stegng - A steganography tool for png's

Description

Hide information in PNG images disguised as parts of the image format. Information may be a simple string or an entire file. Information hidden by stegng can also be extracted from the PNG file.

Usage

stegng expects an input file to work with, stegng -i file.png If no other options are given the program simply performs checks on the file, mainly if it's a valid PNG file.

Options

• -i <PATH> specifies the input file
• -o <PATH> specifies the output file, if -i and -o are the only options given the program simply copies the input image
• -p tells the program to print the chunks present in the image in a human readable format
• -s remove the non-critical chunks from the image before writing them to the output file
• -j <STRING> injects the string specified by <STRING> inside the output image. It does this by creating the appropriate number of new chunks (tEXt by default) and placing the <STRING> specified inside the data field of the new chunks, splitting the data into multiple chunks if needed.
• -J <PATH> reads the data to be inserted from the file specified by <PATH>. Same rules apply as the -j option.
• -x <INTEGER> specifies at which chunk index to insert the new chunks, negative numbers insert from the end
• -d <INTEGER> specifies the maximum size in bytes of the data field of the injected chunks before splitting the data in multiple chunks
• -e <STRING> specifies from which chunk to extract the data fields which possible contain data previously injected by the program, example stegng -i image.png -e tEXt
• -t <STRING> tells the program to create and inject the data into chunks of type <STRING>. The type of the new chunk may be a type that is not part of the PNG standard.

Examples

./stegng -i ./media/maze.png -p # print chunks information
./stegng -i ./media/maze.png -j 'this is a secret' -o ./newimage.png # inject the string 'this is a secret'
./stegng -i ./newimage.png -e tEXt # extract injected string
./stegng -i ./media/maze.png -J ./secret_file.gpg -d 300 -o ./newimage.png # inject the file secret_file.gpg, setting the maximum chunk size at 300 bytes
./stegng -i ./newimage.png -e tEXt > secret_file.gpg # extract injected data from tEXt chunk

Installation

git clone https://github.com/begone-prop/stegng.git
cd stegng
make