mirror of
https://github.com/cedricbonhomme/Stegano.git
synced 2025-05-12 17:18:30 +02:00
131 lines
4.4 KiB
Python
Executable file
131 lines
4.4 KiB
Python
Executable file
#!/usr/bin/env python
|
|
# -*- coding: utf-8 -*-
|
|
|
|
# Stegano - Stegano is a pure Python steganography module.
|
|
# Copyright (C) 2010-2019 Cédric Bonhomme - https://www.cedricbonhomme.org
|
|
#
|
|
# For more information : https://git.sr.ht/~cedric/stegano
|
|
#
|
|
# This program is free software: you can redistribute it and/or modify
|
|
# it under the terms of the GNU General Public License as published by
|
|
# the Free Software Foundation, either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# This program is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with this program. If not, see <http://www.gnu.org/licenses/>
|
|
|
|
__author__ = "Cedric Bonhomme"
|
|
__version__ = "$Revision: 0.4 $"
|
|
__date__ = "$Date: 2016/08/04 $"
|
|
__revision__ = "$Date: 2019/06/01 $"
|
|
__license__ = "GPLv3"
|
|
|
|
from typing import IO, Union
|
|
|
|
from stegano import tools
|
|
|
|
|
|
def hide(
|
|
input_image: Union[str, IO[bytes]],
|
|
message: str,
|
|
encoding: str = "UTF-8",
|
|
shift: int = 0,
|
|
auto_convert_rgb: bool = False,
|
|
):
|
|
"""Hide a message (string) in an image with the
|
|
LSB (Least Significant Bit) technique.
|
|
"""
|
|
message_length = len(message)
|
|
assert message_length != 0, "message length is zero"
|
|
|
|
img = tools.open_image(input_image)
|
|
|
|
if img.mode not in ["RGB", "RGBA"]:
|
|
if not auto_convert_rgb:
|
|
print("The mode of the image is not RGB. Mode is {}".format(img.mode))
|
|
answer = input("Convert the image to RGB ? [Y / n]\n") or "Y"
|
|
if answer.lower() == "n":
|
|
raise Exception("Not a RGB image.")
|
|
img = img.convert("RGB")
|
|
|
|
encoded = img.copy()
|
|
width, height = img.size
|
|
index = 0
|
|
|
|
message = str(message_length) + ":" + str(message)
|
|
message_bits = "".join(tools.a2bits_list(message, encoding))
|
|
message_bits += "0" * ((3 - (len(message_bits) % 3)) % 3)
|
|
|
|
npixels = width * height
|
|
len_message_bits = len(message_bits)
|
|
if len_message_bits > npixels * 3:
|
|
raise Exception(
|
|
"The message you want to hide is too long: {}".format(message_length)
|
|
)
|
|
for row in range(height):
|
|
for col in range(width):
|
|
if shift != 0:
|
|
shift -= 1
|
|
continue
|
|
if index + 3 <= len_message_bits:
|
|
|
|
# Get the colour component.
|
|
pixel = img.getpixel((col, row))
|
|
r = pixel[0]
|
|
g = pixel[1]
|
|
b = pixel[2]
|
|
|
|
# Change the Least Significant Bit of each colour component.
|
|
r = tools.setlsb(r, message_bits[index])
|
|
g = tools.setlsb(g, message_bits[index + 1])
|
|
b = tools.setlsb(b, message_bits[index + 2])
|
|
|
|
# Save the new pixel
|
|
if img.mode == "RGBA":
|
|
encoded.putpixel((col, row), (r, g, b, pixel[3]))
|
|
else:
|
|
encoded.putpixel((col, row), (r, g, b))
|
|
|
|
index += 3
|
|
else:
|
|
img.close()
|
|
return encoded
|
|
|
|
|
|
def reveal(input_image: Union[str, IO[bytes]], encoding: str = "UTF-8", shift: int = 0):
|
|
"""Find a message in an image (with the LSB technique).
|
|
"""
|
|
img = tools.open_image(input_image)
|
|
width, height = img.size
|
|
buff, count = 0, 0
|
|
bitab = []
|
|
limit = None
|
|
for row in range(height):
|
|
for col in range(width):
|
|
if shift != 0:
|
|
shift -= 1
|
|
continue
|
|
# pixel = [r, g, b] or [r,g,b,a]
|
|
pixel = img.getpixel((col, row))
|
|
if img.mode == "RGBA":
|
|
pixel = pixel[:3] # ignore the alpha
|
|
for color in pixel:
|
|
buff += (color & 1) << (tools.ENCODINGS[encoding] - 1 - count)
|
|
count += 1
|
|
if count == tools.ENCODINGS[encoding]:
|
|
bitab.append(chr(buff))
|
|
buff, count = 0, 0
|
|
if bitab[-1] == ":" and limit is None:
|
|
try:
|
|
limit = int("".join(bitab[:-1]))
|
|
except Exception:
|
|
pass
|
|
|
|
if len(bitab) - len(str(limit)) - 1 == limit:
|
|
img.close()
|
|
return "".join(bitab)[len(str(limit)) + 1:]
|