fix: refactor sign.js and related tests (#1243)

* fix: refactor sign.js and related tests

* fix: remove unused dep

* fix: update package.json correctly

package.json

@@ -47,7 +47,6 @@
     "eslint-plugin-node": "^5.2.1",
     "eslint-plugin-promise": "^3.8.0",
     "eslint-plugin-standard": "^3.1.0",
-    "ethereumjs-util": "^5.2.0",
     "ethjs-abi": "^0.2.1",
     "ganache-cli": "6.1.0",
     "solidity-coverage": "^0.5.4",

test/AutoIncrementing.test.js

-const { hashMessage } = require('./helpers/sign');
-
 const AutoIncrementing = artifacts.require('AutoIncrementingImpl');
 
 require('chai')
@@ -7,8 +5,8 @@ require('chai')
   .should();
 
 const EXPECTED = [1, 2, 3, 4];
-const KEY1 = hashMessage('key1');
-const KEY2 = hashMessage('key2');
+const KEY1 = web3.sha3('key1');
+const KEY2 = web3.sha3('key2');
 
 contract('AutoIncrementing', function ([_, owner]) {
   beforeEach(async function () {

test/helpers/sign.js

-const utils = require('ethereumjs-util');
-const { soliditySha3 } = require('web3-utils');
+const { sha3, soliditySha3 } = require('web3-utils');
 
 const REAL_SIGNATURE_SIZE = 2 * 65; // 65 bytes in hexadecimal string legnth
 const PADDED_SIGNATURE_SIZE = 2 * 96; // 96 bytes in hexadecimal string length
 
 const DUMMY_SIGNATURE = `0x${web3.padLeft('', REAL_SIGNATURE_SIZE)}`;
 
-/**
- * Hash and add same prefix to the hash that ganache use.
- * @param {string} message the plaintext/ascii/original message
- * @return {string} the hash of the message, prefixed, and then hashed again
- */
-function hashMessage (message) {
-  const messageHex = Buffer.from(utils.sha3(message).toString('hex'), 'hex');
-  const prefix = utils.toBuffer('\u0019Ethereum Signed Message:\n' + messageHex.length.toString());
-  return utils.bufferToHex(utils.sha3(Buffer.concat([prefix, messageHex])));
+// messageHex = '0xdeadbeef'
+function toEthSignedMessageHash (messageHex) {
+  const messageBuffer = Buffer.from(messageHex.substring(2), 'hex');
+  const prefix = Buffer.from(`\u0019Ethereum Signed Message:\n${messageBuffer.length}`);
+  return sha3(Buffer.concat([prefix, messageBuffer]));
 }
 
-// signs message in node (auto-applies prefix)
-// message must be in hex already! will not be autoconverted!
-const signMessage = (signer, message = '') => {
-  return web3.eth.sign(signer, message);
+// signs message in node (ganache auto-applies "Ethereum Signed Message" prefix)
+// messageHex = '0xdeadbeef'
+const signMessage = (signer, messageHex = '0x') => {
+  return web3.eth.sign(signer, messageHex); // actually personal_sign
 };
 
 // @TODO - remove this when we migrate to web3-1.0.0
@@ -62,18 +57,18 @@ const getBouncerSigner = (contract, signer) => (redeemer, methodName, methodArgs
     } else {
       const abi = contract.abi.find(abi => abi.name === methodName);
       const name = transformToFullName(abi);
-      const signature = web3.sha3(name).slice(0, 10);
+      const signature = sha3(name).slice(0, 10);
       parts.push(signature);
     }
   }
 
-  // ^ substr to remove `0x` because in solidity the address is a set of byes, not a string `0xabcd`
-  const hashOfMessage = soliditySha3(...parts);
-  return signMessage(signer, hashOfMessage);
+  // return the signature of the "Ethereum Signed Message" hash of the hash of `parts`
+  const messageHex = soliditySha3(...parts);
+  return signMessage(signer, messageHex);
 };
 
 module.exports = {
-  hashMessage,
   signMessage,
+  toEthSignedMessageHash,
   getBouncerSigner,
 };

test/library/ECRecovery.test.js

-const { hashMessage, signMessage } = require('../helpers/sign');
+const { signMessage, toEthSignedMessageHash } = require('../helpers/sign');
 const { expectThrow } = require('../helpers/expectThrow');
 
 const ECRecoveryMock = artifacts.require('ECRecoveryMock');
@@ -6,67 +6,61 @@ const ECRecoveryMock = artifacts.require('ECRecoveryMock');
 require('chai')
   .should();
 
