From 1e964045026aec6222afc89a5e3bc817fa5ebcee Mon Sep 17 00:00:00 2001
From: Matt Bray <mattjbray@gmail.com>
Date: Thu, 24 Mar 2022 17:35:20 +0000
Subject: [PATCH] feat: raise Invalid_argument for bad hex values

---
 src/opentelemetry.ml | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/opentelemetry.ml b/src/opentelemetry.ml
index 0ce8abb2..60da40b7 100644
--- a/src/opentelemetry.ml
+++ b/src/opentelemetry.ml
@@ -152,9 +152,9 @@ module Util_ = struct
     let n_of_c = function
       | '0' .. '9' as c -> Char.code c - Char.code '0'
       | 'a' .. 'f' as c -> 10 + Char.code c - Char.code 'a'
-      | _ -> failwith "invalid hex char"
+      | _ -> raise (Invalid_argument "invalid hex char")
     in
-    assert (String.length s mod 2 = 0);
+    if (String.length s mod 2 <> 0) then raise (Invalid_argument "hex sequence must be of even length");
     let res = Bytes.make (String.length s / 2) '\x00' in
     for i=0 to String.length s/2-1 do
       let n1 = n_of_c (String.get s (2*i)) in
@@ -180,7 +180,7 @@ end = struct
   type t = bytes
   let to_bytes self = self
   let create () : t = Collector.rand_bytes_16()
-  let of_bytes b = assert(Bytes.length b=16); b
+  let of_bytes b = if Bytes.length b=16 then b else raise (Invalid_argument "trace IDs must be 16 bytes in length")
   let to_hex self = Util_.bytes_to_hex self
   let of_hex s = of_bytes (Util_.bytes_of_hex s)
 end
@@ -198,7 +198,7 @@ end = struct
   type t = bytes
   let to_bytes self = self
   let create () : t = Collector.rand_bytes_8()
-  let of_bytes b = assert(Bytes.length b=8); b
+  let of_bytes b = if Bytes.length b=8 then b else raise (Invalid_argument "span IDs must be 8 bytes in length")
   let to_hex self = Util_.bytes_to_hex self
   let of_hex s = of_bytes (Util_.bytes_of_hex s)
 end
@@ -620,7 +620,6 @@ module Trace_context = struct
       let consume expected ~offset ~or_ =
         let len = String.length expected in
         let* str, offset = blit ~offset ~len ~or_ in
-        (* Printf.printf "got %S\n%!" str; *)
         if str = expected then Ok offset else Error or_
       in
       let offset = 0 in
@@ -630,14 +629,14 @@ module Trace_context = struct
       let* trace_id =
         match Trace_id.of_hex trace_id with
         | trace_id -> Ok trace_id
-        | exception Failure _ -> Error "Expected hex-encoded trace-id"
+        | exception Invalid_argument _ -> Error "Expected hex-encoded trace-id"
       in
       let* offset = consume "-" ~offset ~or_:"Expected delimiter" in
       let* parent_id, offset = blit ~offset ~len:16 ~or_:"Expected 16-digit parent-id" in
       let* parent_id =
         match Span_id.of_hex parent_id with
         | parent_id -> Ok parent_id
-        | exception Failure _ -> Error "Expected hex-encoded parent-id"
+        | exception Invalid_argument _ -> Error "Expected hex-encoded parent-id"
       in
       let* offset = consume "-" ~offset ~or_:"Expected delimiter" in
       let* _flags, _offset = blit ~offset ~len:2 ~or_:"Expected 2-digit flags" in