From b1d8d568f881ed62f104cac46c6b1cfb1632df8a Mon Sep 17 00:00:00 2001
From: Billy Rennekamp <billy.rennekamp@gmail.com>
Date: Wed, 4 Oct 2023 11:48:09 +0200
Subject: [PATCH] fix negative input bug

---
 build/main.cjs           | 6 +++++-
 js/witness_calculator.js | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/build/main.cjs b/build/main.cjs
index 235f1b6..c1f739b 100644
--- a/build/main.cjs
+++ b/build/main.cjs
@@ -473,7 +473,11 @@ class WitnessCalculatorCircom2 {
             const hLSB = parseInt(h.slice(8,16), 16);
             const fArr = flatArray(input[k]);
             for (let i=0; i<fArr.length; i++) {
-        const arrFr = toArray32(fArr[i],this.n32);
+        let possibleNegative = BigInt(fArr[i]);
+        while (possibleNegative < 0n) {
+            possibleNegative += this.prime;
+        }
+        const arrFr = toArray32(possibleNegative % this.prime, this.n32);
         for (let j=0; j<this.n32; j++) {
             this.instance.exports.writeSharedRWMemory(j,arrFr[this.n32-1-j]);
         }
diff --git a/js/witness_calculator.js b/js/witness_calculator.js
index 7db0bf8..916a969 100644
--- a/js/witness_calculator.js
+++ b/js/witness_calculator.js
@@ -421,7 +421,11 @@ class WitnessCalculatorCircom2 {
             const hLSB = parseInt(h.slice(8,16), 16);
             const fArr = flatArray(input[k]);
             for (let i=0; i<fArr.length; i++) {
-        const arrFr = toArray32(fArr[i],this.n32)
+        let possibleNegative = BigInt(fArr[i])
+        while (possibleNegative < 0n) {
+            possibleNegative += this.prime
+        }
+        const arrFr = toArray32(possibleNegative % this.prime, this.n32)
         for (let j=0; j<this.n32; j++) {
             this.instance.exports.writeSharedRWMemory(j,arrFr[this.n32-1-j]);
         }