| # -*- coding: utf-8 -*- |
| |
| # Copyright 2018 Telefonica S.A. |
| # |
| # 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. |
| |
| import yaml |
| import logging |
| from http import HTTPStatus |
| from copy import deepcopy |
| from Crypto.Cipher import AES |
| from base64 import b64decode, b64encode |
| from osm_common.common_utils import FakeLock |
| from threading import Lock |
| |
| __author__ = "Alfonso Tierno <alfonso.tiernosepulveda@telefonica.com>" |
| |
| |
| class DbException(Exception): |
| |
| def __init__(self, message, http_code=HTTPStatus.NOT_FOUND): |
| self.http_code = http_code |
| Exception.__init__(self, "database exception " + str(message)) |
| |
| |
| class DbBase(object): |
| |
| def __init__(self, logger_name='db', lock=False): |
| """ |
| Constructor of dbBase |
| :param logger_name: logging name |
| :param lock: Used to protect simultaneous access to the same instance class by several threads: |
| False, None: Do not protect, this object will only be accessed by one thread |
| True: This object needs to be protected by several threads accessing. |
| Lock object. Use thi Lock for the threads access protection |
| """ |
| self.logger = logging.getLogger(logger_name) |
| self.secret_key = None # 32 bytes length array used for encrypt/decrypt |
| if not lock: |
| self.lock = FakeLock() |
| elif lock is True: |
| self.lock = Lock() |
| elif isinstance(lock, Lock): |
| self.lock = lock |
| else: |
| raise ValueError("lock parameter must be a Lock classclass or boolean") |
| |
| def db_connect(self, config, target_version=None): |
| """ |
| Connect to database |
| :param config: Configuration of database. Contains among others: |
| host: database hosst (mandatory) |
| port: database port (mandatory) |
| name: database name (mandatory) |
| user: database username |
| password: database password |
| commonkey: common OSM key used for sensible information encryption |
| materpassword: same as commonkey, for backward compatibility. Deprecated, to be removed in the future |
| :param target_version: if provided it checks if database contains required version, raising exception otherwise. |
| :return: None or raises DbException on error |
| """ |
| raise DbException("Method 'db_connect' not implemented") |
| |
| def db_disconnect(self): |
| """ |
| Disconnect from database |
| :return: None |
| """ |
| pass |
| |
| def get_list(self, table, q_filter=None): |
| """ |
| Obtain a list of entries matching q_filter |
| :param table: collection or table |
| :param q_filter: Filter |
| :return: a list (can be empty) with the found entries. Raises DbException on error |
| """ |
| raise DbException("Method 'get_list' not implemented") |
| |
| def get_one(self, table, q_filter=None, fail_on_empty=True, fail_on_more=True): |
| """ |
| Obtain one entry matching q_filter |
| :param table: collection or table |
| :param q_filter: Filter |
| :param fail_on_empty: If nothing matches filter it returns None unless this flag is set tu True, in which case |
| it raises a DbException |
| :param fail_on_more: If more than one matches filter it returns one of then unless this flag is set tu True, so |
| that it raises a DbException |
| :return: The requested element, or None |
| """ |
| raise DbException("Method 'get_one' not implemented") |
| |
| def del_list(self, table, q_filter=None): |
| """ |
| Deletes all entries that match q_filter |
| :param table: collection or table |
| :param q_filter: Filter |
| :return: Dict with the number of entries deleted |
| """ |
| raise DbException("Method 'del_list' not implemented") |
| |
| def del_one(self, table, q_filter=None, fail_on_empty=True): |
| """ |
| Deletes one entry that matches q_filter |
| :param table: collection or table |
| :param q_filter: Filter |
| :param fail_on_empty: If nothing matches filter it returns '0' deleted unless this flag is set tu True, in |
| which case it raises a DbException |
| :return: Dict with the number of entries deleted |
| """ |
| raise DbException("Method 'del_one' not implemented") |
| |
| def create(self, table, indata): |
| """ |
| Add a new entry at database |
| :param table: collection or table |
| :param indata: content to be added |
| :return: database id of the inserted element. Raises a DbException on error |
| """ |
| raise DbException("Method 'create' not implemented") |
| |
| def set_one(self, table, q_filter, update_dict, fail_on_empty=True): |
| """ |
| Modifies an entry at database |
| :param table: collection or table |
