify different
 308                 authentication methods for different system applications without
 309                 having to recompile these applications. PAM is also useful
 310                 for implementing a particular policy for authorization. For example,
 311                 a system administrator may only allow console logins from users
 312                 stored in the local password file but only allow users resolved from
 313                 a NIS database to log in over the network.</P
 314 ><P
 315 >Winbind uses the authentication management and password
 316                 management PAM interface to integrate Windows NT users into a
 317                 UNIX system. This allows Windows NT users to log in to a UNIX
 318                 machine and be authenticated against a suitable Primary Domain
 319                 Controller. These users can also change their passwords and have
 320                 this change take effect directly on the Primary Domain Controller.
 321                 </P
 322 ><P
 323 >PAM is configured by providing control files in the directory
 324                 <TT
 325 CLASS="FILENAME"
 326 >/etc/pam.d/</TT
 327 > for each of the services that
 328                 require authentication. When an authentication request is made
 329                 by an application the PAM code in the C library looks up this
 330                 control file to determine what modules to load to do the
 331                 authentication check and in what order. This interface makes adding
 332                 a new authentication service for Winbind very easy, all that needs
 333                 to be done is that the <TT
 334 CLASS="FILENAME"
 335 >pam_winbind.so</TT
 336 > module
 337                 is copied to <TT
 338 CLASS="FILENAME"
 339 >/lib/security/</TT
 340 > and the PAM
 341                 control files for relevant services are updated to allow
 342                 authentication via winbind. See the PAM documentation
 343                 for more details.</P
 344 ></DIV
 345 ><DIV
 346 CLASS="SECT2"
 347 ><HR><H2
 348 CLASS="SECT2"
 349 ><A
 350 NAME="AEN64"
 351 >User and Group ID Allocation</A
 352 ></H2
 353 ><P
 354 >When a user or group is created under Windows NT
 355                 is it allocated a numerical relative identifier (RID). This is
 356                 slightly different to UNIX which has a range of numbers that are
 357                 used to identify users, and the same range in which to identify
 358                 groups. It is winbind's job to convert RIDs to UNIX id numbers and
 359                 vice versa.  When winbind is configured it is given part of the UNIX
 360                 user id space and a part of the UNIX group id space in which to
 361                 store Windows NT users and groups. If a Windows NT user is
 362                 resolved for the first time, it is allocated the next UNIX id from
 363                 the range. The same process applies for Windows NT groups. Over
 364                 time, winbind will have mapped all Windows NT users and groups
 365                 to UNIX user ids and group ids.</P
 366 ><P
 367 >The results of this mapping are stored persistently in
 368                 an ID mapping database held in a tdb database). This ensures that
 369                 RIDs are mapped to UNIX IDs in a consistent way.</P
 370 ></DIV
 371 ><DIV
 372 CLASS="SECT2"
 373 ><HR><H2
 374 CLASS="SECT2"
 375 ><A
 376 NAME="AEN68"
 377 >Result Caching</A
 378 ></H2
 379 ><P
 380 >An active system can generate a lot of user and group
 381                 name lookups. To reduce the network cost of these lookups winbind
 382                 uses a caching scheme based on the SAM sequence number supplied
 383                 by NT domain controllers.  User or group information returned
 384                 by a PDC is cached by winbind along with a sequence number also
 385                 returned by the PDC. This sequence number is incremented by
 386                 Windows NT whenever any user or group information is modified. If
 387                 a cached entry has expired, the sequence number is requested from
 388                 the PDC and compared against the sequence number of the cached entry.
