59 行
1.7 KiB
Python
59 行
1.7 KiB
Python
# SPDX-FileCopyrightText: 2022 n9k [https://git.076.ne.jp/ninya9k]
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# SPDX-License-Identifier: AGPL-3.0-or-later
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import secrets
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from quart import current_app
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from anonstream.helpers.captcha import generate_captcha_digest, generate_captcha_image
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CONFIG = current_app.config
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CAPTCHAS = current_app.captchas
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CAPTCHA_FACTORY = current_app.captcha_factory
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CAPTCHA_SIGNER = current_app.captcha_signer
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def generate_random_captcha_solution():
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return ''.join(
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secrets.choice(CONFIG['CAPTCHA_ALPHABET'])
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for _ in range(CONFIG['CAPTCHA_LENGTH'])
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)
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def _get_random_cached_captcha_digest():
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chosen_index = secrets.randbelow(len(CAPTCHAS))
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for index, digest in enumerate(CAPTCHAS):
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if index == chosen_index:
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break
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return digest
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def get_random_captcha_digest():
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if len(CAPTCHAS) >= CONFIG['MAX_CAPTCHAS']:
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digest = _get_random_cached_captcha_digest()
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else:
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salt = secrets.token_bytes(16)
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solution = generate_random_captcha_solution()
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digest = generate_captcha_digest(CAPTCHA_SIGNER, salt, solution)
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CAPTCHAS[digest] = {'solution': solution}
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while len(CAPTCHAS) >= CONFIG['MAX_CAPTCHAS']:
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CAPTCHAS.popitem(last=False)
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return digest
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def get_random_captcha_digest_for(user):
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if user['verified']:
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return None
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else:
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return get_random_captcha_digest()
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def get_captcha_image(digest):
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try:
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captcha = CAPTCHAS[digest]
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except KeyError:
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return None
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else:
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if 'image' not in captcha:
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captcha['image'] = generate_captcha_image(
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factory=CAPTCHA_FACTORY,
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solution=captcha.pop('solution'),
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)
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return captcha['image']
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