def ladder

bend-collections-laws-crypto@1.0.0.0 · src/crypto/curve25519/x25519.bend:109

import Base

109# bits t = n - 1 down to 0
110def ladder(n: Nat, +c24: List<&2, U32>, +k: List<&2, U32>, +x1: List<&2, U32>, st: St) -> St:
111  match n:
112    case 0n:
113      st
114    case 1n+ +t:
115      ladder(t, c24, k, x1, rung(c24, x1, st, kbit(k, t)))