smbpasswd [-a] [-x] [-d] [-e] [-D debuglevel] [-n] [-r <remote machine>] [-R < name resolve order>] [-m] [-U username[%password]] [-h] [-s] [-w pass] [-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 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.
-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.
-x ” This option specifies that the username following should be deleted from the local smbpasswd file.
-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.
-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.
-D debuglevel ” debuglevel is an integer from 0 to 10. The default value if this parameter is not specified is zero.
-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.
-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.
-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.
-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.
-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 configured to use the experimental “with-ldapsam option. 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.
-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.
Since smbpasswd works in client-server mode communicating with a local smbd for a nonroot 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.