remove dependency on six

as Python2 is not supported anymore, remove the
compatiblility layer provided by the six module

this fixes `TXT::test_parse` and `test_validate_strings`
by creating the proper output bytes in `_unescapify_from()`

dim/dim/__init__.py

@@ -5,7 +5,6 @@
 from datetime import datetime, timedelta
 
 import flask_sqlalchemy
-import six
 import sqlalchemy.orm
 import sqlalchemy.pool
 from flask import Flask, g
@@ -178,7 +177,7 @@ def check_string_length(cls, key, inst):
             max_length = col.type.length
 
             def set_(instance, value, oldvalue, initiator):
-                if isinstance(value, six.string_types) and len(value) > max_length:
+                if isinstance(value, str) and len(value) > max_length:
                     raise InvalidParameterError("Field %s exceeds maximum length %d" % (col.name, max_length))
             event.listen(inst, 'set', set_)
 

dim/dim/ipaddr.py

@@ -1,12 +1,11 @@
 
 
-import six
 from ipaddress import ip_address, IPv4Address, IPv6Address, ip_network
 
 
 def valid_block(addr):
     try:
-        ip_network(six.text_type(addr))
+        ip_network(str(addr))
         return True
     except ValueError:
         return False
@@ -19,8 +18,7 @@ def __init__(self, address, prefix=None, version=None, auto_correct=False):
         '''
         :param auto_correct: if the address has bits set outside its netmask they will be cleared
         '''
-        if isinstance(address, six.string_types):
-            address = six.text_type(address)
+        if isinstance(address, str):
             s = address.split('/')
             if len(s) > 2:
                 raise ValueError('Bad prefix')

dim/dim/jsonrpc.py

@@ -9,7 +9,6 @@
 
 import requests
 from flask import Blueprint, jsonify, json, request, session, current_app, abort, Response
-from six import text_type
 
 from . import ldap_auth
 from dim import db
@@ -168,7 +167,7 @@ def jsonrpc_handler():
     try:
         json_request = json.loads(request.data)
     except Exception as e:
-        return jsonify(error=dict(code=-32700, message='Parse error', data=text_type(e)),
+        return jsonify(error=dict(code=-32700, message='Parse error', data=str(e)),
                        **json_response)
 
     json_response['id'] = json_request.get('id', None)
@@ -189,10 +188,10 @@ def jsonrpc_handler():
                           default=default_for_json)
     except DimError as e:
         logging.info('DimError: %s', e)
-        return jsonify(error=dict(code=e.code, message=text_type(e)), **json_response)
+        return jsonify(error=dict(code=e.code, message=str(e)), **json_response)
     except Exception as e:
         logging.exception(e)
-        return jsonify(error=dict(code=1, message=text_type(e)), **json_response)
+        return jsonify(error=dict(code=1, message=str(e)), **json_response)
 
 
 def default_for_json(o):

dim/dim/models/dns.py

@@ -9,7 +9,6 @@
 
 import flask.json as json
 from flask import current_app as app, g
-from six import text_type
 from sqlalchemy import Column, ForeignKey, BigInteger, Integer, String, Boolean, TIMESTAMP, UniqueConstraint, func, desc, Text, Enum
 from sqlalchemy.orm import relationship, validates, backref
 
@@ -369,7 +368,7 @@ def validate_args(type, **kwargs):
             for field, validate in list(rr_class.validate.items()):
                 kwargs[field] = validate(None, field, kwargs[field])
         except ValueError as e:
-            raise InvalidParameterError(text_type(e))
+            raise InvalidParameterError(str(e))
         return kwargs
 
