mirror of
https://github.com/samba-team/samba.git
synced 2025-01-22 22:04:08 +03:00
Add draft of universal passdb document that combines ENCRYPTION.sgml,
Samba-LDAP-HOWTO.sgml, pdb_mysql.sgml and pdb_xml.sgml (This used to be commit fc26d1bfd15e8762628f115dd18e9d716bbea0e8)
This commit is contained in:
parent
3e734b7a44
commit
5296e0d1e8
933
docs/docbook/projdoc/passdb.sgml
Normal file
933
docs/docbook/projdoc/passdb.sgml
Normal file
@ -0,0 +1,933 @@
|
||||
<chapter id="passdb">
|
||||
<chapterinfo>
|
||||
<author>
|
||||
<firstname>Jelmer</firstname><surname>Vernooij</surname>
|
||||
<affiliation>
|
||||
<orgname>The Samba Team</orgname>
|
||||
<address><email>jelmer@samba.org</email></address>
|
||||
</affiliation>
|
||||
</author>
|
||||
<author>
|
||||
<firstname>Gerald (Jerry)</firstname><surname>Carter</surname>
|
||||
<affiliation>
|
||||
<orgname>Samba Team</orgname>
|
||||
<address><email>jerry@samba.org</email></address>
|
||||
</affiliation>
|
||||
</author>
|
||||
<author>
|
||||
<firstname>Olivier (lem)</firstname><surname>Lemaire</surname>
|
||||
<affiliation>
|
||||
<orgname>IDEALX</orgname>
|
||||
<address><email>olem@IDEALX.org</email></address>
|
||||
</affiliation>
|
||||
</author>
|
||||
<author>
|
||||
<firstname>Jeremy</firstname><surname>Allison</surname>
|
||||
<affiliation>
|
||||
<orgname>Samba Team</orgname>
|
||||
<address>
|
||||
<email>jra@samba.org</email>
|
||||
</address>
|
||||
</affiliation>
|
||||
</author>
|
||||
<pubdate>February 2003</pubdate>
|
||||
</chapterinfo>
|
||||
|
||||
<title>User information database</title>
|
||||
|
||||
<sect1>
|
||||
<title>Introduction</title>
|
||||
|
||||
<para>Newer windows clients send encrypted passwords over
|
||||
the wire, instead of plain text passwords. The newest clients
|
||||
will only send encrypted passwords and refuse to send plain text
|
||||
passwords, unless their registry is tweaked.</para>
|
||||
|
||||
<para>These passwords can't be converted to unix style encrypted
|
||||
passwords. Because of that you can't use the standard unix
|
||||
user database, and you have to store the Lanman and NT hashes
|
||||
somewhere else. For more information, see the documentation
|
||||
about the <command>passdb backend = </command> parameter.
|
||||
</para>
|
||||
</sect1>
|
||||
|
||||
<sect1>
|
||||
<title>Important Notes About Security</title>
|
||||
|
||||
<para>The unix and SMB password encryption techniques seem similar
|
||||
on the surface. This similarity is, however, only skin deep. The unix
|
||||
scheme typically sends clear text passwords over the network when
|
||||
logging in. This is bad. The SMB encryption scheme never sends the
|
||||
cleartext password over the network but it does store the 16 byte
|
||||
hashed values on disk. This is also bad. Why? Because the 16 byte hashed
|
||||
values are a "password equivalent". You cannot derive the user's
|
||||
password from them, but they could potentially be used in a modified
|
||||
client to gain access to a server. This would require considerable
|
||||
technical knowledge on behalf of the attacker but is perfectly possible.
|
||||
You should thus treat the smbpasswd file as though it contained the
|
||||
cleartext passwords of all your users. Its contents must be kept
|
||||
secret, and the file should be protected accordingly.</para>
|
||||
|
||||
<para>Ideally we would like a password scheme which neither requires
|
||||
plain text passwords on the net or on disk. Unfortunately this
|
||||
is not available as Samba is stuck with being compatible with
|
||||
other SMB systems (WinNT, WfWg, Win95 etc). </para>
|
||||
|
||||
<warning>
|
||||
<para>Note that Windows NT 4.0 Service pack 3 changed the
|
||||
default for permissible authentication so that plaintext
|
||||
passwords are <emphasis>never</emphasis> sent over the wire.
