A Captcha Alternative, based on Winograd Schemas. python winograd.py for a demo.
Question and answer generator written by Richard Ye, winolib wrapper and web integration written by The Dod.
This wrapper uses winograd.py to generate a challenge and verify a user's answer to such a challenge in a way that is practical for stateless web applications.
Each challenge has a token that can only be used once (to avoid replay and brute-force attacks),
but since a replay can also happen by accident (reload, back button, etc.), there's a distinct failure mode
for an "attack or honest mistake" where winolib returns None (as opposed to the False it returns when the user fails the captcha test).
When None is returned, best is to fail (e.g. redisplays the form) without displaying a [confusing and untrue] "captcha failed" error.
>>> from WinoCaptcha import winolib
>>> winolib.get_question()
{'token': '51bee4c7XLP0eZjFBiMOjAq8xjPp714Wk7oZ520DrM458Si62go',
'question': 'Despite the fact that they usually come pretty close to each other, Dawn won against Melissa because she had such a good start. Who had a good start?'}
>>> winolib.check_answer('51bee4c7XLP0eZjFBiMOjAq8xjPp714Wk7oZ520DrM458Si62go','dawn') # right answer
True
>>> `winolib.check_answer('51bee4c7XLP0eZjFBiMOjAq8xjPp714Wk7oZ520DrM458Si62go','dawn')` # replay attempt
'None'
>>> winolib.get_question()
{'token': '51bee51eFgISvqyS0SycT0lp9UWAZAeJkHe5Oif8xR2jWZJLXw',
'question': "Erica tried to get a coffee with Andrea, but she wasn't available. Who was not available?"}
>>> winolib.check_answer('51bee51eFgISvqyS0SycT0lp9UWAZAeJkHe5Oif8xR2jWZJLXw','bla') # wrong answer
False
The MIT License (MIT)
Copyright (c) 2013 Richard Ye and The Dod.
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