We now have client-side SMB signing support!

We now have client-side SMB signing support!

This checking allows us to connect to Microsoft servers the use SMB signing,
within a few restrictions:

 - I've not get the NTLMSSP stuff going - it appears to work, but if you break
the sig - say by writing a zero in it - it still passes...
 - We don't currently verfiy the server's reply
 - It works against one of my test servers, but not the other...

However, it provides an excellent basis to work from.  Enable it with 'client
signing' in your smb.conf.

Doc to come (tomorrow) and this is not for 3.0, till we get it complete.

The CIFS Spec is misleading - the session key (for NTLMv1 at least) is the
standard session key, ie MD4(NT#).

Thanks to jra for the early work on this.

Andrew Bartlett