SMBPASSWD(5)		 File Formats and Conventions		  SMBPASSWD(5)



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:

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

		  o   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.

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

		  o   X - This means the password does not expire.

		  o   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 part of version 4.10.16 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.



Samba 4.10.16			  11/17/2023			  SMBPASSWD(5)