use Jsont.Error for unsupported CS denom

better fix

.jjconflict-side-1/src/denomination.ml

@@ -0,0 +1,71 @@
+open Crypto
+
+type t = {
+  pub: RsaPublicKey.t;
+  priv: RsaPrivateKey.t;
+  section_name: string;
+  value: Amount.t;
+  stamp_start: Timestamp.t;
+  stamp_expire_withdraw: Timestamp.t;
+  stamp_expire_deposit: Timestamp.t;
+  stamp_expire_legal: Timestamp.t;
+  fee_withdraw: Amount.t;
+  fee_deposit: Amount.t;
+  fee_refresh: Amount.t;
+  fee_refund: Amount.t;
+  age_mask: int;
+  h_pub: Bin_type.DenominationHash.t;
+  master_sig: EddsaSignature.t option;
+}
+
+let make
+    ({
+       section_name;
+       value;
+       duration_withdraw;
+       duration_spend;
+       duration_legal;
+       fee_withdraw;
+       fee_deposit;
+       fee_refresh;
+       fee_refund;
+       cipher;
+       rsa_keysize;
+       age_restricted= _;
+     } :
+      Config.Coin.t) =
+  assert (cipher = `RSA);
+
+  let stamp_start = Ptime_clock.now () |> Option.some in
+  let stamp_expire_withdraw =
+    Timestamp.add_span_exn stamp_start (Some duration_withdraw)
+  in
+  let stamp_expire_deposit =
+    Timestamp.add_span_exn stamp_start (Some duration_spend)
+  in
+  let stamp_expire_legal =
+    Timestamp.add_span_exn stamp_start (Some duration_legal)
+  in
+
+  let open Mirage_crypto_pk.Rsa in
+  let priv = generate ~bits:rsa_keysize () in
+  let pub = pub_of_priv priv in
+  let h_pub = Bin_type.DenominationHash.hash (RsaPublicKey.to_octets pub) in
+  let master_sig = None in
+  {
+    pub;
+    priv;
+    section_name;
+    value;
+    stamp_start;
+    stamp_expire_withdraw;
+    stamp_expire_deposit;
+    stamp_expire_legal;
+    fee_withdraw;
+    fee_deposit;
+    fee_refresh;
+    fee_refund;
+    age_mask= 0;
+    h_pub;
+    master_sig;
+  }