Provided by: samba-common-bin_4.3.11+dfsg-0ubuntu0.16.04.34_amd64 bug

NAME

       smbpasswd - The Samba encrypted password file

SYNOPSIS

       smbpasswd

DESCRIPTION

       This tool is part of the samba(7) suite.

       smbpasswd is the Samba encrypted password file. It contains the username, Unix user id and
       the SMB hashed passwords of the user, as well as account flag information and the time the
       password was last changed. This file format has been evolving with Samba and has had
       several different formats in the past.

FILE FORMAT

       The format of the smbpasswd file used by Samba 2.2 is very similar to the familiar Unix
       passwd(5) file. It is an ASCII file containing one line for each user. Each field within
       each line is separated from the next by a colon. Any entry beginning with '#' is ignored.
       The smbpasswd file contains the following information for each user:

       name
           This is the user name. It must be a name that already exists in the standard UNIX
           passwd file.

       uid
           This is the UNIX uid. It must match the uid field for the same user entry in the
           standard UNIX passwd file. If this does not match then Samba will refuse to recognize
           this smbpasswd file entry as being valid for a user.

       Lanman Password Hash
           This is the LANMAN hash of the user's password, encoded as 32 hex digits. The LANMAN
           hash is created by DES encrypting a well known string with the user's password as the
           DES key. This is the same password used by Windows 95/98 machines. Note that this
           password hash is regarded as weak as it is vulnerable to dictionary attacks and if two
           users choose the same password this entry will be identical (i.e. the password is not
           "salted" as the UNIX password is). If the user has a null password this field will
           contain the characters "NO PASSWORD" as the start of the hex string. If the hex string
           is equal to 32 'X' characters then the user's account is marked as disabled and the
           user will not be able to log onto the Samba server.

           WARNING !!  Note that, due to the challenge-response nature of the SMB/CIFS
           authentication protocol, anyone with a knowledge of this password hash will be able to
           impersonate the user on the network. For this reason these hashes are known as plain
           text equivalents and must NOT be made available to anyone but the root user. To
           protect these passwords the smbpasswd file is placed in a directory with read and
           traverse access only to the root user and the smbpasswd file itself must be set to be
           read/write only by root, with no other access.

       NT Password Hash
           This is the Windows NT hash of the user's password, encoded as 32 hex digits. The
           Windows NT hash is created by taking the user's password as represented in 16-bit,
           little-endian UNICODE and then applying the MD4 (internet rfc1321) hashing algorithm
           to it.

           This password hash is considered more secure than the LANMAN Password Hash as it
           preserves the case of the password and uses a much higher quality hashing algorithm.
           However, it is still the case that if two users choose the same password this entry
           will be identical (i.e. the password is not "salted" as the UNIX password is).

           WARNING !!. Note that, due to the challenge-response nature of the SMB/CIFS
           authentication protocol, anyone with a knowledge of this password hash will be able to
           impersonate the user on the network. For this reason these hashes are known as plain
           text equivalents and must NOT be made available to anyone but the root user. To
           protect these passwords the smbpasswd file is placed in a directory with read and
           traverse access only to the root user and the smbpasswd file itself must be set to be
           read/write only by root, with no other access.

       Account Flags
           This section contains flags that describe the attributes of the users account. This
           field is bracketed by '[' and ']' characters and is always 13 characters in length
           (including the '[' and ']' characters). The contents of this field may be any of the
           following characters:

           •   U - This means this is a "User" account, i.e. an ordinary user.

           •   N - This means the account has no password (the passwords in the fields LANMAN
               Password Hash and NT Password Hash are ignored). Note that this will only allow
               users to log on with no password if the
                null passwords parameter is set in the smb.conf(5) config file.

           •   D - This means the account is disabled and no SMB/CIFS logins will be allowed for
               this user.

           •   X - This means the password does not expire.

           •   W - This means this account is a "Workstation Trust" account. This kind of account
               is used in the Samba PDC code stream to allow Windows NT Workstations and Servers
               to join a Domain hosted by a Samba PDC.

       Other flags may be added as the code is extended in future. The rest of this field space
       is filled in with spaces. For further information regarding the flags that are supported
       please refer to the man page for the pdbedit command.

       Last Change Time
           This field consists of the time the account was last modified. It consists of the
           characters 'LCT-' (standing for "Last Change Time") followed by a numeric encoding of
           the UNIX time in seconds since the epoch (1970) that the last change was made.

       All other colon separated fields are ignored at this time.

VERSION

       This man page is correct for version 3 of the Samba suite.

SEE ALSO

       smbpasswd(8), Samba(7), and the Internet RFC1321 for details on the MD4 algorithm.

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.

       The original Samba man pages were written by Karl Auer. The man page sources were
       converted to YODL format (another excellent piece of Open Source software, available at
       ftp://ftp.icce.rug.nl/pub/unix/) and updated for the Samba 2.0 release by Jeremy Allison.
       The conversion to DocBook for Samba 2.2 was done by Gerald Carter. The conversion to
       DocBook XML 4.2 for Samba 3.0 was done by Alexander Bokovoy.