| :param q_filter: Filter |
| :param update_dict: Plain dictionary with the content to be updated. It is a dot separated keys and a value |
| :param fail_on_empty: If nothing matches filter it returns None unless this flag is set tu True, in which case |
| it raises a DbException |
| :return: Dict with the number of entries modified. None if no matching is found. |
| """ |
| raise DbException("Method 'set_one' not implemented") |
| |
| def set_list(self, table, q_filter, update_dict): |
| """ |
| Modifies al matching entries at database |
| :param table: collection or table |
| :param q_filter: Filter |
| :param update_dict: Plain dictionary with the content to be updated. It is a dot separated keys and a value |
| :return: Dict with the number of entries modified |
| """ |
| raise DbException("Method 'set_list' not implemented") |
| |
| def replace(self, table, _id, indata, fail_on_empty=True): |
| """ |
| Replace the content of an entry |
| :param table: collection or table |
| :param _id: internal database id |
| :param indata: content to replace |
| :param fail_on_empty: If nothing matches filter it returns None unless this flag is set tu True, in which case |
| it raises a DbException |
| :return: Dict with the number of entries replaced |
| """ |
| raise DbException("Method 'replace' not implemented") |
| |
| def _join_secret_key(self, update_key): |
| """ |
| Returns a xor byte combination of the internal secret_key and the provided update_key. |
| It does not modify the internal secret_key. Used for adding salt, join keys, etc. |
| :param update_key: Can be a string, byte or None. Recommended a long one (e.g. 32 byte length) |
| :return: joined key in bytes with a 32 bytes length. Can be None if both internal secret_key and update_key |
| are None |
| """ |
| if not update_key: |
| return self.secret_key |
| elif isinstance(update_key, str): |
| update_key_bytes = update_key.encode() |
| else: |
| update_key_bytes = update_key |
| |
| new_secret_key = bytearray(self.secret_key) if self.secret_key else bytearray(32) |
| for i, b in enumerate(update_key_bytes): |
| new_secret_key[i % 32] ^= b |
| return bytes(new_secret_key) |
| |
| def set_secret_key(self, new_secret_key, replace=False): |
| """ |
| Updates internal secret_key used for encryption, with a byte xor |
| :param new_secret_key: string or byte array. It is recommended a 32 byte length |
| :param replace: if True, old value of internal secret_key is ignored and replaced. If false, a byte xor is used |
| :return: None |
| """ |
| if replace: |
| self.secret_key = None |
| self.secret_key = self._join_secret_key(new_secret_key) |
| |
| def encrypt(self, value, schema_version=None, salt=None): |
| """ |
| Encrypt a value |
| :param value: value to be encrypted. It is string/unicode |
| :param schema_version: used for version control. If None or '1.0' no encryption is done. |
| If '1.1' symmetric AES encryption is done |
| :param salt: optional salt to be used. Must be str |
| :return: Encrypted content of value |
| """ |
| if not self.secret_key or not schema_version or schema_version == '1.0': |
| return value |
| else: |
| secret_key = self._join_secret_key(salt) |
| cipher = AES.new(secret_key) |
| padded_private_msg = value + ('\0' * ((16-len(value)) % 16)) |
| encrypted_msg = cipher.encrypt(padded_private_msg) |
| encoded_encrypted_msg = b64encode(encrypted_msg) |
| return encoded_encrypted_msg.decode("ascii") |
| |
| def decrypt(self, value, schema_version=None, salt=None): |
| """ |
| Decrypt an encrypted value |
| :param value: value to be decrypted. It is a base64 string |
| :param schema_version: used for known encryption method used. If None or '1.0' no encryption has been done. |
| If '1.1' symmetric AES encryption has been done |
| :param salt: optional salt to be used |
| :return: Plain content of value |
| """ |
| if not self.secret_key or not schema_version or schema_version == '1.0': |
| return value |
| else: |
| secret_key = self._join_secret_key(salt) |
| encrypted_msg = b64decode(value) |
| cipher = AES.new(secret_key) |
| decrypted_msg = cipher.decrypt(encrypted_msg) |
| unpadded_private_msg = decrypted_msg.decode().rstrip('\0') |
| return unpadded_private_msg |
| |
| |
| def deep_update_rfc7396(dict_to_change, dict_reference, key_list=None): |
| """ |
| Modifies one dictionary with the information of the other following https://tools.ietf.org/html/rfc7396 |
| Basically is a recursive python 'dict_to_change.update(dict_reference)', but a value of None is used to delete. |
