gss(5) File Formats Manual gss(5)

gsshow to configure gss framework

The gss GSS.frameworks have several configuration domains, all can configured with defaults(1).

Configuration can be stored both in the user's configuration ( ~/Library/Preferences) and system ( /Library/Preferences ).

Use gsstool(1) to list the supported options and their settings:

gsstool supported-mech --options

Common options are:

NTLM 'Force NTLMv1'
Force client to use NTLMv1
Enable support for NTLMv1 in both client and server
Enable support for NTLMv2 in both client and server
NTLM 'NTLM session key'
Require backends to support for NTLMv2 session key, Lion and earlier dont support this. Session keys is required for NTLM MIC that stops reflection attacks.
NTLM 'AllowedHosts'
What hosts that NTLM is allowed to be used for. When there a host that is not on the list, NTLM will not be used. File globbing is used when matching and it's case insensitive. When there is no configuration, all hosts are allowed.
defaults write AllowedHosts -array host.local '*.my.domain'

If you want to disable NTLM support completely in both the acceptor (server) and initiator (client), you need disable both NTLMv1 and NTLMv2, and set their values to boolean false or 0.

defaults write NTLMv1 -bool false
defaults write NTLMv2 -bool false

You can use the defaults write command to change the options, for simple boolean options, use this:

defaults write NTLMv1 -bool false

You can also turn on debugging (output in syslog) using:

defaults write DebugLevel -int 10
open -a Console

defaults(1), gss_mo(3), heimdal_debug(1)

September 1, 2010 HEIMDAL