I have a program which I'm using to encrypt and decrypt user inputted text, and then outputting the result onto the GUI for my user to see.
vigernkey = open("vigernkey.txt", "r+") # opens the text file
finish_message = ""
ciphertext_file = open("cip.txt", "r+") # opens the text file for the ciphertext
pygame.init() # initialises the library that allows a GUI to be opened
# Encrypt subroutine:
def vigenere(x):
ciphertext = []
vigkey = [] # this declares the list which will store the key for each individual letter
for letter in x:
individualletterkey = secrets.choice(string.ascii_letters) # this generates the key for each letter as a
# random character in the ASCII set
newletter = ord(letter) ^ ord(individualletterkey) # This transforms the letters of the key and the
# plaintext into numbers and performs an XOR operation on the two to create the encoding of the ciphertext
# character
vigkey.append(individualletterkey) # this stores the key of each letter in a list, so it can be passed on
# to the intended recipient for decryption
ciphertext.append(newletter) # this adds the newly encrypted letter to the ciphertext
for element in vigkey: # this loop ensures that the key for every letter is in a text file that can be passed
# on to the intended recipient for them to decrypt the ciphertext
vigernkey.write(str(element))
vigernkey.write("\n") # Each character in the key will be stored in an individual line
for element in ciphertext:
ciphertext_file.write(str(element)) # Each character in the ciphertext will be stored in a line in a file
ciphertext_file.write("\n")
global finish_message
finish_message = "The key is in the file vigernkey.txt, and the ciphertext is in the file cip.txt"
return ciphertext, finish_message
# Decrypt subroutine:
def vigenere_decrypt(y):
y = [int(x) for x in y]
Plaintext = "" # this declares the plaintext variable
vigkey = vigernkey.read().splitlines()
for i in range(len(y)):
newletter = chr(y[i] ^ ord(vigkey[i]))
Plaintext += newletter # this adds each newly decrypted character to the Plaintext
return Plaintext
# GUI creation:
WIDTH, HEIGHT = 900, 500 # this declares the size of the window the GUI will open in
WIN = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Vigenere cipher") # this titles the window
FPS = 60 # this declares the magnitude of the framerate of the window
TRANSPARENT = (0, 0, 0, 0) # This tuple allows objects on the screen to "disappear" when they are no longer needed
WHITE = (255, 255, 255)
BLUE = (0, 0, 255)
class Button: # This class will be used as buttons to allow the user to make selections in the program
def __init__(self, x, y, image):
self.image = image
self.rect = self.image.get_rect()
self.rect.topleft = (x, y)
def draw(self): # This method allows the button to draw itself on the screen
WIN.blit(self.image, (self.rect.x, self.rect.y))
def isclicked(self, event):
x, y = pygame.mouse.get_pos()
if event.type == pygame.MOUSEBUTTONDOWN:
if self.rect.collidepoint(x, y):
return 1
else:
return 0
class InputBox:
def __init__(self, x, y, w, h, text=''):
self.rect = pygame.Rect(x, y, w, h)
self.colour = WHITE
self.text = text
self.txt_surface = FONT.render(text, True, self.colour)
self.active = False
self.done = False
def handle_event(self, event):
if event.type == pygame.MOUSEBUTTONDOWN:
# If the user clicked on the input_box rect.
if self.rect.collidepoint(event.pos):
# Toggle the active variable.
self.active = not self.active
else:
self.active = False
self.colour = WHITE if self.active else BLUE
if event.type == pygame.KEYDOWN:
if self.active:
if event.key == pygame.K_RETURN:
self.text = ''
self.done = True
elif event.key == pygame.K_BACKSPACE:
self.text = self.text[:-1]
else:
self.text += event.unicode
# Re-render the text.
self.txt_surface = FONT.render(self.text, True, self.colour)
def update(self):
# Resize the box if the text is too long.
width = max(200, self.txt_surface.get_width() + 10)
self.rect.w = width
def draw(self, screen):
