mailto(samba-bugs@samba.anu.edu.au) 

manpage(smbpasswd)(5)(23 Oct 1998)(Samba)(SAMBA)

label(NAME)
manpagename(smbpasswd)(The Samba encrypted password file)

label(SYNOPSIS)
manpagesynopsis() 

smbpasswd is the bf(Samba) encrypted password file.

label(DESCRIPTION)
manpagedescription()

This file is part of the bf(Samba) suite.

smbpasswd is the bf(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.

label(FILEFORMAT)
manpagesection(FILE FORMAT)

The format of the smbpasswd file used by Samba 2.0 is very similar to
the familiar unix bf(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:

startit()

label(name)
dit(bf(name)) nl() nl()

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

label(uid)
dit(bf(uid)) nl() nl()

	This is the UNIX uid. It must match the uid field for the same
	user entry in the standard UNIX passwd file.

label(LanmanPasswordHash)
dit(bf(Lanman Password Hash)) nl() nl()

	This is the em(LANMAN) hash of the users password, encoded as 32 hex
	digits. The em(LANMAN) hash is created by DES encrypting a well known
	string with the users 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 (ie.
	the password is not em("salted") as the UNIX password is). If the
	user has a null password this field will contain the characters
	tt("NO PASSWORD") as the start of the hex string. If the hex string
	is equal to 32 tt('X') characters then the users account is marked as
	em(disabled) and the user will not be able to log onto the Samba
	server.

	em(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 of the network.
	For this reason these hashes are known as em("plain text equivalent")
	and must em(NOT) be made available to anyone but the root user. To
	protect these passwords the bf(smbpasswd) file is placed in a
	directory with read and traverse access only to the root user and the
	bf(smbpasswd) file itself must be set to be read/write only by root,
	with no other access.

label(NTPasswordHash)
dit(bf(NT Password Hash)) nl() nl()

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

	This password hash is considered more secure than the link(bf(Lanman
	Password Hash))(LanmanPasswordHash) 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 (ie. the password is not em("salted") as the
	UNIX password is).

	em(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 of the network.
	For this reason these hashes are known as em("plain text equivalent")
	and must em(NOT) be made available to anyone but the root user. To
	protect these passwords the bf(smbpasswd) file is placed in a
	directory with read and traverse access only to the root user and the
	bf(smbpasswd) file itself must be set to be read/write only by root,
	with no other access.

enddit()

label(VERSION)
manpagesection(VERSION)

This man page is correct for version 2.0 of the Samba suite.

label(SEEALSO)
manpageseealso()

url(bf(smbpasswd (8)))(smbpasswd.8.html), url(bf(samba
(7)))(samba.7.html), and the Internet RFC1321 for details on the MD4
algorithm.

label(AUTHOR)
manpageauthor()

The original Samba software and related utilities were created by
Andrew Tridgell (samba-bugs@samba.anu.edu.au). 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) and updated for the Samba2.0 release by Jeremy
Allison, email(samba-bugs@samba.anu.edu.au).

See url(bf(samba (7)))(samba.7.html) to find out how to get a full
list of contributors and details on how to submit bug reports,
comments etc.