From 8dd5973c386929668736d36a9ef9c2ace3921615 Mon Sep 17 00:00:00 2001
From: swrup <swrup@protonmail.com>
Date: Mon, 6 Oct 2025 19:51:56 +0200
Subject: [PATCH] + Rsa_denomination_key

---
 src/json.ml  | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 src/types.ml | 27 +++++++++++++++++++++++----
 test/test.ml |  5 +++++
 3 files changed, 74 insertions(+), 4 deletions(-)

diff --git a/src/json.ml b/src/json.ml
index 876d5f5c..219329e4 100644
--- a/src/json.ml
+++ b/src/json.ml
@@ -84,3 +84,49 @@ module Eddsa = struct
     let enc = Jsont.Base.enc pub_to_string in
     Jsont.Base.string (Jsont.Base.map ~kind:"EddsaPublicKey" ~dec ~enc ())
 end
+
+module Rsa_denomination_key = struct
+  open Rsa_denomination_key
+
+  let jsont =
+    let make age_mask rsa_pub = { age_mask; rsa_pub } in
+    let age_mask v = v.age_mask in
+    let rsa_pub v = v.rsa_pub in
+    Jsont.Object.map ~kind:"RsaDenominationKey" make
+    |> Jsont.Object.mem "age_mask" Jsont.int ~enc:age_mask
+    |> Jsont.Object.mem "rsa_pub" Jsont.string ~enc:rsa_pub
+    |> Jsont.Object.finish
+end
+
+module CS_denomination_key = struct
+  open CS_denomination_key
+
+  let jsont =
+    let make age_mask cs_pub = { age_mask; cs_pub } in
+    let age_mask v = v.age_mask in
+    let cs_pub v = v.cs_pub in
+    Jsont.Object.map ~kind:"CSDenominationKey" make
+    |> Jsont.Object.mem "age_mask" Jsont.int ~enc:age_mask
+    |> Jsont.Object.mem "cs_pub" Jsont.string ~enc:cs_pub
+    |> Jsont.Object.finish
+end
+
+module Denomination_key = struct
+  open Denomination_key
+
+  let rsa v = Rsa v
+  let cs v = CS v
+
+  let jsont =
+    let open Jsont.Object in
+    let rsa = Case.map "RSA" Rsa_denomination_key.jsont ~dec:rsa in
+    let cs = Case.map "CS" CS_denomination_key.jsont ~dec:cs in
+    let enc_case = function
+      | Rsa v -> Case.value rsa v
+      | CS v -> Case.value cs v
+    in
+    let cases = Case.[ make rsa; make cs ] in
+    map ~kind:"DenominationKey" Fun.id
+    |> case_mem "cipher" Jsont.string ~enc:Fun.id ~enc_case cases
+    |> finish
+end
diff --git a/src/types.ml b/src/types.ml
index e85ce833..1774509e 100644
--- a/src/types.ml
+++ b/src/types.ml
@@ -130,19 +130,17 @@ module Eddsa = struct
   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*)
 end
 
 module Rsa = struct
+  (* TODO
+     GNUNET_CRYPTO custom encode/decode *)
   (* RSA public key converted to Crockford Base32. *)
   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
@@ -151,3 +149,24 @@ module Hash_code = struct
   (* 32-byte value representing a point on Curve25519. *)
   type cs25519Point = string
 end
+
+module Rsa_denomination_key = struct
+  type t = {
+      age_mask: int
+    ; rsa_pub: string (* Rsa.pub *)
+  }
+end
+
+module CS_denomination_key = struct
+  (* Clause Schnorr *)
+  type t = {
+      age_mask: int
+    ; cs_pub: string
+  }
+end
+
+module Denomination_key = struct
+  type t =
+    | Rsa of Rsa_denomination_key.t
+    | CS of CS_denomination_key.t
+end
diff --git a/test/test.ml b/test/test.ml
index 3f0f835f..2f33d2f3 100644
--- a/test/test.ml
+++ b/test/test.ml
@@ -17,6 +17,11 @@ let () =
   check Timestamp.jsont {|{"t_s": "never"}|};
   check_bad Timestamp.jsont {|{"t_s": "123456780"}|};
   check_bad Timestamp.jsont {|{"t_s": "agagou"}|};
+
+  check Denomination_key.jsont
+    {|{"cipher": "RSA", "age_mask": 18, "rsa_pub": "agagouh"}|};
+  check Denomination_key.jsont
+    {|{"cipher": "CS", "age_mask": 18, "cs_pub": "ouhagag"}|};
   ()
 
 let () =