expand upgrade and improve this code for effectively decrypting crypt14 files using brute force: import os
import tkinter as tk
from tkinter import filedialog, messagebox, simpledialog, ttk
import threading
import itertools
import string
from cryptography.fernet import Fernet


class Crypt14Decryptor:
    def __init__(self, master):
        self.master = master
        master.title("Crypt14 Decryptor with Analysis")

        self.label = tk.Label(master, text="Select .crypt14 files for analysis:")
        self.label.pack()

        self.filepath_entry = tk.Entry(master, width=50)
        self.filepath_entry.pack()

        self.browse_button = tk.Button(master, text="Browse", command=self.browse_files)
        self.browse_button.pack()

        self.analyze_button = tk.Button(master, text="Analyze & Compare", command=self.analyze_files)
        self.analyze_button.pack()

        self.analysis_result = tk.Label(master, text="", wraplength=400)
        self.analysis_result.pack()

        self.key_label = tk.Label(master, text="Enter decryption key or pattern:")
        self.key_label.pack()

        self.key_entry = tk.Entry(master, show='*', width=50)
        self.key_entry.pack()

        self.decrypt_button = tk.Button(master, text="Decrypt Selected File", command=self.start_decrypt)
        self.decrypt_button.pack()

        # Press buttons to analyze results
        self.file_list = []  # Store selected file paths

    def browse_files(self):
        """Method to allow user to select multiple .crypt14 files."""
        filenames = filedialog.askopenfilenames(filetypes=[("Crypt14 files", "*.crypt14")])
        self.filepath_entry.delete(0, tk.END)
        self.file_list = filenames  # Save the list of filenames
        self.filepath_entry.insert(0, ", ".join(os.path.basename(fn) for fn in self.file_list))

    def analyze_files(self):
        """Analyze the selected files for patterns."""
        if not self.file_list:
            messagebox.showerror("Error", "Please select .crypt14 files for analysis.")
            return

        # Placeholder for analysis (this could be enhanced)
        formula = "Pattern Analysis Result:\n"
        key_length_set = set()
        # Analyzing the length of files as an indicator
        for filepath in self.file_list:
            key_length_set.add(os.path.splitext(os.path.basename(filepath))[0].count('x'))  # Assume 'x' denotes a pattern

        formula += f"Key Lengths Analyzed: {key_length_set}\n"
        formula += f"Possible Common Key Length: {' or '.join(map(str, key_length_set))}"

        # Display the formula
        self.analysis_result.config(text=formula)

    def start_decrypt(self):
        """Decrypt selected file using provided key."""
        selected_key = self.key_entry.get()
        if not selected_key:
            messagebox.showerror("Error", "Please provide a decryption key or formula.")
            return

        # Assume we are trying to decrypt the last selected file for the demonstration.
        if not self.file_list:
            messagebox.showerror("Error", "No files selected to decrypt.")
            return

        filepath = self.file_list[-1]  # Just an example to decrypt the last one chosen

        try:
            key = selected_key.encode()  # Encode to bytes
            if len(key) != 44:
                messagebox.showerror("Error", "Invalid key length.")
                return

            with open(filepath, 'rb') as file:
                encrypted_data = file.read()
                fernet = Fernet(key)  # Create Fernet object with the provided key
                decrypted_data = fernet.decrypt(encrypted_data)  # Attempt decryption

            output_file = filepath.replace('.crypt14', '')
            with open(output_file, 'wb') as file:
                file.write(decrypted_data)

            messagebox.showinfo("Success", f"File decrypted successfully: {output_file}")
        except Exception as e:
            messagebox.showerror("Error", f"An error occurred during decryption: {str(e)}")

if __name__ == "__main__":
    root = tk.Tk()
    decryptor = Crypt14Decryptor(root)
    root.mainloop()