Yolinux.com

smbpasswd manpage

Search topic Section


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 smbpasswd(5) file.

       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:

		  o   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.

		  o   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.

		  o   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.

		  o   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 4.8.3 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 4.8.3			  01/09/2019			  SMBPASSWD(8)