reject noncanonical CTAP2 CBOR encodings

This commit is contained in:
Reynir Björnsson 2021-10-08 18:49:18 +02:00
parent cb8a3bbb41
commit 9e8f765703
5 changed files with 889 additions and 19 deletions

View file

@ -6,10 +6,11 @@ module SE = EndianString.BigEndian_unsafe
exception Error of string exception Error of string
let (@@) f x = f x exception Noncanonical of string
let (|>) x f = f x
let list_iteri f l = let i = ref 0 in List.iter (fun x -> f !i x; incr i) l
let fail fmt = ksprintf (fun s -> raise (Error s)) fmt let fail fmt = ksprintf (fun s -> raise (Error s)) fmt
let noncanonical fmt = ksprintf (fun s -> raise (Noncanonical s))
("noncanonical CTAP2 CBOR: " ^^ fmt)
module Encode = struct module Encode = struct
@ -115,16 +116,22 @@ module Simple = struct
let two_min_int32 = 2 * Int32.to_int Int32.min_int let two_min_int32 = 2 * Int32.to_int Int32.min_int
let extract_number byte1 r = let extract_number byte1 r =
let guard_min min n = if n < min
then noncanonical "non-compact number encoding: %d < %d" n min
else n
in
match get_additional byte1 with match get_additional byte1 with
| n when n < 24 -> n | n when n < 24 -> n
| 24 -> get_byte r | 24 -> guard_min 24 @@ get_byte r
| 25 -> get_n r 2 SE.get_uint16 | 25 -> guard_min 256 @@ get_n r 2 SE.get_uint16
| 26 -> | 26 ->
let n = Int32.to_int @@ get_n r 4 SE.get_int32 in let n = guard_min (256*256) @@ Int32.to_int @@ get_n r 4 SE.get_int32 in
if n < 0 then n - two_min_int32 else n if n < 0 then n - two_min_int32 else n
| 27 -> | 27 ->
let n = get_n r 8 SE.get_int64 in let n = get_n r 8 SE.get_int64 in
if n > int64_max_int || n < 0L then fail "extract_number: %Lu" n; if n > int64_max_int || n < 0L then fail "extract_number: %Lu" n;
if Int64.compare n 0x1_0000_0000L < 0
then noncanonical "non-compact number encoding: %Ld < %Ld" n 0x1_0000_0000L;
Int64.to_int n Int64.to_int n
| n -> fail "bad additional %d" n | n -> fail "bad additional %d" n
@ -140,23 +147,57 @@ module Simple = struct
in in
if half land 0x8000 = 0 then value else ~-. value if half land 0x8000 = 0 then value else ~-. value
let monotonic s s' =
let major_typ s = int_of_char s.[0] lsr 5 in
let get_number s = match get_additional (int_of_char s.[0]) with
| n when n < 24 -> 1, Int64.of_int n
| 24 -> 2, Int64.of_int (int_of_char s.[1])
| 25 -> 3, Int64.of_int (SE.get_uint16 s 1)
| 26 -> 5, Int64.logand 0xFFFFFFFFL (Int64.of_int32 (SE.get_int32 s 1))
| 27 -> 9, SE.get_int64 s 1
| _ -> assert false
in
major_typ s < major_typ s' ||
major_typ s = major_typ s' &&
let off, n = get_number s and _, n' = get_number s' in
Int64.unsigned_compare n n' < 0 ||
Int64.unsigned_compare n n' = 0 &&
begin
List.mem (major_typ s) [2; 3; 4; 5; 7 (* XXX: unsure about 7 *)] &&
let len = Int64.to_int n in
String.sub s off len < String.sub s' off len
end
exception Break exception Break
let extract_list byte1 r f = let extract_list byte1 r f =
if is_indefinite byte1 then if is_indefinite byte1 then
