Method smb2SessionSetup

impacket/smbserver.py:3199–3263

(connId, smbServer, recvPacket)

    @staticmethod
    def smb2SessionSetup(connId, smbServer, recvPacket):
        connData = smbServer.getConnectionData(connId, checkStatus=False)

        sessionSetupData = smb2.SMB2SessionSetup(recvPacket['Data'])

        connData['Capabilities'] = sessionSetupData['Capabilities']

        securityBlob = sessionSetupData['Buffer']

        rawNTLM = False
        authType = None
        if struct.unpack('B', securityBlob[0:1])[0] == ASN1_AID:
            # NEGOTIATE packet
            blob = SPNEGO_NegTokenInit(securityBlob)
            token = blob['MechToken']
            if len(blob['MechTypes'][0]) > 0:
                # Is this GSSAPI NTLM or something else we don't support?
                authType = blob['MechTypes'][0]
                supported_mechtypes = []
                if smbServer.getKerberosSupport() and smbServer.getComputerAccountCredentials()["username"]:
                    # if computer account credentials are provided, we can also use kerberos
                    supported_mechtypes += [TypesMech['MS KRB5 - Microsoft Kerberos 5'], TypesMech['KRB5 - Kerberos 5'], TypesMech['KRB5 - Kerberos 5 - User to User']]
                if smbServer.getNTLMSupport():
                    supported_mechtypes += [TypesMech['NTLMSSP - Microsoft NTLM Security Support Provider']]
                if authType not in supported_mechtypes:
                    # Nope, do we know it?
                    if authType in MechTypes:
                        mechStr = MechTypes[authType]
                    else:
                        mechStr = hexlify(authType)
                    smbServer.log("Unsupported MechType '%s'" % mechStr, logging.DEBUG, connData=connData)

                    return [SMB2Commands.generic_negTokenResp()], None, STATUS_MORE_PROCESSING_REQUIRED
        elif struct.unpack('B', securityBlob[0:1])[0] == ASN1_SUPPORTED_MECH:
            # AUTH packet
            blob = SPNEGO_NegTokenResp(securityBlob)
            token = blob['ResponseToken']
            if b'NTLMSSP\x00' in token and smbServer.getNTLMSupport():
                authType = TypesMech['NTLMSSP - Microsoft NTLM Security Support Provider']
            elif smbServer.getKerberosSupport():
                authType = TypesMech['MS KRB5 - Microsoft Kerberos 5']
            else:
                return [SMB2Commands.generic_negTokenResp()], None, STATUS_MORE_PROCESSING_REQUIRED
        elif securityBlob.startswith(b'NTLMSSP\x00') and smbServer.getNTLMSupport():
            # No GSSAPI stuff, raw NTLMSSP
            rawNTLM = True
            token = securityBlob
            authType = TypesMech['NTLMSSP - Microsoft NTLM Security Support Provider']
        else:
            smbServer.log("Unknown or unsupported security blob type", logging.ERROR, connData=connData)
            return [SMB2Commands.generic_negTokenResp()], None, STATUS_MORE_PROCESSING_REQUIRED
        
        if authType in [TypesMech['MS KRB5 - Microsoft Kerberos 5'], TypesMech['KRB5 - Kerberos 5'], TypesMech['KRB5 - Kerberos 5 - User to User']]:
            respSMBCommand, errorCode = SMB2Commands._kerberos_auth(token, connData, smbServer)
        elif authType == TypesMech['NTLMSSP - Microsoft NTLM Security Support Provider']:
            respSMBCommand, errorCode = SMB2Commands._ntlm_auth(token, connData, smbServer, rawNTLM)

        # From now on, the client can ask for other commands