def hash_len

bend-collections-laws-crypto@1.0.0.0 · proofs/crypto/argon2/password.bend:54

import Base
import bend-collections-laws-crypto@1.0.0.0/proofs/lib/logic.bend as L
import bend-collections-laws-crypto@1.0.0.0/src/crypto/blake/blake2b/sized.bend as H

54def hash_len(+nn: Nat, +bs: List<&2, U32>, +h: {Nat.is_le(nn, 64n) == True{} : Bool}) -> {len(H.hash(nn, bs)) == nn : Nat}:
55  +c = H.chain(nn, H.pack(bs), List.length(&2, U32, bs))
56  len_take(H.chain_bytes(c), nn, L.subst(Nat, z => {Nat.is_le(nn, z) == True{} : Bool}, 64n, len(H.chain_bytes(c)), Equal.sym(Nat, len(H.chain_bytes(c)), 64n, chain_len(c)), h))