Case sensitivite filesystems and pycrypto dependency break module

[tsujamin]

I am unable to use potr on my Macbook due to case insensitivity but preserving nature of HFS+.

File "/usr/local/lib/python2.7/site-packages/potr/__init__.py", line 21, in <module>
from potr import context
File "/usr/local/lib/python2.7/site-packages/potr/context.py", line 43, in <module>
from potr import crypt
File "/usr/local/lib/python2.7/site-packages/potr/crypt.py", line 25, in <module>
from potr.compatcrypto import SHA256, SHA1, SHA1HMAC, SHA256HMAC, \
File "/usr/local/lib/python2.7/site-packages/potr/compatcrypto/__init__.py", line 21, in <module>
from potr.compatcrypto.pycrypto import *
File "/usr/local/lib/python2.7/site-packages/potr/compatcrypto/pycrypto.py", line 18, in <module>
from Crypto import Cipher
ImportError: No module named Crypto

The issue appears to be caused by the importing of pycrypto in the uppercase form in the following lines

from Crypto import Cipher
from Crypto.Hash import SHA256 as _SHA256
from Crypto.Hash import SHA as _SHA1
from Crypto.Hash import HMAC as _HMAC
from Crypto.PublicKey import DSA
from Crypto.Random import random

It appears that when pip installs pycrypto, it names the module in the lower-cased convention such that the upper-case variant, used by potr, cannot be imported

>>> import Crypto
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named Crypto
>>> import crypto
>>>

For the moment I've renamed my local pycrypto to the upper-case, and I was going to submit a trivial PR to lower-case the imports in potr but I'm not well versed enough on running Python on other platforms to know whether this might introduce new issues.

I'm also not sure if this is technically a potr problem of a pycrypto problem, so I'm happy to move this issue if required.

[koolfy]

Hello, Thanks for the report ! I don't think potr was properly tested around a OS X environment, so tread with care, and report any anomalies you might find. I'll test the lowercase in other environments this evening and get back to you. I don't have a OS X for testing though, so stay around for confirming the resolution soon :)

[koolfy]

Ok, this is going to be a little less trivial than I thought :p

Python 2.7.9 (default, Mar 8 2015, 00:52:26)
[GCC 4.9.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.

import crypto
Traceback (most recent call last):
File "", line 1, in
ImportError: No module named crypto
import Crypto

But nothing we can't handle.

Can anyone try it on windows and see which one it is?

[azrdev]

@koolfy handling this should be something like

try:
  import crypto
except ImportError:
  import Crypto as crypto

[koolfy]

Yes, that's what I had in mind :) I'll make the fix in a few. Still curious about which one windows would accept, if not both.

[afflux]

I'd argue this is a bug in pycrypto or python on HFS+. The module name is Crypto, we shouldn't import crypto. How do other packages deal with this?

[tsujamin]

@koolfy as far as I can recall, NTFS suffers the same issue as HFS+ (Case-Insensitive but Preserving). As to whether it's a pycrypto bug or not, I'm not sure as they don't necessarily have a method to control the casing of their module? I'd be interested to see how packages usually deal with this though too.

[koolfy]

So, I just pushed an ugly fix, while we discuss the issue.

I didn't test it, as I don't currently have case-stupid^W mac OSX or Windows machines at hand at the moment.
So I need you guys to check it out and tell me how it works on the three environments.

Linux should be fine, but I tested it in a hurry, so again, don't trust me on this.

It's branching from the staging branch, and I won't merge it to staging until

1. I have confirmation that this actually does work
2. I have confirmation that there isn't a better way to fix this (I'd gladly open a bug report somewhere else so we don't have to deal with this, but I don't think we'll get around it. It's not pretty but it doesn't break much)

I'll have a look at how other packages deal with this, but I suspect I'll find the same try except.

Thoughts?

[tsujamin]

Looking good from OS X

[koolfy]

Great news. I'm not sure I'll wait for a windows confirmation, we could be waiting for quite some time :p I'll have a look around other projects, if I don't find something better I'll merge to staging.

[koolfy]

Merged this to Staging, I'm closing this for now, don't hesitate to reopen if something breaks or a better approach exists