 389                 If the sequence numbers do not match, then the cached information
 390                 is discarded and up to date information is requested directly
 391                 from the PDC.</P
 392 ></DIV
 393 ></DIV
 394 ><DIV
 395 CLASS="SECT1"
 396 ><HR><H1
 397 CLASS="SECT1"
 398 ><A
 399 NAME="AEN71"
 400 >Installation and Configuration</A
 401 ></H1
 402 ><P
 403 >Many thanks to John Trostel <A
 404 HREF="mailto:jtrostel@snapserver.com"
 405 TARGET="_top"
 406 >jtrostel@snapserver.com</A
 407 >
 408 for providing the original Linux version of this HOWTO which
 409 describes how to get winbind services up and running
 410 to control access and authenticate users on your Linux box using
 411 the winbind services which are included with the SAMBA 2.2.2 and later
 412 releases.</P
 413 ><DIV
 414 CLASS="SECT2"
 415 ><HR><H2
 416 CLASS="SECT2"
 417 ><A
 418 NAME="AEN75"
 419 >Introduction</A
 420 ></H2
 421 ><P
 422 >This HOWTO describes the procedures used to get winbind up and
 423 running on a RedHat 7.1 system.  Winbind is capable of providing access
 424 and authentication control for Windows Domain users through an NT
 425 or Win2K PDC for 'regular' services, such as telnet and ftp, as
 426 well providing dynamic uid/gid allocation for Samba.</P
 427 ><P
 428 >This HOWTO has been written from a 'RedHat-centric' perspective, so if
 429 you are using another distribution (or operating system), you may have
 430 to modify the instructions somewhat to fit the way your distribution works.</P
 431 ><P
 432 ></P
 433 ><UL
 434 ><LI
 435 ><P
 436 >       <I
 437 CLASS="EMPHASIS"
 438 >Why should I to this?</I
 439 >
 440         </P
 441 ><P
 442 >This allows the SAMBA administrator to rely on the
 443         authentication mechanisms on the NT/Win2K PDC for the authentication
 444         of domain members.  NT/Win2K users no longer need to have separate
 445         accounts on the SAMBA server.
 446         </P
 447 ></LI
 448 ><LI
 449 ><P
 450 >       <I
 451 CLASS="EMPHASIS"
 452 >Who should be reading this document?</I
 453 >
 454         </P
 455 ><P
 456 >       This HOWTO is designed for system administrators.  If you are
 457         implementing SAMBA on a file server and wish to (fairly easily)
 458         integrate existing NT/Win2K users from your PDC onto the
 459         SAMBA server, this HOWTO is for you.
 460         </P
 461 ></LI
 462 ></UL
 463 ></DIV
 464 ><DIV
 465 CLASS="SECT2"
 466 ><HR><H2
 467 CLASS="SECT2"
 468 ><A
 469 NAME="AEN88"
 470 >Requirements</A
 471 ></H2
 472 ><P
 473 >If you have a samba configuration file that you are currently
 474 using... <I
 475 CLASS="EMPHASIS"
 476 >BACK IT UP!</I
 477 >  If your system already uses PAM,
 478 <I
 479 CLASS="EMPHASIS"
 480 >back up the <TT
 481 CLASS="FILENAME"
 482 >/etc/pam.d</TT
 483 > (or <TT
 484 CLASS="FILENAME"
 485 >/etc/pam.conf</TT
 486 >)
 487 directory contents!</I
 488 > If you haven't already made a boot disk,
 489 <I
 490 CLASS="EMPHASIS"
 491 >MAKE ONE NOW!</I
 492 ></P
 493 ><P
 494 >Messing with the pam configuration files can make it nearly impossible
 495 to log in to your machine. That's why you want to be able to boot back
 496 into your machine in single user mode and restore your
 497 <TT
 498 CLASS="FILENAME"
 499 >/etc/pam.d</TT
 500 > (or <TT
 501 CLASS="FILENAME"
 502 >pam.conmf</TT
 503 >) back to
 504 the original state they were in if
 505 you get frustrated with the way things are going.</P
 506 ><P
 507 >The first SAMBA release to inclue a stable winbindd daemon was 2.2.2.  Please refer to the
 508 <A
 509 HREF="http://samba.org/"
 510 TARGET="_top"
 511 >main SAMBA web page</A
 512 > or,
 513 better yet, your closest SAMBA mirror site for instructions on
 514 downloading the source code.  it is generally advised to obtain the lates
 515 Samba release as bugs are constantly being fixed.</P
 516 ><P
 517 >To allow Domain users the ability to access SAMBA shares and
 518 files, as well as potentially other services provided by your
 519 SAMBA machine, PAM (pluggable authentication modules) must
 520 be setup properly on your machine.  In order to compile the
 521 winbind modules, you must have at the PAM libraries and header files resident
 522 on your system.  For recent RedHat systems (7.x, for instance), that
 523 means installing both <TT
 524 CLASS="FILENAME"
 525 >pam</TT
 526 > and <TT
 527 CLASS="FILENAME"
 528 >pam-devel</TT
 529 > RPM.
