dune: add mte library; + wip key jsont

src/types.ml

@@ -112,20 +112,39 @@ module Amount = struct
 end
 
 module Eddsa = struct
+  (* TODO test *)
   (* EdDSA and ECDHE public keys always point on Curve25519
      and represented  using the standard 256 bits Ed25519 compact format,
      converted to Crockford Base32. *)
-  type pub = string
-  type priv = string
+  type pub = Mirage_crypto_ec.Ed25519.pub
 
+  let pub_of_string s =
+    let open Mirage_crypto_ec in
+    match Base_32.decode s with
+    | Error _ as err -> err
+    | Ok octets -> (
+        match Ed25519.pub_of_octets octets with
+        | Error e -> Fmt.error "%a" pp_error e
+        | Ok pub -> Ok pub)
+
+  let pub_to_string pub =
+    pub |> Mirage_crypto_ec.Ed25519.pub_to_octets |> Base_32.encode
+
+  (*type priv = string*)
   (* EdDSA signatures are transmitted as 64-bytes base32
    binary-encoded objects with just the R and S values (base32_ binary-only). *)
-  type signature = string
+  (*type signature = string*)
 end
 
 module Rsa = struct
   (* RSA public key converted to Crockford Base32. *)
-  type pub = string
+  type pub = Mirage_crypto_pk.Rsa.pub
+
+  (* TODO
+     how to read/write pub rsa key
+     what format is used? *)
+  let pub_of_string _s = assert false
+  let pub_to_string _pub = assert false
 end
 
 module Hash_code = struct