From bc06e06d34c4a5da1272e1f2eab3e00fe3d7a0d4 Mon Sep 17 00:00:00 2001
From: Gerald Carter You must choose to start smbd and nmbd either
+>You must choose to start smbd and nmbd either
as daemons or from inetd. Don't try
+>. Don't try
to do both! Either you can put them in inetd.conf and have them started on demand
+> and have them started on demand
by inetd /etc/rc.local. See the man pages for details
- on the command line options. Take particular care to read
- the bit about what user you need to be in order to start
+>. See the man pages for details
+ on the command line options. Take particular care to read
+ the bit about what user you need to be in order to start
Samba. In many cases you must be root. The main advantage of starting nmbd as a daemon is that they will
- respond slightly more quickly to an initial connection
- request. This is, however, unlikely to be a problem.
1.6. Step 5: Starting the smbd and nmbd
This document describes how to use an LDAP directory for storing Samba user -account information normally stored in the smbpasswd(5) file. It is -assumed that the reader already has a basic understanding of LDAP concepts -and has a working directory server already installed. For more information -on LDAP architectures and Directories, please refer to the following sites.
OpenLDAP - http://www.openldap.org/
iPlanet Directory Server - http://iplanet.netscape.com/directory
Note that O'Reilly Publishing is working on -a guide to LDAP for System Administrators which has a planned release date of -early summer, 2002.
It may also be helpful to supplement the reading of the HOWTO with -the Samba-PDC-LDAP-HOWTO -maintained by Ignacio Coupeau.
Traditionally, when configuring "encrypt -passwords = yes" in Samba's smb.conf file, user account -information such as username, LM/NT password hashes, password change times, and account -flags have been stored in the smbpasswd(5) file. There are several -disadvantages to this approach for sites with very large numbers of users (counted -in the thousands).
The first is that all lookups must be performed sequentially. Given that -there are approximately two lookups per domain logon (one for a normal -session connection such as when mapping a network drive or printer), this -is non-optimal. What is needed is an indexed approach such as is used in -databases.
The second problem is that administrators who desired to replicate a -smbpasswd file to more than one Samba server were left to use external -tools such as rsync(1) and ssh(1) -and wrote custom, in-house scripts.
And finally, the amount of information which is stored in an -smbpasswd entry leaves no room for additional attributes such as -a home directory, password expiration time, or even a Relative -Identified (RID).
As a result of these defeciencies, a more robust means of storing user attributes -used by smbd was developed. The API which defines access to user accounts -is referred to as the samdb interface (previously this was called the passdb -API, and is still so named in the CVS trees). In Samba 2.2.3, enabling support -for a samdb backend (e.g. --with-ldapsam or ---with-tdbsam) requires compile time support.
When compiling Samba to include the --with-ldapsam autoconf -option, smbd (and associated tools) will store and lookup user accounts in -an LDAP directory. In reality, this is very easy to understand. If you are -comfortable with using an smbpasswd file, simply replace "smbpasswd" with -"LDAP directory" in all the documentation.
There are a few points to stress about what the --with-ldapsam -does not provide. The LDAP support referred to in the this documentation does not -include:
A means of retrieving user account information from - an Windows 2000 Active Directory server.
A means of replacing /etc/passwd.
The second item can be accomplished by using LDAP NSS and PAM modules. LGPL -versions of these libraries can be obtained from PADL Software -(http://www.padl.com/). However, -the details of configuring these packages are beyond the scope of this document.
The LDAP samdb code in 2.2.3 has been developed and tested using the OpenLDAP -2.0 server and client libraries. The same code should be able to work with -Netscape's Directory Server and client SDK. However, due to lack of testing -so far, there are bound to be compile errors and bugs. These should not be -hard to fix. If you are so inclined, please be sure to forward all patches to -samba-patches@samba.org and -jerry@samba.org.
Samba 2.2.3 includes the necessary schema file for OpenLDAP 2.0 in -examples/LDAP/samba.schema. (Note that this schema -file has been modified since the experimental support initially included -in 2.2.2). The sambaAccount objectclass is given here:
objectclass ( 1.3.1.5.1.4.1.7165.2.2.2 NAME 'sambaAccount' SUP top STRUCTURAL - DESC 'Samba Account' - MUST ( uid $ rid ) - MAY ( cn $ lmPassword $ ntPassword $ pwdLastSet $ logonTime $ - logoffTime $ kickoffTime $ pwdCanChange $ pwdMustChange $ acctFlags $ - displayName $ smbHome $ homeDrive $ scriptPath $ profilePath $ - description $ userWorkstations $ primaryGroupID )) |
The samba.schema file has been formatted for OpenLDAP 2.0. The OID's are -owned by the Samba Team and as such is legal to be openly published. -If you translate the schema to be used with Netscape DS, please -submit the modified schema file as a patch to jerry@samba.org
Just as the smbpasswd file is mean to store information which supplements a -user's /etc/passwd entry, so is the sambaAccount object -meant to supplement the UNIX user account information. A sambaAccount is a -STRUCTURAL objectclass so it can be stored individually -in the directory. However, there are several fields (e.g. uid) which overlap -with the posixAccount objectclass outlined in RFC2307. This is by design.
