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'''
Parent class of all parser
'''
import hachoir_core.error
import hachoir_parser
import hachoir_editor
import sys
import os
import subprocess
import mimetypes
import mat
POSTFIX = ".cleaned"
class Generic_parser(object):
def __init__(self, realname, filename, parser, editor, backup):
self.filename = filename
self.realname = realname
self.shortname = os.path.basename(filename)
self.mime = mimetypes.guess_type(filename)[0]
self.parser = parser
self.editor = editor
self.backup = backup
def is_clean(self):
'''
Check if the file is clean from harmful metadatas
'''
for field in self.editor:
if self._should_remove(field):
return False
return True
def remove_all(self):
'''
Remove all the files that are compromizing
'''
for field in self.editor:
if self._should_remove(field):
self._remove(field)
hachoir_core.field.writeIntoFile(self.editor, self.filename + POSTFIX)
if self.backup is False:
mat.secure_remove(self.filename) #remove the old file
os.rename(self.filename+ POSTFIX, self.filename)#rename the new
def remove_all_ugly(self):
'''
If the remove_all() is not efficient enough,
this method is implemented :
It is efficient, but destructive.
In a perfect world, with nice fileformat,
this method does not exist.
'''
self.remove_all()
def _remove(self, field):
'''
Remove the given field
'''
del self.editor[field.name]
def search(self, value):
return self.__search(value, self.editor)
def __search(self, value, graph):
'''
Search a given file
'''
for node in graph:
try:
iter(node)
return node.value + self.__search(value, node)
except:
if node.name == value:
return value
return False
def get_meta(self):
'''
return a dict with all the meta of the file
'''
metadata = {}
for field in self.editor:
if self._should_remove(field):
try:
metadata[field.name] = field.value
except:
metadata[field.name] = "harmful content"
return metadata
def _should_remove(self, key):
'''
return True if the field is compromizing
abstract method
'''
raise NotImplementedError()
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