PROOF.pbkdf2_out_len: def of bend-osdev-crypto@0.1.0.0
Import: import bend-osdev-crypto@0.1.0.0/PROOF.bend as PROOF
Lines 573-586 of bend-osdev-crypto@0.1.0.0/PROOF.bend: https://jend.leeeet.dev/read.txt?path=bend-osdev-crypto@0.1.0.0/PROOF.bend&start_line=573&end_line=586

import Base
import bend-osdev-bytes@0.1.0.0/bytes.bend as B
import bend-osdev-crypto@0.1.0.0/pbkdf2.bend as Pb

# PBKDF2: the output generator gives n bytes, whatever the MAC (induction
# on n), and its first n bytes are the same whatever comes after
def pbkdf2_out_len(~K: Data, ~compute: K -> B.Octets -> B.Octets, n: Nat, cur: List<&2, U32>, +k: K, +salt: B.Octets, +c: Nat, +i: U32) -> {B.len(Pb.cr.pbkdf2.out(~K, ~compute, n, cur, k, salt, c, i)) == n : Nat}:
  match n:
    case 0n:
      {==}
    case 1n+p:
      match cur:
        case Con{h, t}:
          %pbkdf2_out_len(~K, ~compute, p, t, k, salt, c, i) : {B.len(Pb.cr.pbkdf2.out(~K, ~compute, 1n+p, Con{h, t}, k, salt, c, i)) == 1n+_ : Nat}
          {==}
        case Nil{}:
          %pbkdf2_out_len(~K, ~compute, p, Pb.cr.pbkdf2.tail(Pb.cr.pbkdf2.block(~K, ~compute, k, salt, c, U32.add(i, 1))), k, salt, c, U32.add(i, 1)) : {B.len(Pb.cr.pbkdf2.out(~K, ~compute, 1n+p, Nil{}, k, salt, c, i)) == 1n+_ : Nat}
          {==}

Uses (9):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.add
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-bytes@0.1.1.0/bytes.bend&name=Octets
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-bytes@0.1.1.0/bytes.bend&name=len
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-crypto@0.1.0.0/pbkdf2.bend&name=cr.pbkdf2.block
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-crypto@0.1.0.0/pbkdf2.bend&name=cr.pbkdf2.out
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-crypto@0.1.0.0/pbkdf2.bend&name=cr.pbkdf2.tail