From a5d321a00f0dc5ad3c336bcf2eb3cf768e1c8ea0 Mon Sep 17 00:00:00 2001
From: swrup <swrup@protonmail.com>
Date: Sat, 28 Feb 2026 01:27:25 +0100
Subject: [PATCH]

---
 src/crypto.ml       | 11 ++++++-----
 test/test_crypto.ml | 36 +++++++++++++++++++++++++++++++++---
 2 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/src/crypto.ml b/src/crypto.ml
index afc0276b..6e001920 100644
--- a/src/crypto.ml
+++ b/src/crypto.ml
@@ -282,13 +282,14 @@ end = struct
   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 pub_len = String.length pub in
-    let b = Bytes.create (4 + 4 + pub_len) in
+    let b = Bytes.create (4 + 4) in
     Bytes.set_int32_be b 0 age_mask;
     Bytes.set_int32_be b 4 cipher;
-    Bytes.blit_string pub 0 b (4 + 4) pub_len;
-    SHA512.(digest_bytes b)
+    let pub = RsaPublicKey.to_octets pub in
+    let ctx = SHA512.init () in
+    let ctx = SHA512.feed_bytes ctx b in
+    let ctx = SHA512.feed_string ctx pub in
+    SHA512.get ctx
 
   let of_octets s =
     match SHA512.of_raw_string_opt s with
diff --git a/test/test_crypto.ml b/test/test_crypto.ml
index 13cac4df..fba6e4ce 100644
--- a/test/test_crypto.ml
+++ b/test/test_crypto.ml
@@ -99,9 +99,8 @@ let () =
     "3KHKZJZ30ABB4E56MA2V0EQWGCWH0QQG9P2ZHYHR186C5HZXJMM4N9WXAQTKS94QSV9Y17GGNXN5MB1PZZFG7Q0FY88QPKKRG4MYCPSMTZK5W59R0MJVNJ4P4AQM96TDG5W7RV8GSNR1QQZ1GNHW3CX6D6ZRTMXB2NKB5SSYTDJS79F5ZFBRZ4HVED9JBBPWSR79KVV5QQ4APBGHBCKGMF9NJJS53A1BVYHDEVYAGFYF2SNEP827ZP50FKJ5GKGV8NQ15ESEZ69AT7GJG0T3TZVENY2YN9CVR98W3BKEZ53J7VTANARG8SJS8AMJQ7S23P5HRJ7XE9KTNRNXKH49MXV9JHHYE5535N7AGWEKR47SBCGNF44Z7XJ9RV5BQV12ZRJKN4HBZQHDNCMH3QKX9Z6G64"
   in
   let open Crypto in
-  let pub =
-    rsa_public_key |> decode |> RsaPublicKey.of_octets |> Result.get_ok
-  in
+  let pub = rsa_public_key |> RsaPublicKey.of_b32 |> Result.get_ok in
+  assert (RsaPublicKey.to_b32 pub = rsa_public_key);
   let bks = blinding_key_secret |> decode in
   let msg = decode message_hash in
   let bmsg = Fdh_rsa.blind_msg pub ~bks msg in
@@ -123,3 +122,34 @@ let () =
   assert (Result.is_ok res);
 
   ()
+
+(* denomination-hash test value from taler-wallet-core/src/withdraw.test.ts *)
+let test1 =
+  ( "040000XT67C8KBD6B75TTQ3SK8FWXMNQW4372T3BDDGPAMB9RFCA03638W8T3F71WFEFK9NP32VKYVNFXPYRWQ1N1HDKV5J0DFEKHBPJCYSWCBJDRNWD7G8BN8PT97FA9AMV75MYEK4X54D1HGJ207JSVJBGFCATSPNTEYNHEQF1F220W00TBZR1HNPDQFD56FG0DJQ9KGHM8EC33H6AY9YN9CNX5R3Z4TZ4Q23W47SBHB13H6W74FQJG1F50X38VRSC4SR8RWBAFB7S4K8D2H4NMRFSQT892A3T0BTBW7HM5C0H2CK6FRKG31F7W9WP1S29013K5CXYE55CT8TH6N8J9B780R42Y5S3ZB6J6E9H76XBPSGH4TGYSR2VZRB98J417KCQMZKX1BB67E7W5KVE37TC9SJ904002",
+    "Q21FQSSG4FXNT96Z14CHXM8N1RZAG9GPHAV8PRWS0PZAAVWH7PBW6R97M2CH19KKP65NNSWXY7B6S53PT3CBM342E357ZXDDJ8RDVW8"
+  )
+
+let test2 =
+  ( "040000Y63CF78QFPKRY77BRK9P557Q1GQWX3NCZ3HSYSK0Z7TT0KGRA7N4SKBKEHSTVHX1Z9DNXMJR4EXSY1TXCKV0GJ3T3YYC6Z0JNMJFVYQAV4FX5J90NZH1N33MZTV8HS9SMNAA9S6K73G4P99GYBB01B0P6M1KXZ5JRDR7VWBR3MEJHHGJ6QBMCJR3NWJRE3WJW9PRY8QPQ2S7KFWTWRESH2DBXCXWBD2SRN6P9YX8GRAEMFEGXC9V5GVJTEMH6ZDGNXFPWZE3JVJ2Q4N9GDYKBCHZCJ7M7M2RJ9ZV4Y64NAN9BT6XDC68215GKKRHTW1BBF1MYY6AR3JCTT9HYAM923RMVQR3TAEB7SDX8J76XRZWYH3AGJCZAQGMN5C8SSH9AHQ9RNQJQ15CN45R37X4YNFJV904002",
+    "447WA23SCBATMABHA0793F92MYTBYVPYMMQHCPKMKVY5P7RZRFMQ6VRW0Y8HRA7177GTBT0TBT08R21DZD129AJ995H9G09XBFE55G8"
+  )
+
+let () =
+  let f (rsa_pub, h_pub) =
+    let open Crypto in
+    assert (
+      rsa_pub
+      |> RsaPublicKey.of_b32
+      |> Result.get_ok
+      |> RsaPublicKey.to_octets
+      = (rsa_pub |> B32.decode |> Result.get_ok));
+
+    let h_pub' =
+      DenominationHash.to_b32
+        (DenominationHash.hash_of_rsa
+           (Result.get_ok @@ RsaPublicKey.of_b32 rsa_pub))
+    in
+    Fmt.pr "--@."; Fmt.pr "@.%s@." h_pub; Fmt.pr "@.%s@." h_pub'
+  in
+
+  f test1; f test2