def decryptMessage(message, key, alphabet):
key1 = len(message)
new_alphabet = AffineCipher.encryptMessage(alphabet, key1, alphabet)
out1 = ''
count = 0
num = len(new_alphabet)
first_symbol = True
for symbol in message:
symbol_index = new_alphabet.find(symbol)
if symbol_index > -1:
symbol_index -= new_alphabet.find(new_alphabet[count])
if first_symbol is True:
symbol_index -= len(message)
first_symbol = False
out1 += new_alphabet[(symbol_index) % num]
else:
out1 += symbol
count = (count + 1) % num
out2 = TranspositionCipher.decryptMessage(out1, key)
return out2
def run_algorithm(self):
# Cleaning the warning messages
self.warning.grid_forget()
self.result.configure(state='normal')
self.result.delete(0.0, END)
self.result.configure(state='disabled')
# Getting the cipher
cipher = self.cipher.get()
# Getting the alphabet
self.setDefaultAlphabet()
if self.alphabetButton.get() == 2 and cipher != 5:
self.alphabet = self.alphabetEntry.get()
if len(self.alphabet) == 0:
# Warning message
self.warning[
"text"] = "Your custom alphabet cannot be empty.\nTip: you should consider enter a large alphabet."
self.warning.grid(row=self.affine_row + 6,
column=11,
sticky=W + W,
padx=10,
columnspan=2,
rowspan=2)
return
# Getting the key
if len(self.keyEntry.get()) == 0:
# Warning message
self.warning["text"] = "Please enter a valid key (numbers only)."
self.warning.grid(row=self.affine_row + 6,
column=11,
sticky=W + W,
padx=10,
columnspan=2,
rowspan=2)
return
self.key = int(self.keyEntry.get())
# Getting the message
# Put end-1c for avoid getting '\n' at the end of the input.
message = self.plainText.get("1.0", 'end-1c')
if len(message) == 0:
# Warning message
self.warning[
"text"] = "I think you forgot to enter your message..."
self.warning.grid(row=self.affine_row + 6,
column=11,
sticky=W + W,
padx=10,
columnspan=2,
rowspan=2)
return
# Configuring the result
self.result.configure(state='normal')
# Encrypt according to the selected cipher
if cipher == 1: # Affine Cipher
valid = AffineCipher.validateKey(self.key, len(self.alphabet))
if valid is True:
# Continue the algorithm
self.result.insert(
0.0,
AffineCipher.decryptMessage(message, self.key,
self.alphabet))
else:
# Show a warning message
self.warning[
"text"] = "This key can't be used with this alphabet.\nPlease enter another key."
self.warning.grid(row=self.affine_row + 6,
column=11,
sticky=W + W,
padx=10,
columnspan=2,
rowspan=2)
elif cipher == 2: # Caesar Cipher
self.result.insert(
0.0,
CaesarCipher.decryptMessage(message, self.key, self.alphabet))
elif cipher == 3: # Multiplicative Cipher
valid = MultiplicativeCipher.validateKey(self.key,
len(self.alphabet))
if valid is True:
# Continue the algorithm
self.result.insert(
0.0,
MultiplicativeCipher.decryptMessage(
message, self.key, self.alphabet))
else:
# Show a warning message
self.warning[
"text"] = "This key can't be used with this alphabet.\nPlease enter another key."
self.warning.grid(row=self.affine_row + 6,
column=11,
sticky=W + W,
padx=10,
columnspan=2,
rowspan=2)
elif cipher == 4: # My Cipher
valid = MyCipher.validateKey(self.key, len(self.alphabet))
if valid is True:
# Continue the algorithm
self.result.insert(
0.0,
MyCipher.decryptMessage(message, self.key, self.alphabet))
else:
# Show a warning message
self.warning[
"text"] = "This key can't be used with this alphabet.\nPlease enter another key."
self.warning.grid(row=self.affine_row + 6,
column=11,
sticky=W + W,
padx=10,
columnspan=2,
rowspan=2)
elif cipher == 5: # Transposition Cipher
self.result.insert(
0.0, TranspositionCipher.decryptMessage(message, self.key))
# Setting result for read-only again
self.result.configure(state='disabled')