 530 The former is installed by default on all Linux systems of which the author is aware.</P
 531 ></DIV
 532 ><DIV
 533 CLASS="SECT2"
 534 ><HR><H2
 535 CLASS="SECT2"
 536 ><A
 537 NAME="AEN104"
 538 >Testing Things Out</A
 539 ></H2
 540 ><P
 541 >Before starting, kill off all the SAMBA related daemons running on your server.  Kill off
 542 all <B
 543 CLASS="COMMAND"
 544 >smbd</B
 545 >, <B
 546 CLASS="COMMAND"
 547 >nmbd</B
 548 >, and <B
 549 CLASS="COMMAND"
 550 >winbindd</B
 551 > processes that may
 552 be running (<B
 553 CLASS="COMMAND"
 554 >winbindd</B
 555 > will only be running if you have ao previous Winbind
 556 installation...but why would you be reading tis if that were the case?).  To use PAM, you will
 557 want to make sure that you have the standard PAM package (for RedHat) which supplies the <TT
 558 CLASS="FILENAME"
 559 >/etc/pam.d</TT
 560 >
 561 directory structure, including the pam modules are used by pam-aware
 562 services, several pam libraries, and the <TT
 563 CLASS="FILENAME"
 564 >/usr/doc</TT
 565 >
 566 and <TT
 567 CLASS="FILENAME"
 568 >/usr/man</TT
 569 > entries for pam.  Samba will require
 570 the pam-devel package if you plan to build the <TT
 571 CLASS="FILENAME"
 572 >pam_winbind.so</TT
 573 > library or
 574 include the <B
 575 CLASS="COMMAND"
 576 >--with-pam</B
 577 > option to the configure script.
 578 This package includes the header files needed to compile pam-aware applications.</P
 579 ><P
 580 >[I have no idea which Solaris packages are quired for PAM libraries and
 581 development files.  If you know, please mail me the information and I will include
 582 it in the next revision of this HOWTO.  --jerry@samba.org]</P
 583 ><DIV
 584 CLASS="SECT3"
 585 ><HR><H3
 586 CLASS="SECT3"
 587 ><A
 588 NAME="AEN117"
 589 >Configure and Compile SAMBA</A
 590 ></H3
 591 ><P
 592 >The configuration and compilation of SAMBA is straightforward.</P
 593 ><P
 594 ><PRE
 595 CLASS="PROGRAMLISTING"
 596 ><TT
 597 CLASS="PROMPT"
 598 >root#</TT
 599 > <B
 600 CLASS="COMMAND"
 601 >./configure --with-winbind</B
 602 >
 603 <TT
 604 CLASS="PROMPT"
 605 >root#</TT
 606 > <B
 607 CLASS="COMMAND"
 608 >make</B
 609 >
 610 <TT
 611 CLASS="PROMPT"
 612 >root#</TT
 613 > <B
 614 CLASS="COMMAND"
 615 >make install</B
 616 ></PRE
 617 ></P
 618 ><P
 619 >This will, by default, install SAMBA in <TT
 620 CLASS="FILENAME"
 621 >/usr/local/samba</TT
 622 >.