let l = ref [] in noncanonical "indefinite length array or map"
try while true do l := f r :: !l done; assert false with Break -> List.rev !l
else else
let n = extract_number byte1 r in Array.to_list @@ Array.init n (fun _ -> f r) let n = extract_number byte1 r in Array.to_list @@ Array.init n (fun _ -> f r)
let rec extract_pair r = let rec extract_pair ((s, i) as r) =
let start = !i in
let a = extract r in let a = extract r in
let finish = !i in
let raw = String.sub s start (finish - start) in
let b = try extract r with Break -> fail "extract_pair: unexpected break" in let b = try extract r with Break -> fail "extract_pair: unexpected break" in
a,b raw, (a,b)
and extract_string byte1 r f = and extract_map byte1 r =
let kvs = extract_list byte1 r extract_pair in
let _, kvs =
List.fold_right (fun (curr, kv) (next, acc) ->
match next with
| None -> (Some curr, kv :: acc)
| Some next ->
if not (monotonic curr next) then noncanonical "unsorted map";
(Some curr, kv :: acc))
kvs (None, [])
in
kvs
and extract_string byte1 r =
if is_indefinite byte1 then if is_indefinite byte1 then
let b = Buffer.create 10 in noncanonical "indefinite length string"
try while true do Buffer.add_string b (f @@ extract r) done; assert false with Break -> Buffer.contents b
else else
let n = extract_number byte1 r in get_s r n let n = extract_number byte1 r in get_s r n
and extract r = and extract r =
@ -164,11 +205,11 @@ module Simple = struct
match byte1 lsr 5 with match byte1 lsr 5 with
| 0 -> `Int (extract_number byte1 r) | 0 -> `Int (extract_number byte1 r)
| 1 -> `Int (-1 - extract_number byte1 r) | 1 -> `Int (-1 - extract_number byte1 r)
| 2 -> `Bytes (extract_string byte1 r (function `Bytes s -> s | _ -> fail "extract: not a bytes chunk")) | 2 -> `Bytes (extract_string byte1 r)
| 3 -> `Text (extract_string byte1 r (function `Text s -> s | _ -> fail "extract: not a text chunk")) | 3 -> `Text (extract_string byte1 r)
| 4 -> `Array (extract_list byte1 r extract) | 4 -> `Array (extract_list byte1 r extract)
| 5 -> `Map (extract_list byte1 r extract_pair) | 5 -> `Map (extract_map byte1 r)
| 6 -> let _tag = extract_number byte1 r in extract r | 6 -> noncanonical "tagged value"
| 7 -> | 7 ->
begin match get_additional byte1 with begin match get_additional byte1 with
| n when n < 20 -> `Simple n | n when n < 20 -> `Simple n
@ -215,11 +256,11 @@ module Simple = struct
| `Text s -> bprintf b "\"%s\"" s | `Text s -> bprintf b "\"%s\"" s
| `Array l -> | `Array l ->
put "["; put "[";
l |> list_iteri (fun i x -> if i <> 0 then put ", "; write x); l |> List.iteri (fun i x -> if i <> 0 then put ", "; write x);
put "]" put "]"
| `Map m -> | `Map m ->
put "{"; put "{";
m |> list_iteri (fun i (k,v) -> if i <> 0 then put ", "; write k; put ": "; write v); m |> List.iteri (fun i (k,v) -> if i <> 0 then put ", "; write k; put ": "; write v);
put "}" put "}"
in in
write item; write item;

