96 lines
3.0 KiB
Python
96 lines
3.0 KiB
Python
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# modes/hash_mode.py
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import math
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class HashMode:
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"""
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Учебная хэш-функция.
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Варианты:
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1 = sin-based
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2 = cos-based
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3 = xor-based
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"""
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def run(self, variant: str, message: str, salt: str = "", bytes: int = 16) -> str:
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if not (2 <= bytes <= 16):
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raise ValueError("Параметр bytes должен быть в диапазоне [2, 16]")
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data = (message + salt).encode("utf-8")
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if variant == "1":
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out = self._sin_hash(data)
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elif variant == "2":
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out = self._cos_hash(data)
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elif variant == "3":
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out = self._xor_hash(data)
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else:
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raise ValueError(f"Неизвестный вариант: {variant}")
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# Обрезаем до нужного числа байт
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truncated = self._truncate_bytes(out, bytes)
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return ''.join(f"{x:02x}" for x in truncated)
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# --- служебные ------------------------------------------------------
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def _truncate_bytes(self, out: bytearray, bytes: int) -> bytearray:
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if bytes >= len(out):
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return out
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truncated = out[:bytes]
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# примешиваем все отброшенные байты в оставшиеся
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for i, b in enumerate(out[bytes:], start=1):
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truncated[i % len(truncated)] ^= b
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return truncated
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# --- реализации ------------------------------------------------------
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def _sin_hash(self, data: bytes) -> bytearray:
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out = [0x55 ^ i for i in range(16)]
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if not data:
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return out
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angle = (2 * math.pi) / (len(out) * len(data))
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for i, b in enumerate(data, 1):
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for j in range(len(out)):
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val = int((math.sin(b + (i + j) * angle) + 1) * 127)
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out[j] ^= val & 0xFF
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return out
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def _cos_hash(self, data: bytes) -> bytearray:
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out = [0x77 ^ i for i in range(16)]
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if not data:
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return out
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angle = (2 * math.pi) / (len(out) * len(data))
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for i, b in enumerate(data, 1):
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for j in range(len(out)):
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val = int((math.cos(b + (i + j) * angle) + 1) * 127)
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out[j] ^= val & 0xFF
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return out
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def _mix_bits(self, mix: int) -> bytearray:
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# количество байт у числа = (битовая длина + 7) // 8
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count = (mix.bit_length() + 7) // 8
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for i in range(1, count):
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mix ^= (mix >> (8 * i))
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return mix
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def _xor_hash(self, data: bytes) -> bytearray:
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out = [0xAA ^ i for i in range(16)]
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if not data:
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return out
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phi = (1 + 5 ** 0.5) / 2 # золотое сечение
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for i, b in enumerate(data, 1):
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for j in range(16):
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mix = (b * (i + j + 1)) ^ int(phi * 1e6)
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mix = self._mix_bits(mix)
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out[j] ^= mix & 0xFF # только младший байт
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return out
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