# Blit the text.
screen.blit(self.txt_surface, (self.rect.x + 5, self.rect.y + 5))
# Blit the rect.
pygame.draw.rect(screen, self.colour, self.rect, 2)
FONT = pygame.font.Font(None, 32)
encryptimg = pygame.image.load(os.path.join("Assets", "Encrypt_button.png")) # This line and the next contain the
# images that will be the program's buttons and allow them to be utilised in the programs
decryptimg = pygame.image.load(os.path.join("Assets", "Decrypt_button.png"))
encrypt_button = Button(100, 150, encryptimg) # These following two lines create the buttons to select the two main
# subroutines
decrypt_button = Button(550, 150, decryptimg)
textbox = InputBox(100, 100, 140, 32)
GREY = (54, 45, 45)
def draw_window(): # this function colours the window
WIN.fill(GREY) # this colours the window grey
encrypt_button.draw()
decrypt_button.draw()
pygame.display.update() # this updates the colouring of the window the next time the frame cycles
def reset_window(): # this functions draws a version of the window with a textbox instead of buttons
WIN.fill(GREY)
textbox.draw(WIN)
pygame.display.update()
def Coursework(): # the application loop that all pygame programs require to function
clock = pygame.time.Clock() # this creates a variable, that, when a value is assigned to it, it will be the
# refresh rate of the application
run = True
encrypt = False
decrypt = False
finished = False
draw_window()
while run: # everything in this loop will only happen when the window is open
clock.tick(FPS) # this refreshes the frame every 1/FPS seconds, setting a framerate for the program
for event in pygame.event.get(): # the event loop that ensures that any events are properly managed
if event.type == pygame.QUIT:
run = False # this closes the window if the user quits the program
textbox.handle_event(event)
if encrypt_button.isclicked(event) == 1: # The two following loops create a text box on the screen
# when one of the options is chosen
reset_window()
encrypt = True
if decrypt_button.isclicked(event):
reset_window()
decrypt = True
if encrypt: # the following code encrypts the user input and outputs a message onto the screen
ciphertext_file.truncate(0)
vigernkey.truncate(0)
vigernkey.seek(0)
ciphertext_file.seek(0)
reset_window()
textbox.update()
if textbox.done:
encr_text = vigenere(textbox.text)
print(finish_message)
textbox.text = finish_message
elif decrypt: # the following code decrypts the contents of cip.txt and outputs the result onto the screen
reset_window()
textbox.update()
if textbox.done:
ciphtext = ciphertext_file.read().splitlines()
decr_text = vigenere_decrypt(ciphtext)
print(decr_text)
textbox.text = decr_text
pygame.quit()
if __name__ == "__main__": # this ensures that the GUI will open when this specific program is running
Coursework()
However, when the encrypt and decrypt subroutines have finished and I want to output their text, the program doesn't stop when the text has been outputted. What happens is that the code repeats the function; in the encrypt case, for example, the program would encrypt the inputted text, output the variable "finish_message" onto the screen, and then repeate the function on the text currently in the text box - in this case the variable finish_message.
I've tried to stop it by setting self.active and self.done to false at the end of the if loops, but what this does is it stops the text from being encrypted/decrypted at all. How can I effectively stop this function but still allow it to decrypt/encrypt the initial input?
EDIT: I tried to use the finished variable in this manner:
if not finished:
if encrypt: # the following code encrypts the user input and outputs a message onto the screen
ciphertext_file.truncate(0)
vigernkey.truncate(0)
vigernkey.seek(0)
ciphertext_file.seek(0)
reset_window()
textbox.update()
if textbox.done:
encr_text = vigenere(textbox.text)
print(finish_message)
textbox.text = finish_message
finished = True
elif decrypt: # the following code decrypts the contents of cip.txt and outputs the result onto the screen
reset_window()
textbox.update()
if textbox.done:
ciphtext = ciphertext_file.read().splitlines()
decr_text = vigenere_decrypt(ciphtext)
print(decr_text)
textbox.text = decr_text
finished = True
but then the text I was trying to output didn't output.
