rsteg is a simple steganography utility for encoding files in images, written in Rust.
The payload file is processed as a series of individual bits, which replace the least significant bit of each color channel (RGBA) of each pixel in the cover image. It treats each pixel as containing 1 byte of information for each channel, meaning that 1 bit of payload data are encoded per channel per pixel.
The first 32 bits of encoded data are used to represent an integer which provides the size of the payload, in bytes. This is used to determine the cutoff for extracting the payload.
To install dependencies and build the project, run cargo build [--release] in the project directory. The rsteg binary will be located in the targets directory.
Usage: ./rsteg <encode/decode> [options]
Options:
-i input_image input image filename
-f payload_file payload filename
-o output_file output filename (image OR payload)
-c channels optional number of color channels (def: 4)
-h, --help print this help menu
Examples:
./rsteg encode -i test_cover.jpg -f test_payload.txt -o processed.png
./rsteg decode -i processed.png -o retrieved_payload.txt