def kb_ctr_len

bend-osdev-crypto@0.1.0.0 · PROOF.bend:647

import Base
import bend-osdev-bytes@0.1.0.0/bytes.bend as B
import bend-osdev-crypto@0.1.0.0/kbkdf.bend as Kb

647def kb_ctr_len(~K: Data, ~compute: K -> B.Octets -> B.Octets, n: Nat, cur: List<&2, U32>, +k: K, +rlen: Nat, +fixed: B.Octets, +i: U32) -> {B.len(Kb.cr.kb.ctr(~K, ~compute, n, cur, k, rlen, fixed, i)) == n : Nat}:
648  match n:
649    case 0n:
650      {==}
651    case 1n+p:
652      match cur:
653        case Con{h, t}:
654          %kb_ctr_len(~K, ~compute, p, t, k, rlen, fixed, i) : {B.len(Kb.cr.kb.ctr(~K, ~compute, 1n+p, Con{h, t}, k, rlen, fixed, i)) == 1n+_ : Nat}
655          {==}
656        case Nil{}:
657          %kb_ctr_len(~K, ~compute, p, Kb.cr.kb.tail(B.Octets.to_list(compute(k, B.Octets.append(Kb.CrKbkdf.counter(rlen, U32.add(i, 1)), fixed)))), k, rlen, fixed, U32.add(i, 1)) : {B.len(Kb.cr.kb.ctr(~K, ~compute, 1n+p, Nil{}, k, rlen, fixed, i)) == 1n+_ : Nat}
658          {==}