20 lines
481 B
Text
20 lines
481 B
Text
import "utils/pack/nonStrictUnpack256" as unpack256
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// Compress JubJub Curve Point to 256bit array using big endianness bit order
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// Python reference code from pycrypto:
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// def compress(self):
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// x = self.x.n
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// y = self.y.n
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// return int.to_bytes(y | ((x & 1) << 255), 32, "big")
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def main(field[2] pt) -> (bool[256]):
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field x = pt[0]
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field y = pt[1]
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bool[256] xBits = unpack256(x)
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bool[256] yBits = unpack256(y)
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bool sign = xBits[255]
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yBits[0] = sign
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return yBits
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