|
||||
The solution to this is either to switch to encrypted passwords
|
||||
with Samba or edit the Windows NT registry to re-enable plaintext
|
||||
passwords. See the document WinNT.txt for details on how to do
|
||||
this.</para>
|
||||
|
||||
<para>Other Microsoft operating systems which also exhibit
|
||||
this behavior includes</para>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para>MS DOS Network client 3.0 with
|
||||
the basic network redirector installed</para></listitem>
|
||||
|
||||
<listitem><para>Windows 95 with the network redirector
|
||||
update installed</para></listitem>
|
||||
|
||||
<listitem><para>Windows 98 [se]</para></listitem>
|
||||
|
||||
<listitem><para>Windows 2000</para></listitem>
|
||||
</itemizedlist>
|
||||
|
||||
<para><emphasis>Note :</emphasis>All current release of
|
||||
Microsoft SMB/CIFS clients support authentication via the
|
||||
SMB Challenge/Response mechanism described here. Enabling
|
||||
clear text authentication does not disable the ability
|
||||
of the client to participate in encrypted authentication.</para>
|
||||
</warning>
|
||||
|
||||
<sect2>
|
||||
<title>Advantages of SMB Encryption</title>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para>plain text passwords are not passed across
|
||||
the network. Someone using a network sniffer cannot just
|
||||
record passwords going to the SMB server.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>WinNT doesn't like talking to a server
|
||||
that isn't using SMB encrypted passwords. It will refuse
|
||||
to browse the server if the server is also in user level
|
||||
security mode. It will insist on prompting the user for the
|
||||
password on each connection, which is very annoying. The
|
||||
only things you can do to stop this is to use SMB encryption.
|
||||
</para></listitem>
|
||||
</itemizedlist>
|
||||
</sect2>
|
||||
|
||||
|
||||
<sect2>
|
||||
<title>Advantages of non-encrypted passwords</title>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para>plain text passwords are not kept
|
||||
on disk. </para></listitem>
|
||||
|
||||
<listitem><para>uses same password file as other unix
|
||||
services such as login and ftp</para></listitem>
|
||||
|
||||
<listitem><para>you are probably already using other
|
||||
services (such as telnet and ftp) which send plain text
|
||||
passwords over the net, so sending them for SMB isn't
|
||||
such a big deal.</para></listitem>
|
||||
</itemizedlist>
|
||||
</sect2>
|
||||
</sect1>
|
||||
|
||||
|
||||
<sect1>
|
||||
<title>The smbpasswd Command</title>
|
||||
|
||||
<para>The smbpasswd command maintains the two 32 byte password fields
|
||||
in the smbpasswd file. If you wish to make it similar to the unix
|
||||
<command>passwd</command> or <command>yppasswd</command> programs,
|
||||
install it in <filename>/usr/local/samba/bin/</filename> (or your
|
||||
main Samba binary directory).</para>
|
||||
|
||||
<para><command>smbpasswd</command> now works in a client-server mode
|
||||
where it contacts the local smbd to change the user's password on its
|
||||
behalf. This has enormous benefits - as follows.</para>
|
||||
|
||||
<para><command>smbpasswd</command> now has the capability
|
||||
to change passwords on Windows NT servers (this only works when
|
||||
the request is sent to the NT Primary Domain Controller if you
|
||||
are changing an NT Domain user's password).</para>
|
||||
|
||||
<para>To run smbpasswd as a normal user just type :</para>
|
||||
|
||||
<para><prompt>$ </prompt><userinput>smbpasswd</userinput></para>
|
||||
<para><prompt>Old SMB password: </prompt><userinput><type old value here -
|
||||
or hit return if there was no old password></userinput></para>
|
||||
<para><prompt>New SMB Password: </prompt><userinput><type new value>
|
||||
</userinput></para>
|
||||
<para><prompt>Repeat New SMB Password: </prompt><userinput><re-type new value
|
||||
</userinput></para>
|
||||
|
||||
<para>If the old value does not match the current value stored for
|
||||
that user, or the two new values do not match each other, then the
|
||||
password will not be changed.</para>
|
||||
|
||||
<para>If invoked by an ordinary user it will only allow the user
|
||||
to change his or her own Samba password.</para>
|
||||
|
||||
<para>If run by the root user smbpasswd may take an optional
|
||||
argument, specifying the user name whose SMB password you wish to
|
||||
change. Note that when run as root smbpasswd does not prompt for
|
||||
or check the old password value, thus allowing root to set passwords
|
||||
for users who have forgotten their passwords.</para>
|
||||
|
||||
<para><command>smbpasswd</command> is designed to work in the same way
|
||||
and be familiar to UNIX users who use the <command>passwd</command> or
|
||||
<command>yppasswd</command> commands.</para>
|
||||
|
||||
<para>For more details on using <command>smbpasswd</command> refer
|
||||
to the man page which will always be the definitive reference.</para>
|
||||
</sect1>
|
||||
|
||||
<!--
|
||||
<sect1>
|
||||
<title>The <command>pdbedit</command> command</title>
|
||||
FIXME
|
||||
</sect1>
|
||||
-->
|
||||
|
||||
<sect1>
|
||||
<title>LDAP</title>
|
||||
|
||||
<sect2>
|
||||
<title>Introduction</title>
|
||||
|
||||
<para>
|
||||
This document describes how to use an LDAP directory for storing Samba user
|
||||
account information traditionally stored in the smbpasswd(5) file. It is
|
||||
assumed that the reader already has a basic understanding of LDAP concepts
|
||||
and has a working directory server already installed. For more information
|
||||
on LDAP architectures and Directories, please refer to the following sites.
