1 <html><head><meta http-equiv=
"Content-Type" content=
"text/html; charset=ISO-8859-1"><title>smbpasswd
</title><link rel=
"stylesheet" href=
"samba.css" type=
"text/css"><meta name=
"generator" content=
"DocBook XSL Stylesheets V1.60.1"></head><body bgcolor=
"white" text=
"black" link=
"#0000FF" vlink=
"#840084" alink=
"#0000FF"><div class=
"refentry" lang=
"en"><a name=
"smbpasswd.5"></a><div class=
"titlepage"><div></div><div></div></div><div class=
"refnamediv"><h2>Name
</h2><p>smbpasswd
— The Samba encrypted password file
</p></div><div class=
"refsynopsisdiv"><h2>Synopsis
</h2><p><tt class=
"filename">smbpasswd
</tt></p></div><div class=
"refsect1" lang=
"en"><h2>DESCRIPTION
</h2><p>This tool is part of the
<a href=
"Samba.7.html"><span class=
"citerefentry"><span class=
"refentrytitle">Samba
</span>(
7)
</span></a> suite.
</p><p>smbpasswd is the Samba encrypted password file. It contains
2 the username, Unix user id and the SMB hashed passwords of the
3 user, as well as account flag information and the time the
4 password was last changed. This file format has been evolving with
5 Samba and has had several different formats in the past.
</p></div><div class=
"refsect1" lang=
"en"><h2>FILE FORMAT
</h2><p>The format of the smbpasswd file used by Samba
2.2
6 is very similar to the familiar Unix
<tt class=
"filename">passwd(
5)
</tt>
7 file. It is an ASCII file containing one line for each user. Each field
8 ithin each line is separated from the next by a colon. Any entry
9 beginning with '#' is ignored. The smbpasswd file contains the
10 following information for each user:
</p><div class=
"variablelist"><dl><dt><span class=
"term">name
</span></dt><dd><p> This is the user name. It must be a name that
11 already exists in the standard UNIX passwd file.
</p></dd><dt><span class=
"term">uid
</span></dt><dd><p>This is the UNIX uid. It must match the uid
12 field for the same user entry in the standard UNIX passwd file.
13 If this does not match then Samba will refuse to recognize
14 this smbpasswd file entry as being valid for a user.
15 </p></dd><dt><span class=
"term">Lanman Password Hash
</span></dt><dd><p>This is the LANMAN hash of the user's password,
16 encoded as
32 hex digits. The LANMAN hash is created by DES
17 encrypting a well known string with the user's password as the
18 DES key. This is the same password used by Windows
95/
98 machines.
19 Note that this password hash is regarded as weak as it is
20 vulnerable to dictionary attacks and if two users choose the
21 same password this entry will be identical (i.e. the password
22 is not
"salted" as the UNIX password is). If the user has a
23 null password this field will contain the characters
"NO PASSWORD"
24 as the start of the hex string. If the hex string is equal to
25 32 'X' characters then the user's account is marked as
26 <tt class=
"constant">disabled
</tt> and the user will not be able to
27 log onto the Samba server.
</p><p><span class=
"emphasis"><em>WARNING !!
</em></span> Note that, due to
28 the challenge-response nature of the SMB/CIFS authentication
29 protocol, anyone with a knowledge of this password hash will
30 be able to impersonate the user on the network. For this
31 reason these hashes are known as
<span class=
"emphasis"><em>plain text
32 equivalents
</em></span> and must
<span class=
"emphasis"><em>NOT
</em></span> be made
33 available to anyone but the root user. To protect these passwords
34 the smbpasswd file is placed in a directory with read and
35 traverse access only to the root user and the smbpasswd file
36 itself must be set to be read/write only by root, with no
37 other access.
</p></dd><dt><span class=
"term">NT Password Hash
</span></dt><dd><p>This is the Windows NT hash of the user's
38 password, encoded as
32 hex digits. The Windows NT hash is
39 created by taking the user's password as represented in
40 16-bit, little-endian UNICODE and then applying the MD4
41 (internet rfc1321) hashing algorithm to it.
</p><p>This password hash is considered more secure than
42 the LANMAN Password Hash as it preserves the case of the
43 password and uses a much higher quality hashing algorithm.