View file

@ -2,6 +2,8 @@
exception Error of string exception Error of string
exception Noncanonical of string
module Simple : sig module Simple : sig
type t = type t =

720
cbor/appendix_a.json Normal file
View file

@ -0,0 +1,720 @@
[
{
"cbor": "AA==",
"hex": "00",
"roundtrip": true,
"decoded": 0
},
{
"cbor": "AQ==",
"hex": "01",
"roundtrip": true,
"decoded": 1
},
{
"cbor": "Cg==",
"hex": "0a",
"roundtrip": true,
"decoded": 10
},
{
"cbor": "Fw==",
"hex": "17",
"roundtrip": true,
"decoded": 23
},
{
"cbor": "GBg=",
"hex": "1818",
"roundtrip": true,
"decoded": 24
},
{
"cbor": "GBk=",
"hex": "1819",
"roundtrip": true,
"decoded": 25
},
{
"cbor": "GGQ=",
"hex": "1864",
"roundtrip": true,
"decoded": 100
},
{
"cbor": "GQPo",
"hex": "1903e8",
"roundtrip": true,
"decoded": 1000
},
{
"cbor": "GgAPQkA=",
"hex": "1a000f4240",
"roundtrip": true,
"decoded": 1000000
},
{
"cbor": "GwAAAOjUpRAA",
"hex": "1b000000e8d4a51000",
"roundtrip": true,
"decoded": 1000000000000
},
{
"cbor": "G///////////",
"hex": "1bffffffffffffffff",
"roundtrip": true,
"decoded": 18446744073709551615
},
{
"cbor": "wkkBAAAAAAAAAAA=",
"hex": "c249010000000000000000",
"roundtrip": true,
"noncanonical": true,
"decoded": 18446744073709551616
},
{
"cbor": "O///////////",
"hex": "3bffffffffffffffff",
"roundtrip": true,
"decoded": -18446744073709551616
},
{
"cbor": "w0kBAAAAAAAAAAA=",
"hex": "c349010000000000000000",
"roundtrip": true,
"noncanonical": true,
"decoded": -18446744073709551617
},
{
"cbor": "IA==",
"hex": "20",
"roundtrip": true,
"decoded": -1
},
{
"cbor": "KQ==",
"hex": "29",
"roundtrip": true,
"decoded": -10
},
{
"cbor": "OGM=",
"hex": "3863",
"roundtrip": true,
"decoded": -100
},
{
"cbor": "OQPn",
"hex": "3903e7",
"roundtrip": true,
"decoded": -1000
},
{
"cbor": "+QAA",
"hex": "f90000",
"roundtrip": true,
"decoded": 0.0
},
{
"cbor": "+YAA",
"hex": "f98000",
"roundtrip": true,
"decoded": -0.0
},
{
"cbor": "+TwA",
"hex": "f93c00",
"roundtrip": true,
"decoded": 1.0
},
{
"cbor": "+z/xmZmZmZma",
"hex": "fb3ff199999999999a",
"roundtrip": true,
"decoded": 1.1
},
{
"cbor": "+T4A",
"hex": "f93e00",
"roundtrip": true,
"decoded": 1.5
},
{
"cbor": "+Xv/",
"hex": "f97bff",
"roundtrip": true,
"decoded": 65504.0
},
{
"cbor": "+kfDUAA=",
"hex": "fa47c35000",
"roundtrip": true,
"decoded": 100000.0
},
{
"cbor": "+n9///8=",
"hex": "fa7f7fffff",
"roundtrip": true,
"decoded": 3.4028234663852886e+38
},
{
"cbor": "+3435DyIAHWc",
"hex": "fb7e37e43c8800759c",
"roundtrip": true,
"decoded": 1.0e+300
},
{
"cbor": "+QAB",
"hex": "f90001",
"roundtrip": true,
"decoded": 5.960464477539063e-08
},
{
"cbor": "+QQA",
"hex": "f90400",
"roundtrip": true,
"decoded": 6.103515625e-05
},
{
"cbor": "+cQA",
"hex": "f9c400",
"roundtrip": true,
"decoded": -4.0
},
{
"cbor": "+8AQZmZmZmZm",
"hex": "fbc010666666666666",
"roundtrip": true,
"decoded": -4.1
},
{
"cbor": "+XwA",
"hex": "f97c00",
"roundtrip": true,
"diagnostic": "Infinity"
},
{
"cbor": "+X4A",
"hex": "f97e00",
"roundtrip": true,
"diagnostic": "NaN"
},
{
"cbor": "+fwA",
"hex": "f9fc00",
"roundtrip": true,
"diagnostic": "-Infinity"
},
{
"cbor": "+n+AAAA=",
"hex": "fa7f800000",
"roundtrip": false,
"diagnostic": "Infinity"
},
{
"cbor": "+n/AAAA=",