|
||||
</para>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para>OpenLDAP - <ulink url="http://www.openldap.org/">http://www.openldap.org/</ulink></para></listitem>
|
||||
<listitem><para>iPlanet Directory Server - <ulink url="http://iplanet.netscape.com/directory">http://iplanet.netscape.com/directory</ulink></para></listitem>
|
||||
</itemizedlist>
|
||||
|
||||
<para>
|
||||
Note that <ulink url="http://www.ora.com/">O'Reilly Publishing</ulink> is working on
|
||||
a guide to LDAP for System Administrators which has a planned release date of
|
||||
early summer, 2002.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Two additional Samba resources which may prove to be helpful are
|
||||
</para>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para>The <ulink url="http://www.unav.es/cti/ldap-smb/ldap-smb-3-howto.html">Samba-PDC-LDAP-HOWTO</ulink>
|
||||
maintained by Ignacio Coupeau.</para></listitem>
|
||||
|
||||
<listitem><para>The NT migration scripts from <ulink url="http://samba.idealx.org/">IDEALX</ulink> that are
|
||||
geared to manage users and group in such a Samba-LDAP Domain Controller configuration.
|
||||
</para></listitem>
|
||||
</itemizedlist>
|
||||
|
||||
</sect2>
|
||||
|
||||
<sect2>
|
||||
<title>Introduction</title>
|
||||
|
||||
<para>
|
||||
Traditionally, when configuring <ulink url="smb.conf.5.html#ENCRYPTPASSWORDS">"encrypt
|
||||
passwords = yes"</ulink> in Samba's <filename>smb.conf</filename> file, user account
|
||||
information such as username, LM/NT password hashes, password change times, and account
|
||||
flags have been stored in the <filename>smbpasswd(5)</filename> file. There are several
|
||||
disadvantages to this approach for sites with very large numbers of users (counted
|
||||
in the thousands).
|
||||
</para>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para>
|
||||
The first is that all lookups must be performed sequentially. Given that
|
||||
there are approximately two lookups per domain logon (one for a normal
|
||||
session connection such as when mapping a network drive or printer), this
|
||||
is a performance bottleneck for lareg sites. What is needed is an indexed approach
|
||||
such as is used in databases.
|
||||
</para></listitem>
|
||||
|
||||
<listitem><para>
|
||||
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 <command>rsync(1)</command> and <command>ssh(1)</command>
|
||||
and wrote custom, in-house scripts.
|
||||
</para></listitem>
|
||||
|
||||
<listitem><para>
|
||||
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).
|
||||
</para></listitem>
|
||||
</itemizedlist>
|
||||
|
||||
<para>
|
||||
As a result of these defeciencies, a more robust means of storing user attributes
|
||||
used by smbd was developed. The API which defines access to user accounts
|
||||
is commonly referred to as the samdb interface (previously this was called the passdb
|
||||
API, and is still so named in the CVS trees). In Samba 2.2.3, enabling support
|
||||
for a samdb backend (e.g. <parameter>--with-ldapsam</parameter> or
|
||||
<parameter>--with-tdbsam</parameter>) requires compile time support.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
When compiling Samba to include the <parameter>--with-ldapsam</parameter> 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.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
There are a few points to stress about what the <parameter>--with-ldapsam</parameter>
|
||||
does not provide. The LDAP support referred to in the this documentation does not
|
||||
include:
|
||||
</para>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para>A means of retrieving user account information from
|
||||
an Windows 2000 Active Directory server.</para></listitem>
|
||||
<listitem><para>A means of replacing /etc/passwd.</para></listitem>
|
||||
</itemizedlist>
|
||||
|
||||
<para>
|
||||
The second item can be accomplished by using LDAP NSS and PAM modules. LGPL
|
||||
versions of these libraries can be obtained from PADL Software
|
||||
(<ulink url="http://www.padl.com/">http://www.padl.com/</ulink>). However,
|
||||
the details of configuring these packages are beyond the scope of this document.
|
||||
</para>
|
||||
|
||||
</sect2>
|
||||
|
||||
<sect2>
|
||||
<title>Supported LDAP Servers</title>
|
||||
|
||||
<para>
|
||||
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
|
||||
<ulink url="samba-patches@samba.org">samba-patches@samba.org</ulink> and
|
||||
<ulink url="jerry@samba.org">jerry@samba.org</ulink>.
