ntlm_auth

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NTLM_AUTH(1) NTLM_AUTH(1)

NAME
ntlm_auth - tool to allow external access to Winbind’s NTLM authenti-
cation function

SYNOPSIS
ntlm_auth [-ddebuglevel] [-llogdir] [-s<smbconfigfile>]

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

ntlm_auth is a helper utility that authenticates users using NT/LM
authentication. It returns 0 if the users is authenticated success-
fully and 1 if access was denied. ntlm_auth uses winbind to access the
user and authentication data for a domain. This utility is only
indended to be used by other programs (currently Squid and
mod_ntlm_winbind)

OPERATIONAL REQUIREMENTS
The winbindd(8) daemon must be operational for many of these commands
to function.

Some of these commands also require access to the directory win-
bindd_privileged in $LOCKDIR. This should be done either by running
this command as root or providing group access to the winbindd_privi-
leged directory. For security reasons, this directory should not be
world-accessable.

OPTIONS
--helper-protocol=PROTO
Operate as a stdio-based helper. Valid helper protocols are:

squid-2.4-basic
Server-side helper for use with Squid 2.4’s basic (plaintext)
authentication.

squid-2.5-basic
Server-side helper for use with Squid 2.5’s basic (plaintext)
authentication.

squid-2.5-ntlmssp
Server-side helper for use with Squid 2.5’s NTLMSSP authenti-
cation.

Requires access to the directory winbindd_privileged in
$LOCKDIR. The protocol used is described here:
http://devel.squid-cache.org/ntlm/squid_helper_protocol.html.
This protocol has been extended to allow the NTLMSSP Negoti-
ate packet to be included as an argument to the YR command.
(Thus avoiding loss of information in the protocol exchange).

ntlmssp-client-1
Client-side helper for use with arbitary external programs
that may wish to use Samba’s NTLMSSP authentication knowlege.

This helper is a client, and as such may be run by any user.
The protocol used is effectivly the reverse of the previous
protocol. A YR command (without any arguments) starts the
authentication exchange.

gss-spnego
Server-side helper that implements GSS-SPNEGO. This uses a
protocol that is almost the same as squid-2.5-ntlmssp, but
has some subtle differences that are undocumented outside the
source at this stage.

Requires access to the directory winbindd_privileged in
$LOCKDIR.

gss-spnego-client
Client-side helper that implements GSS-SPNEGO. This also uses
a protocol similar to the above helpers, but is currently
undocumented.

ntlm-server-1
Server-side helper protocol, intended for use by a RADIUS
server or the ’winbind’ plugin for pppd, for the provision of
MSCHAP and MSCHAPv2 authentication.

This protocol consists of lines in for form: Parameter: value
and Paramter:: Base64-encode value. The presence of a single
period indicates that one side has finished supplying data to
the other. (Which in turn could cause the helper to authenti-
cate the user).

Curently implemented parameters from the external program to
the helper are:

Username
The username, expected to be in Samba’s unix charset.

Example1.Username: bob

Example2.Username:: Ym9i

Username
The user’s domain, expected to be in Samba’s unix
charset.

Example3.Domain: WORKGROUP

Example4.Domain:: V09SS0dST1VQ

Full-Username
The fully qualified username, expected to be in Samba’s

and qualified with the winbind separator.

Example5.Full-Username: WORKGROUPb

Example6.Full-Username:: V09SS0dST1VQYm9i

LANMAN-Challenge
The 8 byte LANMAN Challenge value, generated randomly
by the server, or (in cases such as MSCHAPv2) generated
in some way by both the server and the client.

Example7.LANMAN-Challege: 0102030405060708

LANMAN-Response
The 24 byte LANMAN Response value, calculated from the
user’s password and the supplied LANMAN Challenge. Typ-
ically, this is provided over the network by a client
wishing to authenticate.

Example8.LANMAN-Response:
0102030405060708090A0B0C0D0E0F101112131415161718

NT-Response
The >= 24 byte NT Response calculated from the user’s
password and the supplied LANMAN Challenge. Typically,
this is provided over the network by a client wishing
to authenticate.

