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Data_encoding: early detection of some oversized data

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This commit is contained in:
Grégoire Henry 2018-06-08 14:58:44 +02:00 committed by Benjamin Canou
parent a5cec8fca0
commit e3272bebc5
2 changed files with 40 additions and 34 deletions
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68
src/lib_data_encoding/binary_stream_reader.ml
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@ -218,11 +218,11 @@ let rec skip n state k =
(** Main recursive reading function, in continuation passing style. *)
let rec read_rec
: type next ret.
next Encoding.t -> state -> ((next * state) -> ret status) -> ret status
= fun e state k ->
bool -> next Encoding.t -> state -> ((next * state) -> ret status) -> ret status
= fun whole e state k ->
let resume buffer =
let stream = Binary_stream.push buffer state.stream in
try read_rec e { state with stream }k
try read_rec whole e { state with stream }k
with Read_error err -> Error err in
let open Encoding in
assert (Encoding.classify e <> `Variable || state.remaining_bytes <> None) ;
@ -251,7 +251,7 @@ let rec read_rec
let size = remaining_bytes state in
Atom.fixed_length_string size resume state k
| Padded (e, n) ->
read_rec e state @@ fun (v, state) ->
read_rec false e state @@ fun (v, state) ->
skip n state @@ (fun state -> k (v, state))
| RangedInt { minimum ; maximum } ->
Atom.ranged_int ~minimum ~maximum resume state k
@ -263,49 +263,49 @@ let rec read_rec
read_list e state @@ fun (l, state) ->
k (Array.of_list l, state)
| List e -> read_list e state k
| (Obj (Req { encoding = e })) -> read_rec e state k
| (Obj (Dft { encoding = e })) -> read_rec e state k
| (Obj (Req { encoding = e })) -> read_rec whole e state k
| (Obj (Dft { encoding = e })) -> read_rec whole e state k
| (Obj (Opt { kind = `Dynamic ; encoding = e })) ->
Atom.bool resume state @@ fun (present, state) ->
if not present then
k (None, state)
else
read_rec e state @@ fun (v, state) ->
read_rec whole e state @@ fun (v, state) ->
k (Some v, state)
| (Obj (Opt { kind = `Variable ; encoding = e })) ->
let size = remaining_bytes state in
if size = 0 then
k (None, state)
else
read_rec e state @@ fun (v, state) ->
read_rec whole e state @@ fun (v, state) ->
k (Some v, state)
| Objs { kind = `Fixed sz ; left ; right } ->
ignore (check_remaining_bytes state sz : int option) ;
ignore (check_allowed_bytes state sz : int option) ;
read_rec left state @@ fun (left, state) ->
read_rec right state @@ fun (right, state) ->
read_rec false left state @@ fun (left, state) ->
read_rec whole right state @@ fun (right, state) ->
k ((left, right), state)
| Objs { kind = `Dynamic ; left ; right } ->
read_rec left state @@ fun (left, state) ->
read_rec right state @@ fun (right, state) ->
read_rec false left state @@ fun (left, state) ->
read_rec whole right state @@ fun (right, state) ->
k ((left, right), state)
| Objs { kind = `Variable ; left ; right } ->
read_variable_pair left right state k
| Tup e -> read_rec e state k
| Tup e -> read_rec whole e state k
| Tups { kind = `Fixed sz ; left ; right } ->
ignore (check_remaining_bytes state sz : int option) ;
ignore (check_allowed_bytes state sz : int option) ;
read_rec left state @@ fun (left, state) ->
read_rec right state @@ fun (right, state) ->
read_rec false left state @@ fun (left, state) ->
read_rec whole right state @@ fun (right, state) ->
k ((left, right), state)
| Tups { kind = `Dynamic ; left ; right } ->
read_rec left state @@ fun (left, state) ->
read_rec right state @@ fun (right, state) ->
read_rec false left state @@ fun (left, state) ->
read_rec whole right state @@ fun (right, state) ->
k ((left, right), state)
| Tups { kind = `Variable ; left ; right } ->
read_variable_pair left right state k
| Conv { inj ; encoding } ->
