Provided by: samba-common-bin_4.15.13+dfsg-0ubuntu0.20.04.8_amd64 
NAME
smbpasswd - change a user's SMB password
SYNOPSIS
smbpasswd [-a] [-c <config file>] [-x] [-d] [-e] [-D debuglevel] [-n]
[-r <remote machine>] [-R <name resolve order>] [-m] [-U username[%password]] [-h] [-s]
[-w pass] [-W] [-i] [-L] [username]
DESCRIPTION
This tool is part of the samba(7) suite.
The smbpasswd program has several different functions, depending on whether it is run by
the root user or not. When run as a normal user it allows the user to change the password
used for their SMB sessions on any machines that store SMB passwords.
By default (when run with no arguments) it will attempt to change the current user's SMB
password on the local machine. This is similar to the way the passwd(1) program works.
smbpasswd differs from how the passwd program works however in that it is not setuid root
but works in a client-server mode and communicates with a locally running smbd(8). As a
consequence in order for this to succeed the smbd daemon must be running on the local
machine. On a UNIX machine the encrypted SMB passwords are usually stored in the default
passdb backend.
When run by an ordinary user with no options, smbpasswd will prompt them for their old SMB
password and then ask them for their new password twice, to ensure that the new password
was typed correctly. No passwords will be echoed on the screen whilst being typed. If you
have a blank SMB password (specified by the string "NO PASSWORD" in the smbpasswd file)
then just press the <Enter> key when asked for your old password.
smbpasswd can also be used by a normal user to change their SMB password on remote
machines, such as Windows NT Primary Domain Controllers. See the (-r) and -U options
below.
When run by root, smbpasswd allows new users to be added and deleted in the smbpasswd
file, as well as allows changes to the attributes of the user in this file to be made.
When run by root, smbpasswd accesses the local smbpasswd file directly, thus enabling
changes to be made even if smbd is not running.
OPTIONS
-a
This option specifies that the username following should be added to the local
smbpasswd file, with the new password typed (type <Enter> for the old password). This
option is ignored if the username following already exists in the smbpasswd file and
it is treated like a regular change password command. Note that the default passdb
backends require the user to already exist in the system password file (usually
/etc/passwd), else the request to add the user will fail.
This option is only available when running smbpasswd as root.
-c
This option can be used to specify the path and file name of the smb.conf
configuration file when it is important to use other than the default file and / or
location.
-x
This option specifies that the username following should be deleted from the local
smbpasswd file.
This option is only available when running smbpasswd as root.
-d
This option specifies that the username following should be disabled in the local
smbpasswd file. This is done by writing a 'D' flag into the account control space in
the smbpasswd file. Once this is done all attempts to authenticate via SMB using this
username will fail.
If the smbpasswd file is in the 'old' format (pre-Samba 2.0 format) there is no space
in the user's password entry to write this information and the command will FAIL. See
smbpasswd(5) for details on the 'old' and new password file formats.
This option is only available when running smbpasswd as root.
-e
This option specifies that the username following should be enabled in the local
smbpasswd file, if the account was previously disabled. If the account was not
disabled this option has no effect. Once the account is enabled then the user will be
able to authenticate via SMB once again.
If the smbpasswd file is in the 'old' format, then smbpasswd will FAIL to enable the
account. See smbpasswd(5) for details on the 'old' and new password file formats.
This option is only available when running smbpasswd as root.
-D debuglevel
debuglevel is an integer from 0 to 10. The default value if this parameter is not
specified is zero.
The higher this value, the more detail will be logged to the log files about the
activities of smbpasswd. At level 0, only critical errors and serious warnings will be
logged.
Levels above 1 will generate considerable amounts of log data, and should only be used
when investigating a problem. Levels above 3 are designed for use only by developers
and generate HUGE amounts of log data, most of which is extremely cryptic.
-n
This option specifies that the username following should have their password set to
null (i.e. a blank password) in the local smbpasswd file. This is done by writing the
string "NO PASSWORD" as the first part of the first password stored in the smbpasswd
file.
Note that to allow users to logon to a Samba server once the password has been set to
"NO PASSWORD" in the smbpasswd file the administrator must set the following parameter
in the [global] section of the smb.conf file :
null passwords = yes
This option is only available when running smbpasswd as root.