 623 See the main SAMBA documentation if you want to install SAMBA somewhere else.
 624 It will also build the winbindd executable and NSS library.</P
 625 ></DIV
 626 ><DIV
 627 CLASS="SECT3"
 628 ><HR><H3
 629 CLASS="SECT3"
 630 ><A
 631 NAME="AEN130"
 632 >Configure <TT
 633 CLASS="FILENAME"
 634 >nsswitch.conf</TT
 635 > and the
 636 winbind libraries</A
 637 ></H3
 638 ><P
 639 >The libraries needed to run the <B
 640 CLASS="COMMAND"
 641 >winbindd</B
 642 > daemon
 643 through nsswitch need to be copied to their proper locations.</P
 644 ><P
 645 ><TT
 646 CLASS="PROMPT"
 647 >root#</TT
 648 > <B
 649 CLASS="COMMAND"
 650 >cp nsswitch/libnss_winbind.so /lib</B
 651 >
 652 <TT
 653 CLASS="PROMPT"
 654 >root#</TT
 655 > <B
 656 CLASS="COMMAND"
 657 >chmod 755 /lib/libnss_winbind.so</B
 658 ></P
 659 ><P
 660 >It necessary to make the following symbolic link:</P
 661 ><P
 662 ><TT
 663 CLASS="PROMPT"
 664 >root#</TT
 665 > <B
 666 CLASS="COMMAND"
 667 >ln -s /lib/libnss_winbind.so /lib/libnss_winbind.so.2</B
 668 ></P
 669 ><P
 670 >The <TT
 671 CLASS="FILENAME"
 672 >.2</TT
 673 > extension is due to the version of glibc used on your Linux host.
 674 for most modern systems, the file extension is correct.  However, some other operating systems,
 675 Solaris 7/8 being the most common, the destination filename should be replaced with
 676 <TT
 677 CLASS="FILENAME"
 678 >/lib/nss_winbind.so.1</TT
 679 ></P
 680 ><P
 681 >Now, as root edit <TT
 682 CLASS="FILENAME"
 683 >/etc/nsswitch.conf</TT
 684 > to
 685 allow user and group entries to be visible from the <B
 686 CLASS="COMMAND"
 687 >winbindd</B
 688 >
 689 daemon.  After editing, the file look appear:</P
 690 ><P
 691 ><PRE
 692 CLASS="PROGRAMLISTING"
 693 >       passwd:     files winbind
 694         shadow:     files
 695         group:      files winbind</PRE
 696 ></P
 697 ></DIV
 698 ><DIV
 699 CLASS="SECT3"
 700 ><HR><H3
 701 CLASS="SECT3"
 702 ><A
 703 NAME="AEN152"
 704 >Configure <TT
 705 CLASS="FILENAME"
 706 >smb.conf</TT
 707 ></A
 708 ></H3
 709 ><P
 710 >Several parameters are needed in the smb.conf file to control
 711 the behavior of <B
 712 CLASS="COMMAND"
 713 >winbindd</B
 714 >. Configure
 715 <TT
 716 CLASS="FILENAME"
 717 >smb.conf</TT
 718 > These are described in more detail in
 719 the <A
 720 HREF="winbindd.8.html"
 721 TARGET="_top"
 722 >winbindd(8)</A
 723 > man page.  My
 724 <TT
 725 CLASS="FILENAME"
 726 >smb.conf</TT
 727 > file was modified to
 728 include the following entries in the [global] section:</P
 729 ><P
 730 ><PRE
 731 CLASS="PROGRAMLISTING"
 732 >[global]
 733      &#60;...&#62;
 734      # separate domain and username with '+', like DOMAIN+username
 735      <A
 736 HREF="winbindd.8.html#WINBINDSEPARATOR"
 737 TARGET="_top"
 738 >winbind separator</A
 739 > = +
 740      # use uids from 10000 to 20000 for domain users
 741      <A
 742 HREF="winbindd.8.html#WINBINDUID"
 743 TARGET="_top"
 744 >winbind uid</A
 745 > = 10000-20000
 746      # use gids from 10000 to 20000 for domain groups
 747      <A
 748 HREF="winbindd.8.html#WINBINDGID"
 749 TARGET="_top"
 750 >winbind gid</A
