# designate.objects.rrdata_txt

# Source code for designate.objects.rrdata_txt

    # Copyright (c) 2014 Rackspace Hosting
    # All Rights Reserved.
    #
    #    Licensed under the Apache License, Version 2.0 (the "License"); you may
    #    not use this file except in compliance with the License. You may obtain
    #    a copy of the License at
    #
    #         http://www.apache.org/licenses/LICENSE-2.0
    #
    #    Unless required by applicable law or agreed to in writing, software
    #    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
    #    License for the specific language governing permissions and limitations
    #    under the License.
    from designate.objects import base
    from designate.objects import fields
    from designate.objects.record import Record
    from designate.objects.record import RecordList

    @base.DesignateRegistry.register
    class TXT(Record):
        """
        TXT Resource Record Type
        Defined in: RFC1035
        """
        fields = {
            'txt_data': fields.TxtField()
        }

        @staticmethod
        def _is_wrapped_in_double_quotes(value):
            return value.startswith('"') and value.endswith('"')

        @staticmethod
        def _is_missing_double_quote(value):
            return ((value.startswith('"') and not value.endswith('"')) or
                    (not value.startswith('"') and value.endswith('"')))

        def _validate_record_single_string(self, value):
            if len(value) > 255:
                raise ValueError(
                    'Any TXT record string exceeding 255 characters has to be '
                    'split.'
                )

            if '\n' in value:
                raise ValueError(
                    'TXT record must not contain a literal newline character.'
                )

            if self._is_missing_double_quote(value):
                raise ValueError(
                    'TXT record is missing a double quote either at beginning '
                    'or at end.'
                )

            if not self._is_wrapped_in_double_quotes(value):
                # value with spaces should be quoted as per RFC1035 5.1
                for element in value:
                    if element.isspace():
                        raise ValueError(
                            'Empty spaces are not allowed in TXT record, '
                            'unless wrapped in double quotes.'
                        )
            else:
                # quotes within value should be escaped with backslash
                strip_value = value.strip('"')
                for index, char in enumerate(strip_value):
                    if char == '"':
                        if strip_value[index - 1] != "\\":
                            raise ValueError(
                                'Quotation marks should be escaped with backslash.'
                            )

        def from_string(self, value):
            if len(value) > 255:
                # expecting record containing multiple strings as
                # per rfc7208 3.3 and rfc1035 3.3.14
                stripped_value = value.strip('"')
                if (not self._is_wrapped_in_double_quotes(value) and
                        '" "' not in stripped_value):
                    raise ValueError(
                        'TXT record strings over 255 characters have to be split '
                        'into multiple strings wrapped in double quotes.'
                    )

                record_strings = stripped_value.split('" "')
                for record_string in record_strings:
                    # add back the delimiting quotes after
                    # strip and split for each string
                    record_string = f'"{record_string}"'
                    # further validate each string individually
                    self._validate_record_single_string(value=record_string)
            else:
                # validate single TXT record string
                self._validate_record_single_string(value=value)

            self.txt_data = value

        # The record type is defined in the RFC. This will be used when the record
        # is sent by mini-dns.
        RECORD_TYPE = 16

    @base.DesignateRegistry.register
    class TXTList(RecordList):

        LIST_ITEM_TYPE = TXT
        fields = {
            'objects': fields.ListOfObjectsField('TXT'),
        }

this page last updated: 2026-08-19 02:25:39

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.

found an error? report a bug