read_rec encoding state @@ fun (v, state) ->
read_rec whole encoding state @@ fun (v, state) ->
k (inj v, state)
| Union { tag_size ; cases } -> begin
Atom.tag tag_size resume state @@ fun (ctag, state) ->
@ -318,7 +318,7 @@ let rec read_rec
with
| exception Not_found -> Error (Unexpected_tag ctag)
| Case { encoding ; inj } ->
read_rec encoding state @@ fun (v, state) ->
read_rec whole encoding state @@ fun (v, state) ->
k (inj v, state)
end
| Dynamic_size { kind ; encoding = e } ->
@ -326,7 +326,7 @@ let rec read_rec
let remaining = check_remaining_bytes state sz in
let state = { state with remaining_bytes = Some sz } in
ignore (check_allowed_bytes state sz : int option) ;
read_rec e state @@ fun (v, state) ->
read_rec true e state @@ fun (v, state) ->
if state.remaining_bytes <> Some 0 then
Error Extra_bytes
else
@ -337,8 +337,14 @@ let rec read_rec
match state.allowed_bytes with
| None -> limit
| Some current_limit -> min current_limit limit in
begin
match state.remaining_bytes with
| Some remaining when whole && limit < remaining ->
raise Size_limit_exceeded
| _ -> ()
end ;
let state = { state with allowed_bytes = Some limit } in
read_rec e state @@ fun (v, state) ->
read_rec whole e state @@ fun (v, state) ->
let allowed_bytes =
match old_allowed_bytes with
| None -> None
@ -350,10 +356,10 @@ let rec read_rec
let read = limit - remaining in
Some (old_limit - read) in
k (v, { state with allowed_bytes })
| Describe { encoding = e } -> read_rec e state k
| Splitted { encoding = e } -> read_rec e state k
| Mu { fix } -> read_rec (fix e) state k
| Delayed f -> read_rec (f ()) state k
| Describe { encoding = e } -> read_rec whole e state k
| Splitted { encoding = e } -> read_rec whole e state k
| Mu { fix } -> read_rec whole (fix e) state k
| Delayed f -> read_rec whole (f ()) state k
and remaining_bytes { remaining_bytes } =
match remaining_bytes with
@ -371,18 +377,18 @@ and read_variable_pair
let size = remaining_bytes state in
match Encoding.classify e1, Encoding.classify e2 with
| (`Dynamic | `Fixed _), `Variable ->
read_rec e1 state @@ fun (left, state) ->
read_rec e2 state @@ fun (right, state) ->
read_rec false e1 state @@ fun (left, state) ->
read_rec true e2 state @@ fun (right, state) ->
k ((left, right), state)
| `Variable, `Fixed n ->
if n > size then
Error Not_enough_data
else
let state = { state with remaining_bytes = Some (size - n) } in
read_rec e1 state @@ fun (left, state) ->
read_rec true e1 state @@ fun (left, state) ->
assert (state.remaining_bytes = Some 0) ;
let state = { state with remaining_bytes = Some n } in
read_rec e2 state @@ fun (right, state) ->
read_rec true e2 state @@ fun (right, state) ->
assert (state.remaining_bytes = Some 0) ;
k ((left, right), state)
| _ -> assert false (* Should be rejected by [Encoding.Kind.combine] *)
@ -396,12 +402,12 @@ and read_list
if size = 0 then
k (List.rev acc, state)
else
read_rec e state @@ fun (v, state) ->
read_rec false e state @@ fun (v, state) ->
loop state (v :: acc) in
loop state []
let read_rec e state k =
try read_rec e state k
try read_rec false e state k
with Read_error err -> Error err

6
src/lib_data_encoding/test/read_failure.ml
View File

@ -161,11 +161,11 @@ let test_bounded_string_list =
test "a" ~total:0 ~elements:0 [""] 4 4 @
test "b1" ~total:3 ~elements:4 [""] 4 4 @
test "b2" ~total:4 ~elements:3 [""] 4 4 @
test "c1" ~total:19 ~elements:4 ["";"";"";"";""] 20 4 @
test "c1" ~total:19 ~elements:4 ["";"";"";"";""] 4 4 @
test "c2" ~total:20 ~elements:3 ["";"";"";"";""] 4 4 @
test "d1" ~total:20 ~elements:5 ["";"";"";"";"a"] 24 4 @
test "d1" ~total:20 ~elements:5 ["";"";"";"";"a"] 4 4 @
test "d2" ~total:21 ~elements:4 ["";"";"";"";"a"] 24 24 @
test "e" ~total:30 ~elements:10 ["ab";"c";"def";"gh";"ijk"] 32 4
test "e" ~total:30 ~elements:10 ["ab";"c";"def";"gh";"ijk"] 4 4
let tests =
all_ranged_int 100 400 @