"hex": "fa7fc00000",
"roundtrip": false,
"diagnostic": "NaN"
},
{
"cbor": "+v+AAAA=",
"hex": "faff800000",
"roundtrip": false,
"diagnostic": "-Infinity"
},
{
"cbor": "+3/wAAAAAAAA",
"hex": "fb7ff0000000000000",
"roundtrip": false,
"diagnostic": "Infinity"
},
{
"cbor": "+3/4AAAAAAAA",
"hex": "fb7ff8000000000000",
"roundtrip": false,
"diagnostic": "NaN"
},
{
"cbor": "+//wAAAAAAAA",
"hex": "fbfff0000000000000",
"roundtrip": false,
"diagnostic": "-Infinity"
},
{
"cbor": "9A==",
"hex": "f4",
"roundtrip": true,
"decoded": false
},
{
"cbor": "9Q==",
"hex": "f5",
"roundtrip": true,
"decoded": true
},
{
"cbor": "9g==",
"hex": "f6",
"roundtrip": true,
"decoded": null
},
{
"cbor": "9w==",
"hex": "f7",
"roundtrip": true,
"diagnostic": "undefined"
},
{
"cbor": "8A==",
"hex": "f0",
"roundtrip": true,
"diagnostic": "simple(16)"
},
{
"cbor": "+Bg=",
"hex": "f818",
"roundtrip": true,
"diagnostic": "simple(24)"
},
{
"cbor": "+P8=",
"hex": "f8ff",
"roundtrip": true,
"diagnostic": "simple(255)"
},
{
"cbor": "wHQyMDEzLTAzLTIxVDIwOjA0OjAwWg==",
"hex": "c074323031332d30332d32315432303a30343a30305a",
"roundtrip": true,
"noncanonical": true,
"diagnostic": "0(\"2013-03-21T20:04:00Z\")"
},
{
"cbor": "wRpRS2ew",
"hex": "c11a514b67b0",
"roundtrip": true,
"noncanonical": true,
"diagnostic": "1(1363896240)"
},
{
"cbor": "wftB1FLZ7CAAAA==",
"hex": "c1fb41d452d9ec200000",
"roundtrip": true,
"noncanonical": true,
"diagnostic": "1(1363896240.5)"
},
{
"cbor": "10QBAgME",
"hex": "d74401020304",
"roundtrip": true,
"noncanonical": true,
"diagnostic": "23(h'01020304')"
},
{
"cbor": "2BhFZElFVEY=",
"hex": "d818456449455446",
"roundtrip": true,
"noncanonical": true,
"diagnostic": "24(h'6449455446')"
},
{
"cbor": "2CB2aHR0cDovL3d3dy5leGFtcGxlLmNvbQ==",
"hex": "d82076687474703a2f2f7777772e6578616d706c652e636f6d",
"roundtrip": true,
"noncanonical": true,
"diagnostic": "32(\"http://www.example.com\")"
},
{
"cbor": "QA==",
"hex": "40",
"roundtrip": true,
"diagnostic": "h''"
},
{
"cbor": "RAECAwQ=",
"hex": "4401020304",
"roundtrip": true,
"diagnostic": "h'01020304'"
},
{
"cbor": "YA==",
"hex": "60",
"roundtrip": true,
"decoded": ""
},
{
"cbor": "YWE=",
"hex": "6161",
"roundtrip": true,
"decoded": "a"
},
{
"cbor": "ZElFVEY=",
"hex": "6449455446",
"roundtrip": true,
"decoded": "IETF"
},
{
"cbor": "YiJc",
"hex": "62225c",
"roundtrip": true,
"decoded": "\"\\"
},
{
"cbor": "YsO8",
"hex": "62c3bc",
"roundtrip": true,
"decoded": "ü"
},
{
"cbor": "Y+awtA==",
"hex": "63e6b0b4",
"roundtrip": true,
"decoded": "水"
},
{
"cbor": "ZPCQhZE=",
"hex": "64f0908591",
"roundtrip": true,
"decoded": "𐅑"
},
{
"cbor": "gA==",
"hex": "80",
"roundtrip": true,
"decoded": [
]
},
{
"cbor": "gwECAw==",
"hex": "83010203",
"roundtrip": true,
"decoded": [
1,
2,
3
]
},
{
"cbor": "gwGCAgOCBAU=",
"hex": "8301820203820405",
"roundtrip": true,
"decoded": [
1,
[
2,
3
],
[
4,
5
]
]
},
{
"cbor": "mBkBAgMEBQYHCAkKCwwNDg8QERITFBUWFxgYGBk=",
"hex": "98190102030405060708090a0b0c0d0e0f101112131415161718181819",
"roundtrip": true,
"decoded": [
1,
2,
3,
4,
5,
6,
7,
8,
9,
10,
11,
12,
13,
14,
15,
16,
17,
18,
19,
20,
21,
22,
23,
24,
25
]
},
{
"cbor": "oA==",
"hex": "a0",
"roundtrip": true,
"decoded": {
}
