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diff --git a/docs/Samba3-HOWTO/TOSHARG-RightsAndPriviliges.xml b/docs/Samba3-HOWTO/TOSHARG-RightsAndPriviliges.xml new file mode 100644 index 0000000000..a8c2811511 --- /dev/null +++ b/docs/Samba3-HOWTO/TOSHARG-RightsAndPriviliges.xml @@ -0,0 +1,278 @@ +<?xml version="1.0" encoding="iso-8859-1"?> +<!DOCTYPE chapter PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc"> +<chapter id="rights"> +<chapterinfo> + &author.jerry; + &author.jht; +</chapterinfo> + +<title>User Rights and Privileges</title> + +<para> +The administration of Windows user, group and machine accounts in the Samba +domain controlled network necessitates interfacing between the MS Windows +networking environment and the UNIX operating system environment. The right +(permission) to add machines to the Windows security domain can be assigned +(set) to non-administrative users both in Windows NT4 domains as well as in +Active Directory domains. +</para> + +<para> +The addition of Windows NT4/2kX/XPPro machines to the domain necessitates the +creation of a machine account for each machine added. The machine account is +a necessity that is used to validate that the machine can be trusted to permit +user logons. +</para> + +<para> +Machine accounts are analogous to user accounts, and thus in implementing them +on a UNIX machine that is hosting Samba (i.e.: On which Samba is running) it is +necessary to create a special type of user account. Machine accounts differ from +a normal user account in that the account name (login ID) is terminated with a $ +sign. An additional difference is that this type of account should not ever be able +to log into the UNIX environment as a system user and therefore is set to have a +shell of <command>/bin/false</command> and a home directory of +<command>/dev/null.</command> +</para> + +<para> +The creation of UNIX system accounts has traditionally been the sole right of +the system administrator, better known as the <constant>root</constant> account. +It is possible in the UNIX environment to create multiple users who have the +same UID. Any UNIX user who has a UID=0 is inherently the same as the +<constant>root</constant> account. +</para> + +<para> +All versions of Samba call system interface scripts that permit CIFS function +calls that are used to manage users, groups and machine accounts to be affected +in the UNIX environment. All versions of Samba up to and including version 3.0.10 +required the use of a Windows Administrator account that unambiguously maps to +the UNIX <constant>root</constant> account to permit the execution of these +interface scripts. The reuqirement to do this has understandably met with some +disdain and consternation among Samba administrators, particularly where it became +necessary to permit people who should not posses <constant>root</constant> level +access to the UNIX host system. +</para> + +<sect1> +<title>Rights Management Capabilities</title> + +<para> +Samba 3.0.11 introduces support for the Windows privilege model. This model +allows certain rights to be assigned to a user or group SID. In order to enable +this feature, <smbconfoption name="enable privileges">yes</smbconfoption> +must be defined in the <smbconfsection name="global"/> section of the &smb.conf; file. +</para> + +<para> +Currently, the rights supported in Samba 3 are listed in <link linkend="rp-privs"/>. +The remainder of this chapter explains how to manage and use these privileges on Samba servers. +</para> + +<table id="rp-privs"> + <title>Current Privilege Capabilities</title> + <tgroup cols="2"> + <colspec align="right"/> + <colspec align="left"/> + <thead> + <row> + <entry align="center">Privilege</entry> + <entry align="center">Description</entry> + </row> + </thead> + <tbody> + <row> + <entry><para>SeMachineAccountPrivilege</para></entry> + <entry><para>Add machines to domain</para></entry> + </row> + <row> + <entry><para>SePrintOperatorPrivilege</para></entry> + <entry><para>Manage printers</para></entry> + </row> + <row> + <entry><para>SeAddUsersPrivilege</para></entry> + <entry><para>Add users and groups to the domain</para></entry> + </row> + <row> + <entry><para>SeRemoteShutdownPrivilege</para></entry> + <entry><para>Force shutdown from a remote system</para></entry> + </row> + <row> + <entry><para>SeDiskOperatorPrivilege</para></entry> + <entry><para>Manage disk share</para></entry> + </row> + </tbody> + </tgroup> +</table> + +<sect2> +<title>Using the <quote>net rpc rights</quote> Utility</title> + +<para> +There are two primary means of managing the rights assigned to users and groups +on a Samba server. The <command>NT4 User Manager for Domains</command> may be +used from any Windows NT4, 2000 or XP Professional domain member client to +connect to a Samba domain controller and view/modify the rights assignments. +This application, however, appears to have bugs when run on a client running +Windows 2000 or later, therefore Samba provides a command line utility for +performing the necessary administrative actions. +</para> + +<para> +The <command>net rpc rights</command> utility in Samba 3.0.11 has 3 new subcommands: +</para> + +<variablelist> + <varlistentry><term>list [name|accounts]</term> + <listitem><para> + When called with no arguments, <command>net rpc list</command> + will simply list the available rights on the server. When passed + a specific user or group name, the tool lists the privileges + currently assigned to the specified account. When invoked using + the special string <constant>accounts</constant>, + <command>net rpc rights list</command> will return a list of all + privileged accounts on the server and the assigned rights. + </para></listitem> + </varlistentry> + + <varlistentry><term>grant <user> <right [right ...]