+ less failwith

src/data_file.ml

@@ -10,22 +10,15 @@ let read fname =
       let+ content = File.read fname in
       Some content
 
-let read_eddsa fname =
-  let+ content_opt = read fname in
-  Option.map EddsaPrivateKey.of_octets content_opt
-
-let read_rsa fname =
-  let+ content_opt = read fname in
-  Option.map RsaPrivateKey.of_octets content_opt
-
 let write_eddsa fname priv = EddsaPrivateKey.to_octets priv |> File.write fname
 let write_rsa fname priv = RsaPrivateKey.to_octets priv |> File.write fname
 
 let load_signkey conn fname =
-  let* opt = read_eddsa fname in
+  let* opt = read fname in
   match opt with
   | None -> Ok None
-  | Some priv -> (
+  | Some data -> (
+      let priv = EddsaPrivateKey.of_octets data in
       let pub = EddsaPrivateKey.pub_of_priv priv in
       let* opt = Pg.lookup_signing_key conn pub in
       match opt with
@@ -44,10 +37,15 @@ let load_signkey conn fname =
           Ok (Some v))
 
 let load_denom conn ~section_name fname =
-  let* opt = read_rsa fname in
+  let* opt = read fname in
   match opt with
   | None -> Ok None
-  | Some priv -> (
+  | Some data -> (
+      let* priv =
+        RsaPrivateKey.of_octets data |> function
+        | Error e -> Error (`Msg e)
+        | Ok v -> Ok v
+      in
       let pub = RsaPrivateKey.pub_of_priv priv in
       let h_pub = Bin_type.DenominationHash.hash (RsaPublicKey.to_octets pub) in
       let* opt = Pg.lookup_denomination_key conn h_pub in