},
{
"cbor": "ogECAwQ=",
"hex": "a201020304",
"roundtrip": true,
"diagnostic": "{1: 2, 3: 4}"
},
{
"cbor": "omFhAWFiggID",
"hex": "a26161016162820203",
"roundtrip": true,
"decoded": {
"a": 1,
"b": [
2,
3
]
}
},
{
"cbor": "gmFhoWFiYWM=",
"hex": "826161a161626163",
"roundtrip": true,
"decoded": [
"a",
{
"b": "c"
}
]
},
{
"cbor": "pWFhYUFhYmFCYWNhQ2FkYURhZWFF",
"hex": "a56161614161626142616361436164614461656145",
"roundtrip": true,
"decoded": {
"a": "A",
"b": "B",
"c": "C",
"d": "D",
"e": "E"
}
},
{
"cbor": "X0IBAkMDBAX/",
"hex": "5f42010243030405ff",
"roundtrip": false,
"noncanonical": true,
"diagnostic": "(_ h'0102', h'030405')"
},
{
"cbor": "f2VzdHJlYWRtaW5n/w==",
"hex": "7f657374726561646d696e67ff",
"roundtrip": false,
"noncanonical": true,
"decoded": "streaming"
},
{
"cbor": "n/8=",
"hex": "9fff",
"roundtrip": false,
"noncanonical": true,
"decoded": [
]
},
{
"cbor": "nwGCAgOfBAX//w==",
"hex": "9f018202039f0405ffff",
"roundtrip": false,
"noncanonical": true,
"decoded": [
1,
[
2,
3
],
[
4,
5
]
]
},
{
"cbor": "nwGCAgOCBAX/",
"hex": "9f01820203820405ff",
"roundtrip": false,
"noncanonical": true,
"decoded": [
1,
[
2,
3
],
[
4,
5
]
]
},
{
"cbor": "gwGCAgOfBAX/",
"hex": "83018202039f0405ff",
"roundtrip": false,
"noncanonical": true,
"decoded": [
1,
[
2,
3
],
[
4,
5
]
]
},
{
"cbor": "gwGfAgP/ggQF",
"hex": "83019f0203ff820405",
"roundtrip": false,
"noncanonical": true,
"decoded": [
1,
[
2,
3
],
[
4,
5
]
]
},
{
"cbor": "nwECAwQFBgcICQoLDA0ODxAREhMUFRYXGBgYGf8=",
"hex": "9f0102030405060708090a0b0c0d0e0f101112131415161718181819ff",
"roundtrip": false,
"noncanonical": true,
"decoded": [
1,
2,
3,
4,
5,
6,
7,
8,
9,
10,
11,
12,
13,
14,
15,
16,
17,
18,
19,
20,
21,
22,
23,
24,
25
]
},
{
"cbor": "v2FhAWFinwID//8=",
"hex": "bf61610161629f0203ffff",
"roundtrip": false,
"noncanonical": true,
"decoded": {
"a": 1,
"b": [
2,
3
]
}
},
{
"cbor": "gmFhv2FiYWP/",
"hex": "826161bf61626163ff",
"roundtrip": false,
"noncanonical": true,
"decoded": [
"a",
{
"b": "c"
}
]
},
{
"cbor": "v2NGdW71Y0FtdCH/",
"hex": "bf6346756ef563416d7421ff",
"roundtrip": false,
"noncanonical": true,
"decoded": {
"Fun": true,
"Amt": -2
}
},
{
"cbor": "pGJya/VidXD1ZHBsYXT0aWNsaWVudFBpbvU=",
"hex": "a462726bf5627570f564706c6174f469636c69656e7450696ef5",
"roundtrip": false,
"decoded": {
"rk": true,
"up": true,
"plat": false,
"clientPin": true
}
},
{
"cbor": "pGRwbGF09GJya/VpY2xpZW50UGlu9WJ1cPU=",
"hex": "a464706c6174f462726bf569636c69656e7450696ef5627570f5",
"roundtrip": false,
"noncanonical": true,
"decoded": {
"up": true,
"clientPin": true,
"rk": true,
"plat": false
}
},
{
"cbor": "GAE=",
"hex": "1801",
"roundtrip": false,
"noncanonical": true,
"decoded": 1
},
{
"cbor": "GQAB",
"hex": "190001",
"roundtrip": false,
"noncanonical": true,
"decoded": 1
},
{
"cbor": "GgAAAAE=",
"hex": "1a00000001",
"roundtrip": false,
"noncanonical": true,
"decoded": 1
},
{
"cbor": "GwAAAAAAAAAB",
"hex": "1b0000000000000001",
"roundtrip": false,
"noncanonical": true,
"decoded": 1
},
{
"cbor": "OAA=",
"hex": "3800",
"roundtrip": false,
"noncanonical": true,
"decoded": -1
},
{
"cbor": "OwAAAAAAAQRp",
"hex": "3B0000000000010469",
"roundtrip": false,
"noncanonical": true,
"decoded": -66666
}
]

