49 lines
1.4 KiB
Python
49 lines
1.4 KiB
Python
from os import urandom
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from itertools import count
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from base64 import b64encode, b64decode
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from hashlib import sha256
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class pow_base:
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@property
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def base(self):
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return self._base
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@property
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def difficulty(self):
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return self._difficulty
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def __init__(self, difficulty, base=None):
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self._difficulty = difficulty
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self._base = urandom(self._bits//8) if not base else base
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self._target = 2 ** (self._bits - difficulty)
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def work(self, max_attempts=0, start=0, step=1):
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cycles = count(start, step) if max_attempts == 0 else range(start, max_attempts, step)
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for nonce in cycles:
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if self.verify(nonce):
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return nonce
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raise RuntimeError('Failed to find a nonce in {} iterations!'.format(max_attempts))
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def verify(self, nonce):
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hexresult = self._hexdigest(self._base + str(nonce).encode('ascii'))
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return int(hexresult, 16) < self._target
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def export(self):
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return str(self.difficulty) + ':' + b64encode(self.base).decode()
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@classmethod
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def load(cls, export):
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difficulty, base = export.split(':', 1)
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return cls(int(difficulty), b64decode(base.encode('ascii')))
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class pow_hashlib_base(pow_base):
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def _hexdigest(self, data):
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return self._hasher(data).hexdigest()
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class pow256(pow_hashlib_base):
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_bits = 256
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_hasher = sha256
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