6 <html><head><title>smbpasswd (5)</title>
8 <link rev="made" href="mailto:samba-bugs@samba.org">
14 <h1>smbpasswd (5)</h1>
21 <p><br><a name="NAME"></a>
23 smbpasswd - The Samba encrypted password file
24 <p><br><a name="SYNOPSIS"></a>
27 <p><br>smbpasswd is the <strong>Samba</strong> encrypted password file.
28 <p><br><a name="DESCRIPTION"></a>
31 <p><br>This file is part of the <strong>Samba</strong> suite.
32 <p><br>smbpasswd is the <strong>Samba</strong> encrypted password file. It contains
33 the username, Unix user id and the SMB hashed passwords of the
34 user, as well as account flag information and the time the password
35 was last changed. This file format has been evolving with Samba
36 and has had several different formats in the past.
37 <p><br><a name="FILEFORMAT"></a>
40 <p><br>The format of the smbpasswd file used by Samba 2.0 is very similar to
41 the familiar Unix <strong>passwd (5)</strong> file. It is an ASCII file containing
42 one line for each user. Each field within each line is separated from
43 the next by a colon. Any entry beginning with # is ignored. The
44 smbpasswd file contains the following information for each user:
46 <p><br><a name="name"></a>
47 <li><strong><strong>name</strong></strong> <br> <br>
48 <p><br>This is the user name. It must be a name that already exists
49 in the standard UNIX passwd file.
50 <p><br><a name="uid"></a>
51 <li><strong><strong>uid</strong></strong> <br> <br>
52 <p><br>This is the UNIX uid. It must match the uid field for the same
53 user entry in the standard UNIX passwd file. If this does not
54 match then Samba will refuse to recognize this <strong>smbpasswd</strong> file entry
55 as being valid for a user.
56 <p><br><a name="LanmanPasswordHash"></a>
57 <li><strong><strong>Lanman Password Hash</strong></strong> <br> <br>
58 <p><br>This is the <em>LANMAN</em> hash of the users password, encoded as 32 hex
59 digits. The <em>LANMAN</em> hash is created by DES encrypting a well known
60 string with the users password as the DES key. This is the same
61 password used by Windows 95/98 machines. Note that this password hash
62 is regarded as weak as it is vulnerable to dictionary attacks and if
63 two users choose the same password this entry will be identical (i.e.
64 the password is not <em>"salted"</em> as the UNIX password is). If the
65 user has a null password this field will contain the characters
66 <code>"NO PASSWORD"</code> as the start of the hex string. If the hex string
67 is equal to 32 <code>'X'</code> characters then the users account is marked as
68 <em>disabled</em> and the user will not be able to log onto the Samba
70 <p><br><em>WARNING !!</em>. Note that, due to the challenge-response nature of the
71 SMB/CIFS authentication protocol, anyone with a knowledge of this
72 password hash will be able to impersonate the user on the network.
73 For this reason these hashes are known as <em>"plain text equivalent"</em>
74 and must <em>NOT</em> be made available to anyone but the root user. To
75 protect these passwords the <strong>smbpasswd</strong> file is placed in a
76 directory with read and traverse access only to the root user and the
77 <strong>smbpasswd</strong> file itself must be set to be read/write only by root,
79 <p><br><a name="NTPasswordHash"></a>
80 <li><strong><strong>NT Password Hash</strong></strong> <br> <br>
81 <p><br>This is the <em>Windows NT</em> hash of the users password, encoded as 32
82 hex digits. The <em>Windows NT</em> hash is created by taking the users
83 password as represented in 16-bit, little-endian UNICODE and then
84 applying the <em>MD4</em> (internet rfc1321) hashing algorithm to it.
85 <p><br>This password hash is considered more secure than the <a href="smbpasswd.5.html#LanmanPasswordHash"><strong>Lanman
86 Password Hash</strong></a> as it preserves the case of the
87 password and uses a much higher quality hashing algorithm. However, it
88 is still the case that if two users choose the same password this
89 entry will be identical (i.e. the password is not <em>"salted"</em> as the
91 <p><br><em>WARNING !!</em>. Note that, due to the challenge-response nature of the
92 SMB/CIFS authentication protocol, anyone with a knowledge of this
93 password hash will be able to impersonate the user on the network.
94 For this reason these hashes are known as <em>"plain text equivalent"</em>
95 and must <em>NOT</em> be made available to anyone but the root user. To
96 protect these passwords the <strong>smbpasswd</strong> file is placed in a
97 directory with read and traverse access only to the root user and the
98 <strong>smbpasswd</strong> file itself must be set to be read/write only by root,
100 <p><br><a name="AccountFlags"></a>
101 <li><strong><strong>Account Flags</strong></strong> <br> <br>
102 <p><br>This section contains flags that describe the attributes of the users
103 account. In the <strong>Samba2.0</strong> release this field is bracketed by <code>'['</code>
104 and <code>']'</code> characters and is always 13 characters in length (including
105 the <code>'['</code> and <code>']'</code> characters). The contents of this field may be
106 any of the characters.
