ntlm_auth - tool to allow external access to Winbind's NTLM authentication function
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 successfully and 1 if access was denied. ntlm_auth uses winbind to access the user and authentication data for a domain. This utility is only intended to be used by other programs (currently Squid and mod_ntlm_winbind)
The winbindd(8) daemon must be operational for many of these commands to function.
Some of these commands also require access to the directory winbindd_privileged in $LOCKDIR. This should be done either by running this command as root or providing group access to the winbindd_privileged directory. For security reasons, this directory should not be world-accessable.
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 Negotiate packet to be included as an argument to the YR command. (Thus avoiding loss of information in the protocol exchange).
This helper is a client, and as such may be run by any user. The protocol used is effectively the reverse of the previous protocol. A YR command (without any arguments) starts the authentication exchange.
Requires access to the directory winbindd_privileged in $LOCKDIR.
This protocol consists of lines in the form: Parameter: value and Parameter:: 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 authenticate the user).
Currently implemented parameters from the external program to the helper are:
Implementers should take care to base64 encode any data (such as usernames/passwords) that may contain malicious user data, such as a newline. They may also need to decode strings from the helper, which likewise may have been base64 encoded.
If not specified on the command line, this is prompted for when required.
For the NTLMSSP based server roles, this parameter specifies the expected password, allowing testing without winbindd operational.
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 log level parameter in the /etc/samba/smb.conf file.
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
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 addition 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='WORKGROUP\Domain Users' auth_param basic program ntlm_auth --helper-protocol=squid-2.5-basic --require-membership-of='WORKGROUP\Domain Users'
If you're experiencing problems with authenticating Internet Explorer running under MS Windows 9X or Millennium Edition against ntlm_auth's NTLMSSP authentication helper (--helper-protocol=squid-2.5-ntlmssp), then please read the Microsoft Knowledge Base article #239869 and follow instructions described there.
This man page is part of version 4.19.3-Debian of the Samba suite.
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.