+# -*- 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 <alfonso.tiernosepulveda@telefonica.com>"
class DbException(Exception):
def __init__(self, message, http_code=HTTPStatus.NOT_FOUND):
- # TODO change to http.HTTPStatus instead of int that allows .value and .name
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={}):
+ 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):
+ 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 del_list(self, table, filter={}):
- raise DbException("Method 'del_list' 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 del_one(self, table, filter={}, fail_on_empty=True):
- raise DbException("Method 'del_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")
+
+ @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 deep_update(dict_to_change, dict_reference, key_list=None):
+ 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.
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(array_to_change[index], values_to_edit_delete[index], _key_list)
+ 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 to delete the None values
- deep_update(array_to_change[index], values_to_edit_delete[index], _key_list)
+ # 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)))
_key_list[-1] = str(k)
insert_value_copy = deepcopy(insert_value)
if isinstance(insert_value_copy, dict):
- # calling deep_update to delete the None values
- deep_update(insert_value_copy, insert_value, _key_list)
+ # 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()
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 to delete the None values
- deep_update(dict_to_change[k], dict_reference[k], key_list)
+ # 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(dict_to_change[k], dict_reference[k], key_list)
+ 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 to delete the None values
- deep_update(dict_to_change[k], dict_reference[k], key_list)
+ # 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)