44 However, it is still the case that if two users choose the same
45 password this entry will be identical (i.e. the password is
46 not
"salted" as the UNIX password is).
</p><p><span class=
"emphasis"><em>WARNING !!
</em></span>. Note that, due to
47 the challenge-response nature of the SMB/CIFS authentication
48 protocol, anyone with a knowledge of this password hash will
49 be able to impersonate the user on the network. For this
50 reason these hashes are known as
<span class=
"emphasis"><em>plain text
51 equivalents
</em></span> and must
<span class=
"emphasis"><em>NOT
</em></span> be made
52 available to anyone but the root user. To protect these passwords
53 the smbpasswd file is placed in a directory with read and
54 traverse access only to the root user and the smbpasswd file
55 itself must be set to be read/write only by root, with no
56 other access.
</p></dd><dt><span class=
"term">Account Flags
</span></dt><dd><p>This section contains flags that describe
57 the attributes of the users account. In the Samba
2.2 release
58 this field is bracketed by '[' and ']' characters and is always
59 13 characters in length (including the '[' and ']' characters).
60 The contents of this field may be any of the following characters:
61 </p><div class=
"itemizedlist"><ul type=
"disc"><li><p><span class=
"emphasis"><em>U
</em></span> - This means
62 this is a
"User" account, i.e. an ordinary user. Only User
63 and Workstation Trust accounts are currently supported
64 in the smbpasswd file.
</p></li><li><p><span class=
"emphasis"><em>N
</em></span> - This means the
65 account has no password (the passwords in the fields LANMAN
66 Password Hash and NT Password Hash are ignored). Note that this
67 will only allow users to log on with no password if the
<i class=
"parameter"><tt>
68 null passwords
</tt></i> parameter is set in the
69 <a href=
"smb.conf.5.html"><span class=
"citerefentry"><span class=
"refentrytitle">smb.conf
</span>(
5)
</span></a> config file.
</p></li><li><p><span class=
"emphasis"><em>D
</em></span> - This means the account
70 is disabled and no SMB/CIFS logins will be allowed for this user.
</p></li><li><p><span class=
"emphasis"><em>W
</em></span> - This means this account
71 is a
"Workstation Trust" account. This kind of account is used
72 in the Samba PDC code stream to allow Windows NT Workstations
73 and Servers to join a Domain hosted by a Samba PDC.
</p></li></ul></div><p>Other flags may be added as the code is extended in future.
74 The rest of this field space is filled in with spaces.
</p></dd><dt><span class=
"term">Last Change Time
</span></dt><dd><p>This field consists of the time the account was
75 last modified. It consists of the characters 'LCT-' (standing for
76 "Last Change Time") followed by a numeric encoding of the UNIX time
77 in seconds since the epoch (
1970) that the last change was made.
78 </p></dd></dl></div><p>All other colon separated fields are ignored at this time.
</p></div><div class=
"refsect1" lang=
"en"><h2>VERSION
</h2><p>This man page is correct for version
3.0 of
79 the Samba suite.
</p></div><div class=
"refsect1" lang=
"en"><h2>SEE ALSO
</h2><p><a href=
"smbpasswd.8.html"><span class=
"citerefentry"><span class=
"refentrytitle">smbpasswd
</span>(
8)
</span></a>,
<a href=
"Samba.7.html"><span class=
"citerefentry"><span class=
"refentrytitle">Samba
</span>(
7)
</span></a>, and
80 the Internet RFC1321 for details on the MD4 algorithm.
81 </p></div><div class=
"refsect1" lang=
"en"><h2>AUTHOR
</h2><p>The original Samba software and related utilities
82 were created by Andrew Tridgell. Samba is now developed
83 by the Samba Team as an Open Source project similar
84 to the way the Linux kernel is developed.
</p><p>The original Samba man pages were written by Karl Auer.
85 The man page sources were converted to YODL format (another
86 excellent piece of Open Source software, available at
<ulink url=
"ftp://ftp.icce.rug.nl/pub/unix/">
87 ftp://ftp.icce.rug.nl/pub/unix/
</ulink>) and updated for the Samba
2.0
88 release by Jeremy Allison. The conversion to DocBook for
89 Samba
2.2 was done by Gerald Carter. The conversion to DocBook XML
4.2
90 for Samba
3.0 was done by Alexander Bokovoy.
</p></div></div></body></html>