|
||||
</para>
|
||||
|
||||
</sect2>
|
||||
|
||||
<sect2>
|
||||
<title>Schema and Relationship to the RFC 2307 posixAccount</title>
|
||||
|
||||
|
||||
<para>
|
||||
Samba 3.0 includes the necessary schema file for OpenLDAP 2.0 in
|
||||
<filename>examples/LDAP/samba.schema</filename>. The sambaAccount objectclass is given here:
|
||||
</para>
|
||||
|
||||
<para><programlisting>
|
||||
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 $ domain ))
|
||||
</programlisting></para>
|
||||
|
||||
<para>
|
||||
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 <ulink
|
||||
url="jerry@samba.org">jerry@samba.org</ulink>
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Just as the smbpasswd file is mean to store information which supplements a
|
||||
user's <filename>/etc/passwd</filename> entry, so is the sambaAccount object
|
||||
meant to supplement the UNIX user account information. A sambaAccount is a
|
||||
<constant>STRUCTURAL</constant> 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.
|
||||
</para>
|
||||
|
||||
<!--olem: we should perhaps have a note about shadowAccounts too as many
|
||||
systems use them, isn'it ? -->
|
||||
|
||||
<para>
|
||||
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.
|
||||
</para>
|
||||
</sect2>
|
||||
|
||||
<sect2>
|
||||
<title>Configuring Samba with LDAP</title>
|
||||
|
||||
|
||||
<sect3>
|
||||
<title>OpenLDAP configuration</title>
|
||||
|
||||
<para>
|
||||
To include support for the sambaAccount object in an OpenLDAP directory
|
||||
server, first copy the samba.schema file to slapd's configuration directory.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
<prompt>root# </prompt><command>cp samba.schema /etc/openldap/schema/</command>
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Next, include the <filename>samba.schema</filename> file in <filename>slapd.conf</filename>.
|
||||
The sambaAccount object contains two attributes which depend upon other schema
|
||||
files. The 'uid' attribute is defined in <filename>cosine.schema</filename> and
|
||||
the 'displayName' attribute is defined in the <filename>inetorgperson.schema</filename>
|
||||
file. Both of these must be included before the <filename>samba.schema</filename> file.
|
||||
</para>
|
||||
|
||||
<para><programlisting>
|
||||
## /etc/openldap/slapd.conf
|
||||
|
||||
## schema files (core.schema is required by default)
|
||||
include /etc/openldap/schema/core.schema
|
||||
|
||||
## needed for sambaAccount
|
||||
include /etc/openldap/schema/cosine.schema
|
||||
include /etc/openldap/schema/inetorgperson.schema
|
||||
include /etc/openldap/schema/samba.schema
|
||||
|
||||
## uncomment this line if you want to support the RFC2307 (NIS) schema
|
||||
## include /etc/openldap/schema/nis.schema
|
||||
|
||||
....
|
||||
</programlisting></para>
|
||||
|
||||
<para>
|
||||
It is recommended that you maintain some indices on some of the most usefull attributes,
|
||||
like in the following example, to speed up searches made on sambaAccount objectclasses
|
||||
(and possibly posixAccount and posixGroup as well).
|
||||
</para>
|
||||
<para><programlisting>
|
||||
# Indices to maintain
|
||||
## required by OpenLDAP 2.0
|
||||
index objectclass eq
|
||||
|
||||
## support pb_getsampwnam()
|
||||
index uid pres,eq
|
||||
## support pdb_getsambapwrid()
|
||||
index rid eq
|
||||
|
||||
## uncomment these if you are storing posixAccount and
|
||||
## posixGroup entries in the directory as well
|
||||
##index uidNumber eq
|
||||
##index gidNumber eq
|
||||
##index cn eq
|
||||
##index memberUid eq
|
||||
</programlisting></para>
|
||||
</sect3>
|
||||
|
||||
|
||||
<sect3>
|
||||
<title>Configuring Samba</title>
|
||||
<!--lem: <title>smb.conf LDAP parameters</title> -->
|
||||
|
||||
<para>
|
||||
The following parameters are available in smb.conf only with <parameter>--with-ldapsam</parameter>
|
||||
was included with compiling Samba.