-r remote machine name
This option allows a user to specify what machine they wish to change their password
on. Without this parameter smbpasswd defaults to the local host. The remote machine
name is the NetBIOS name of the SMB/CIFS server to contact to attempt the password
change. This name is resolved into an IP address using the standard name resolution
mechanism in all programs of the Samba suite. See the -R name resolve order parameter
for details on changing this resolving mechanism.
The username whose password is changed is that of the current UNIX logged on user. See
the -U username parameter for details on changing the password for a different
username.
Note that if changing a Windows NT Domain password the remote machine specified must
be the Primary Domain Controller for the domain (Backup Domain Controllers only have a
read-only copy of the user account database and will not allow the password change).
Note that Windows 95/98 do not have a real password database so it is not possible to
change passwords specifying a Win95/98 machine as remote machine target.
-R name resolve order
This option allows the user of smbpasswd to determine what name resolution services to
use when looking up the NetBIOS name of the host being connected to.
The options are :"lmhosts", "host", "wins" and "bcast". They cause names to be
resolved as follows:
• lmhosts: Lookup an IP address in the Samba lmhosts file. If the line in
lmhosts has no name type attached to the NetBIOS name (see the lmhosts(5)
for details) then any name type matches for lookup.
• host: Do a standard host name to IP address resolution, using the system
/etc/hosts, NIS, or DNS lookups. This method of name resolution is
operating system depended for instance on IRIX or Solaris this may be
controlled by the /etc/nsswitch.conf file). Note that this method is only
used if the NetBIOS name type being queried is the 0x20 (server) name type,
otherwise it is ignored.
• wins: Query a name with the IP address listed in the wins server parameter.
If no WINS server has been specified this method will be ignored.
• bcast: Do a broadcast on each of the known local interfaces listed in the
interfaces parameter. This is the least reliable of the name resolution
methods as it depends on the target host being on a locally connected
subnet.
The default order is lmhosts, host, wins, bcast and without this parameter or any
entry in the smb.conf(5) file the name resolution methods will be attempted in this
order.
-m
This option tells smbpasswd that the account being changed is a MACHINE account.
Currently this is used when Samba is being used as an NT Primary Domain Controller.
This option is only available when running smbpasswd as root.
-U username
This option may only be used in conjunction with the -r option. When changing a
password on a remote machine it allows the user to specify the user name on that
machine whose password will be changed. It is present to allow users who have
different user names on different systems to change these passwords.
-h
This option prints the help string for smbpasswd, selecting the correct one for
running as root or as an ordinary user.
-s
This option causes smbpasswd to be silent (i.e. not issue prompts) and to read its old
and new passwords from standard input, rather than from /dev/tty (like the passwd(1)
program does). This option is to aid people writing scripts to drive smbpasswd
-w password
This parameter is only available if Samba has been compiled with LDAP support. The -w
switch is used to specify the password to be used with the ldap admin dn. Note that
the password is stored in the secrets.tdb and is keyed off of the admin's DN. This
means that if the value of ldap admin dn ever changes, the password will need to be
manually updated as well.
-W
NOTE: This option is same as "-w" except that the password should be entered using
stdin.
This parameter is only available if Samba has been compiled with LDAP support. The -W
switch is used to specify the password to be used with the ldap admin dn. Note that
the password is stored in the secrets.tdb and is keyed off of the admin's DN. This
means that if the value of ldap admin dn ever changes, the password will need to be
manually updated as well.
-i
This option tells smbpasswd that the account being changed is an interdomain trust
account. Currently this is used when Samba is being used as an NT Primary Domain
Controller. The account contains the info about another trusted domain.
This option is only available when running smbpasswd as root.
-L
Run in local mode.
username
This specifies the username for all of the root only options to operate on. Only root
can specify this parameter as only root has the permission needed to modify attributes
directly in the local smbpasswd file.
NOTES
Since smbpasswd works in client-server mode communicating with a local smbd for a non-root
user then the smbd daemon must be running for this to work. A common problem is to add a
restriction to the hosts that may access the smbd running on the local machine by
specifying either allow hosts or deny hosts entry in the smb.conf(5) file and neglecting
to allow "localhost" access to the smbd.
In addition, the smbpasswd command is only useful if Samba has been set up to use
encrypted passwords.
VERSION
This man page is part of version 4.15.13-Ubuntu of the Samba suite.
SEE ALSO
smbpasswd(5), Samba(7).
AUTHOR
The original Samba software and related utilities were created by Andrew Tridgell. Samba
is now developed by the Samba Team as an Open Source project similar to the way the Linux
kernel is developed.