     @staticmethod

dim/dim/rpc.py

@@ -7,7 +7,6 @@
 import sys
 import re
 
-from six import text_type
 import flask.json as json
 from flask import current_app as app, g
 from sqlalchemy import between, and_, or_, not_, select, String, desc
@@ -1181,7 +1180,7 @@ def ippool_add_subnet(self, pool, cidr,
             try:
                 reserve(rip, pool.layer3domain)
             except DimError as e:
-                Messages.info(text_type(e))
+                Messages.info(str(e))
         block.set_attrs(attributes)
         record_history(pool, action='create subnet', **_cidr(block))
         if include_messages:
@@ -3128,9 +3127,9 @@ def delete_zone_or_view():
                     except DimError as e:
                         deleted = False
                         if delete_zone:
-                            Messages.warn('Zone %s was not deleted: %s' % (name, text_type(e)))
+                            Messages.warn('Zone %s was not deleted: %s' % (name, str(e)))
                         else:
-                            Messages.warn('Zone %s view %s was not deleted: %s' % (name, view.name, text_type(e)))
+                            Messages.warn('Zone %s view %s was not deleted: %s' % (name, view.name, str(e)))
                 else:
                     delete_zone_or_view()
 
@@ -3358,7 +3357,7 @@ def find_parent():
                     kwargs['ip'] = self._ip_mark(check_ip(ip, layer3domain, {'host': True}), layer3domain=layer3domain,
                                                  attributes=None, parse_rr=True, allow_overlap=allow_overlap)
                 else:
-                    raise InvalidParameterError('Invalid IP %s: %s' % (kwargs['ip'], text_type(e)))
+                    raise InvalidParameterError('Invalid IP %s: %s' % (kwargs['ip'], str(e)))
         if rr_type == 'PTR' and ('ip' in kwargs) and ('name' not in kwargs):
             kwargs['name'] = dim.dns.get_ptr_name(kwargs['ip'])
 

dim/dim/rrtype.py

@@ -3,10 +3,10 @@
 import re
 
 import dns.rdata
-from six import int2byte
 from dim.errors import InvalidParameterError
 from dim.messages import Messages
 from dim.util import make_fqdn
+from typing import Tuple, List, Union
 
 
 def label_is_valid(label):
@@ -136,7 +136,7 @@ def validate_property_tag(self, key, value):
     return value
 
 
-def _unescapify_from(value, offset):
+def _unescapify_from(value, offset: int) -> Tuple[bytes, int]:
     '''
     Unescape dns character string in value[offset:]. Returns a tuple of (bytearray unescaped_string,
     the position where the processing of value stopped).
@@ -150,7 +150,7 @@ def _unescapify_from(value, offset):
     The processing of value stops at the first unescaped double quote. This position is returned
     along with the unescaped string created thus far.
     '''
-    string = ''
+    string = b''
     i = offset
     while i < len(value):
         if value[i] == '"':
@@ -161,18 +161,21 @@ def _unescapify_from(value, offset):
             try:
                 escape_sequence = value[i]
                 if value[i + 1] in ('"', '\\'):
+                    # escaped " or /
                     escape_sequence = value[i:i + 2]
-                    string += str(value[i + 1])
+                    string += str(value[i + 1]).encode('utf-8')
                     i += 2
                 else:
+                    # assume escaped ordinal value (int) with a fixed length of 3
+                    # e.g. \097 for the character a
                     escape_sequence = value[i:i + 4]
-                    string += int2byte(int(value[i + 1:i + 4]))
+                    string += bytes((int(value[i + 1:i + 4]),))
                     i += 4
             except:
                 raise ValueError('Invalid escape sequence: %s' % escape_sequence)
         else:
             if 32 <= ord(value[i]) <= 126:
-                string += value[i]
+                string += value[i].encode('utf-8')
                 i += 1
             else:
                 raise ValueError('Invalid character at position %d in: %s' % (i, value))
@@ -201,7 +204,7 @@ def _parse_strings(value):
     return strings
 
 
-def validate_strings(self, key, value):
+def validate_strings(self, key, value: Union[str, List[str]]):
     if isinstance(value, str):
         strings = _parse_strings(value)
     elif isinstance(value, list):

dim/requirements.txt

@@ -10,4 +10,3 @@ dnspython~=2.1
 simplejson~=3.17
 requests~=2.25
 pycryptodome~=3.10
-six