import tkinter as tk

from tkinter import filedialog

import hashlib

def copy_button():

window.clipboard_clear()

window.clipboard_append(checksum_entry.get())

label_file_explorer.configure(

text="Checksum copies to clipboard. Save it to somewhere safe before closing this window")

def browse_files():

filename = filedialog.askopenfilename(initialdir="/",

title="Select a File",

filetypes=(

("All files",

"*.*"),

))

# if we click on upload file button but then click cancel

if not filename or not isinstance(filename, str):

label_file_explorer.configure(text="No file uploaded.")

return

# read file in binary mode.

with open(filename, "rb") as input_file:

# text is bytes type in rb mode

text = input_file.read()

# checksum of whole text at once

checksum = hashlib.sha256(text).hexdigest()

print("complete file checksum: " + checksum) # type is string

# calculating checksum for one byte at a time and updating the hash

byte_count = len(text)

byte_chunks = [text[i: i + 2] for i in range(0, byte_count, 2)]

# new hash object with sha256 algorithm

h = hashlib.new('sha256')

for single_byte in byte_chunks:

h.update(single_byte)

# final checksum of hash

combined_checksum = h.hexdigest()

print("byte by byte checksum: " + combined_checksum)

msg = "File Opened: " + filename

# Change label contents

label_file_explorer.configure(text=msg)

# clear the entry field before inserting checksum there

checksum_entry.delete(0, tk.END)

checksum_entry.insert(0, checksum)

# starting program

window = tk.Tk()

window.title('File Checksum Generator')

title = tk.Label(text="Generate file checksum. Upload a file.", pady=20)

title.pack()

label_file_explorer = tk.Label(window, text="", width=100, height=4, pady=10)

button_explore = tk.Button(window, text="Browse Files", command=browse_files, pady=20)

button_copy = tk.Button(window, text="Copy Checksum", command=copy_button, pady=10)

button_exit = tk.Button(window, text="Exit", command=exit, pady=10)

checksum_entry = tk.Entry(width=70)

checksum_entry.insert(0, "Checksum will appear here")

button_explore.pack()

label_file_explorer.pack()

checksum_entry.pack()

button_copy.pack()

button_exit.pack()

window.mainloop()