23 lines
No EOL
797 B
Text
23 lines
No EOL
797 B
Text
import "../../../utils/pack/bool/pack128" as pack128
|
|
import "../../../utils/pack/bool/unpack128" as unpack128
|
|
import "./512bitPadded" as sha256
|
|
|
|
// A function that takes an array of 4 field elements as inputs, unpacks each of them to 128
|
|
// bits (big endian), concatenates them and applies sha256.
|
|
// It then returns an array of two field elements, each representing 128 bits of the result.
|
|
def main(field[4] preimage) -> (field[2]):
|
|
|
|
bool[128] a = unpack128(preimage[0])
|
|
bool[128] b = unpack128(preimage[1])
|
|
bool[128] c = unpack128(preimage[2])
|
|
bool[128] d = unpack128(preimage[3])
|
|
|
|
bool[256] lhs = [...a, ...b]
|
|
bool[256] rhs = [...c, ...d]
|
|
|
|
bool[256] r = sha256(lhs, rhs)
|
|
|
|
field res0 = pack128(r[..128])
|
|
field res1 = pack128(r[128..])
|
|
|
|
return [res0, res1] |