py2 to 3 base64 issues
On Fri, Aug 9, 2019 at 12:23 PM Chris Angelico <rosuav at gmail.com> wrote:
> On Sat, Aug 10, 2019 at 2:09 AM Larry Martell <larry.martell at gmail.com> wrote:
> > I have some python 2 code:
> > def decode(key, string):
> > decoded_chars = 
> > string = base64.urlsafe_b64decode(string)
> > for i in range(len(string)):
> > key_c = key[i % len(key)]
> > encoded_c = chr(abs(ord(string[i]) - ord(key_c) % 256))
> > decoded_chars.append(encoded_c)
> > decoded_string = "".join(decoded_chars)
> > return decoded_string
> > and if I call it like this in py2 it works as expected:
> > s = 'V3NYVY95iImnnJWCmqphWFFzU1qvqsV6x83Mxa7HipZitZeMxbe709jJtbfW6Y6blQ=='
> > key = '!@#$VERYsecRet)('
> > decode(key, s)
> > In py3 it fails with
> > TypeError: ord() expected string of length 1, but int found
> > I know that in py3 base64.urlsafe_b64decode is returning bytes not
> > chars and that is what that is happening, and I thought the solution
> > would be to decode it, but what codec would I use for this?
> Should be safe to decode it as ASCII, since Base 64 uses strictly
> ASCII characters. But since you're working with bytes, possibly all
> you need to do is remove the ord calls, since ord(u"x") is the same as
> b"x". You'll then need to change the join() at the end to be just
> "decoded_string = bytes(decoded_chars)", or possibly that followed by
> a decode-to-text, depending on how your data works.
That doesn't work:
-> encoded_c = chr(abs(string[i] - ord(key_c) % 256))
TypeError: "unsupported operand type(s) for -: 'str' and 'int'"