From 0e32995f26944e23fd22b7cbfea474e0c509aa4e Mon Sep 17 00:00:00 2001
From: Jordi Baylina <jordi@baylina.cat>
Date: Tue, 16 Jun 2020 17:04:49 +0200
Subject: [PATCH] Fix Dataview Offsets

---
 src/groth16_prover.js      | 2 +-
 src/misc.js                | 2 +-
 src/powersoftau_utils.js   | 2 +-
 src/zkey_export_bellman.js | 4 ++--
 src/zkey_new.js            | 2 +-
 5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/groth16_prover.js b/src/groth16_prover.js
index 1a3e064..76579b9 100644
--- a/src/groth16_prover.js
+++ b/src/groth16_prover.js
@@ -104,7 +104,7 @@ async function buldABC(curve, zkey, witness, coeffs) {
     const sCoef = 4*3 + zkey.n8r;
 
     const elementsPerChunk = Math.floor(zkey.domainSize/concurrency);
-    const coeffsDV = new DataView(coeffs.buffer);
+    const coeffsDV = new DataView(coeffs.buffer, coeffs.byteOffset, coeffs.byteLength);
     const promises = [];
 
     const cutPoints = [];
diff --git a/src/misc.js b/src/misc.js
index cb26c65..f36d4ae 100644
--- a/src/misc.js
+++ b/src/misc.js
@@ -36,7 +36,7 @@ function log2( V )
 
 
 function formatHash(b) {
-    const a = new DataView(b.buffer);
+    const a = new DataView(b.buffer, b.byteOffset, b.byteLength);
     let S = "";
     for (let i=0; i<4; i++) {
         if (i>0) S += "\n";
diff --git a/src/powersoftau_utils.js b/src/powersoftau_utils.js
index 26e98eb..f2d09e5 100644
--- a/src/powersoftau_utils.js
+++ b/src/powersoftau_utils.js
@@ -362,7 +362,7 @@ function keyFromBeacon(curve, challangeHash, beaconHash, numIterationsExp) {
         }
     }
 
-    const curHashV = new DataView(curHash.buffer);
+    const curHashV = new DataView(curHash.buffer, curHash.byteOffset, curHash.byteLength);
     const seed = [];
     for (let i=0; i<8; i++) {
         seed[i] = curHashV.getUint32(i*4, false);
diff --git a/src/zkey_export_bellman.js b/src/zkey_export_bellman.js
index 2f151e6..ffb85bb 100644
--- a/src/zkey_export_bellman.js
+++ b/src/zkey_export_bellman.js
@@ -117,7 +117,7 @@ module.exports  = async function phase2exportMPCParams(zkeyName, mpcparamsName,
         }
 
         const buffSize = new Uint8Array(4);
-        const buffSizeV = new DataView(buffSize.buffer);
+        const buffSizeV = new DataView(buffSize.buffer, buffSize.byteOffset, buffSize.byteLength);
         buffSizeV.setUint32(0, buff.byteLength / sG, false);
 
         await fdMPCParams.write(buffSize);
@@ -126,7 +126,7 @@ module.exports  = async function phase2exportMPCParams(zkeyName, mpcparamsName,
 
     async function writeU32(n) {
         const buffSize = new Uint8Array(4);
-        const buffSizeV = new DataView(buffSize.buffer);
+        const buffSizeV = new DataView(buffSize.buffer, buffSize.byteOffset, buffSize.byteLength);
         buffSizeV.setUint32(0, n, false);
 
         await fdMPCParams.write(buffSize);
diff --git a/src/zkey_new.js b/src/zkey_new.js
index 26260fe..f26df77 100644
--- a/src/zkey_new.js
+++ b/src/zkey_new.js
@@ -471,7 +471,7 @@ module.exports  = async function phase2new(r1csName, ptauName, zkeyName, verbose
 
     function hashU32(n) {
         const buff = new Uint8Array(4);
-        const buffV = new DataView(buff.buffer);
+        const buffV = new DataView(buff.buffer, buff.byteOffset, buff.byteLength);
         buffV.setUint32(0, n, false);
         csHasher.update(buff);
     }