Method __process_answer_structure

impacket/dns.py:372–452

(self, offset, num)

        return self.__process_answer_structure(offset, arcount)
    
    def __process_answer_structure(self, offset, num):
        aux  = []
        data = self.get_body_as_string()
        for _ in range(num):
            offset, qname = self.parseCompressedMessage(data, offset)
            qtype  = data[offset:offset+self.__TYPE_LEN]
            qtype  = struct.unpack("!H", qtype)[0]
            offset  += self.__TYPE_LEN
            
            qclass = data[offset:offset+self.__CLASS_LEN]
            qclass = struct.unpack("!H", qclass)[0]
            offset  += self.__CLASS_LEN
            
            qttl_raw = data[offset:offset+self.__TTL_LEN]
            qttl = struct.unpack("!L", qttl_raw)[0]
            offset  += self.__TTL_LEN
            
            qrdlength = data[offset:offset+self.__RDLENGTH_LEN]
            qrdlength = struct.unpack("!H", qrdlength)[0]
            offset  += self.__RDLENGTH_LEN
            
            qrdata = {}
            if qtype == DNSType.A:
                # IP Address  Unsigned 32-bit value representing the IP address
                qrdata["IPAddress"] = socket.inet_ntoa(data[offset:offset+qrdlength])
                offset  += self.__TYPE_A_LEN
            elif qtype == DNSType.SOA:
                # Primary NS  Variable length. The name of the Primary Master for the domain. May be a label, pointer or any combination.
                offset, primaryNs = self.parseCompressedMessage(data, offset)
                qrdata["PrimaryNS"] = primaryNs
                # Admin MB  Variable length. The administrator's mailbox. May be a label, pointer or any combination.
                offset, adminMb = self.parseCompressedMessage(data, offset)
                qrdata["AdminMB"] = adminMb
                # Serial Number  Unsigned 32-bit integer.
                qrdata["SerialNumber"] = struct.unpack("!L", data[offset:offset+self.__SERIAL_LEN])[0]
                offset += self.__SERIAL_LEN
                # Refresh interval  Unsigned 32-bit integer.
                qrdata["RefreshInterval"] = struct.unpack("!L", data[offset:offset+self.__REFRESH_LEN])[0]
                offset += self.__REFRESH_LEN
                # Retry Interval  Unsigned 32-bit integer.
                qrdata["RetryInterval"] = struct.unpack("!L", data[offset:offset+self.__RETRY_LEN])[0]
                offset += self.__RETRY_LEN
                # Expiration Limit  Unsigned 32-bit integer.
                qrdata["ExpirationLimit"] = struct.unpack("!L", data[offset:offset+self.__EXPIRATION_LEN])[0]
                offset += self.__EXPIRATION_LEN
                # Minimum TTL  Unsigned 32-bit integer.
                qrdata["MinimumTTL"] = struct.unpack("!L", data[offset:offset+self.__MINTTL_LEN])[0]
                offset += self.__MINTTL_LEN
            elif qtype == DNSType.MX:
                # Preference  Unsigned 16-bit integer.
                qrdata["Preference"] = struct.unpack("!H", data[offset:offset+self.__PREF_LEN])[0]
                # Mail Exchanger  The name host name that provides the service. May be a label, pointer or any combination.
                offset, mailExch = self.parseCompressedMessage(data, offset)
                qrdata["MailExchanger"] = mailExch
            elif qtype == DNSType.PTR or qtype == DNSType.NS or qtype == DNSType.CNAME:
                # Name  The host name that represents the supplied IP address (in the case of a PTR) or the NS name for the supplied domain (in the case of NS). May be a label, pointer or any combination.
                offset, name = self.parseCompressedMessage(data, offset)
                qrdata["Name"] = str(name.decode('ascii'))