import os
import numpy as np
import re

def xor_files(key_string, extension=".txt", prefix="dec_", bytes_required=6):
    key_bytes = bytes([int(x, 16) for x in key_string.split()])
    #assert len(key_bytes) == bytes_required, f"Key must be exactly {bytes_required} bytes"
    
    # Get all files in the current directory
    all_files = [f for f in os.listdir() if f.lower().endswith(extension)]
    
    for filename in all_files:
        print(f"Processing {filename}...")

        with open(filename, 'rb') as f:
            data = np.frombuffer(f.read(), dtype=np.uint8)

        # Create the key array and repeat it to match the data length
        key_array = np.array(list(key_bytes), dtype=np.uint8)
        repeats = len(data) // len(key_array) + 1
        full_key = np.tile(key_array, repeats)[:len(data)]

        result = np.bitwise_xor(data, full_key)

        output_filename = f"{prefix}{filename}"
        with open(output_filename, 'wb') as f:
            f.write(result.tobytes())

        print(f"Created {output_filename}")

# Example usage
if __name__ == "__main__":
    key = "AA BB CC DD EE FF"
    xor_files(key)