use correct denomination hash (with age-mask and cipher)

src/crypto.ml

@@ -209,13 +209,12 @@ module RsaPublicKey = struct
   let of_octets = Binary_format_rsa.pub_of_octets
   let to_b32 t = B32.encode (to_octets t)
 
-  let jsont =
-    let of_b32 s =
-      let* s = B32.decode s in
-      let+ v = of_octets s in
-      v
-    in
-    Jsont.of_of_string ~kind:"RsaPublicKey" of_b32 ~enc:to_b32
+  let of_b32 s =
+    let* s = B32.decode s in
+    let+ v = of_octets s in
+    v
+
+  let jsont = Jsont.of_of_string ~kind:"RsaPublicKey" of_b32 ~enc:to_b32
 
   let caqti : t Caqti_type.t =
     Caqti_type.custom
@@ -257,6 +256,63 @@ module RsaSignature = struct
     Jsont.of_of_string ~kind:"RsaSignature" of_b32 ~enc:to_b32
 end
 
+module DenominationHash : sig
+  type t
+
+  val bin : t Bin.t
+  val caqti : t Caqti_type.t
+  val jsont : t Jsont.t
+  val hash_of_rsa : RsaPublicKey.t -> t
+  val of_octets : string -> t
+  val to_octets : t -> string
+  val of_b32 : B32.t -> (t, string) result
+  val to_b32 : t -> B32.t
+end = struct
+  open Digestif
+
+  type t = SHA512.t
+
+  type cipher =
+    | RSA
+    | CS [@ocaml.warning "-37"]
+
+  (* = GNUNET_CRYPTO_BSA_(RSA|CS) *)
+  let cipher_to_int32 = function RSA -> 1_l | CS -> 2_l
+
+  let hash_of_rsa pub =
+    let age_mask = 0_l in
+    let cipher = cipher_to_int32 RSA in
+    let pub = RsaPublicKey.to_octets pub in
+    let len = String.length pub in
+    let buf = Bytes.create (4 + 4 + len) in
+    Bytes.set_int32_be buf 0 age_mask;
+    Bytes.set_int32_be buf 4 cipher;
+    Bytes.blit_string pub 0 buf 8 len;
+    SHA512.digest_bytes buf
+
+  let of_octets s =
+    match SHA512.of_raw_string_opt s with
+    | None -> Fmt.failwith "H64.of_octets failure"
+    | Some t -> t
+
+  let to_octets = SHA512.to_raw_string
+  let of_b32 s = Result.map of_octets (B32.decode s)
+  let to_b32 t = B32.encode (to_octets t)
+
+  let bin =
+    let open Bin in
+    map (bytes 64) of_octets to_octets
+
+  let caqti =
+    let open Caqti_type in
+    custom
+      ~encode:(fun v -> Ok (to_octets v))
+      ~decode:(fun v -> Ok (of_octets v))
+      octets
+
+  let jsont = Jsont.of_of_string ~kind:"DenominationHash" of_b32 ~enc:to_b32
+end
+
 (* some type aliases, just for prettier .mli *)
 type eddsa_priv = EddsaPrivateKey.t
 type eddsa_pub = EddsaPublicKey.t
@@ -264,4 +320,4 @@ type eddsa_sig = EddsaSignature.t
 type rsa_priv = RsaPrivateKey.t
 type rsa_pub = RsaPublicKey.t
 type rsa_sig = RsaSignature.t
-type denom_hash = Hash.DenominationHash.t
+type denom_hash = DenominationHash.t