def finish

bend-collections-laws-crypto@1.0.0.0 · src/crypto/curve25519/x25519.bend:117

import Base
import bend-collections-laws-crypto@1.0.0.0/src/crypto/curve25519/field.bend as F

117# the final cswap, then x2 * z2^(p - 2), encoded
118def finish(st: St) -> List<&2, U32>:
119  match st:
120    case St{+x2, +z2, +x3, +z3, +swap}:
121      F.to_bytes(F.mul(F.select(swap, x2, x3), F.inv(F.select(swap, z2, z3))))