|
||||
</para>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para><ulink url="smb.conf.5.html#LDAPSSL">ldap ssl</ulink></para></listitem>
|
||||
<listitem><para><ulink url="smb.conf.5.html#LDAPSERVER">ldap server</ulink></para></listitem>
|
||||
<listitem><para><ulink url="smb.conf.5.html#LDAPADMINDN">ldap admin dn</ulink></para></listitem>
|
||||
<listitem><para><ulink url="smb.conf.5.html#LDAPSUFFIX">ldap suffix</ulink></para></listitem>
|
||||
<listitem><para><ulink url="smb.conf.5.html#LDAPFILTER">ldap filter</ulink></para></listitem>
|
||||
<listitem><para><ulink url="smb.conf.5.html#LDAPPORT">ldap port</ulink></para></listitem>
|
||||
</itemizedlist>
|
||||
|
||||
<para>
|
||||
These are described in the <ulink url="smb.conf.5.html">smb.conf(5)</ulink> man
|
||||
page and so will not be repeated here. However, a sample smb.conf file for
|
||||
use with an LDAP directory could appear as
|
||||
</para>
|
||||
|
||||
<para><programlisting>
|
||||
## /usr/local/samba/lib/smb.conf
|
||||
[global]
|
||||
security = user
|
||||
encrypt passwords = yes
|
||||
|
||||
netbios name = TASHTEGO
|
||||
workgroup = NARNIA
|
||||
|
||||
# ldap related parameters
|
||||
|
||||
# define the DN to use when binding to the directory servers
|
||||
# The password for this DN is not stored in smb.conf. Rather it
|
||||
# must be set by using 'smbpasswd -w <replaceable>secretpw</replaceable>' 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=Samba Manager,ou=people,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))"
|
||||
</programlisting></para>
|
||||
|
||||
|
||||
</sect3>
|
||||
</sect2>
|
||||
|
||||
|
||||
<sect2>
|
||||
<title>Accounts and Groups management</title>
|
||||
|
||||
<para>
|
||||
As users accounts are managed thru the sambaAccount objectclass, you should
|
||||
modify you existing administration tools to deal with sambaAccount attributes.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Machines accounts are managed with the sambaAccount objectclass, just
|
||||
like users accounts. However, it's up to you to stored thoses accounts
|
||||
in a different tree of you LDAP namespace: you should use
|
||||
"ou=Groups,dc=plainjoe,dc=org" to store groups and
|
||||
"ou=People,dc=plainjoe,dc=org" to store users. Just configure your
|
||||
NSS and PAM accordingly (usually, in the /etc/ldap.conf configuration
|
||||
file).
|
||||
</para>
|
||||
|
||||
<para>
|
||||
In Samba release 3.0, the group management system is based on posix
|
||||
groups. This means that Samba make usage of the posixGroup objectclass.
|
||||
For now, there is no NT-like group system management (global and local
|
||||
groups).
|
||||
</para>
|
||||
|
||||
</sect2>
|
||||
|
||||
<sect2>
|
||||
<title>Security and sambaAccount</title>
|
||||
|
||||
|
||||
<para>
|
||||
There are two important points to remember when discussing the security
|
||||
of sambaAccount entries in the directory.
|
||||
</para>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para><emphasis>Never</emphasis> retrieve the lmPassword or
|
||||
ntPassword attribute values over an unencrypted LDAP session.</para></listitem>
|
||||
<listitem><para><emphasis>Never</emphasis> allow non-admin users to
|
||||
view the lmPassword or ntPassword attribute values.</para></listitem>
|
||||
</itemizedlist>
|
||||
|
||||
<para>
|
||||
These password hashes are clear text equivalents and can be used to impersonate
|
||||
the user without deriving the original clear text strings. For more information
|
||||
on the details of LM/NT password hashes, refer to the <ulink
|
||||
url="ENCRYPTION.html">ENCRYPTION chapter</ulink> of the Samba-HOWTO-Collection.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
To remedy the first security issue, the "ldap ssl" smb.conf parameter defaults
|
||||
to require an encrypted session (<command>ldap ssl = on</command>) 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
|
||||
(<command>ldap ssl = off</command>).
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Note that the LDAPS protocol is deprecated in favor of the LDAPv3 StartTLS
|
||||
extended operation. However, the OpenLDAP library still provides support for
|
||||
the older method of securing communication between clients and servers.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
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 <filename>slapd.conf</filename>:
|
||||
</para>
|
||||
|
||||
<para><programlisting>
|
||||
## allow the "ldap admin dn" access, but deny everyone else
|
||||
access to attrs=lmPassword,ntPassword
|
||||
by dn="cn=Samba Admin,ou=people,dc=plainjoe,dc=org" write
|
||||
by * none
|
||||
</programlisting></para>
|
||||
|
||||
|
||||
</sect2>
|
||||
|
||||
|
||||
|
||||
<sect2>
|
||||
<title>LDAP specials attributes for sambaAccounts</title>
|
||||
|
||||
<para>
|
||||
The sambaAccount objectclass is composed of the following attributes:
|
||||
</para>
|
||||
|
||||
<itemizedlist>
|
||||
|
||||
<listitem><para><constant>lmPassword</constant>: the LANMAN password 16-byte hash stored as a character
|
||||
representation of a hexidecimal string.</para></listitem>
|
||||
|
||||
<listitem><para><constant>ntPassword</constant>: the NT password hash 16-byte stored as a character
|
||||
representation of a hexidecimal string.</para></listitem>
|
||||
|
||||
<listitem><para><constant>pwdLastSet</constant>: The integer time in seconds since 1970 when the
|
||||
<constant>lmPassword</constant> and <constant>ntPassword</constant> attributes were last set.
