CODEWITHSUNDEEP
pythonxorordbinascii
user16042504
user16042504

Reputation: 31

Differences of the ord() function between Python 2.7 and 3.9

Good morning people! I've been trying to convert this code written in Python 2 to Python 3.It's a simple function to encrypt strings using XOR. What I have so far:

import binascii

def encrypt(content: str, key: str) -> str:
    key_id = 0
    xored = ""
    for c in content:
        xored += chr(ord(key[key_id % len(key)]) ^ ord(c))
        key_id += 1
    return binascii.hexlify(xored.encode())

def decrypt(content: str, key: str) -> str:
    key_id = 0
    xored = ""
    for c in binascii.unhexlify(content):
        xored += chr(ord(key[key_id % len(key)]) ^ ord(c))
        key_id += 1
    return binascii.hexlify(xored.encode())

The code in Python 2 works perfectly, but when testing the code above (in Python 3), I'm having problems decoding messages. (The encrypt() function seems to be working perfectly.) The following error happens:

>>> encrypt("foo", "123")
b'575d5c'
>>> decrypt(b"575d5c", "123")
Traceback (most recent call last):
  File "<pyshell#2>", line 1, in <module>
    decrypt(b"575d5c", "123")
  File "/home/user/Code/Python/xorcrypt.py", line 15, in decrypt
    xored += chr(ord(key[key_id % len(key)]) ^ ord(c))
TypeError: ord() expected string of length 1, but int found

I checked both documentation, but couldn't identify any difference in versions: ord() in Python 2 and ord() in Python 3. In addition, I searched other sources, but I didn't find any mention of the problem:

What is Python ord Function

Porting Python 2 Code to Python 3

Cheatsheet Python 2 to 3

Am I looking at the correct spot? Or would the ord() function not be the problem in this case? Thank you very much in advance!

Upvotes: 2

Views: 516

Answers (1)

BoarGules
BoarGules

Reputation: 16951

The difference is not in ord() but in binascii.unhexlify(). In Python 2 it returns a string and if you index into that string you get a string of length 1, that you can call ord() on. But in Python 3 it returns a bytes and if you index into that, you get a small integer that you can't call ord() on, and don't need to.

Upvotes: 4

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