| It implements an extra feature that allows modifying an array. RFC7396 only allows replacing the entire array. |
| For that, dict_reference should contains a dict with keys starting by "$" with the following meaning: |
| $[index] <index> is an integer for targeting a concrete index from dict_to_change array. If the value is None |
| the element of the array is deleted, otherwise it is edited. |
| $+[index] The value is inserted at this <index>. A value of None has not sense and an exception is raised. |
| $+ The value is appended at the end. A value of None has not sense and an exception is raised. |
| $val It looks for all the items in the array dict_to_change equal to <val>. <val> is evaluated as yaml, |
| that is, numbers are taken as type int, true/false as boolean, etc. Use quotes to force string. |
| Nothing happens if no match is found. If the value is None the matched elements are deleted. |
| $key: val In case a dictionary is passed in yaml format, if looks for all items in the array dict_to_change |
| that are dictionaries and contains this <key> equal to <val>. Several keys can be used by yaml |
| format '{key: val, key: val, ...}'; and all of them mast match. Nothing happens if no match is |
| found. If value is None the matched items are deleted, otherwise they are edited. |
| $+val If no match if found (see '$val'), the value is appended to the array. If any match is found nothing |
| is changed. A value of None has not sense. |
| $+key: val If no match if found (see '$key: val'), the value is appended to the array. If any match is found |
| nothing is changed. A value of None has not sense. |
| If there are several editions, insertions and deletions; editions and deletions are done first in reverse index |
| order; then insertions also in reverse index order; and finally appends in any order. So indexes used at |
| insertions must take into account the deleted items. |
| :param dict_to_change: Target dictionary to be changed. |
| :param dict_reference: Dictionary that contains changes to be applied. |
| :param key_list: This is used internally for recursive calls. Do not fill this parameter. |
| :return: none or raises and exception only at array modification when there is a bad format or conflict. |
| """ |
| def _deep_update_array(array_to_change, _dict_reference, _key_list): |
| to_append = {} |
| to_insert_at_index = {} |
| values_to_edit_delete = {} |
| indexes_to_edit_delete = [] |
| array_edition = None |
| _key_list.append("") |
| for k in _dict_reference: |
| _key_list[-1] = str(k) |
| if not isinstance(k, str) or not k.startswith("$"): |
| if array_edition is True: |
| raise DbException("Found array edition (keys starting with '$') and pure dictionary edition in the" |
| " same dict at '{}'".format(":".join(_key_list[:-1]))) |
| array_edition = False |
| continue |
| else: |
| if array_edition is False: |
| raise DbException("Found array edition (keys starting with '$') and pure dictionary edition in the" |
| " same dict at '{}'".format(":".join(_key_list[:-1]))) |
| array_edition = True |
| insert = False |
| indexes = [] # indexes to edit or insert |
| kitem = k[1:] |
| if kitem.startswith('+'): |
| insert = True |
| kitem = kitem[1:] |
| if _dict_reference[k] is None: |
| raise DbException("A value of None has not sense for insertions at '{}'".format( |
| ":".join(_key_list))) |
| |
| if kitem.startswith('[') and kitem.endswith(']'): |
| try: |
| index = int(kitem[1:-1]) |
| if index < 0: |
| index += len(array_to_change) |
| if index < 0: |
| index = 0 # skip outside index edition |
| indexes.append(index) |
| except Exception: |
| raise DbException("Wrong format at '{}'. Expecting integer index inside quotes".format( |
| ":".join(_key_list))) |
| elif kitem: |
| # match_found_skip = False |
| try: |
| filter_in = yaml.safe_load(kitem) |
| except Exception: |
| raise DbException("Wrong format at '{}'. Expecting '$<yaml-format>'".format(":".join(_key_list))) |
| if isinstance(filter_in, dict): |
| for index, item in enumerate(array_to_change): |
| for filter_k, filter_v in filter_in.items(): |
| if not isinstance(item, dict) or filter_k not in item or item[filter_k] != filter_v: |
| break |
| else: # match found |
| if insert: |
| # match_found_skip = True |
| insert = False |
| break |
| else: |
| indexes.append(index) |
| else: |
| index = 0 |
| try: |
| while True: # if not match a ValueError exception will be raise |
| index = array_to_change.index(filter_in, index) |
| if insert: |