108 <p><br><a name="capU"></a>
109 <li > <strong>'U'</strong> This means this is a <em>"User"</em> account, i.e. an ordinary
110 user. Only <strong>User</strong> and <a href="smbpasswd.5.html#capW"><strong>Workstation Trust</strong></a> accounts are
111 currently supported in the <strong>smbpasswd</strong> file.
112 <p><br><a name="capN"></a>
113 <li > <strong>'N'</strong> This means the account has <em>no</em> password (the passwords
114 in the fields <a href="smbpasswd.5.html#LanmanPasswordHash"><strong>Lanman Password Hash</strong></a> and
115 <a href="smbpasswd.5.html#NTPasswordHash"><strong>NT Password Hash</strong></a> are ignored). Note that this
116 will only allow users to log on with no password if the
117 <a href="smb.conf.5.html#nullpasswords"><strong>null passwords</strong></a> parameter is set
118 in the <a href="smb.conf.5.html"><strong>smb.conf (5)</strong></a> config file.
119 <p><br><a name="capD"></a>
120 <li > <strong>'D'</strong> This means the account is disabled and no SMB/CIFS logins
121 will be allowed for this user.
122 <p><br><a name="capW"></a>
123 <li > <strong>'W'</strong> This means this account is a <em>"Workstation Trust"</em> account.
124 This kind of account is used in the Samba PDC code stream to allow Windows
125 NT Workstations and Servers to join a Domain hosted by a Samba PDC.
127 <p><br>Other flags may be added as the code is extended in future. The rest of
128 this field space is filled in with spaces.
129 <p><br><a name="LastChangeTime"></a>
130 <li><strong><strong>Last Change Time</strong></strong> <br> <br>
131 <p><br>This field consists of the time the account was last modified. It consists of
132 the characters <code>LCT-</code> (standing for <em>"Last Change Time"</em>) followed by a numeric
133 encoding of the UNIX time in seconds since the epoch (1970) that the last change
135 <p><br><li><strong><strong>Following fields</strong></strong> <br> <br>
136 <p><br>All other colon separated fields are ignored at this time.
138 <p><br><a name="NOTES"></a>
141 <p><br>In previous versions of Samba (notably the 1.9.18 series) this file
142 did not contain the <a href="smbpasswd.5.html#AccountFlags"><strong>Account Flags</strong></a> or
143 <a href="smbpasswd.5.html#LastChangeTime"><strong>Last Change Time</strong></a> fields. The Samba 2.0
144 code will read and write these older password files but will not be able to
145 modify the old entries to add the new fields. New entries added with
146 <a href="smbpasswd.8.html"><strong>smbpasswd (8)</strong></a> will contain the new fields
147 in the added accounts however. Thus an older <strong>smbpasswd</strong> file used
148 with Samba 2.0 may end up with some accounts containing the new fields
150 <p><br>In order to convert from an old-style <strong>smbpasswd</strong> file to a new
151 style, run the script <strong>convert_smbpasswd</strong>, installed in the
152 Samba <code>bin/</code> directory (the same place that the <a href="smbd.8.html"><strong>smbd</strong></a>
153 and <a href="nmbd.8.html"><strong>nmbd</strong></a> binaries are installed) as follows:
157 cat old_smbpasswd_file | convert_smbpasswd > new_smbpasswd_file
162 <p><br>The <strong>convert_smbpasswd</strong> script reads from stdin and writes to stdout
163 so as not to overwrite any files by accident.
164 <p><br>Once this script has been run, check the contents of the new smbpasswd
165 file to ensure that it has not been damaged by the conversion script
166 (which uses <strong>awk</strong>), and then replace the <code><old smbpasswd file></code>
167 with the <code><new smbpasswd file></code>.
168 <p><br><a name="VERSION"></a>
171 <p><br>This man page is correct for version 2.0 of the Samba suite.
172 <p><br><a name="SEEALSO"></a>
175 <p><br><a href="smbpasswd.8.html"><strong>smbpasswd (8)</strong></a>, <a href="samba.7.html"><strong>samba
176 (7)</strong></a>, and the Internet RFC1321 for details on the MD4
178 <p><br><a name="AUTHOR"></a>
181 <p><br>The original Samba software and related utilities were created by
182 Andrew Tridgell <a href="mailto:samba-bugs@samba.org"><em>samba-bugs@samba.org</em></a>. Samba is now developed
183 by the Samba Team as an Open Source project similar to the way the
184 Linux kernel is developed.
185 <p><br>The original Samba man pages were written by Karl Auer. The man page
186 sources were converted to YODL format (another excellent piece of Open
187 Source software, available at
188 <a href="ftp://ftp.icce.rug.nl/pub/unix/"><strong>ftp://ftp.icce.rug.nl/pub/unix/</strong></a>)
189 and updated for the Samba2.0 release by Jeremy
190 Allison, <a href="mailto:samba-bugs@samba.org"><em>samba-bugs@samba.org</em></a>.
191 <p><br>See <a href="samba.7.html"><strong>samba (7)</strong></a> to find out how to get a full
192 list of contributors and details on how to submit bug reports,