View file

@ -1,5 +1,16 @@
(library (library
(name cbor) (name cbor)
(public_name webauthn.cbor) (public_name webauthn.cbor)
(modules CBOR)
(wrapped false) (wrapped false)
(libraries ocplib-endian)) (libraries ocplib-endian))
(executable
(name test)
(modules test)
(libraries webauthn.cbor yojson))
(rule
(alias runtest)
(deps test.exe appendix_a.json)
(action (run ./test.exe appendix_a.json)))

96
cbor/test.ml Normal file
View file

@ -0,0 +1,96 @@
type result = Decoded of Yojson.Basic.t | Diagnostic of string
type test = {
cbor : string;
result : result;
noncanonical : bool;
}
let (@@) f x = f x
let (|>) x f = f x
let eprintfn fmt = Printf.ksprintf prerr_endline fmt
let fail fmt = Printf.ksprintf failwith fmt
let of_hex s =
assert (String.length s mod 2 = 0);
let n = String.length s / 2 in
let r = Bytes.create n in
for i = 0 to pred n do
Bytes.set r i @@ Char.chr @@ int_of_string ("0x" ^ String.sub s (i*2) 2)
done;
Bytes.to_string r
let read file =
let open Yojson.Basic in
Yojson.Safe.from_file file (* large ints *)
|> Yojson.Safe.to_basic
|> Util.to_list
|> List.map begin function
| `Assoc a ->
let cbor = of_hex @@ Util.to_string @@ List.assoc "hex" a in
let result =
try
Diagnostic (Util.to_string @@ List.assoc "diagnostic" a)
with Not_found ->
Decoded (List.assoc "decoded" a)
in
let noncanonical = try
Util.to_bool @@ List.assoc "noncanonical" a
with Not_found -> false
in
{ cbor; result; noncanonical }
| _ -> assert false
end
let rec json_of_cbor : CBOR.Simple.t -> Yojson.Basic.t = function
| (`Null | `Bool _ | `Int _ | `Float _ as x) -> x
| `Undefined | `Simple _ -> `Null
| `Bytes x -> `String x
| `Text x -> `String x
| `Array x -> `List (List.map json_of_cbor x)
| `Map x -> `Assoc (List.map (fun (k,v) ->
match k with
| `Text s -> s, json_of_cbor v
| _ -> fail "json_of_cbor: expected string key") x)
let () =
match List.tl @@ Array.to_list Sys.argv with
| file::[] ->
eprintfn "I: running tests from %s" file;
let tests = read file in
eprintfn "I: total tests = %d" (List.length tests);
let ok = ref 0 in
let failed = ref 0 in
let ignored = ref 0 in
let nr = ref (-1) in
tests |> List.iter begin fun test ->
try
incr nr;
if test.noncanonical then
try let cbor = CBOR.Simple.decode test.cbor in
fail "expected reject noncanonical CBOR, got %s"
(CBOR.Simple.to_diagnostic cbor)
with CBOR.Noncanonical _ -> incr ok
else
let cbor = CBOR.Simple.decode test.cbor in
let diag = CBOR.Simple.to_diagnostic cbor in
let () = match test.result with
| Diagnostic s ->
if s <> diag then fail "expected %s, got %s" s diag
| Decoded json ->
let json' = json_of_cbor cbor in
if json <> json' then fail "expected %s, got %s, aka %s"
(Yojson.Basic.to_string json) (Yojson.Basic.to_string json') diag
in
incr ok
with exn ->
let ignore = List.mem !nr [10; 12] in
eprintfn "%s test %d: %s"
(if ignore then "W: ignoring" else "E:") !nr (match exn with Failure s -> s | _ -> Printexc.to_string exn);
incr (if ignore then ignored else failed)
end;
eprintfn "I: finished. tests ok = %d failed = %d ignored = %d" !ok !failed !ignored;
exit (if !failed = 0 then 0 else 1)
| _ ->
eprintfn "E: no test file given";
exit 2