Example9.NT-Response:
0102030405060708090A0B0C0D0E0F101112131415161718

Password
The user’s password. This would be provided by a net-
work client, if the helper is being used in a legacy
situation that exposes plaintext passwords in this way.

Example10.Password: samba2

Example11.Password:: c2FtYmEy

Request-User-Session-Key
Apon sucessful authenticaiton, return the user session
key associated with the login.

Example12.Request-User-Session-Key: Yes

Request-LanMan-Session-Key
Apon sucessful authenticaiton, return the LANMAN ses-
sion key associated with the login.

Example13.Request-LanMan-Session-Key: Yes

Warning
Implementors should take care to base64 encode
any data (such as usernames/passwords) that may
contain malicous user data, such as a newline.
They may also need to decode strings from the
helper, which likewise may have been base64 encoded.

--username=USERNAME
Specify username of user to authenticate

--domain=DOMAIN
Specify domain of user to authenticate

--workstation=WORKSTATION
Specify the workstation the user authenticated from

--challenge=STRING
NTLM challenge (in HEXADECIMAL)

--lm-response=RESPONSE
LM Response to the challenge (in HEXADECIMAL)

--nt-response=RESPONSE
NT or NTLMv2 Response to the challenge (in HEXADECIMAL)

--password=PASSWORD
User’s plaintext password

If not specified on the command line, this is prompted for when
required.

For the NTLMSSP based server roles, this paramter specifies the
expected password, allowing testing without winbindd operational.

--request-lm-key
Retreive LM session key

--request-nt-key
Request NT key

--diagnostics
Perform Diagnostics on the authentication chain. Uses the password
from --password or prompts for one.

--require-membership-of={SID|Name}
Require that a user be a member of specified group (either name or
SID) for authentication to succeed.

-V
Prints the program version number.

-s <configuration file>
The file specified contains the configuration details required by
the server. The information in this file includes server-specific
information such as what printcap file to use, as well as descrip-
tions of all the services that the server is to provide. See
smb.conf for more information. The default configuration file name
is determined at compile time.

-d|--debuglevel=level
level is an integer from 0 to 10. The default value if this parame-
ter is not specified is zero.

The higher this value, the more detail will be logged to the log
files about the activities of the server. At level 0, only critical
errors and serious warnings will be logged. Level 1 is a reasonable
level for day-to-day running - it generates a small amount of
information about operations carried out.

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.

Note that specifying this parameter here will override the

parameter in the smb.conf file.

-l|--logfile=logdirectory
Base directory name for log/debug files. The extension ".progname"
will be appended (e.g. log.smbclient, log.smbd, etc...). The log
file is never removed by the client.

-h|--help
Print a summary of command line options.

EXAMPLE SETUP
To setup ntlm_auth for use by squid 2.5, with both basic and NTLMSSP
authentication, the following should be placed in the squid.conf file.

auth_param ntlm program ntlm_auth --helper-protocol=squid-2.5-ntlmssp
auth_param basic program ntlm_auth --helper-protocol=squid-2.5-basic
auth_param basic children 5
auth_param basic realm Squid proxy-caching web server
auth_param basic credentialsttl 2 hours

Note
This example assumes that ntlm_auth has been installed into your path,
and that the group permissions on winbindd_privileged are as described
above.

To setup ntlm_auth for use by squid 2.5 with group limitation in addi-
tion to the above example, the following should be added to the
squid.conf file.

auth_param ntlm program ntlm_auth --helper-protocol=squid-2.5-ntlmssp --require-membership-of=’WORKGROUPauth_param basic program ntlm_auth --helper-protocol=squid-2.5-basic --require-membership-of=’WORKGROUP

TROUBLESHOOTING
If you’re experiencing problems with authenticating Internet Explorer
running under MS Windows 9X or Millenium Edition against ntlm_auth’s
NTLMSSP authentication helper (--helper-protocol=squid-2.5-ntlmssp),
then please read the Microsoft Knowledge Base article #239869 and fol-
low instructions described there.

VERSION
This man page is correct for version 3.0 of the Samba suite.

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 ntlm_auth manpage was written by Jelmer Vernooij and Andrew
Bartlett.

NTLM_AUTH(1)