Error with CACHE_URL passwords that end with '='

[davidfischer]

This is somewhat similar to #194. A cache password that ends with the = character raises an error when calling env.cache. Even escaping it (%3D) will not work.

It looks like the cast method works by trying to just convert to a value and if that fails with a ValueError, it assumes the value is string (see code). However, a string that ends in a = will throw a SyntaxError instead of a ValueError:

>>> import ast
>>> ast.literal_eval('mypassword=')
Traceback (most recent call last):
...
SyntaxError: unexpected EOF while parsing

If you think the solution is just to catch a SyntaxError in addition to a ValueError, I'm happy to make a PR.

Normally I'd just change the password but on Azure the generated cache passwords always end with a = for some reason.

[ksze]

on Azure the generated cache passwords always end with a = for some reason

The "=" is often used as a padding character at the end of base64-encoded strings. Is the password really just the base64 of a long array of random bytes?

[davidfischer]

Correct.

[pix666]

A few more examples for which a SyntaxError exception is raised by _cast(). Escaping does not help.

• anything- (minus at the end)
• anything* (asterisk at the end)
• *anything (asterisk at the start)
• anything. (dot at the end)
• anything.1 (dot near digit)
• (anything (unbalanced braces anywhere)
• anything-v1.2 (God knows why. For some reason anything-1.2 works well)

I came across this when I tried to set the value of key_prefix for Redis.

[sergeyklay]

Possible related #288 (comment)

I'll try to sort out

[sergeyklay]

This is resolved in develop branch. Thank you for the report, and for helping us make django-environ better. And I am sorry about the delay.