class Seal:
"""
Class Seal represents digital seal.
It combines digital envelope and digital signature.
"""
def __init__(self, encryption_algorithm, key_type, rsa_key_size, message,
mode, sha_type):
"""
Initialization method.
:param encryption_algorithm: which symmetric algorithm will be used
:param key_type: key size for the symmetric algorithm
:param rsa_key_size: key size for the asymmetric algorithm
:param message: encryption data
:param mode: mode of the symmetric algorithm
:param sha_type: SHA-2 type
"""
self._sha = sha_type
self._rsa_key = rsa_key_size
# generate envelope
self._envelope = Envelope(encryption_algorithm, key_type, rsa_key_size,
message, mode)
self._signature = None
# envelope encryption result
self._env_res = None
def seal(self):
"""
Seal method.
"""
self._env_res = self._envelope.encrypt()
message = str(self._envelope.cipher) + str(self._envelope.crypt_key)
self._signature = Signature(self._sha, self._rsa_key, message)
self._signature.sign()
def unseal(self):
"""
Unseal method.
:return: original message
"""
msg = self._envelope.decrypt(self._env_res)
# verifies the signature
verification = self._signature.verify()
return msg, verification
def run_selected():
new_window = Toplevel(root)
new_window.geometry("400x270")
calc_side_geometry(new_window)
noError = True
if button_value.get() == 1:
algorithm = cat1
mode = cat1_2
rsa = cat1_3
elif button_value.get() == 2:
sha = cat2
rsa = cat2_2
else:
algorithm = cat3
mode = cat3_2
rsa = cat3_3
sha = cat3_4
# check if everything is selected
if button_value.get() == 1:
task = 'Digitalna omotnica'
if algorithm.get() == 'Select' or mode.get() == 'Select' or rsa.get(
) == 'Select':
messagebox.showerror('Error', "Niste odabrali sve vrijednosti!")
new_window.destroy()
noError = False
elif button_value.get() == 2:
task = 'Digitalni potpis'
if sha.get() == 'Select' or rsa.get() == 'Select':
messagebox.showerror('Error', "Niste odabrali sve vrijednosti!")
new_window.destroy()
noError = False
elif button_value.get() == 3:
task = 'Digitalni pečat'
if algorithm.get() == 'Select' or mode.get() == 'Select' or rsa.get(
) == 'Select' or sha.get() == 'Select':
messagebox.showerror('Error', "Niste odabrali sve vrijednosti!")
new_window.destroy()
noError = False
if text.get() == "" and noError:
messagebox.showerror('Error', "Niste unijeli tekst!")
new_window.destroy()
noError = False
if noError:
Label(new_window, text=task.upper(),
font=font_style_2).pack(pady=(2, 5))
Label(new_window, text="Tekst koji ste unijeli:",
font=font_style).pack(pady=(40, 5))
Label(new_window, text=text.get()).pack()
if button_value.get() == 1:
Label(new_window,
text="Tekst koji je dobiven dekriptiranjem:",
font=font_style).pack(pady=(40, 5))
envelope = Envelope(algorithm.get().split()[0],
algorithm.get().split()[1],
int(rsa.get().split()[1]), text.get(),
mode.get())
sym_obj = envelope.encrypt()
decrypted = envelope.decrypt(sym_obj)
Label(new_window, text=decrypted).pack()
elif button_value.get() == 2:
Label(new_window,
text="Ishod digitalnog potpisivanja:",
font=font_style).pack(pady=(40, 5))
signature = Signature(sha.get()[3:], int(rsa.get().split()[1]),
text.get())
signature.sign()
verification = signature.verify()
Label(new_window, text=verification).pack()
else:
seal = Seal(algorithm.get().split()[0],
algorithm.get().split()[1], int(rsa.get().split()[1]),
text.get(), mode.get(),
sha.get()[3:])
seal.seal()
decrypted, verification = seal.unseal()
Label(new_window,
text="Tekst koji je dobiven dekriptiranjem:",
font=font_style).pack(pady=(20, 5))
Label(new_window, text=decrypted).pack()
Label(new_window,
text="Ishod digitalnog potpisivanja:",
font=font_style).pack(pady=(20, 5))
Label(new_window, text=verification).pack()
