3.1.5.2 Receiving a SEND Command
Expected AUTH_STATE: send_not_received
On receiving the SEND command from the server, the client MUST send an IS command to the server and set AUTH_STATE to negotiate_data_sent. The client MUST set the fields of the IS command message as follows:
AuthenticationType set to 0x0F (NTLM).
Modifier set to 0x00.
NTLM_CommandCode set to NTLM_NEGOTIATE.
NTLM_DataSize set to the size of NTLM Data in number of bytes.
NTLM_BufferType set to 0x00000002.
NTLM_Data set to NTLM NEGOTIATE_MESSAGE as received from the local NTLM software. How to obtain an NTLM NEGOTIATE_MESSAGE is specified in [MS-NLMP].
If the AUTH_STATE is not equal to send_not_received when the client receives a SEND command, the client SHOULD treat this as an error condition and take an appropriate implementation-dependent action.<3>