add timestamps; use Ptime

src/secmod_keys.ml

@@ -7,6 +7,9 @@ type t = {
        + b32 *)
     string ->
     string;
+  stamp_start: Ptime.t;
+  stamp_expire: Ptime.t;
+  stamp_end: Ptime.t;
 }
 
 let make ~name =
@@ -16,8 +19,24 @@ let make ~name =
        - look if it exists
        - if not, create it (TOFU initialization scheme)
        - write it *)
+  (* TODO time
+     correctly set those: *)
+  let stamp_start = Ptime_clock.now () in
+  let stamp_expire =
+    match Ptime.add_span stamp_start Config.Exchange.signkey_legal_duration with
+    | None ->
+        Fmt.failwith "Ptime.add_span: result is not in the range [min;max]"
+    | Some v -> v
+  in
+  let stamp_end = stamp_expire in
   let priv, pub = Mirage_crypto_ec.Ed25519.generate () in
-  { pub; sign= Mirage_crypto_ec.Ed25519.sign ~key:priv }
+  {
+    pub;
+    sign= Mirage_crypto_ec.Ed25519.sign ~key:priv;
+    stamp_start;
+    stamp_expire;
+    stamp_end;
+  }
 
 let signkey_device = make ~name:"signkey"