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import io
import typing
from kaitaistruct import KaitaiStream
from mitmproxy.contrib.kaitaistruct import png
from mitmproxy.contrib.kaitaistruct import gif
from mitmproxy.contrib.kaitaistruct import jpeg
from mitmproxy.contrib.kaitaistruct import ico
Metadata = typing.List[typing.Tuple[str, str]]
def parse_png(data: bytes) -> Metadata:
img = png.Png(KaitaiStream(io.BytesIO(data)))
parts = [
('Format', 'Portable network graphics'),
('Size', "{0} x {1} px".format(img.ihdr.width, img.ihdr.height))
]
for chunk in img.chunks:
if chunk.type == 'gAMA':
parts.append(('gamma', str(chunk.body.gamma_int / 100000)))
elif chunk.type == 'pHYs':
aspectx = chunk.body.pixels_per_unit_x
aspecty = chunk.body.pixels_per_unit_y
parts.append(('aspect', "{0} x {1}".format(aspectx, aspecty)))
elif chunk.type == 'tEXt':
parts.append((chunk.body.keyword, chunk.body.text))
elif chunk.type == 'iTXt':
parts.append((chunk.body.keyword, chunk.body.text))
elif chunk.type == 'zTXt':
parts.append((chunk.body.keyword, chunk.body.text_datastream.decode('iso8859-1')))
return parts
def parse_gif(data: bytes) -> Metadata:
img = gif.Gif(KaitaiStream(io.BytesIO(data)))
descriptor = img.logical_screen_descriptor
parts = [
('Format', 'Compuserve GIF'),
('Version', "GIF{}".format(img.hdr.version)),
('Size', "{} x {} px".format(descriptor.screen_width, descriptor.screen_height)),
('background', str(descriptor.bg_color_index))
]
ext_blocks = []
for block in img.blocks:
if block.block_type.name == 'extension':
ext_blocks.append(block)
comment_blocks = []
for block in ext_blocks:
if block.body.label._name_ == 'comment':
comment_blocks.append(block)
for block in comment_blocks:
entries = block.body.body.entries
for entry in entries:
comment = entry.bytes
if comment != b'':
parts.append(('comment', str(comment)))
return parts
def parse_jpeg(data: bytes) -> Metadata:
img = jpeg.Jpeg(KaitaiStream(io.BytesIO(data)))
parts = [
('Format', 'JPEG (ISO 10918)')
]
for segment in img.segments:
if segment.marker._name_ == 'sof0':
parts.append(('Size', "{0} x {1} px".format(segment.data.image_width, segment.data.image_height)))
if segment.marker._name_ == 'app0':
parts.append(('jfif_version', "({0}, {1})".format(segment.data.version_major, segment.data.version_minor)))
parts.append(('jfif_density', "({0}, {1})".format(segment.data.density_x, segment.data.density_y)))
parts.append(('jfif_unit', str(segment.data.density_units._value_)))
if segment.marker._name_ == 'com':
parts.append(('comment', str(segment.data)))
if segment.marker._name_ == 'app1':
if hasattr(segment.data, 'body'):
for field in segment.data.body.data.body.ifd0.fields:
if field.data is not None:
parts.append((field.tag._name_, field.data.decode('UTF-8').strip('\x00')))
return parts
def parse_ico(data: bytes) -> Metadata:
img = ico.Ico(KaitaiStream(io.BytesIO(data)))
parts = [
('Format', 'ICO'),
('Number of images', str(img.num_images)),
]
for i, image in enumerate(img.images):
parts.append(
(
'Image {}'.format(i + 1), "Size: {} x {}\n"
"{: >18}Bits per pixel: {}\n"
"{: >18}PNG: {}".format(256 if not image.width else image.width,
256 if not image.height else image.height,
'', image.bpp,
'', image.is_png)
)
)
return parts
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