In order to store all user account information (UNIX and Samba) in the directory, -it is necessary to use the sambaAccount and posixAccount objectclasses in -combination. However, smbd will still obtain the user's UNIX account -information via the standard C library calls (e.g. getpwnam(), et. al.). -This means that the Samba server must also have the LDAP NSS library installed -and functioning correctly. This division of information makes it possible to -store all Samba account information in LDAP, but still maintain UNIX account -information in NIS while the network is transitioning to a full LDAP infrastructure.
To include support for the sambaAccount object in an OpenLDAP directory -server, first copy the samba.schema file to slapd's configuration directory.
root# cp samba.schema /etc/openldap/schema/
Next, include the samba.schema file in slapd.conf. -The sambaAccount object contains two attributes which depend upon other schema -files. The 'uid' attribute is defined in cosine.schema and -the 'displayName' attribute is defined in the inetorgperson.schema -file. Bother of these must be included before the samba.schema file.
## /etc/openldap/slapd.conf - -## schema files (core.schema is required by default) -include /etc/openldap/schema/core.schema - -## needed for sambaAccount -include /etc/openldap/schema/cosine.schema -include /etc/openldap/schema/inetorgperson.schema -include /etc/openldap/schema/samba.schema - -## uncomment this line if you want to support the RFC2307 (NIS) schema -## include /etc/openldap/schema/nis.schema - -.... |
The following parameters are available in smb.conf only with --with-ldapsam -was included with compiling Samba.
These are described in the smb.conf(5) man -page and so will not be repeated here. However, a sample smb.conf file for -use with an LDAP directory could appear as
## /usr/local/samba/lib/smb.conf -[global] - security = user - encrypt passwords = yes - - netbios name = TASHTEGO - workgroup = NARNIA - - # ldap related parameters - - # define the DN to use when binding to the directory servers - # The password for this DN is not stored in smb.conf. Rather it - # must be set by using 'smbpasswd -w secretpw' to store the - # passphrase in the secrets.tdb file. If the "ldap admin dn" values - # changes, this password will need to be reset. - ldap admin dn = "cn=Manager,dc=samba,dc=org" - - # specify the LDAP server's hostname (defaults to locahost) - ldap server = ahab.samba.org - - # Define the SSL option when connecting to the directory - # ('off', 'start tls', or 'on' (default)) - ldap ssl = start tls - - # define the port to use in the LDAP session (defaults to 636 when - # "ldap ssl = on") - ldap port = 389 - - # specify the base DN to use when searching the directory - ldap suffix = "ou=people,dc=samba,dc=org" - - # generally the default ldap search filter is ok - # ldap filter = "(&(uid=%u)(objectclass=sambaAccount))" |
There are two important points to remember when discussing the security -of sambaAccount entries in the directory.
Never retrieve the lmPassword or - ntPassword attribute values over an unencrypted LDAP session.
Never allow non-admin users to - view the lmPassword or ntPassword attribute values.
These password hashes are clear text equivalents and can be used to impersonate -the user without deriving the original clear text strings.
To remedy the first security issue, the "ldap ssl" smb.conf parameter defaults -to require an encrypted session (ldap ssl = on) using -the default port of 636 -when contacting the directory server. When using an OpenLDAP 2.0 server, it -is possible to use the use the StartTLS LDAP extended operation in the place of -LDAPS. In either case, you are strongly discouraged to disable this security -(ldap ssl = off).
The second security precaution is to prevent non-administrative users from -harvesting password hashes from the directory. This can be done using the -following ACL in slapd.conf:
## allow users to update their own password, but not to browse others -access to attrs=userPassword,lmPassword,ntPassword - by self write - by * auth |
You may of course, add in write access to administrative DN's as necessary.
There are currently four sambaAccount attributes which map directly onto -smb.conf parameters.
smbHome -> "logon home"
profilePath -> "logon path"
homeDrive -> "logon drive"
scriptPath -> "logon script"
First of all, these parameters are only used when Samba is acting as a -PDC or a domain (refer to the Samba-PDC-HOWTO -for details on how to configure Samba as a Primary Domain Controller). -Furthermore, these attributes are only stored with the sambaAccount entry if -the values are non-default values. For example, assume TASHTEGO has now been -configured as a PDC and that logon home = \\%L\%u was defined in -its smb.conf file. When a user named "becky" logons to the domain, -the logon home string is expanded to \\TASHTEGO\becky.
