From 0a24b41d70710c606f3075111006b3ecda90cc70 Mon Sep 17 00:00:00 2001
From: swrup <swrup@protonmail.com>
Date: Fri, 17 Oct 2025 22:04:35 +0200
Subject: [PATCH] implement hash

  TODO good handling of 0-terminated C-string
---
 src/binary_formats.ml | 39 ++++++++++++++++++++++++++++++++++++---
 src/dune              |  1 +
 src/management.ml     | 12 ++----------
 src/types.ml          |  4 ++--
 test/test.ml          |  4 ++++
 5 files changed, 45 insertions(+), 15 deletions(-)

diff --git a/src/binary_formats.ml b/src/binary_formats.ml
index 9a17ee57..43c1b409 100644
--- a/src/binary_formats.ml
+++ b/src/binary_formats.ml
@@ -26,6 +26,15 @@
      - outdated doc(?)
    - some missing struct documentation *)
 
+(* TODO hash and C(ancer)-terminated strings
+
+   - "A JSON object is canonicalized by converting it to an ASCII byte array
+      with the algorithm specified in RFC 8785. The resulting bytes are
+      terminated with a single 0-byte and then hashed with SHA512."
+   - from the code it looks like its the same for all stringy-strings
+     !! that are not raw bytes data
+ *)
+
 module UTIL = struct
   let int32_size = 4
   let int64_size = 8
@@ -71,9 +80,21 @@ module UTIL = struct
       record (fun v -> { v }) |+ field (bytes 64) (fun t -> t.v) |> sealr
   end
 
-  module MK_HASH_32 () = struct
+  module MK_HASH_32 () : sig
+    type t = private { hash: string }
+
+    val of_string : string -> t
+    val bin : t Bin.t
+  end = struct
     type t = { hash: string }
 
+    let of_string s =
+      match String.length s = 32 with
+      | false -> Fmt.failwith "SHA256 failure: data is not 32 bytes"
+      | true ->
+          let hash = Digestif.SHA256.(to_raw_string (digest_string s)) in
+          { hash }
+
     let bin =
       let open Bin in
       record (fun hash -> { hash })
@@ -81,9 +102,21 @@ module UTIL = struct
       |> sealr
   end
 
-  module MK_HASH_64 () = struct
+  module MK_HASH_64 () : sig
+    type t = private { hash: string }
+
+    val f : string -> t
+    val bin : t Bin.t
+  end = struct
     type t = { hash: string }
 
+    let f s =
+      match String.length s = 64 with
+      | false -> Fmt.failwith "SHA512 failure: data is not 64bytes"
+      | true ->
+          let hash = Digestif.SHA512.(to_raw_string (digest_string s)) in
+          { hash }
+
     let bin =
       let open Bin in
       record (fun hash -> { hash })
@@ -183,7 +216,7 @@ module EncryptedLinkSecretP = MK_64 ()
 module DenominationBlindingKeyP = MK_32 ()
 
 (* GNUNET_CRYPTO format *)
-module RsaPublicKey = struct
+module GNUNET_RsaPublicKey = struct
   (* libgnuutil format:
      https://docs.gnunet.org/doxygen/d9/dbe/structGNUNET__CRYPTO__RsaPublicKeyHeaderP.html
      https://docs.gnunet.org/doxygen/d6/d70/group__libgnunetutil.html#ga9c99a81e8cd649c1c925d23211a0738f
diff --git a/src/dune b/src/dune
index 168b23c8..8126b6ec 100644
--- a/src/dune
+++ b/src/dune
@@ -18,6 +18,7 @@
   angstrom
   zarith ;
   mirage-crypto
+  digestif
   duration
   vif
   fmt
diff --git a/src/management.ml b/src/management.ml
index 6fbfc9ee..2d30f027 100644
--- a/src/management.ml
+++ b/src/management.ml
@@ -28,16 +28,8 @@ let mk_future_denom denom_secmod_sign_f
   in
   let denom_secmod_sig =
     let open Binary_formats in
-    let h_denom_pub =
-      (* TODO hash *)
-      let hash = pub |> Types.RsaPublicKey.to_b32 in
-      DenominationHash.{ hash }
-    in
-    let h_section_name =
-      (* TODO hash *)
-      let hash = section_name in
-      HashCode.{ hash }
-    in
+    let h_denom_pub = DenominationHash.f (RsaPublicKey.to_octets pub) in
+    let h_section_name = HashCode.f section_name in
     let anchor_time =
       TimeAbsoluteNBO.{ v= Util.ptime_to_int64_us stamp_start }
     in
diff --git a/src/types.ml b/src/types.ml
index 73c500dd..8b97da6c 100644
--- a/src/types.ml
+++ b/src/types.ml
@@ -134,7 +134,7 @@ module RsaPublicKey = struct
   type t = Mirage_crypto_pk.Rsa.pub
 
   let to_octets ({ n; e } : Mirage_crypto_pk.Rsa.pub) =
-    let open Binary_formats.RsaPublicKey in
+    let open Binary_formats.GNUNET_RsaPublicKey in
     let header = { n_len= Z.size n; e_len= Z.size e } in
     let v = { header; n; e } in
     let s = Bin.to_string bin v in
@@ -143,7 +143,7 @@ module RsaPublicKey = struct
   let of_b32 s =
     let open Syntax in
     let* s = B32.decode s in
-    let* v = Util.bin_of_string Binary_formats.RsaPublicKey.bin s in
+    let* v = Util.bin_of_string Binary_formats.GNUNET_RsaPublicKey.bin s in
     let+ v = Mirage_crypto_pk.Rsa.pub ~n:v.n ~e:v.e |> unwrap_err_msg in
     v
 
diff --git a/test/test.ml b/test/test.ml
index 8d4bd866..26a811ac 100644
--- a/test/test.ml
+++ b/test/test.ml
@@ -75,6 +75,8 @@ let () =
   check_bad ", \"foo\"";
   ()
 
+(*
+
 let () =
   let open Binary_formats.WithdrawConfirmationPS in
   let str64 = String.init 64 (fun i -> Char.unsafe_chr (i + 1)) in
@@ -88,3 +90,5 @@ let () =
   Printf.printf "%s" raw_str;
   *)
   ()
+
+  *)