 751 > = 10000-20000
 752      # allow enumeration of winbind users and groups
 753      # might need to disable these next two for performance
 754      # reasons on the winbindd host
 755      <A
 756 HREF="winbindd.8.html#WINBINDENUMUSERS"
 757 TARGET="_top"
 758 >winbind enum users</A
 759 > = yes
 760      <A
 761 HREF="winbindd.8.html#WINBINDENUMGROUP"
 762 TARGET="_top"
 763 >winbind enum groups</A
 764 > = yes
 765      # give winbind users a real shell (only needed if they have telnet/sshd/etc... access)
 766      <A
 767 HREF="winbindd.8.html#TEMPLATEHOMEDIR"
 768 TARGET="_top"
 769 >template homedir</A
 770 > = /home/winnt/%D/%U
 771      <A
 772 HREF="winbindd.8.html#TEMPLATESHELL"
 773 TARGET="_top"
 774 >template shell</A
 775 > = /bin/bash</PRE
 776 ></P
 777 ></DIV
 778 ><DIV
 779 CLASS="SECT3"
 780 ><HR><H3
 781 CLASS="SECT3"
 782 ><A
 783 NAME="AEN169"
 784 >Join the SAMBA server to the PDC domain</A
 785 ></H3
 786 ><P
 787 >Enter the following command to make the SAMBA server join the
 788 PDC domain, where <TT
 789 CLASS="REPLACEABLE"
 790 ><I
 791 >DOMAIN</I
 792 ></TT
 793 > is the name of
 794 your Windows domain and <TT
 795 CLASS="REPLACEABLE"
 796 ><I
 797 >Administrator</I
 798 ></TT
 799 > is
 800 a domain user who has administrative privileges in the domain.</P
 801 ><P
 802 ><TT
 803 CLASS="PROMPT"
 804 >root#</TT
 805 > <B
 806 CLASS="COMMAND"
 807 >/usr/local/samba/bin/smbpasswd -j DOMAIN -r PDC -U Administrator</B
 808 ></P
 809 ><P
 810 >The proper response to the command should be: "Joined the domain
 811 <TT
 812 CLASS="REPLACEABLE"
 813 ><I
 814 >DOMAIN</I
 815 ></TT
 816 >" where <TT
 817 CLASS="REPLACEABLE"
 818 ><I
 819 >DOMAIN</I
 820 ></TT
 821 >
 822 is your DOMAIN name.</P
 823 ></DIV
 824 ><DIV
 825 CLASS="SECT3"
 826 ><HR><H3
 827 CLASS="SECT3"
 828 ><A
 829 NAME="AEN180"
 830 >Start up the winbindd daemon and test it!</A
 831 ></H3
 832 ><P
 833 >Eventually, you will want to modify your smb startup script to
 834 automatically invoke the winbindd daemon when the other parts of
 835 SAMBA start, but it is possible to test out just the winbind
 836 portion first.  To start up winbind services, enter the following
 837 command as root:</P
 838 ><P
 839 ><TT
 840 CLASS="PROMPT"
 841 >root#</TT
 842 > <B
 843 CLASS="COMMAND"
 844 >export PATH=$PATH:/usr/local/samba/bin</B
 845 >
 846 <TT
 847 CLASS="PROMPT"
 848 >root#</TT
 849 > <B
 850 CLASS="COMMAND"
 851 >winbindd</B
 852 ></P
 853 ><P
 854 >I'm always paranoid and like to make sure the daemon
 855 is really running...</P
 856 ><P
 857 ><TT
 858 CLASS="PROMPT"
 859 >root#</TT
 860 > <B
 861 CLASS="COMMAND"
 862 >ps -ae | grep winbindd</B
 863 ></P
 864 ><P
 865 >This command should produce output like this, if the daemon is running</P
 866 ><P
 867 >3025 ?        00:00:00 winbindd</P
 868 ><P
 869 >Note that a sample RedHat init script for starting winbindd is included in
 870 the SAMBA sourse distribution as <TT
 871 CLASS="FILENAME"
 872 >packaging/RedHat/winbind.init</TT
 873 >.</P
 874 ><P
 875 >Now... for the real test, try to get some information about the
 876 users on your PDC</P
 877 ><P
