stegPNG

A pure python 3 png library intended to make steganography and analysis easier. The library is still in beta and misses lots of planned content. Part of a future project.

Example:

import stegpng
img = stegpng.open('test.png')
#We can manipulate the chunks directly
chunk = img.chunks[0] #The first chunk of a png file should always be IHDR
if chunk.type != "IHDR":
  print("Not a valid png")
  exit()
chunk['size'] = chunk['width'], int(chunk['height'] / 2) #This has a chance to break the image, but could also hide half of it.
#Or, a much quicker solution which only works for the size of the image:
img.size = img.width, int(img.height/2)
img.save('test.png)

What is already implemented or not:

• Png file decoding
• A few chunks' content decoding (see the list bellow)
• Various automated steganography methods
• Documentation
• Anything you would like me to implement

Installation:

There are several ways to install stegpng, see below.

PIP

Using pip is probably the easiest way to install a python package:

pip3 install stegpng

You may need to run the command with elevated priviledges.

Github

If you really want the latest version, clone the repository:

git clone https://github.com/WHGhost/stegPNG

And then, run setup.py:

./stegPNG/setup.py install

Install in editable mode:

First, clone the github repository, and then, from the git repository, run

pip3 install -e .

PNG chunks support:

• IHDR
• PLTE
• IDAT (Interlaced images, bit depth other than 8 and indexation are not supported yet)
• IEND
• tRNS
• cHRM
• gAMA
• iCCP
• sBIT
• sRGB
• tEXt
• iTXt
• zTXt
• bKGD
• pHYs
• sPLT (Read-only)
• tIME
• Any other proprietary chunk