def _CalculateHashesFileEntry(
self, file_system, file_entry, parent_path_segments, output_writer):
"""Recursive calculates hashes starting with the file entry.
Args:
file_system (dfvfs.FileSystem): file system.
file_entry (dfvfs.FileEntry): file entry.
parent_path_segments (str): path segments of the full path of the parent
file entry.
output_writer (StdoutWriter): output writer.
"""
path_segments = parent_path_segments + [file_entry.name]
lookup_path = tuple(path_segments[1:])
for data_stream in file_entry.data_streams:
hash_value = None
if (lookup_path, data_stream.name) not in self._PATHS_TO_IGNORE:
hash_value = self._CalculateHashDataStream(file_entry, data_stream.name)
display_path = self._GetDisplayPath(
file_entry.path_spec, path_segments, data_stream.name)
output_writer.WriteFileHash(display_path, hash_value or 'N/A')
try:
for sub_file_entry in file_entry.sub_file_entries:
self._CalculateHashesFileEntry(
file_system, sub_file_entry, path_segments, output_writer)
except (IOError, dfvfs_errors.AccessError,
dfvfs_errors.BackEndError) as exception:
path_specification_string = helpers.GetPathSpecificationString(
file_entry.path_spec)
logging.warning((
'Unable to open path specification:\n{0:s}'
'with error: {1!s}').format(path_specification_string, exception))
def _CalculateHashDataStream(self, file_entry, data_stream_name):
"""Calculates a message digest hash of the data of the file entry.
Args:
file_entry (dfvfs.FileEntry): file entry.
data_stream_name (str): name of the data stream.
Returns:
str: digest hash or None.
"""
if file_entry.IsDevice() or file_entry.IsPipe() or file_entry.IsSocket():
# Ignore devices, FIFOs/pipes and sockets.
return None
hash_context = hashlib.sha256()
try:
file_object = file_entry.GetFileObject(data_stream_name=data_stream_name)
except IOError as exception:
path_specification_string = helpers.GetPathSpecificationString(
file_entry.path_spec)
logging.warning((
'Unable to open path specification:\n{0:s}'
'with error: {1!s}').format(path_specification_string, exception))
return None
if not file_object:
return None
try:
data = file_object.read(self._READ_BUFFER_SIZE)
while data:
hash_context.update(data)
data = file_object.read(self._READ_BUFFER_SIZE)
except IOError as exception:
path_specification_string = helpers.GetPathSpecificationString(
file_entry.path_spec)
logging.warning((
'Unable to read from path specification:\n{0:s}'
'with error: {1!s}').format(path_specification_string, exception))
return None
return hash_context.hexdigest()
def CalculateHashes(self, base_path_specs, output_writer):
"""Recursive calculates hashes starting with the base path specification.
Args:
base_path_specs (list[dfvfs.PathSpec]): source path specification.
output_writer (StdoutWriter): output writer.
"""
for base_path_spec in base_path_specs:
file_system = resolver.Resolver.OpenFileSystem(base_path_spec)
file_entry = resolver.Resolver.OpenFileEntry(base_path_spec)
if file_entry is None:
path_specification_string = helpers.GetPathSpecificationString(
base_path_spec)
logging.warning('Unable to open base path specification:\n{0:s}'.format(
path_specification_string))
continue
self._CalculateHashesFileEntry(file_system, file_entry, [], output_writer)
def ListFileEntries(self, base_path_specs, output_writer):
"""Lists file entries in the base path specification.
Args:
base_path_specs (list[dfvfs.PathSpec]): source path specification.
output_writer (StdoutWriter): output writer.
"""
for base_path_spec in base_path_specs:
file_system = resolver.Resolver.OpenFileSystem(base_path_spec)
file_entry = resolver.Resolver.OpenFileEntry(base_path_spec)
if file_entry is None:
path_specification_string = helpers.GetPathSpecificationString(
base_path_spec)
logging.warning(
'Unable to open base path specification:\n{0:s}'.format(
path_specification_string))
return
self._ListFileEntry(file_system, file_entry, [], output_writer)