smbpasswd — change a user's SMB password
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]
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
This option prints the help string for
smbpasswd
, selecting the correct one for running as root
or as an ordinary user.
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
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.
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.
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.
Run in local mode.
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.
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.