 878 ><TT
 879 CLASS="PROMPT"
 880 >root#</TT
 881 > <B
 882 CLASS="COMMAND"
 883 >wbinfo -u</B
 884 ></P
 885 ><P
 886 >This should echo back a list of users on your Windows users on
 887 your PDC.  For example, I get the following response:</P
 888 ><P
 889 ><PRE
 890 CLASS="PROGRAMLISTING"
 891 >CEO+Administrator
 892 CEO+burdell
 893 CEO+Guest
 894 CEO+jt-ad
 895 CEO+krbtgt
 896 CEO+TsInternetUser</PRE
 897 ></P
 898 ><P
 899 >Obviously, I have named my domain 'CEO' and my <TT
 900 CLASS="PARAMETER"
 901 ><I
 902 >winbind
 903 separator</I
 904 ></TT
 905 > is '+'.</P
 906 ><P
 907 >You can do the same sort of thing to get group information from
 908 the PDC:</P
 909 ><P
 910 ><PRE
 911 CLASS="PROGRAMLISTING"
 912 ><TT
 913 CLASS="PROMPT"
 914 >root#</TT
 915 > <B
 916 CLASS="COMMAND"
 917 >/usr/local/samba/bin/wbinfo -g</B
 918 >
 919 CEO+Domain Admins
 920 CEO+Domain Users
 921 CEO+Domain Guests
 922 CEO+Domain Computers
 923 CEO+Domain Controllers
 924 CEO+Cert Publishers
 925 CEO+Schema Admins
 926 CEO+Enterprise Admins
 927 CEO+Group Policy Creator Owners</PRE
 928 ></P
 929 ><P
 930 >The function 'getent' can now be used to get unified
 931 lists of both local and PDC users and groups.
 932 Try the following command:</P
 933 ><P
 934 ><TT
 935 CLASS="PROMPT"
 936 >root#</TT
 937 > <B
 938 CLASS="COMMAND"
 939 >getent passwd</B
 940 ></P
 941 ><P
 942 >You should get a list that looks like your <TT
 943 CLASS="FILENAME"
 944 >/etc/passwd</TT
 945 >
 946 list followed by the domain users with their new uids, gids, home
 947 directories and default shells.  If you do not, verify that the permissions on the
 948 libnss_winbind.so library are <TT
 949 CLASS="FILENAME"
 950 >rwxr-xr-x</TT
 951 >.</P
 952 ><P
 953 >The same thing can be done for groups with the command</P
 954 ><P
 955 ><TT
 956 CLASS="PROMPT"
 957 >root#</TT
 958 > <B
 959 CLASS="COMMAND"
 960 >getent group</B
 961 ></P
 962 ></DIV
 963 ><DIV
 964 CLASS="SECT3"
 965 ><HR><H3
 966 CLASS="SECT3"
 967 ><A
 968 NAME="AEN221"
 969 >Configure Winbind and PAM</A
 970 ></H3
 971 ><P
 972 >At this point we are assured that <B
 973 CLASS="COMMAND"
 974 >winbindd</B
 975 > and <B
 976 CLASS="COMMAND"
 977 >smbd</B
 978 >
 979 are working together.  If you want to use winbind to provide authentication for other
 980 services, keep reading.  The pam configuration files need to be altered in
 981 this step.  (Did you remember to make backups of your original
 982 <TT
 983 CLASS="FILENAME"
 984 >/etc/pam.d</TT
 985 > (or <TT
 986 CLASS="FILENAME"
 987 >/etc/pam.conf</TT
 988 >) file[s]? If not, do it now.)</P
 989 ><P
 990 >You will need a PAM module to use <B
 991 CLASS="COMMAND"
 992 >winbindd</B
 993 > with these other services.  This
 994 module will be compiled in the <TT
 995 CLASS="FILENAME"
 996 >../source/nsswitch</TT
 997 > directory
 998 by invoking the command</P
 999 ><P
1000 ><TT
1001 CLASS="PROMPT"
1002 >root#</TT
1003 > <B
1004 CLASS="COMMAND"
1005 >make nsswitch/pam_winbind.so</B
1006 ></P
1007 ><P
1008 >from the <TT
1009 CLASS="FILENAME"
1010 >../source</TT
1011 > directory.  The
1012 <TT
1013 CLASS="FILENAME"
