Steganography.py

import os


def get_valid_file():
    filename = input("Enter the PNG file name: ").strip()
    return filename if os.path.exists(filename) else "r.png"

def hide_data_in_png():
    png_filename = get_valid_file()
    print(f"Using file: {png_filename}")

    hidden_data = input("Enter the data to hide: ").encode()

    with open(png_filename, "ab") as f:
        f.write(hidden_data)

    print(f"Data hidden successfully in '{png_filename}'.")


def extract_hidden_data():
    png_filename = input("Enter the PNG file name: ").strip()

    if not os.path.exists(png_filename):
        print("Error: File not found!")
        return

    with open(png_filename, "rb") as f:
        content = f.read()

    iend_marker = b"\x49\x45\x4E\x44\xAE\x42\x60\x82"

    offset = content.find(iend_marker)

    if offset == -1:
        print("Error: IEND marker not found! Not a valid PNG file.")
        return

    extra_data_start = offset + len(iend_marker)
    extra_data = content[extra_data_start:]

    if extra_data:
        print("🔍 Hidden Data Found:", extra_data.decode(errors="ignore"))

        with open("hidden_data.txt", "wb") as hidden_file:
            hidden_file.write(extra_data)

        print("Hidden data saved to 'hidden_data.txt'")
    else:
        print("No hidden data found.")


choice = input(
    "Do you want to (1) Hide Data or (2) Extract Data? Enter 1 or 2: "
).strip()

if choice == "1":
    hide_data_in_png()
elif choice == "2":
    extract_hidden_data()
else:
    print("Invalid choice. Please enter 1 or 2.")