21 lines
647 B
Python
21 lines
647 B
Python
from random import randint
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import hashlib, base64
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# FIXME hash can be reused
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def generate(key):
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'''
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Generate a simple CAPTCHA.
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It is based on a simple math expression which stops the simplest of bots.
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'''
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# The parameters are chosen such that they are simple to solve on paper.
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a = randint(1, 10)
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b = randint(1, 10)
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c = randint(10, 20)
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return f'{a} * {b} + {c} = ', _hash_answer(key, str(a * b + c))
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def verify(key, answer, hash):
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return _hash_answer(key, answer) == hash
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def _hash_answer(key, answer):
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return base64.b64encode(hashlib.sha256((key + answer).encode('utf-8')).digest()).decode('ascii')
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