1014 >pam_winbind.so</TT
1015 > file should be copied to the location of
1016 your other pam security modules.  On Linux and Solaris systems, this is the
1017 <TT
1018 CLASS="FILENAME"
1019 >/lib/security</TT
1020 > directory.</P
1021 ><P
1022 ><TT
1023 CLASS="PROMPT"
1024 >root#</TT
1025 > <B
1026 CLASS="COMMAND"
1027 >cp nsswitch/pam_winbind.so /lib/security</B
1028 >
1029 <TT
1030 CLASS="PROMPT"
1031 >root#</TT
1032 > <B
1033 CLASS="COMMAND"
1034 >chmod 755 /lib/security/pam_winbind.so</B
1035 ></P
1036 ><P
1037 >Other services, such as the normal login on the console (or a terminal
1038 session), telnet logins, and ftp service, can be modified to allow the use of winbind
1039 as an authentication service.  In order to enable these
1040 services, you may first need to change the entries in
1041 <TT
1042 CLASS="FILENAME"
1043 >/etc/xinetd.d</TT
1044 > (or <TT
1045 CLASS="FILENAME"
1046 >/etc/inetd.conf</TT
1047 >).
1048 RedHat 7.1 uses the new xinetd.d structure, in this case you need
1049 to change the lines in <TT
1050 CLASS="FILENAME"
1051 >/etc/xinetd.d/telnet</TT
1052 >
1053 and <TT
1054 CLASS="FILENAME"
1055 >/etc/xinetd.d/wu-ftp</TT
1056 > from</P
1057 ><P
1058 ><PRE
1059 CLASS="PROGRAMLISTING"
1060 >enable = no</PRE
1061 ></P
1062 ><P
1063 >to</P
1064 ><P
1065 ><PRE
1066 CLASS="PROGRAMLISTING"
1067 >enable = yes</PRE
1068 ></P
1069 ><P
1070 >For ftp services to work properly, you will also need to either
1071 have individual directories for the domain users already present on
1072 the server, or change the home directory template to a general
1073 directory for all domain users.  These can be easily set using
1074 the <TT
1075 CLASS="FILENAME"
1076 >smb.conf</TT
1077 > global entry
1078 <B
1079 CLASS="COMMAND"
1080 >template homedir</B
1081 >.</P
1082 ><P
1083 >The <TT
1084 CLASS="FILENAME"
1085 >/etc/pam.d/ftp</TT
1086 > file can be changed
1087 to allow winbind ftp access in a manner similar to the
1088 samba file.  My <TT
1089 CLASS="FILENAME"
1090 >/etc/pam.d/ftp</TT
1091 > file was
1092 changed to look like this:</P
1093 ><P
1094 ><PRE
1095 CLASS="PROGRAMLISTING"
1096 >auth       required     /lib/security/pam_listfile.so item=user sense=deny file=/etc/ftpusers onerr=succeed
1097 auth       sufficient   /lib/security/pam_winbind.so
1098 auth       required     /lib/security/pam_stack.so service=system-auth
1099 auth       required     /lib/security/pam_shells.so
1100 account    sufficient   /lib/security/pam_winbind.so
1101 account    required     /lib/security/pam_stack.so service=system-auth
1102 session    required     /lib/security/pam_stack.so service=system-auth</PRE
1103 ></P
1104 ><P
1105 >The <TT
1106 CLASS="FILENAME"
1107 >/etc/pam.d/login</TT
1108 > file can be changed nearly the
1109 same way.  It now looks like this:</P
1110 ><P
1111 ><PRE
1112 CLASS="PROGRAMLISTING"
1113 >auth       required     /lib/security/pam_securetty.so
1114 auth       sufficient   /lib/security/pam_winbind.so
1115 auth       sufficient   /lib/security/pam_unix.so use_first_pass
1116 auth       required     /lib/security/pam_stack.so service=system-auth
1117 auth       required     /lib/security/pam_nologin.so
