Source code for dfwinreg.virtual

# -*- coding: utf-8 -*-
"""Virtual Windows Registry key implementation."""

import collections

from dfwinreg import definitions
from dfwinreg import interface
from dfwinreg import key_paths


[docs]class VirtualWinRegistryKey(interface.WinRegistryKey): """Virtual Windows Registry key. Virtual Windows Registry key are keys that do not exist on-disk but do exist at run-time, sucha a example HKEY_LOCAL_MACHINE\\System. The virtual key is used to "mount" the SYSTEM Windows Registry file onto the key HKEY_LOCAL_MACHINE\\System. """ def __init__(self, name, key_path='', registry=None): """Initializes a Windows Registry key. Args: name (str): name of the Windows Registry key. key_path (Optional[str]): Windows Registry key path. registry (Optional[WinRegistry]): Windows Registry. """ super(VirtualWinRegistryKey, self).__init__(key_path=key_path) self._name = name self._registry = registry self._registry_key = None self._subkeys = collections.OrderedDict() @property def class_name(self): """str: class name of the key or None if not available.""" if not self._registry_key and self._registry: self._GetKeyFromRegistry() if not self._registry_key: return None return self._registry_key.class_name @property def last_written_time(self): """dfdatetime.DateTimeValues: last written time or None.""" if not self._registry_key and self._registry: self._GetKeyFromRegistry() if not self._registry_key: return None return self._registry_key.last_written_time @property def name(self): """str: name of the key.""" return self._name @property def number_of_subkeys(self): """int: number of subkeys within the key.""" if not self._registry_key and self._registry: self._GetKeyFromRegistry() return len(self._subkeys) @property def number_of_values(self): """int: number of values within the key.""" if not self._registry_key and self._registry: self._GetKeyFromRegistry() if self._registry_key: return self._registry_key.number_of_values return 0 @property def offset(self): """int: offset of the key within the Windows Registry file or None.""" if not self._registry_key and self._registry: self._GetKeyFromRegistry() if not self._registry_key: return None return self._registry_key.offset def _GetKeyFromRegistry(self): """Determines the key from the Windows Registry.""" if not self._registry: return try: self._registry_key = self._registry.GetKeyByPath(self._key_path) except RuntimeError: pass if not self._registry_key: return for sub_registry_key in self._registry_key.GetSubkeys(): self.AddSubkey(sub_registry_key.name, sub_registry_key) self._registry = None def _JoinKeyPath(self, path_segments): """Joins the path segments into key path. Args: path_segments (list[str]): Windows Registry key path segments. Returns: str: key path. """ # This is an optimized way to combine the path segments into a single path # and combine multiple successive path separators to one. # Split all the path segments based on the path (segment) separator. path_segments = [ segment.split(definitions.KEY_PATH_SEPARATOR) for segment in path_segments] # Flatten the sublists into one list. path_segments = [ element for sublist in path_segments for element in sublist] # Remove empty path segments. path_segments = filter(None, path_segments) return definitions.KEY_PATH_SEPARATOR.join(path_segments)
[docs] def AddSubkey(self, name, registry_key): """Adds a subkey. Args: name (str): name of the Windows Registry subkey. registry_key (WinRegistryKey): Windows Registry subkey. Raises: KeyError: if the subkey already exists. """ name_upper = name.upper() if name_upper in self._subkeys: raise KeyError(f'Subkey: {name:s} already exists.') self._subkeys[name_upper] = registry_key key_path = self._JoinKeyPath([self._key_path, name]) registry_key._key_path = key_path # pylint: disable=protected-access
[docs] def GetSubkeyByIndex(self, index): """Retrieves a subkey by index. Args: index (int): index of the subkey. Returns: WinRegistryKey: Windows Registry subkey or None if not found. Raises: IndexError: if the index is out of bounds. """ if not self._registry_key and self._registry: self._GetKeyFromRegistry() subkeys = list(self._subkeys.values()) if index < 0 or index >= len(subkeys): raise IndexError('Index out of bounds.') return subkeys[index]
[docs] def GetSubkeyByName(self, name): """Retrieves a subkey by name. Args: name (str): name of the subkey. Returns: WinRegistryKey: Windows Registry subkey or None if not found. """ if not self._registry_key and self._registry: self._GetKeyFromRegistry() return self._subkeys.get(name.upper(), None)
[docs] def GetSubkeyByPath(self, key_path): """Retrieves a subkey by path. Args: key_path (str): path of the subkey. Returns: WinRegistryKey: Windows Registry subkey or None if not found. """ if not self._registry_key and self._registry: self._GetKeyFromRegistry() subkey = self for path_segment in key_paths.SplitKeyPath(key_path): subkey = subkey.GetSubkeyByName(path_segment) if not subkey: break return subkey
[docs] def GetSubkeys(self): """Retrieves all subkeys within the key. Returns: generator[WinRegistryKey]: Windows Registry subkey generator. """ if not self._registry_key and self._registry: self._GetKeyFromRegistry() return iter(self._subkeys.values())
[docs] def GetValueByName(self, name): """Retrieves a value by name. Args: name (str): name of the value or an empty string for the default value. Returns: WinRegistryValue: Windows Registry value or None if not found. """ if not self._registry_key and self._registry: self._GetKeyFromRegistry() if not self._registry_key: return None return self._registry_key.GetValueByName(name)
[docs] def GetValues(self): """Retrieves all values within the key. Returns: generator[WinRegistryValue]: Windows Registry value generator. """ if not self._registry_key and self._registry: self._GetKeyFromRegistry() if self._registry_key: return self._registry_key.GetValues() return iter([])