></term> + <listitem><para> + When called with no arguments, This function is used to assign + a list of rights to a specified user or group. For example, + to grant the members of the Domain Admins group on a Samba DC + the capability to add client machines to the domain, one would run: +<screen> +&rootprompt; net -S server -U domadmin rpc rights grant \ + 'DOMAIN\Domain Admins' SeMachineAccountPrivilege +</screen> + More than one privilege can be assigned by specifying a + list of rights separated by spaces. The parameter 'Domain\Domain Admins' + must be quoted with single ticks or using double-quotes to prevent + the back-slash and the space from being interpreted by the system shell. + </para></listitem> + </varlistentry> + + <varlistentry><term>revoke <user> <right [right ...]></term> + <listitem><para> + This command is similar in format to <command>net rpc rights grant</command>. It's + effect is to remove an assigned right (or list of rights) from a user or group. + </para></listitem> + </varlistentry> + +</variablelist> + +<note><para> +You must be connected as a member of the Domain Admins group to be able to +grant or revoke privileges assigned to an account. This capability is +inherent to the Domain Admins group and is not configurable. +</para></note> + +<para> +By default, no privileges are initially assigned to any +account. The reason for this is that certain actions will +be performed as root once smbd determines that a user has +the necessary rights. For example, when joining a client to +a Windows domain, the 'add machine script' must be executed +with superuser rights in most cases. For this reason, you +should be very careful about handing out privileges to +accounts. +</para> + +<para> +Access as the root user (UID=0) bypasses all privilege checks. +</para> + +</sect2> + +<sect2> +<title>Description of Privileges</title> + +<para> +The privileges that have been implemented in Samba-3.0.11 are shown below. +It is possible, and likely, that additional privileges may be implemented in +later releases of Samba. It is also likely that any privileges currently implemented +but not used may be removed from future releases, thus it is important that +the successful as well as unsuccessful use of these facilities should be reported +on the Samba mailing lists. +</para> + +<variablelist> + <varlistentry><term>SeAddUsersPrivilege</term> + <listitem><para> + This right determines whether or not smbd will allow the + user to create new user or group accounts via such tools + as <command>net rpc user add</command> or + <command>NT4 User Manager for Domains.</command> + </para></listitem> + </varlistentry> + + <varlistentry><term>SeDiskOperatorPrivilege</term> + <listitem><para> + Accounts which posses this right will be able to execute + scripts defined by the <command>add/delete/change</command> + share command in &smb.conf; file as root. Such users will + also be able to modify the ACL associated with file shares + on the Samba server. + </para></listitem> + </varlistentry> + + <varlistentry><term>SeMachineAccountPrivilege</term> + <listitem><para> + Controls whether or not the user is able join client + machines to a Samba controlled domain. + </para></listitem> + </varlistentry> + + <varlistentry><term>SePrintOperatorPrivilege</term> + <listitem><para> + This privilege operates identically to the + <smbconfoption name="printer admin"/> + option in the &smb.conf; file (see section 5 man page for &smb.conf;) + except that it is a global right (not on a per printer basis). + Eventually the smb.conf option will be deprecated and administrative + rights to printers will be controlled exclusively by this right and + the security descriptor associated with the printer object in the + <filename>ntprinters.tdb</filename> file. + </para></listitem> + </varlistentry> + + <varlistentry><term>SeRemoteShutdownPrivilege</term> + <listitem><para> + Samba provides two hooks for shutting down or rebooting + the server and for aborting a previously issued shutdown + command. Since this is an operation normally limited by + the operating system to the root user, an account must possess this + right to be able to execute either of these hooks to have any effect. + </para></listitem> + </varlistentry> + +</variablelist> + +</sect2> + +</sect1> + +<sect1> +<title>The Administrator Domain SID</title> + +<para> +Please note that when configured as a DC, it is now required +that an account in the server's passdb backend be set to the +domain SID of the default Administrator account. To obtain the +domain SID on a Samba DC, run the following command: + +<screen> +&rootprompt; net getlocalsid +SID for domain FOO is: S-1-5-21-4294955119-3368514841-2087710299 +</screen> +You may assign the Domain Administrator rid to an account using the <command>pdbedit</command> +command as shown here: +<screen> +&rootprompt; pdbedit -U S-1-5-21-4294955119-3368514841-2087710299-500 -u root -r +</screen> +</para> + +</sect1> + +</chapter> |