|
||||
</para></listitem>
|
||||
|
||||
<listitem><para><constant>acctFlags</constant>: string of 11 characters surrounded by square brackets []
|
||||
representing account flags such as U (user), W(workstation), X(no password expiration), and
|
||||
D(disabled).</para></listitem>
|
||||
|
||||
<listitem><para><constant>logonTime</constant>: Integer value currently unused</para></listitem>
|
||||
|
||||
<listitem><para><constant>logoffTime</constant>: Integer value currently unused</para></listitem>
|
||||
|
||||
<listitem><para><constant>kickoffTime</constant>: Integer value currently unused</para></listitem>
|
||||
|
||||
<listitem><para><constant>pwdCanChange</constant>: Integer value currently unused</para></listitem>
|
||||
|
||||
<listitem><para><constant>pwdMustChange</constant>: Integer value currently unused</para></listitem>
|
||||
|
||||
<listitem><para><constant>homeDrive</constant>: specifies the drive letter to which to map the
|
||||
UNC path specified by homeDirectory. The drive letter must be specified in the form "X:"
|
||||
where X is the letter of the drive to map. Refer to the "logon drive" parameter in the
|
||||
smb.conf(5) man page for more information.</para></listitem>
|
||||
|
||||
<listitem><para><constant>scriptPath</constant>: The scriptPath property specifies the path of
|
||||
the user's logon script, .CMD, .EXE, or .BAT file. The string can be null. The path
|
||||
is relative to the netlogon share. Refer to the "logon script" parameter in the
|
||||
smb.conf(5) man page for more information.</para></listitem>
|
||||
|
||||
<listitem><para><constant>profilePath</constant>: specifies a path to the user's profile.
|
||||
This value can be a null string, a local absolute path, or a UNC path. Refer to the
|
||||
"logon path" parameter in the smb.conf(5) man page for more information.</para></listitem>
|
||||
|
||||
<listitem><para><constant>smbHome</constant>: The homeDirectory property specifies the path of
|
||||
the home directory for the user. The string can be null. If homeDrive is set and specifies
|
||||
a drive letter, homeDirectory should be a UNC path. The path must be a network
|
||||
UNC path of the form \\server\share\directory. This value can be a null string.
|
||||
Refer to the "logon home" parameter in the smb.conf(5) man page for more information.
|
||||
</para></listitem>
|
||||
|
||||
<listitem><para><constant>userWorkstation</constant>: character string value currently unused.
|
||||
</para></listitem>
|
||||
|
||||
<listitem><para><constant>rid</constant>: the integer representation of the user's relative identifier
|
||||
(RID).</para></listitem>
|
||||
|
||||
<listitem><para><constant>primaryGroupID</constant>: the relative identifier (RID) of the primary group
|
||||
of the user.</para></listitem>
|
||||
|
||||
</itemizedlist>
|
||||
|
||||
<para>
|
||||
The majority of these parameters are only used when Samba is acting as a PDC of
|
||||
a domain (refer to the <ulink url="Samba-PDC-HOWTO.html">Samba-PDC-HOWTO</ulink> for details on
|
||||
how to configure Samba as a Primary Domain Controller). The following four attributes
|
||||
are only stored with the sambaAccount entry if the values are non-default values:
|
||||
</para>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para>smbHome</para></listitem>
|
||||
<listitem><para>scriptPath</para></listitem>
|
||||
<listitem><para>logonPath</para></listitem>
|
||||
<listitem><para>homeDrive</para></listitem>
|
||||
</itemizedlist>
|
||||
|
||||
<para>
|
||||
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 <command>logon home = \\%L\%u</command> was defined in
|
||||
its <filename>smb.conf</filename> file. When a user named "becky" logons to the domain,
|
||||
the <parameter>logon home</parameter> 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 <parameter>logon home</parameter> 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).
