val encrypt :
  (#j:id) ->
  (#u:info j) ->
  (st:pne_state u) ->
  (#l:pne_plain_length) ->
  (n:pne_plain u l) ->
  // For confidentiality modeling, this function takes as inputs only the public
  // parts of the header.
  (s:sample) ->
  ST (pne_cipher l)
  (requires fun h0 ->
    invariant st h0 /\
    // cannot talk about freshness because it requires talking about the
    // table which is only available for safe id's
    (is_safe j ==> fresh_sample s st h0))
  (ensures fun h0 c h1 ->
    invariant st h1 /\
    B.modifies (footprint st) h0 h1 /\ (
    if is_safe j then
      exists (c': pne_cipherpad).
      table st h1 == Seq.snoc (table st h0) (Entry s #l n c') /\
      clip_cipherpad c' l == c
    else
      // Our input is: plain packet number, plain bits to be protected
      let pn, bits = PNEPlainPkg?.as_bytes u.plain j l n in
      let k = key st in
      // We output an encrypted packet number and protected bits
      c == encrypt_spec u.calg l pn bits s k))
val encrypt :
  (#j:id) ->
  (#u:info j) ->
  (st:pne_state u) ->
  (#l:pne_plain_length) ->
  (n:pne_plain u l) ->
  // For confidentiality modeling, this function takes as inputs only the public
  // parts of the header.
  (s:sample) ->
  ST (pne_cipher l)
  (requires fun h0 ->
    invariant st h0 /\
    // cannot talk about freshness because it requires talking about the
    // table which is only available for safe id's
    (is_safe j ==> fresh_sample s st h0))
  (ensures fun h0 c h1 ->
    invariant st h1 /\
    B.modifies (footprint st) h0 h1 /\ (
    if is_safe j then
      exists (c': pne_cipherpad).
      table st h1 == Seq.snoc (table st h0) (Entry s #l n c') /\
      clip_cipherpad c' l == c
    else
      // Our input is: plain packet number, plain bits to be protected
      let pn, bits = PNEPlainPkg?.as_bytes u.plain j l n in
      let k = key st in
      // We output an encrypted packet number and protected bits
      c == encrypt_spec u.calg l pn bits s k))
let encrypt #j #u st #l n s =
  let h0 = ST.get () in
  if is_safe j then
    let (| u, p |) = st <: model_state j in
    let log = !*p in
    assert (log == table st h0);
    let cipher: pne_cipherpad = random 4, random_bits () in
    p *= Seq.snoc log (Entry s #l n cipher);
    clip_cipherpad cipher l
  else
    let open QUIC.Spec.Lemmas in
    let pn, bits = PNEPlainPkg?.repr u.plain j l n in
    let k = snd (st <: unsafe_state j) in
    let alg = (fst (st <: unsafe_state j)).calg in
    encrypt_spec alg l pn bits s k
module Model.PNE

module B = LowStar.Buffer
module HS = FStar.HyperStack
module I = Model.Indexing
module U32 = FStar.UInt32
module U128 = FStar.UInt128
module Spec = Spec.Agile.Cipher

module ST = FStar.HyperStack.ST

#set-options "--fuel 0 --ifuel 0"

open FStar.HyperStack
open Mem
open Model.Helpers
open LowStar.BufferOps

let clip_cipherpad cp l =
  let cipher, bits = cp in
  Seq.slice cipher 0 l, bits

let log (#i: id) (u: info i): Type0 =
  Seq.seq (entry #i u)

let model_state j =
  u:info j & B.pointer (log #j u)

let unsafe_state j =
  // I don't understand why we have to go through model.indexing here when
  // the algorithm is readily available in the info
  info j & Spec.key (I.pne_id_ginfo j)

