worked on the chall

gen_files.py

@@ -0,0 +1,82 @@
+import argparse
+import qrcode
+from PIL import Image
+from pathlib import Path
+import random
+
+NUM_PIECES = 3
+TILE = 78
+
+def generate_qrcode(data: str):
+    qr = qrcode.QRCode(version=25, box_size=2, error_correction=qrcode.ERROR_CORRECT_L, border=0)
+    qr.add_data(data)
+    return qr.make_image()
+
+
+def cut_pieces(image):
+    pieces = []
+
+    for x, y in [(x, y) for x in range(NUM_PIECES) for y in range(NUM_PIECES)]:
+        pieces.append(image.crop((x * TILE, y * TILE, x * TILE + TILE, y * TILE + TILE)))
+
+    return pieces
+
+
+def scramble_qr_code(payloadList, decoyList, seed):
+    height_piece, width_piece = payloadList[0].size
+    random.seed(seed)
+    scrambled_width = 3
+    if decoyList is not None:
+        payloadList += random.sample(decoyList, NUM_PIECES)
+        assert len(payloadList) == 12
+        scrambled_width = 4
+    random.shuffle(payloadList)
+
+    new_qr_code = Image.new("RGB", (width_piece * scrambled_width, height_piece * NUM_PIECES))
+    for x, y in [(x, y) for x in range(scrambled_width) for y in range(NUM_PIECES)]:
+        piece = payloadList[x + scrambled_width * y]
+        new_qr_code.paste(piece, (x * width_piece, y * height_piece))
+
+    return new_qr_code
+
+
+def generate_scrambled_qrcode(seed, output_dir, decoy, name):
+    with open("res/secret_message.txt", "r") as secret:
+        message = secret.read()
+     
+    qr_code = generate_qrcode(message + seed)
+    
+    qr_pieces = cut_pieces(qr_code)
+    decoy_pieces = None
+    if decoy:
+        with open("res/decoy.txt", "r") as decoy_msg:
+            decoy = decoy_msg.read()
+
+        decoy_qr_code = generate_qrcode(decoy)
+        decoy_pieces = [piece for id, piece in enumerate(cut_pieces(decoy_qr_code)) if id not in [0, 2, 6]]
+
+    scrambled_qr_code = scramble_qr_code(qr_pieces, decoy_pieces, seed)
+
+    output_dir.mkdir(parents=True, exist_ok=True)
+    scrambled_qr_code.save(output_dir / name)
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Generates a scrambled QR code with optional decoy pieces.")
+    parser.add_argument("seed", type=str, help="The password to scramble the QR code.")
+    parser.add_argument("output_dir", type=Path, help="Directory where the output will be stored")
+    parser.add_argument("--without-decoy", action="store_false", help="Exclude decoy pieces in the scrambled QR code.")
+    parser.add_argument("-o", "--output", type=str, default="secret_message.png", help="The name of the output image file.")
+    
+    args = parser.parse_args()
+
+    generate_scrambled_qrcode(
+        seed=args.seed, 
+        output_dir=args.output_dir,
+        decoy=args.without_decoy, 
+        name=args.output
+    )
+
+
+if __name__ == "__main__":
+    main()