anil.recoil.org
The unpac monorepo manager self-hosting as a monorepo using unpac
Merge pull request #43 from mirage/fix-base64
Be more strict about padding
authored by
GitHub
6227924a
ca1db401
+17
-5
src/base64.ml
+17
-5
src/base64.ml
···
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can raise and avoid appearance of unknown exceptions like an ex-nihilo
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magic rabbit (or magic money?). *)
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exception Out_of_bounds
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exception Too_much_input
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let get_uint8 t off =
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if off < 0 || off >= String.length t then raise Out_of_bounds ;
···
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let n = (len // 4) * 4 in
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let n' = (n // 4) * 3 in
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let res = Bytes.create n' in
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let invalid_pad_overflow = pad in
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let get_uint8_or_padding =
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if pad then (fun t i -> if i >= len then raise Out_of_bounds ; get_uint8 t (off + i) )
···
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if i + 4 = n
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(* end of input in anyway *)
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then match pad with
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| 0 -> 0
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| 4 -> 3
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| 0 ->
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0
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| 4 ->
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(* assert (invalid_pad_overflow = false) ; *)
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(* [get_uint8] lies and if we get [4], that mean we got one or more (at
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most 4) padding character. In this situation, because we round length
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of [res] (see [n // 4]), we need to delete 3 bytes. *)
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| pad -> pad
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| pad ->
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pad
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else match pad with
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| 0 -> dec (j + 3) (i + 4)
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| 4 -> only_padding 3 (i + 4)
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| 4 ->
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(* assert (invalid_pad_overflow = false) ; *)
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only_padding 3 (i + 4)
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(* Same situation than above but we should get only more padding
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characters then. *)
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| pad -> only_padding pad (i + 4) end in
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| pad ->
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if invalid_pad_overflow = true then raise Too_much_input ;
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only_padding pad (i + 4) end in
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match dec 0 0 with
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| 0 -> Ok (Bytes.unsafe_to_string res, 0, n')
···
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| exception Not_found ->
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(* appear when one character of [input] ∉ [alphabet] and this character <> '=' *)
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error_msgf "Malformed input"
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| exception Too_much_input ->
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error_msgf "Too much input"
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let decode ?pad ?(alphabet = default_alphabet) ?off ?len input =
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match decode_sub ?pad alphabet ?off ?len input with
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-2
test/test.ml
+31
-2
test/test.ml
···
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2, 0, "", "BB";
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]
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let nocrypto_tests =
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[ "\x00\x5a\x6d\x39\x76", None
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; "\x5a\x6d\x39\x76", Some "\x66\x6f\x6f"
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; "\x5a\x6d\x39\x76\x76", None
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; "\x5a\x6d\x39\x76\x76\x76", None
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; "\x5a\x6d\x39\x76\x76\x76\x76", None
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; "\x5a\x6d\x39\x76\x00", None
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; "\x5a\x6d\x39\x76\x62\x77\x3d\x3d", Some "\x66\x6f\x6f\x6f"
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; "\x5a\x6d\x39\x76\x62\x77\x3d\x3d\x00", None
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; "\x5a\x6d\x39\x76\x62\x77\x3d\x3d\x00\x01", None
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; "\x5a\x6d\x39\x76\x62\x77\x3d\x3d\x00\x01\x02", None
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; "\x5a\x6d\x39\x76\x62\x77\x3d\x3d\x00\x01\x02\x03", None
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; "\x5a\x6d\x39\x76\x62\x32\x38\x3d", Some "\x66\x6f\x6f\x6f\x6f"
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; "\x5a\x6d\x39\x76\x62\x32\x39\x76", Some "\x66\x6f\x6f\x6f\x6f\x6f"
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; "YWE=", Some "aa"
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; "YWE==", None
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; "YWE===", None
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; "YWE=====", None
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; "YWE======", None ]
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let alphabet_size () =
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List.iter (fun (name,alphabet) ->
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Alcotest.(check int) (sprintf "Alphabet size %s = 64" name)
···
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let test_cfcs () =
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List.iter (fun (off, len, c,r) ->
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Alcotest.(check string) (sprintf "decode %s" r) c (Base64.decode_exn ~pad:false ~off ~len r);
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) cfcs_tests
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) cfcs_tests
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let test_nocrypto () =
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List.iter (fun (input, res) ->
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let res' = match Base64.decode ~pad:true input with
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| Ok v -> Some v
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| Error _ -> None in
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Alcotest.(check (option string)) (sprintf "decode %S" input) res' res ;
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) nocrypto_tests
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exception Malformed
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exception Wrong_padding
···
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; "RFC3548 test vectors", `Quick, test_rfc3548
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; "Hannes test vectors", `Quick, test_hannes
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; "Cfcs test vectors", `Quick, test_cfcs
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; "PHP test vectors", `Quick, test_php ]
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; "PHP test vectors", `Quick, test_php
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; "Nocrypto test vectors", `Quick, test_nocrypto ]
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let () =
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Alcotest.run "Base64" [