Source code for dfvfs.vfs.encrypted_stream_file_system

# -*- coding: utf-8 -*-
"""The encrypted stream file system implementation."""

from dfvfs.lib import definitions
from dfvfs.lib import errors
from dfvfs.path import encrypted_stream_path_spec
from dfvfs.resolver import resolver
from dfvfs.vfs import encrypted_stream_file_entry
from dfvfs.vfs import root_only_file_system


[docs] class EncryptedStreamFileSystem(root_only_file_system.RootOnlyFileSystem): """Encrypted stream file system.""" TYPE_INDICATOR = definitions.TYPE_INDICATOR_ENCRYPTED_STREAM
[docs] def __init__(self, resolver_context, path_spec): """Initializes an encrypted file system. Args: resolver_context (Context): a resolver context. path_spec (PathSpec): a path specification. """ super(EncryptedStreamFileSystem, self).__init__(resolver_context, path_spec) self._encryption_method = None
def _Close(self): """Closes the file system. Raises: IOError: if the close failed. """ self._encryption_method = None def _Open(self, mode='rb'): """Opens the file system defined by path specification. Args: mode (Optional[str]): file access mode. The default is 'rb' which represents read-only binary. Raises: AccessError: if the access to open the file was denied. IOError: if the file system could not be opened. PathSpecError: if the path specification is incorrect. ValueError: if the path specification is invalid. """ if not self._path_spec.HasParent(): raise errors.PathSpecError( 'Unsupported path specification without parent.') resolver.Resolver.key_chain.ExtractCredentialsFromPathSpec(self._path_spec) encryption_method = getattr(self._path_spec, 'encryption_method', None) if not encryption_method: raise errors.PathSpecError( 'Unsupported path specification without encryption method.') self._encryption_method = encryption_method
[docs] def GetFileEntryByPathSpec(self, path_spec): """Retrieves a file entry for a path specification. Args: path_spec (PathSpec): a path specification. Returns: EncryptedStreamFileEntry: a file entry or None if not available. """ return encrypted_stream_file_entry.EncryptedStreamFileEntry( self._resolver_context, self, path_spec, is_root=True, is_virtual=True)
[docs] def GetRootFileEntry(self): """Retrieves the root file entry. Returns: EncryptedStreamFileEntry: a file entry or None if not available. """ path_spec = encrypted_stream_path_spec.EncryptedStreamPathSpec( encryption_method=self._encryption_method, parent=self._path_spec.parent) return self.GetFileEntryByPathSpec(path_spec)