Re: Multiple server challenge packets during NTLM authentication

2014/1/7 Vipul Sharma <[email protected]>:
> Hello,
>
> While running my tests using tsql client, i found that if server sends
> multiple NTLM Challenge packets, then tsql generates a new NTLM AUTH packet
> for every Challenge packet. The sequence is as follows :
>
> Client -> Server (NTLM Negotiate packet)
> Server -> Client (NTLM Challenge packet)
> Client -> Server (NTLM AUTH packet)
> Server -> Client (NTLM Challenge packet)
> Client -> Server (NTLM AUTH packet)
>

Are you sure is not Kerberos ?? For Kerberos (or gssapi) is normal.
SSPI support both NTLM and Kerberos so perhaps it's using Kerberos. If
server connected it definitively is.

> Is this supported by NTLM protocol ? I tested the same sequence with other
> TDS clients(SQL Server Studio) and it threw an error.
>
> Is this a bug ? Can somebody please shed some light on this ?
>
> Thanks,
> Vipul

Frediano