From c0f0421f8ab3de8511c7073c37020e6c298ef78d Mon Sep 17 00:00:00 2001
From: callebtc <93376500+callebtc@users.noreply.github.com>
Date: Wed, 2 Nov 2022 23:43:37 +0100
Subject: [PATCH] for r, dont use bigint but hex string

---
 lnbits/extensions/cashu/static/js/dhke.js           |  8 +++++---
 lnbits/extensions/cashu/templates/cashu/wallet.html | 10 ++++++++--
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/lnbits/extensions/cashu/static/js/dhke.js b/lnbits/extensions/cashu/static/js/dhke.js
index c35a34e9..935bf6d4 100644
--- a/lnbits/extensions/cashu/static/js/dhke.js
+++ b/lnbits/extensions/cashu/static/js/dhke.js
@@ -21,14 +21,16 @@ async function hashToCurve(secretMessage) {
 
 async function step1Alice(secretMessage) {
   const Y = await hashToCurve(secretMessage)
-  const r = bytesToNumber(nobleSecp256k1.utils.randomPrivateKey())
+  const rpk = nobleSecp256k1.utils.randomPrivateKey()
+  const r = bytesToNumber(rpk)
   const P = nobleSecp256k1.Point.fromPrivateKey(r)
   const B_ = Y.add(P)
-  return {B_: B_.toHex(true), r}
+  return {B_: B_.toHex(true), r: nobleSecp256k1.utils.bytesToHex(rpk)}
 }
 
 function step3Alice(C_, r, A) {
-  const rInt = BigInt(r)
+  // const rInt = BigInt(r)
+  const rInt = bytesToNumber(r)
   const C = C_.subtract(A.multiply(rInt))
   return C
 }
diff --git a/lnbits/extensions/cashu/templates/cashu/wallet.html b/lnbits/extensions/cashu/templates/cashu/wallet.html
index 4af9c148..105c1e08 100644
--- a/lnbits/extensions/cashu/templates/cashu/wallet.html
+++ b/lnbits/extensions/cashu/templates/cashu/wallet.html
@@ -1060,7 +1060,11 @@ page_container %}
       promiseToProof: function (id, amount, C_hex, secret, r) {
         const C_ = nobleSecp256k1.Point.fromHex(C_hex)
         const A = this.keys[amount]
-        const C = step3Alice(C_, r, nobleSecp256k1.Point.fromHex(A))
+        const C = step3Alice(
+          C_,
+          nobleSecp256k1.utils.hexToBytes(r),
+          nobleSecp256k1.Point.fromHex(A)
+        )
         return {
           id,
           amount,
@@ -1226,7 +1230,9 @@ page_container %}
         const rs = []
         for (let i = 0; i < amounts.length; i++) {
           const secret = nobleSecp256k1.utils.randomBytes(32)
-          // const secret = nobleSecp256k1.utils.hexToBytes('0000000000000000000000000000000000000000000000000000000000000003')
+          // const secret = nobleSecp256k1.utils.hexToBytes(
+          //   '0000000000000000000000000000000000000000000000000000000000000000'
+          // )
           // todo: base64Url
           const encodedSecret = uint8ToBase64.encode(secret)
           secrets.push(encodedSecret)