Microsoft NTLM authentication

NTLM (NT LAN Manager) is a proprietary connection authentication protocol developed by Microsoft. The following are some important facts that we should know about NTLM authentication:

• NTLM authentication only authenticates a TCP connection and not the user using it.

• It requires a three-way handshake, which puts a limit on the speed and maximum client capacity.

• It is a binary protocol. So only the windows domain controller can be used.

For more details about NTLM, refer to http://en.wikipedia.org/wiki/NTLM. The following auth_param parameters are supported by the NTLM authentication helpers:

auth_param ntlm program COMMAND
auth_param ntlm children NUMBER [startup=N] [idle=N] [concurrency=N]
auth_param ntlm keep_alive on|off

The parameters program and children are similar to the ones in HTTP Basic and Digest authentication. If the parameter keep_alive is set to off, Squid will terminate the connection after the initial requests where browsers enquire about the supported...