Question on NTLMv2 over SMB

Andrew Bartlett abartlet at
Tue Jun 28 02:02:48 GMT 2005

On Mon, 2005-06-27 at 18:54 -0700, Yimin Chen wrote:
> Hi,
> I am running into problem when trying to test NTLMv2 pass-through 
> authentication.
> I am reading "Implementing CIFS" and according to the section 15.5.7, if 
> Domain Controller has "IMCompatibility" set to 0, and I send a LMv2 
> response in the CaseInsensitivePassword field in the SMB Session Setup 
> Andx Request, the Domain controller should compare the response with LM, 
> LMv2, NTLM, NTLMv2 responses and found my response matching with LMv2 
> and then grant the access.
> However, in my testing, I noticed that if I send LMv2 response to the 
> domain controller, the access is denied; if I send LM response to the 
> domain controller, the access is allowed. So I am not sure whether there 
> is some additional configuration I need to do on the domain controller 
> in order for it to accept LMv2 response as well?

More likely you have not got the LMv2 algorithm correct, as far as I
know the password type is always accepted.  Also remember that the 'case
sensitive' password field always seems to take priority, so if you have
any NT response, then it will succeed or fail on that basis.

I need to work on more testing combinations, but for the SAMLOGON stage
(which this all ends up, back at the DC) I have a Samba4 testsuite to
hammer this stuff.  It is RPC-SAMLOGON in smbtorture.

Andrew Bartlett

Andrew Bartlett                      
Samba Developer, SuSE Labs, Novell Inc.
Authentication Developer, Samba Team 
Student Network Administrator, Hawker College
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