// why is this type parameterized over the info?
let pne_state #j u =
  if is_safe j then
    s:model_state j { dfst s == u }
  else
    s:unsafe_state j { fst s == u }

let table #j #u st h =
  let (| u, p |) = st <: model_state j in
  B.deref h p

let key #j #u st =
  snd (st <: unsafe_state j)

let footprint #i #u w =
  if is_safe i then
    B.loc_addr_of_buffer (dsnd (w <: model_state i))
  else
    B.loc_none

let invariant #i #u st h =
  if is_safe i then
    B.live h (dsnd (st <: model_state i))
  else
    True

let frame_invariant #_ #_ _ _ _ _ =
  ()

let frame_table #_ #_ _ _ _ _ =
  ()

let create j u =
  if is_safe j then
    let l: log #j u = Seq.empty #(entry #j u) in
    ((| u, B.malloc q_pne_region l 1ul |) <: model_state j)
  else
    (u, random (Spec.key_length u.calg)) <: unsafe_state j

let coerce j u k =
  (u, k) <: unsafe_state j

let quic_coerce j u ts =
  let k =
    (QUIC.Spec.derive_secret u.halg ts
        QUIC.Spec.label_hp (key_len u)) in
  coerce j u k

let random_bits ():
  HyperStack.ST.ST bits
    (requires fun h0 -> True)
    (ensures fun h0 _ h1 -> h0 == h1)
=
  let r = random 1 in
  LowParse.BitFields.get_bitfield #8 (UInt8.v (Lib.RawIntTypes.u8_to_UInt8 (Seq.index r 0))) 0 5
/
Spec.Agile.Cipher.fsti.checked QUIC.Spec.Lemmas.fst.checked QUIC.Spec.fsti.checked prims.fst.checked Model.Indexing.fsti.checked Model.Helpers.fsti.checked Mem.fst.checked LowStar.BufferOps.fst.checked LowStar.Buffer.fst.checked LowParse.BitFields.fsti.checked Lib.RawIntTypes.fsti.checked FStar.UInt8.fsti.checked FStar.UInt32.fsti.checked FStar.UInt128.fsti.checked FStar.Seq.fst.checked FStar.Pervasives.Native.fst.checked FStar.Pervasives.fsti.checked FStar.HyperStack.ST.fsti.checked FStar.HyperStack.fst.checked
Model.PNE.fst
st: Model.PNE.pne_state u405 -> n: Model.PNE.pne_plain u405 l -> s: Model.PNE.sample
  -> FStar.HyperStack.ST.ST (Model.PNE.pne_cipher l)
Model.PNE.id Model.PNE.info Model.PNE.pne_state Model.PNE.pne_plain_length Model.PNE.pne_plain Model.PNE.sample Model.PNE.is_safe LowStar.Buffer.pointer Model.PNE.log Model.PNE.clip_cipherpad Model.PNE.pne_cipher Prims.unit LowStar.BufferOps.op_Star_Equals LowStar.Buffer.trivial_preorder FStar.Seq.Properties.snoc Model.PNE.entry Model.PNE.Entry Model.PNE.pne_cipherpad FStar.Pervasives.Native.Mktuple2 Model.Helpers.lbytes Model.PNE.bits Model.PNE.random_bits Model.Helpers.random Prims._assert Prims.eq2 FStar.Seq.Base.seq Model.PNE.table LowStar.BufferOps.op_Bang_Star Model.PNE.model_state Prims.bool Model.PNE.length_bits Model.PNE.encrypt_spec Model.PNE.alg Model.PNE.__proj__Mkinfo'__item__calg FStar.Pervasives.Native.fst Spec.Agile.Cipher.key Model.Indexing.pne_id_ginfo Model.PNE.unsafe_state FStar.Pervasives.Native.snd FStar.Pervasives.Native.tuple2 Model.PNE.__proj__PNEPlainPkg__item__as_bytes Model.PNE.__proj__Mkinfo'__item__plain Model.PNE.__proj__PNEPlainPkg__item__repr FStar.Monotonic.HyperStack.mem FStar.HyperStack.ST.get
let encrypt #j #u st #l n s =
  
let h0 = ST.get () in
if is_safe j
then
  let (| u , p |) = st <: model_state j in
  let log = !*p in
  assert (log == table st h0);
  let cipher:pne_cipherpad = random 4, random_bits () in
  p *= Seq.snoc log (Entry s #l n cipher);
  clip_cipherpad cipher l
else
  let open QUIC.Spec.Lemmas in
  let pn, bits = PNEPlainPkg?.repr u.plain j l n in
  let k = snd (st <: unsafe_state j) in
  let alg = (fst (st <: unsafe_state j)).calg in
  encrypt_spec alg l pn bits s k