1118 account    sufficient   /lib/security/pam_winbind.so
1119 account    required     /lib/security/pam_stack.so service=system-auth
1120 password   required     /lib/security/pam_stack.so service=system-auth
1121 session    required     /lib/security/pam_stack.so service=system-auth
1122 session    optional     /lib/security/pam_console.so</PRE
1123 ></P
1124 ><P
1125 >In this case, I added the <B
1126 CLASS="COMMAND"
1127 >auth sufficient /lib/security/pam_winbind.so</B
1128 >
1129 lines as before, but also added the <B
1130 CLASS="COMMAND"
1131 >required pam_securetty.so</B
1132 >
1133 above it, to disallow root logins over the network.  I also added a
1134 <B
1135 CLASS="COMMAND"
1136 >sufficient /lib/security/pam_unix.so use_first_pass</B
1137 >
1138 line after the <B
1139 CLASS="COMMAND"
1140 >winbind.so</B
1141 > line to get rid of annoying
1142 double prompts for passwords.</P
1143 ><P
1144 >Note that a Solaris <TT
1145 CLASS="FILENAME"
1146 >/etc/pam.conf</TT
1147 > confiruation file looks
1148 very similar to this except thaty the service name is included as the first entry
1149 per line.  An example for the login service is given here.</P
1150 ><P
1151 ><PRE
1152 CLASS="PROGRAMLISTING"
1153 >## excerpt from /etc/pam.conf on a Solaris 8 system
1154 login   auth required   /lib/security/pam_winbind.so
1155 login   auth required   /lib/security/$ISA/pam_unix.so.1 try_first_pass
1156 login   auth required   /lib/security/$ISA/pam_dial_auth.so.1 try_first_pass</PRE
1157 ></P
1158 ></DIV
1159 ></DIV
1160 ></DIV
1161 ><DIV
1162 CLASS="SECT1"
1163 ><HR><H1
1164 CLASS="SECT1"
1165 ><A
1166 NAME="AEN274"
1167 >Limitations</A
1168 ></H1
1169 ><P
1170 >Winbind has a number of limitations in its current
1171         released version that we hope to overcome in future
1172         releases:</P
1173 ><P
1174 ></P
1175 ><UL
1176 ><LI
1177 ><P
1178 >The mappings of Windows NT RIDs to UNIX ids
1179                 is not made algorithmically and depends on the order in which
1180                 unmapped users or groups are seen by winbind. It may be difficult
1181                 to recover the mappings of rid to UNIX id mapping if the file
1182                 containing this information is corrupted or destroyed.</P
1183 ></LI
1184 ><LI
1185 ><P
1186 >Currently the winbind PAM module does not take
1187                 into account possible workstation and logon time restrictions
1188                 that may be been set for Windows NT users.</P
1189 ></LI
1190 ></UL
1191 ></DIV
1192 ><DIV
1193 CLASS="SECT1"
1194 ><HR><H1
1195 CLASS="SECT1"
1196 ><A
1197 NAME="AEN282"
1198 >Conclusion</A
1199 ></H1
1200 ><P
1201 >The winbind system, through the use of the Name Service
1202         Switch, Pluggable Authentication Modules, and appropriate
1203         Microsoft RPC calls have allowed us to provide seamless
1204         integration of Microsoft Windows NT domain users on a
1205         UNIX system. The result is a great reduction in the administrative
1206         cost of running a mixed UNIX and NT network.</P
1207 ></DIV
1208 ></DIV
1209 ></BODY
1210 ></HTML
1211 >