src/binary_formats.ml

@@ -188,7 +188,9 @@ module UTIL = struct
 
     let hash s =
       match String.length s = 32 with
-      | false -> Fmt.failwith "SHA256 failure: data is not 32 bytes"
+      | false ->
+          Fmt.failwith "SHA256 failure: data is not 32 bytes, instead is %d"
+            (String.length s)
       | true -> hash s
   end
 
@@ -218,7 +220,7 @@ module UTIL = struct
     val bin : t Bin.t
     val hash : M.src -> t
   end = struct
-    include Hash_64
+    include HHH_64
 
     let hash src = hash (M.to_octets src)
   end
@@ -233,7 +235,7 @@ module UTIL = struct
     val bin : t Bin.t
     val hash : M.src -> t
   end = struct
-    include Hash_32
+    include HHH_32
 
     let hash src = hash (M.to_octets src)
   end

src/types.ml

@@ -84,13 +84,18 @@ end = struct
     (* mirage_crypto: "The result is the concatenation of r and s, as specified in RFC 8032." *)
     Mirage_crypto_ec.Ed25519.sign ~key s
 
-  let of_b32 s = B32.decode s
+  let check_size t =
+    match String.length t = 64 with
+    | false -> Error "EddsaSignature: invalid string length"
+    | true -> Ok ()
 
-  let to_b32 t =
+  let of_b32 s =
-    let s = B32.encode t in
+    let open Syntax in
-    assert (String.length s = 64);
+    let* t = B32.decode s in
-    s
+    let+ () = check_size t in
+    t
 
+  let to_b32 = B32.encode
   let jsont = Jsont.of_of_string ~kind:"EddsaSignature" of_b32 ~enc:to_b32
 end