|
||||
</para>
|
||||
|
||||
|
||||
</sect2>
|
||||
|
||||
|
||||
|
||||
<sect2>
|
||||
<title>Example LDIF Entries for a sambaAccount</title>
|
||||
|
||||
|
||||
<para>
|
||||
The following is a working LDIF with the inclusion of the posixAccount objectclass:
|
||||
</para>
|
||||
|
||||
<para><programlisting>
|
||||
dn: uid=guest2, ou=people,dc=plainjoe,dc=org
|
||||
ntPassword: 878D8014606CDA29677A44EFA1353FC7
|
||||
pwdMustChange: 2147483647
|
||||
primaryGroupID: 1201
|
||||
lmPassword: 552902031BEDE9EFAAD3B435B51404EE
|
||||
pwdLastSet: 1010179124
|
||||
logonTime: 0
|
||||
objectClass: sambaAccount
|
||||
uid: guest2
|
||||
kickoffTime: 2147483647
|
||||
acctFlags: [UX ]
|
||||
logoffTime: 2147483647
|
||||
rid: 19006
|
||||
pwdCanChange: 0
|
||||
</programlisting></para>
|
||||
|
||||
<para>
|
||||
The following is an LDIF entry for using both the sambaAccount and
|
||||
posixAccount objectclasses:
|
||||
</para>
|
||||
|
||||
<para><programlisting>
|
||||
dn: uid=gcarter, ou=people,dc=plainjoe,dc=org
|
||||
logonTime: 0
|
||||
displayName: Gerald Carter
|
||||
lmPassword: 552902031BEDE9EFAAD3B435B51404EE
|
||||
primaryGroupID: 1201
|
||||
objectClass: posixAccount
|
||||
objectClass: sambaAccount
|
||||
acctFlags: [UX ]
|
||||
userPassword: {crypt}BpM2ej8Rkzogo
|
||||
uid: gcarter
|
||||
uidNumber: 9000
|
||||
cn: Gerald Carter
|
||||
loginShell: /bin/bash
|
||||
logoffTime: 2147483647
|
||||
gidNumber: 100
|
||||
kickoffTime: 2147483647
|
||||
pwdLastSet: 1010179230
|
||||
rid: 19000
|
||||
homeDirectory: /home/tashtego/gcarter
|
||||
pwdCanChange: 0
|
||||
pwdMustChange: 2147483647
|
||||
ntPassword: 878D8014606CDA29677A44EFA1353FC7
|
||||
</programlisting></para>
|
||||
|
||||
</sect2>
|
||||
</sect1>
|
||||
|
||||
<sect1>
|
||||
<title>Passdb MySQL plugin</title>
|
||||
|
||||
<sect2>
|
||||
<title>Building</title>
|
||||
|
||||
<para>To build the plugin, run <command>make bin/pdb_mysql.so</command>
|
||||
in the <filename>source/</filename> directory of samba distribution.
|
||||
</para>
|
||||
|
||||
<para>Next, copy pdb_mysql.so to any location you want. I
|
||||
strongly recommend installing it in $PREFIX/lib or /usr/lib/samba/</para>
|
||||
|
||||
</sect2>
|
||||
|
||||
<sect2>
|
||||
<title>Creating the database</title>
|
||||
|
||||
<para>
|
||||
You either can set up your own table and specify the field names to pdb_mysql (see below
|
||||
for the column names) or use the default table. The file <filename>examples/pdb/mysql/mysql.dump</filename>
|
||||
contains the correct queries to create the required tables. Use the command :
|
||||
|
||||
<command>mysql -u<replaceable>username</replaceable> -h<replaceable>hostname</replaceable> -p<replaceable>password</replaceable> <replaceable>databasename</replaceable> < <filename>/path/to/samba/examples/pdb/mysql/mysql.dump</filename></command>
|
||||
|
||||
</para>
|
||||
</sect2>
|
||||
|
||||
<sect2>
|
||||
<title>Configuring</title>
|
||||
|
||||
<para>This plugin lacks some good documentation, but here is some short info:</para>
|
||||
|
||||
<para>Add a the following to the <command>passdb backend</command> variable in your <filename>smb.conf</filename>:
|
||||
<programlisting>
|
||||
passdb backend = [other-plugins] plugin:/location/to/pdb_mysql.so:identifier [other-plugins]
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
<para>The identifier can be any string you like, as long as it doesn't collide with
|
||||
the identifiers of other plugins or other instances of pdb_mysql. If you
|
||||
specify multiple pdb_mysql.so entries in 'passdb backend', you also need to
|
||||
use different identifiers!
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Additional options can be given thru the smb.conf file in the [global] section.
|
||||
</para>
|
||||
|
||||
<para><programlisting>
|
||||
identifier:mysql host - host name, defaults to 'localhost'
|
||||
identifier:mysql password
|
||||
identifier:mysql user - defaults to 'samba'
|
||||
identifier:mysql database - defaults to 'samba'
|
||||
identifier:mysql port - defaults to 3306
|
||||
identifier:table - Name of the table containing users
|
||||
</programlisting></para>
|
||||
|
||||
<para>
|
||||
<emphasis>
|
||||
WARNING: since the password for the mysql user is stored in the
|
||||
smb.conf file, you should make the the smb.conf file
|
||||
readable only to the user that runs samba. This is considered a security
|
||||
bug and will be fixed soon.</emphasis>
|
||||
</para>
|
||||
|
||||
<para>Names of the columns in this table(I've added column types those columns should have first):</para>
|
||||
|
||||
<para><programlisting>
|
||||
identifier:logon time column - int(9)
|
||||
identifier:logoff time column - int(9)
|
||||
identifier:kickoff time column - int(9)
|
||||
identifier:pass last set time column - int(9)
|
||||
identifier:pass can change time column - int(9)
|
||||
identifier:pass must change time column - int(9)
|
||||
identifier:username column - varchar(255) - unix username
|
||||
identifier:domain column - varchar(255) - NT domain user is part of
|
||||
identifier:nt username column - varchar(255) - NT username
|
||||
identifier:fullname column - varchar(255) - Full name of user
|
||||
identifier:home dir column - varchar(255) - Unix homedir path
|
||||
identifier:dir drive column - varchar(2) - Directory drive path (eg: 'H:')
|
||||
identifier:logon script column - varchar(255) - Batch file to run on client side when logging on
|
||||
identifier:profile path column - varchar(255) - Path of profile
|
||||
identifier:acct desc column - varchar(255) - Some ASCII NT user data
|
||||
identifier:workstations column - varchar(255) - Workstations user can logon to (or NULL for all)
|
||||
identifier:unknown string column - varchar(255) - unknown string
|
||||
identifier:munged dial column - varchar(255) - ?
