SMBPASSWD(8)                  System Administration tools                  SMBPASSWD(8)

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 4.9.5-Debian 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.

Samba 4.9.5-Debian                     09/02/2019                          SMBPASSWD(8)

When run by root:
    smbpasswd [options] [username]
otherwise:
    smbpasswd [options]

options:
  -L                   local mode (must be first option)
  -h                   print this usage message
  -s                   use stdin for password prompt
  -c smb.conf file     Use the given path to the smb.conf file
  -D LEVEL             debug level
  -r MACHINE           remote machine
  -U USER              remote username (e.g. SAM/user)
extra options when run by root or in local mode:
  -a                   add user
  -d                   disable user
  -e                   enable user
  -i                   interdomain trust account
  -m                   machine trust account
  -n                   set no password
  -W                   use stdin ldap admin password
  -w PASSWORD          ldap admin password
  -x                   delete user
  -R ORDER             name resolve order