import subprocess import imghdr import json import os import shutil import tempfile import re from typing import Set import cairo import gi gi.require_version('GdkPixbuf', '2.0') from gi.repository import GdkPixbuf from . import abstract # Make pyflakes happy assert Set class _ImageParser(abstract.AbstractParser): """ Since we use `exiftool` to get metadata from all images fileformat, `get_meta` is implemented in this class, and all the image-handling ones are inheriting from it.""" meta_whitelist = set() # type: Set[str] @staticmethod def __handle_problematic_filename(filename: str, callback) -> str: """ This method takes a filename with a problematic name, and safely applies it a `callback`.""" tmpdirname = tempfile.mkdtemp() fname = os.path.join(tmpdirname, "temp_file") shutil.copy(filename, fname) out = callback(fname) shutil.rmtree(tmpdirname) return out def get_meta(self): """ There is no way to escape the leading(s) dash(es) of the current self.filename to prevent parameter injections, so we need to take care of this. """ fun = lambda f: subprocess.check_output(['/usr/bin/exiftool', '-json', f]) if re.search('^[a-z0-9/]', self.filename) is None: out = self.__handle_problematic_filename(self.filename, fun) else: out = fun(self.filename) meta = json.loads(out.decode('utf-8'))[0] for key in self.meta_whitelist: meta.pop(key, None) return meta class PNGParser(_ImageParser): mimetypes = {'image/png', } meta_whitelist = {'SourceFile', 'ExifToolVersion', 'FileName', 'Directory', 'FileSize', 'FileModifyDate', 'FileAccessDate', 'FileInodeChangeDate', 'FilePermissions', 'FileType', 'FileTypeExtension', 'MIMEType', 'ImageWidth', 'BitDepth', 'ColorType', 'Compression', 'Filter', 'Interlace', 'BackgroundColor', 'ImageSize', 'Megapixels', 'ImageHeight'} def __init__(self, filename): super().__init__(filename) try: # better fail here than later cairo.ImageSurface.create_from_png(self.filename) except MemoryError: raise ValueError def remove_all(self): surface = cairo.ImageSurface.create_from_png(self.filename) surface.write_to_png(self.output_filename) return True class GdkPixbufAbstractParser(_ImageParser): """ GdkPixbuf can handle a lot of surfaces, so we're rending images on it, this has the side-effect of completely removing metadata. """ _type = '' def remove_all(self): _, extension = os.path.splitext(self.filename) pixbuf = GdkPixbuf.Pixbuf.new_from_file(self.filename) if extension == '.jpg': extension = '.jpeg' # gdk is picky pixbuf.savev(self.output_filename, extension[1:], [], []) return True def __init__(self, filename): super().__init__(filename) if imghdr.what(filename) != self._type: # better safe than sorry raise ValueError class JPGParser(GdkPixbufAbstractParser): _type = 'jpeg' mimetypes = {'image/jpeg'} meta_whitelist = {'SourceFile', 'ExifToolVersion', 'FileName', 'Directory', 'FileSize', 'FileModifyDate', 'FileAccessDate', "FileInodeChangeDate", 'FilePermissions', 'FileType', 'FileTypeExtension', 'MIMEType', 'ImageWidth', 'ImageSize', 'BitsPerSample', 'ColorComponents', 'EncodingProcess', 'JFIFVersion', 'ResolutionUnit', 'XResolution', 'YCbCrSubSampling', 'YResolution', 'Megapixels', 'ImageHeight'} class TiffParser(GdkPixbufAbstractParser): _type = 'tiff' mimetypes = {'image/tiff'} meta_whitelist = {'Compression', 'ExifByteOrder', 'ExtraSamples', 'FillOrder', 'PhotometricInterpretation', 'PlanarConfiguration', 'RowsPerStrip', 'SamplesPerPixel', 'StripByteCounts', 'StripOffsets', 'BitsPerSample', 'Directory', 'ExifToolVersion', 'FileAccessDate', 'FileInodeChangeDate', 'FileModifyDate', 'FileName', 'FilePermissions', 'FileSize', 'FileType', 'FileTypeExtension', 'ImageHeight', 'ImageSize', 'ImageWidth', 'MIMEType', 'Megapixels', 'SourceFile'}