X-Git-Url: https://osm.etsi.org/gitweb/?a=blobdiff_plain;f=osm_common%2Fdbbase.py;h=5fef9ee61f37d05b4f55b41c6f648b18e072949a;hb=cfc5272864156b706d7147fc4e7c0fe46dc386c8;hp=aa9c24eb3f0788a079c98672fb6ee0a664a16f2f;hpb=5c012612f1292b012dc12b337c611c6f3c083b18;p=osm%2Fcommon.git diff --git a/osm_common/dbbase.py b/osm_common/dbbase.py index aa9c24e..5fef9ee 100644 --- a/osm_common/dbbase.py +++ b/osm_common/dbbase.py @@ -1,4 +1,26 @@ +# -*- 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 __author__ = "Alfonso Tierno " @@ -7,31 +29,392 @@ class DbException(Exception): def __init__(self, message, http_code=HTTPStatus.NOT_FOUND): self.http_code = http_code - Exception.__init__(self, "database exception " + message) + Exception.__init__(self, "database exception " + str(message)) class DbBase(object): - def __init__(self): - pass + def __init__(self, logger_name='db'): + """ + Constructor od dbBase + :param logger_name: logging name + """ + self.logger = logging.getLogger(logger_name) + self.master_password = None + self.secret_key = None - def db_connect(self, config): - pass + 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 + masterpassword: database password used for sensible information encryption + :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, filter={}): - 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, filter={}, fail_on_empty=True, fail_on_more=True): - pass + 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): - pass + """ + 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 del_list(self, table, filter={}): - pass + 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 del_one(self, table, filter={}, fail_on_empty=True): - pass + 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") + + @staticmethod + def _join_passwords(passwd_byte, passwd_str): + """ + Modifies passwd_byte with the xor of passwd_str. Used for adding salt, join passwords, etc + :param passwd_byte: original password in bytes, 32 byte length + :param passwd_str: string salt to be added + :return: modified password in bytes + """ + if not passwd_str: + return passwd_byte + secret_key = bytearray(passwd_byte) + for i, b in enumerate(passwd_str.encode()): + secret_key[i % 32] ^= b + return bytes(secret_key) + + def set_secret_key(self, secret_key): + """ + Set internal secret key used for encryption + :param secret_key: byte array length 32 with the secret_key + :return: None + """ + assert (len(secret_key) == 32) + self.secret_key = self._join_passwords(secret_key, self.master_password) + + 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 schema_version or schema_version == '1.0': + return value + else: + if not self.secret_key: + raise DbException("Cannot encrypt. Missing secret_key", http_code=HTTPStatus.INTERNAL_SERVER_ERROR) + secret_key = self._join_passwords(self.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 schema_version or schema_version == '1.0': + return value + else: + if not self.secret_key: + raise DbException("Cannot decrypt. Missing secret_key", http_code=HTTPStatus.INTERNAL_SERVER_ERROR) + secret_key = self._join_passwords(self.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] 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 . 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 . 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 equal to . 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 '$') and pure dictionary edition in the" + " same dict at '{}'".format(":".join(_key_list[:-1]))) + array_edition = True + insert = False + indexes = [] # indexes to edit or insert + kitem = k[1:] + if kitem.startswith('+'): + insert = True + kitem = kitem[1:] + if _dict_reference[k] is None: + raise DbException("A value of None has not sense for insertions at '{}'".format( + ":".join(_key_list))) + + if kitem.startswith('[') and kitem.endswith(']'): + try: + index = int(kitem[1:-1]) + if index < 0: + index += len(array_to_change) + if index < 0: + index = 0 # skip outside index edition + indexes.append(index) + except Exception: + raise DbException("Wrong format at '{}'. Expecting integer index inside quotes".format( + ":".join(_key_list))) + elif kitem: + # match_found_skip = False + try: + filter_in = yaml.safe_load(kitem) + except Exception: + raise DbException("Wrong format at '{}'. Expecting '$'".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 '$+', '$[]'".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)