| # match_found_skip = True |
| insert = False |
| break |
| indexes.append(index) |
| index += 1 |
| except ValueError: |
| pass |
| |
| # if match_found_skip: |
| # continue |
| elif not insert: |
| raise DbException("Wrong format at '{}'. Expecting '$+', '$[<index]' or '$[<filter>]'".format( |
| ":".join(_key_list))) |
| for index in indexes: |
| if insert: |
| if index in to_insert_at_index and to_insert_at_index[index] != _dict_reference[k]: |
| # Several different insertions on the same item of the array |
| raise DbException("Conflict at '{}'. Several insertions on same array index {}".format( |
| ":".join(_key_list), index)) |
| to_insert_at_index[index] = _dict_reference[k] |
| else: |
| if index in indexes_to_edit_delete and values_to_edit_delete[index] != _dict_reference[k]: |
| # Several different editions on the same item of the array |
| raise DbException("Conflict at '{}'. Several editions on array index {}".format( |
| ":".join(_key_list), index)) |
| indexes_to_edit_delete.append(index) |
| values_to_edit_delete[index] = _dict_reference[k] |
| if not indexes: |
| if insert: |
| to_append[k] = _dict_reference[k] |
| # elif _dict_reference[k] is not None: |
| # raise DbException("Not found any match to edit in the array, or wrong format at '{}'".format( |
| # ":".join(_key_list))) |
| |
| # edition/deletion is done before insertion |
| indexes_to_edit_delete.sort(reverse=True) |
| for index in indexes_to_edit_delete: |
| _key_list[-1] = str(index) |
| try: |
| if values_to_edit_delete[index] is None: # None->Anything |
| try: |
| del (array_to_change[index]) |
| except IndexError: |
| pass # it is not consider an error if this index does not exist |
| elif not isinstance(values_to_edit_delete[index], dict): # NotDict->Anything |
| array_to_change[index] = deepcopy(values_to_edit_delete[index]) |
| elif isinstance(array_to_change[index], dict): # Dict->Dict |
| deep_update_rfc7396(array_to_change[index], values_to_edit_delete[index], _key_list) |
| else: # Dict->NotDict |
| if isinstance(array_to_change[index], list): # Dict->List. Check extra array edition |
| if _deep_update_array(array_to_change[index], values_to_edit_delete[index], _key_list): |
| continue |
| array_to_change[index] = deepcopy(values_to_edit_delete[index]) |
| # calling deep_update_rfc7396 to delete the None values |
| deep_update_rfc7396(array_to_change[index], values_to_edit_delete[index], _key_list) |
| except IndexError: |
| raise DbException("Array edition index out of range at '{}'".format(":".join(_key_list))) |
| |
| # insertion with indexes |
| to_insert_indexes = list(to_insert_at_index.keys()) |
| to_insert_indexes.sort(reverse=True) |
| for index in to_insert_indexes: |
| array_to_change.insert(index, to_insert_at_index[index]) |
| |
| # append |
| for k, insert_value in to_append.items(): |
| _key_list[-1] = str(k) |
| insert_value_copy = deepcopy(insert_value) |
| if isinstance(insert_value_copy, dict): |
| # calling deep_update_rfc7396 to delete the None values |
| deep_update_rfc7396(insert_value_copy, insert_value, _key_list) |
| array_to_change.append(insert_value_copy) |
| |
| _key_list.pop() |
| if array_edition: |
| return True |
| return False |
| |
| if key_list is None: |
| key_list = [] |
| key_list.append("") |
| for k in dict_reference: |
| key_list[-1] = str(k) |
| if dict_reference[k] is None: # None->Anything |
| if k in dict_to_change: |
| del dict_to_change[k] |
| elif not isinstance(dict_reference[k], dict): # NotDict->Anything |
| dict_to_change[k] = deepcopy(dict_reference[k]) |
| elif k not in dict_to_change: # Dict->Empty |
| dict_to_change[k] = deepcopy(dict_reference[k]) |
| # calling deep_update_rfc7396 to delete the None values |
| deep_update_rfc7396(dict_to_change[k], dict_reference[k], key_list) |
| elif isinstance(dict_to_change[k], dict): # Dict->Dict |
| deep_update_rfc7396(dict_to_change[k], dict_reference[k], key_list) |
| else: # Dict->NotDict |
| if isinstance(dict_to_change[k], list): # Dict->List. Check extra array edition |
| if _deep_update_array(dict_to_change[k], dict_reference[k], key_list): |
| continue |
| dict_to_change[k] = deepcopy(dict_reference[k]) |
| # calling deep_update_rfc7396 to delete the None values |
| deep_update_rfc7396(dict_to_change[k], dict_reference[k], key_list) |
| key_list.pop() |
| |
| |
| def deep_update(dict_to_change, dict_reference): |
| """ Maintained for backward compatibility. Use deep_update_rfc7396 instead""" |
| return deep_update_rfc7396(dict_to_change, dict_reference) |