LAWS.pbkdf2_length: law of bend-osdev-crypto@0.1.0.0
Import: import bend-osdev-crypto@0.1.0.0/LAWS.bend as LAWS
Lines 494-508 of bend-osdev-crypto@0.1.0.0/LAWS.bend: https://jend.leeeet.dev/read.txt?path=bend-osdev-crypto@0.1.0.0/LAWS.bend&start_line=494&end_line=508

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

# PBKDF2 over any MAC (pbkdf2.bend), for every MAC, password, salt,
# iteration count and length: a derivation that succeeds gives exactly the
# length asked for (the KDF interface's length law); the unchecked stream
# has that length, and a shorter stream is a prefix of a longer (the KDF
# interface's prefix law)
law pbkdf2_length:
  for ~K: Data
  for ~key: B.Octets -> Result<&2, &2, Cr.CrError, K>
  for ~compute: K -> B.Octets -> B.Octets
  for ~hlen: Nat
  for +p: B.Octets
  for +salt: B.Octets
  for +c: U32
  for +n: Nat
  {Result.map(&2, &2, Cr.CrError, B.Octets, Nat, o => B.Octets.len(o), Pb.CrPbkdf2.pbkdf2(~K, ~key, ~compute, ~hlen, p, salt, c, n)) == Result.map(&2, &2, Cr.CrError, B.Octets, Nat, o => n, Pb.CrPbkdf2.pbkdf2(~K, ~key, ~compute, ~hlen, p, salt, c, n)) : Result<&2, &2, Cr.CrError, Nat>}

Uses (12):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_lt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Result
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Result.map
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_eq
  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=Octets.len
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-crypto@0.1.0.0/PROOF.bend&name=pbkdf2_checked_len
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-crypto@0.1.0.0/crypto.bend&name=CrError
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-crypto@0.1.0.0/pbkdf2.bend&name=CrPbkdf2.pbkdf2
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-crypto@0.1.0.0/pbkdf2.bend&name=cr.pbkdf2.fits