Merge pull request #46 from 0xPolygonHermez/feature/update-snark-input

Feature/update snark input
0xPolygonHermez · Aug 2, 2022 · 7d7d858 · 7d7d858
2 parents 1d391bb + 54447c7
commit 7d7d858
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Showing 4 changed files with 37 additions and 26 deletions.
diff --git a/package.json b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@0xpolygonhermez/zkevm-commonjs",
   "description": "Javascript library implementing common utilities for zkevm",
-  "version": "0.0.36",
+  "version": "0.0.37",
   "main": "index.js",
   "scripts": {
     "setup": "npm i",

diff --git a/src/contract-utils.js b/src/contract-utils.js
@@ -44,15 +44,16 @@ function calculateStarkInput(
 }
 
 /**
- * Compute globalHash for SNARK circuit
+ * Compute input for SNARK circuit
  * @param {String} currentStateRoot - Current state Root
  * @param {String} currentLocalExitRoot - Current local exit root
  * @param {String} newStateRoot - New State root once the batch is processed
  * @param {String} newLocalExitRoot - New local exit root once the batch is processed
  * @param {String} batchHashData - Batch hash data
  * @param {Number} numBatch - Batch number
  * @param {Number} timestamp - Block timestamp
- * @returns {String} - global hash % FrSNARK in hex encoding
+ * @param {String} aggregatorAddress - Aggregator Ethereum address in hex string
+ * @returns {String} - sha256(globalHash, aggregatorAddress) % FrSNARK in hex encoding
  */
 function calculateSnarkInput(
     currentStateRoot,
@@ -62,6 +63,7 @@ function calculateSnarkInput(
     batchHashData,
     numBatch,
     timestamp,
+    aggregatorAddress,
 ) {
     const hashKeccak = calculateStarkInput(
         currentStateRoot,
@@ -73,7 +75,15 @@ function calculateSnarkInput(
         timestamp,
     );
 
-    return `0x${Scalar.mod(Scalar.fromString(hashKeccak, 16), FrSNARK).toString(16).padStart(64, '0')}`;
+    const hashSha256 = ethers.utils.soliditySha256(
+        ['bytes32', 'address'],
+        [
+            hashKeccak,
+            aggregatorAddress,
+        ],
+    );
+
+    return `0x${Scalar.mod(Scalar.fromString(hashSha256, 16), FrSNARK).toString(16).padStart(64, '0')}`;
 }
 
 /**

diff --git a/src/processor.js b/src/processor.js
@@ -56,14 +56,16 @@ module.exports = class Processor {
         this.decodedTxs = [];
         this.builded = false;
         this.starkInput = {};
-        this.snarkInput = '0x';
         this.contractsBytecode = {};
         this.oldStateRoot = root;
         this.currentStateRoot = root;
         this.oldLocalExitRoot = localExitRoot;
         this.newLocalExitRoot = localExitRoot;
         this.globalExitRoot = globalExitRoot;
 
+        this.batchHashData = '0x';
+        this.inputHash = '0x';
+
         this.sequencerAddress = sequencerAddress;
         this.timestamp = timestamp;
 
@@ -107,7 +109,6 @@ module.exports = class Processor {
 
         // Calculate stark and snark input
         await this._computeStarkInput();
-        await this._computeSnarkInput();
 
         this.builded = true;
     }
@@ -519,18 +520,18 @@ module.exports = class Processor {
         const newLocalExitRoot = smtUtils.h4toString(this.newLocalExitRoot);
         const globalExitRoot = smtUtils.h4toString(this.globalExitRoot);
 
-        const batchHashData = calculateBatchHashData(
+        this.batchHashData = calculateBatchHashData(
             this.getBatchL2Data(),
             globalExitRoot,
             this.sequencerAddress,
         );
 
-        const inputHash = calculateStarkInput(
+        this.inputHash = calculateStarkInput(
             oldStateRoot,
             oldLocalExitRoot,
             newStateRoot,
-            newLocalExitRoot, // should be the new exit root, but it's not modified in this version
-            batchHashData,
+            newLocalExitRoot,
+            this.batchHashData,
             this.batchNumber,
             this.timestamp,
         );
@@ -544,39 +545,35 @@ module.exports = class Processor {
             oldLocalExitRoot,
             newLocalExitRoot,
             globalExitRoot,
-            batchHashData,
-            inputHash,
+            batchHashData: this.batchHashData,
+            inputHash: this.inputHash,
             numBatch: this.batchNumber,
             timestamp: this.timestamp,
             contractsBytecode: this.contractsBytecode,
         };
     }
 
     /**
-     * Compute stark input
+     * Compute snark input
+     * @param {String} aggregatorAddress - aggregator ethereum address
+     * @returns {String} Snark input
      */
-    _computeSnarkInput() {
+    _computeSnarkInput(aggregatorAddress) {
         // compute circuit inputs
         const oldStateRoot = smtUtils.h4toString(this.oldStateRoot);
         const newStateRoot = smtUtils.h4toString(this.currentStateRoot);
         const oldLocalExitRoot = smtUtils.h4toString(this.oldLocalExitRoot);
         const newLocalExitRoot = smtUtils.h4toString(this.newLocalExitRoot);
-        const globalExitRoot = smtUtils.h4toString(this.globalExitRoot);
-
-        const batchHashData = calculateBatchHashData(
-            this.getBatchL2Data(),
-            globalExitRoot,
-            this.sequencerAddress,
-        );
 
-        this.snarkInput = calculateSnarkInput(
+        return calculateSnarkInput(
             oldStateRoot,
             oldLocalExitRoot,
             newStateRoot,
             newLocalExitRoot,
-            batchHashData,
+            this.batchHashData,
             this.batchNumber,
             this.timestamp,
+            aggregatorAddress,
         );
     }
 
@@ -598,11 +595,12 @@ module.exports = class Processor {
 
     /**
      * Return snark input
+     * @param {String} aggregatorAddress - aggregator Ethereum address
      */
-    getSnarkInput() {
+    getSnarkInput(aggregatorAddress) {
         this._isBuilded();
 
-        return this.snarkInput;
+        return this._computeSnarkInput(aggregatorAddress);
     }
 
     /**

diff --git a/test/contract-utils.test.js b/test/contract-utils.test.js
@@ -12,7 +12,7 @@ describe('contractUtils', function () {
     let testVector;
 
     const expectedBatchHashData = '0xa4e1166ff3f7ecf8c8ff3049fc2e28b03091d3bf0db4bce702d954840196f79d';
-    const expectedSnarkInputHash = '0x12bcbec575263760c8b89071ddb92de1cab523639aad606b2142c052dfcc42cd';
+    const expectedSnarkInputHash = '0x0b0a9c614cdc5473f2a9251d171230e92e5ae31fab0b165b13586100dad3a2c0';
     const expectedStarkHashExecutor = '0x73855bab378977b439591bdee0bbde9c1b1cf3f48e20418da906ab7abfcc42cf';
 
     before(async () => {
@@ -34,6 +34,8 @@ describe('contractUtils', function () {
     });
 
     it('calculateSnarkInput', async () => {
+        const aggregatorAddress = '0x123456789ABCDDEF123456789ABCDDEF12345678';
+
         const {
             oldLocalExitRoot,
             newLocalExitRoot,
@@ -51,6 +53,7 @@ describe('contractUtils', function () {
             expectedBatchHashData,
             numBatch,
             timestamp,
+            aggregatorAddress,
         );
 
         expect(computedGlobalHash).to.be.equal(expectedSnarkInputHash);