Rename constants

r0qs · Aug 10, 2022 · 6a5ea44 · 6a5ea44
1 parent c0f83b4
commit 6a5ea44
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Showing 5 changed files with 16 additions and 10 deletions.
diff --git a/contracts/MerkleTreeWithHistory.sol b/contracts/MerkleTreeWithHistory.sol
@@ -8,7 +8,7 @@ interface IHasher {
 }
 
 contract MerkleTreeWithHistory {
-    uint256 public constant FIELD_SIZE = 21888242871839275222246405745257275088548364400416034343698204186575808495617;
+    uint256 public constant SCALAR_FIELD_SIZE = 21888242871839275222246405745257275088548364400416034343698204186575808495617;
     uint256 public constant ZERO_VALUE = 0;
 
     IHasher public immutable hasher;
@@ -38,8 +38,8 @@ contract MerkleTreeWithHistory {
      * @return Poseidon(_left, _right)
      */
     function hashLeftRight(bytes32 _left, bytes32 _right) public view returns (bytes32) {
-        require(uint256(_left) < FIELD_SIZE, "_left should be inside the field");
-        require(uint256(_right) < FIELD_SIZE, "_right should be inside the field");
+        require(uint256(_left) < SCALAR_FIELD_SIZE, "_left should be inside the field");
+        require(uint256(_right) < SCALAR_FIELD_SIZE, "_right should be inside the field");
         bytes32[2] memory input;
         input[0] = _left;
         input[1] = _right;

diff --git a/contracts/Notary.sol b/contracts/Notary.sol
@@ -86,6 +86,12 @@ abstract contract Notary is MerkleTreeWithHistory {
         pubSignals[0] = uint256(_root);
         pubSignals[1] = uint256(_nullifierHash);
         pubSignals[2] = uint256(uint160(msg.sender));
+
+        // Ensure that every input must be less than the snark scalar field
+        // This is already checked in the verifiers' code, but we are failing fast here before attempting to verify the proof.
+        for (uint256 i = 0; i < pubSignals.length; i++) {
+            require(pubSignals[i] < SCALAR_FIELD_SIZE, "Input too large");
+        }
         require(verifier.verifyProof(_proof, pubSignals), "Invalid issuance proof");
 
         nullifierHashes[_nullifierHash] = CredentialState(true, false);

diff --git a/src/utils.js b/src/utils.js
@@ -9,7 +9,7 @@ const { unstringifyBigInts } = require('ffjavascript').utils
 // TODO: load from config
 const MERKLE_TREE_HEIGHT = process.env.MERKLE_TREE_HEIGHT || 12
 const ZERO_VALUE = process.env.ZERO_VALUE || 0
-const FIELD_SIZE = BigNumber.from(
+const SCALAR_FIELD_SIZE = BigNumber.from(
   '21888242871839275222246405745257275088548364400416034343698204186575808495617',
 )
 
@@ -80,7 +80,7 @@ function bitArrayToDecimal(array) {
 
 module.exports = {
   MERKLE_TREE_HEIGHT,
-  FIELD_SIZE,
+  SCALAR_FIELD_SIZE,
   randomBN,
   toFixedHex,
   toBuffer,

diff --git a/test/js/MerkleTreeWithHistory.test.js b/test/js/MerkleTreeWithHistory.test.js
@@ -6,7 +6,7 @@ const { MerkleTree } = require('fixed-merkle-tree')
 const { toFixedHex, deploy } = require('../../src/utils')
 const Poseidon = require('../../src/poseidon')
 
-const DEFAULT_ZERO_VALUE = 0
+const ZERO_VALUE = 0
 const MERKLE_TREE_HEIGHT = 5
 
 describe('MerkleTreeWithHistory', function () {
@@ -24,7 +24,7 @@ describe('MerkleTreeWithHistory', function () {
     return poseidonHash([a, b])
   }
 
-  function getNewTree(tree_height = MERKLE_TREE_HEIGHT, zero = DEFAULT_ZERO_VALUE) {
+  function getNewTree(tree_height = MERKLE_TREE_HEIGHT, zero = ZERO_VALUE) {
     return new MerkleTree(tree_height, [], { hashFunction: poseidonHash2, zeroElement: zero })
   }
 
@@ -127,7 +127,7 @@ describe('MerkleTreeWithHistory', function () {
       // initial subtree should be zero
       let subtree0 = await mtContract.filledSubtrees(0)
       let subtree1 = await mtContract.filledSubtrees(1)
-      expect(subtree0).to.equal(toFixedHex(DEFAULT_ZERO_VALUE))
+      expect(subtree0).to.equal(toFixedHex(ZERO_VALUE))
       expect(subtree1).to.equal(toFixedHex(poseidonHash2(0, 0)))
       let nextIdx = await mtContract.nextIndex()
       expect(nextIdx).to.equal(0)

diff --git a/test/js/Notary.test.js b/test/js/Notary.test.js
@@ -7,7 +7,7 @@ const { plonk } = require('snarkjs')
 const { buildEddsa } = require('circomlibjs')
 const { MerkleTree } = require('fixed-merkle-tree')
 const {
-	FIELD_SIZE,
+	SCALAR_FIELD_SIZE,
 	deploy,
 	randomBN,
 	toFixedHex } = require('../../src/utils')
@@ -96,7 +96,7 @@ describe('PrivateNotary', function () {
 			expect(await pvtNotaryImpl.getLastRoot()).to.equal(toFixedHex(tree.root))
 			expect(await pvtNotaryImpl.levels()).to.equal(MERKLE_TREE_HEIGHT)
 			expect(await pvtNotaryImpl.levels()).to.equal(tree.levels)
-			expect(await pvtNotaryImpl.FIELD_SIZE()).to.equal(FIELD_SIZE)
+			expect(await pvtNotaryImpl.SCALAR_FIELD_SIZE()).to.equal(SCALAR_FIELD_SIZE)
 			expect(await pvtNotaryImpl.ZERO_VALUE()).to.equal(ZERO_VALUE)
 		})
 	})