split binary_types + clean up

src/crypto.ml

@@ -10,7 +10,11 @@ module EddsaPublicKey = struct
   type t = pub
 
   let to_octets t = pub_to_octets t
-  let of_octets t = pub_of_octets t
+  let of_octets t = pub_of_octets t |> Result.get_ok
+
+  let bin =
+    let open Bin in
+    map (bytes 32) of_octets to_octets
 
   let of_b32 s =
     let open Syntax in
@@ -23,14 +27,42 @@ module EddsaPublicKey = struct
   let jsont = Jsont.of_of_string ~kind:"EddsaPublicKey" of_b32 ~enc:to_b32
 end
 
+module EddsaPrivateKey = struct
+  (* EdDSA and ECDHE public keys always point on Curve25519
+     and represented  using the standard 256 bits Ed25519 compact format,
+     converted to Crockford Base32. *)
+  open Mirage_crypto_ec.Ed25519
+
+  type t = priv
+
+  let to_octets t = priv_to_octets t
+  let of_octets t = priv_of_octets t |> Result.get_ok
+
+  let bin =
+    let open Bin in
+    map (bytes 32) of_octets to_octets
+
+  let of_b32 s =
+    let open Syntax in
+    let* octets = B32.decode s in
+    match priv_of_octets octets with
+    | Error e -> Fmt.error "%a" Mirage_crypto_ec.pp_error e
+    | Ok priv -> Ok priv
+
+  let to_b32 t = B32.encode (to_octets t)
+  let jsont = Jsont.of_of_string ~kind:"EddsaPrivateKey" of_b32 ~enc:to_b32
+end
+
 module EddsaSignature : sig
   type t
 
-  val to_octets : t -> string
   val sign : key:Mirage_crypto_ec.Ed25519.priv -> string -> t
   val of_b32 : string -> (t, string) result
   val to_b32 : t -> string
+  val to_octets : t -> string
+  val of_octets : string -> t
   val jsont : t Jsont.t
+  val bin : t Bin.t
 end = struct
   (* TODO key format
      endianess issue? *)
@@ -42,6 +74,16 @@ end = struct
 
   let to_octets t = t
 
+  let of_octets v =
+    match String.length v = 64 with
+    | false ->
+        Fmt.failwith "EddsaSignature.of_octets failure: data is not 64 bytes."
+    | true -> v
+
+  let bin =
+    let open Bin in
+    map (bytes 64) of_octets to_octets
+
   let sign ~key s =
     (* mirage_crypto: "The result is the concatenation of r and s, as specified in RFC 8032." *)
     Mirage_crypto_ec.Ed25519.sign ~key s
@@ -96,6 +138,8 @@ module RsaPublicKey = struct
         | true -> Ok ()
       in
       fun s ->
+        Result.get_ok
+        @@
         let open Syntax in
         let len = String.length s in
         let* () = check (len >= 4) in
@@ -115,7 +159,7 @@ module RsaPublicKey = struct
   let of_b32 s =
     let open Syntax in
     let* s = B32.decode s in
-    let* v = of_octets s in
+    let v = of_octets s in
     let+ v = Rsa.pub ~n:v.n ~e:v.e |> unwrap_err_msg in
     v