If the smbHome attribute exists in the entry "uid=becky,ou=people,dc=samba,dc=org", -this value is used. However, if this attribute does not exist, then the value -of the logon home parameter is used in its place. Samba -will only write the attribute value to the directory entry is the value is -something other than the default (e.g. \\MOBY\becky).
The following is a working LDIF with the inclusion of the posixAccount objectclass:
dn: uid=guest2, ou=people,dc=plainjoe,dc=org -ntPassword: 878D8014606CDA29677A44EFA1353FC7 -pwdMustChange: 2147483647 -primaryGroupID: 1201 -lmPassword: 552902031BEDE9EFAAD3B435B51404EE -pwdLastSet: 1010179124 -logonTime: 0 -objectClass: sambaAccount -uid: guest2 -kickoffTime: 2147483647 -acctFlags: [UX ] -logoffTime: 2147483647 -rid: 19006 -pwdCanChange: 0 |
The following is an LDIF entry for using both the sambaAccount and -posixAccount objectclasses:
dn: uid=gcarter, ou=people,dc=plainjoe,dc=org -logonTime: 0 -displayName: Gerald Carter -lmPassword: 552902031BEDE9EFAAD3B435B51404EE -primaryGroupID: 1201 -objectClass: posixAccount -objectClass: sambaAccount -acctFlags: [UX ] -userPassword: {crypt}BpM2ej8Rkzogo -uid: gcarter -uidNumber: 9000 -cn: Gerald Carter -loginShell: /bin/bash -logoffTime: 2147483647 -gidNumber: 100 -kickoffTime: 2147483647 -pwdLastSet: 1010179230 -rid: 19000 -homeDirectory: /home/tashtego/gcarter -pwdCanChange: 0 -pwdMustChange: 2147483647 -ntPassword: 878D8014606CDA29677A44EFA1353FC7 |
Please mail all comments regarding this HOWTO to jerry@samba.org. This documents was -last updated to reflect the Samba 2.2.3 release.
Integration of UNIX and Microsoft Windows NT through @@ -8599,8 +7864,8 @@ CLASS="SECT1" >
It is well known that UNIX and Microsoft Windows NT have @@ -8653,8 +7918,8 @@ CLASS="SECT1" >
Winbind unifies UNIX and Windows NT account management by @@ -8695,8 +7960,8 @@ CLASS="SECT2" >
Winbind is targeted at organizations that have an @@ -8719,8 +7984,8 @@ CLASS="SECT1" >
The winbind system is designed around a client/server @@ -8739,8 +8004,8 @@ CLASS="SECT2" >
Over the last two years, efforts have been underway @@ -8765,8 +8030,8 @@ CLASS="SECT2" >
The Name Service Switch, or NSS, is a feature that is @@ -8845,8 +8110,8 @@ CLASS="SECT2" >
Pluggable Authentication Modules, also known as PAM, @@ -8894,8 +8159,8 @@ CLASS="SECT2" >
When a user or group is created under Windows NT @@ -8920,8 +8185,8 @@ CLASS="SECT2" >
An active system can generate a lot of user and group @@ -8943,8 +8208,8 @@ CLASS="SECT1" >
Many thanks to John Trostel 10.5.1. Introduction9.5.1. Introduction
This HOWTO describes the procedures used to get winbind up and @@ -9013,8 +8278,8 @@ CLASS="SECT2" >
If you have a samba configuration file that you are currently @@ -9071,8 +8336,8 @@ CLASS="SECT2" >
Before starting, it is probably best to kill off all the SAMBA @@ -9116,8 +8381,8 @@ CLASS="SECT3" >
The configuration and compilation of SAMBA is pretty straightforward. @@ -9191,8 +8456,8 @@ CLASS="SECT3" >
Several parameters are needed in the smb.conf file to control @@ -9365,8 +8630,8 @@ CLASS="SECT3" >
Enter the following command to make the SAMBA server join the @@ -9411,8 +8676,8 @@ CLASS="SECT3" >
Eventually, you will want to modify your smb startup script to @@ -9481,7 +8746,7 @@ CEO+TsInternetUserObviously, I have named my domain 'CEO' and my winbindd +>winbind separator is '+'.
If you have made it this far, you know that winbindd and samba are working @@ -9904,8 +9169,8 @@ CLASS="SECT1" >
Winbind has a number of limitations in its current @@ -9945,8 +9210,8 @@ CLASS="SECT1" >
The winbind system, through the use of the Name Service @@ -9962,23 +9227,23 @@ CLASS="CHAPTER" >
Samba is developed in an open environment. Developers use CVS @@ -10189,8 +9454,8 @@ CLASS="SECT1" >
The machine samba.org runs a publicly accessible CVS @@ -10202,8 +9467,8 @@ CLASS="SECT2" >
You can access the source code via your @@ -10223,8 +9488,8 @@ CLASS="SECT2" >
You can also access the source code via a @@ -10329,7 +9594,7 @@ CLASS="COMMAND" >