|
||||
identifier:uid column - int(9) - Unix user ID (uid)
|
||||
identifier:gid column - int(9) - Unix user group (gid)
|
||||
identifier:user sid column - varchar(255) - NT user SID
|
||||
identifier:group sid column - varchar(255) - NT group ID
|
||||
identifier:lanman pass column - varchar(255) - encrypted lanman password
|
||||
identifier:nt pass column - varchar(255) - encrypted nt passwd
|
||||
identifier:plain pass column - varchar(255) - plaintext password
|
||||
identifier:acct control column - int(9) - nt user data
|
||||
identifier:unknown 3 column - int(9) - unknown
|
||||
identifier:logon divs column - int(9) - ?
|
||||
identifier:hours len column - int(9) - ?
|
||||
identifier:unknown 5 column - int(9) - unknown
|
||||
identifier:unknown 6 column - int(9) - unknown
|
||||
</programlisting></para>
|
||||
|
||||
<para>
|
||||
Eventually, you can put a colon (:) after the name of each column, which
|
||||
should specify the column to update when updating the table. You can also
|
||||
specify nothing behind the colon - then the data from the field will not be
|
||||
updated.
|
||||
</para>
|
||||
|
||||
</sect2>
|
||||
|
||||
<sect2>
|
||||
<title>Using plaintext passwords or encrypted password</title>
|
||||
|
||||
<para>
|
||||
I strongly discourage the use of plaintext passwords, however, you can use them:
|
||||
</para>
|
||||
|
||||
<para>
|
||||
If you would like to use plaintext passwords, set 'identifier:lanman pass column' and 'identifier:nt pass column' to 'NULL' (without the quotes) and 'identifier:plain pass column' to the name of the column containing the plaintext passwords.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
If you use encrypted passwords, set the 'identifier:plain pass column' to 'NULL' (without the quotes). This is the default.
|
||||
</para>
|
||||
|
||||
</sect2>
|
||||
|
||||
<sect2>
|
||||
<title>Getting non-column data from the table</title>
|
||||
|
||||
<para>
|
||||
It is possible to have not all data in the database and making some 'constant'.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
For example, you can set 'identifier:fullname column' to :
|
||||
<command>CONCAT(First_name,' ',Sur_name)</command>
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Or, set 'identifier:workstations column' to :
|
||||
<command>NULL</command></para>
|
||||
|
||||
<para>See the MySQL documentation for more language constructs.</para>
|
||||
|
||||
</sect2>
|
||||
</sect1>
|
||||
|
||||
<sect1>
|
||||
<title>Passdb XML plugin</title>
|
||||
|
||||
<sect2>
|
||||
<title>Building</title>
|
||||
|
||||
<para>This module requires libxml2 to be installed.</para>
|
||||
|
||||
<para>To build pdb_xml, run: <command>make bin/pdb_xml.so</command> in
|
||||
the directory <filename>source/</filename>. </para>
|
||||
|
||||
</sect2>
|
||||
|
||||
<sect2>
|
||||
<title>Usage</title>
|
||||
|
||||
<para>The usage of pdb_xml is pretty straightforward. To export data, use:
|
||||
|
||||
<command>pdbedit -e plugin:/usr/lib/samba/pdb_xml.so:filename</command>
|
||||
|
||||
(where filename is the name of the file to put the data in)
|
||||
</para>
|
||||
|
||||
<para>
|
||||
To import data, use:
|
||||
<command>pdbedit -i plugin:/usr/lib/samba/pdb_xml.so:filename -e current-pdb</command>
|
||||
|
||||
Where filename is the name to read the data from and current-pdb to put it in.
|
||||
</para>
|
||||
</sect2>
|
||||
</sect1>
|
||||
|
||||
</chapter>
|
Loading…
x
Reference in New Issue
Block a user