Strange error when trying to use base64 with Tkinter Text

Question

I'm currently making a simple tool that encrypts/decrpyts text with some code found here: https://stackoverflow.com/a/16321853/4285156

It's been working perfectly fine when I run it in CMD. The problem came up when I was trying to use the code together with Tkinter Text() widgets.

Here's a screenshot of my program: https://i.stack.imgur.com/aoNV1.png

As you can see, it encrypts the text "Hello, world." just fine. The problems is that whenever I try to decrypt something, the console gives me an error message and it won't work.

I'm thinking it has to do with the fact that I'm using Text() widgets, but why does it work when I encrypt stuff, but not when trying to decrypt things? As I said earlier, it works fine both ways when I'm not using Tkinter.

Here's the code:

from Tkinter import *
import base64

password = "aS4KmfkKr5662LfLKjrI6Kan4fK"

def encode(key, clear):
    enc = []
    for i in range(len(clear)):
        key_c = key[i % len(key)]
        enc_c = chr((ord(clear[i]) + ord(key_c)) % 256)
        enc.append(enc_c)
    return base64.urlsafe_b64encode("".join(enc))

def decode(key, enc):
    dec = []
    enc = base64.urlsafe_b64decode(enc)
    for i in range(len(enc)):
        key_c = key[i % len(key)]
        dec_c = chr((256 + ord(enc[i]) - ord(key_c)) % 256)
        dec.append(dec_c)
    return "".join(dec)


GUI = Tk()
GUI.title('Cryppy')
GUI.minsize(width=300, height=300)

txt1 = Label(GUI, text="Decrypted Text")
txt1.grid(row=0, column=0, sticky=W, padx=(10,10))

tBox1 = Text(GUI, bd=2, width=60, height=5)
tBox1.grid(row=1, column=0, sticky=W, padx=(10,10))

txt2 = Label(GUI, text="Encrypted Text:")
txt2.grid(row=2, column=0, sticky=W, padx=(10,10))

tBox2 = Text(GUI, bd=2, width=60, height=5)
tBox2.grid(row=3, column=0, sticky=W, padx=(10,10))

def cryptIt():
    codeIt = encode(password, tBox1.get("1.0", "end-1c"))
    print codeIt
    tBox2.delete("1.0", END)
    tBox2.insert(END, codeIt)

def decryptIt():
    decodeIt = decode(password, tBox2.get("1.0", "end-1c"))
    print decodeIt
    tBox1.delete("1.0", END)
    tBox1.insert(END, decodeIt)

bCrypt = Button(GUI, text="Encrypt", command=cryptIt)
bCrypt.grid(row=4, sticky=W, padx=(10,10))

bCrypt2 = Button(GUI, text="Decrypt", command=decryptIt)
bCrypt2.grid(row=4, sticky=W, padx=(65,10))

GUI.mainloop()

And here is the error message

Exception in Tkinter callback
Traceback (most recent call last):
  File "E:\Python27\lib\lib-tk\Tkinter.py", line 1486, in __call__
    return self.func(*args)
  File "C:\Users\Runar\Google Drive\Prosjekter\SyncNote\Source Code\mainEx.py", line 47, in decryptIt
    decodeIt = decode(password, tBox2.get("1.0", "end-1c"))
  File "C:\Users\Runar\Google Drive\Prosjekter\SyncNote\Source Code\mainEx.py", line 16, in decode
    enc = base64.urlsafe_b64decode(enc)
  File "E:\Python27\lib\base64.py", line 112, in urlsafe_b64decode
    return b64decode(s, '-_')
  File "E:\Python27\lib\base64.py", line 71, in b64decode
    s = _translate(s, {altchars[0]: '+', altchars[1]: '/'})
  File "E:\Python27\lib\base64.py", line 36, in _translate
    return s.translate(''.join(translation))
TypeError: character mapping must return integer, None or unicode

Answer 1

I think that urlsafe_b64decode does not work with unicode. just make the input string ascii, e.g.

  enc = base64.urlsafe_b64decode(enc.encode('ascii','ignore'))

Hope this helps.