19 lines
No EOL
760 B
Text
19 lines
No EOL
760 B
Text
import "../../utils/pack/u32/pack128" as pack128
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import "../../utils/pack/u32/unpack128" as unpack128
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import "./512bitPadded" as sha256
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// A function that takes an array of 4 field elements as inputs, unpacks each of them to 128
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// bits (big endian), concatenates them and applies sha256.
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// It then returns an array of two field elements, each representing 128 bits of the result.
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def main(field[4] preimage) -> (field[2]):
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u32[4] a_bits = unpack128(preimage[0])
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u32[4] b_bits = unpack128(preimage[1])
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u32[4] c_bits = unpack128(preimage[2])
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u32[4] d_bits = unpack128(preimage[3])
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u32[8] lhs = [...a_bits, ...b_bits]
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u32[8] rhs = [...c_bits, ...d_bits]
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u32[8] r = sha256(lhs, rhs)
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return [pack128(r[0..4]), pack128(r[4..8])] |