-contract('ECRecovery', function ([_, anyone]) {
-  let ecrecovery;
-  const TEST_MESSAGE = 'OpenZeppelin';
+const TEST_MESSAGE = web3.sha3('OpenZeppelin');
+const WRONG_MESSAGE = web3.sha3('Nope');
 
+contract('ECRecovery', function ([_, anyone]) {
   beforeEach(async function () {
-    ecrecovery = await ECRecoveryMock.new();
+    this.mock = await ECRecoveryMock.new();
   });
 
   it('recover v0', async function () {
     // Signature generated outside ganache with method web3.eth.sign(signer, message)
     const signer = '0x2cc1166f6212628a0deef2b33befb2187d35b86c';
-    const message = web3.sha3(TEST_MESSAGE);
     // eslint-disable-next-line max-len
     const signature = '0x5d99b6f7f6d1f73d1a26497f2b1c89b24c0993913f86e9a2d02cd69887d9c94f3c880358579d811b21dd1b7fd9bb01c1d81d10e69f0384e675c32b39643be89200';
-    (await ecrecovery.recover(message, signature)).should.equal(signer);
+    (await this.mock.recover(TEST_MESSAGE, signature)).should.equal(signer);
   });
 
   it('recover v1', async function () {
     // Signature generated outside ganache with method web3.eth.sign(signer, message)
     const signer = '0x1e318623ab09fe6de3c9b8672098464aeda9100e';
-    const message = web3.sha3(TEST_MESSAGE);
     // eslint-disable-next-line max-len
     const signature = '0x331fe75a821c982f9127538858900d87d3ec1f9f737338ad67cad133fa48feff48e6fa0c18abc62e42820f05943e47af3e9fbe306ce74d64094bdf1691ee53e001';
-    (await ecrecovery.recover(message, signature)).should.equal(signer);
+    (await this.mock.recover(TEST_MESSAGE, signature)).should.equal(signer);
   });
 
   it('recover using web3.eth.sign()', async function () {
-    // Create the signature using account[0]
-    const signature = signMessage(anyone, web3.sha3(TEST_MESSAGE));
+    // Create the signature
+    const signature = signMessage(anyone, TEST_MESSAGE);
 
     // Recover the signer address from the generated message and signature.
-    (await ecrecovery.recover(
-      hashMessage(TEST_MESSAGE),
+    (await this.mock.recover(
+      toEthSignedMessageHash(TEST_MESSAGE),
       signature
     )).should.equal(anyone);
   });
 
   it('recover using web3.eth.sign() should return wrong signer', async function () {
-    // Create the signature using account[0]
-    const signature = signMessage(anyone, web3.sha3(TEST_MESSAGE));
+    // Create the signature
+    const signature = signMessage(anyone, TEST_MESSAGE);
 
     // Recover the signer address from the generated message and wrong signature.
-    (await ecrecovery.recover(hashMessage('Nope'), signature)).should.not.equal(anyone);
+    (await this.mock.recover(WRONG_MESSAGE, signature)).should.not.equal(anyone);
   });
 
-  it('recover should revert when a small hash is sent', async function () {
-    // Create the signature using account[0]
+  // @TODO - remove `skip` once we upgrade to solc^0.5
+  it.skip('recover should revert when a small hash is sent', async function () {
+    // Create the signature
     const signature = signMessage(anyone, TEST_MESSAGE);
-    try {
     await expectThrow(
-        ecrecovery.recover(hashMessage(TEST_MESSAGE).substring(2), signature)
+      this.mock.recover(TEST_MESSAGE.substring(2), signature)
     );
-    } catch (error) {
-      // @TODO(shrugs) - remove this once we upgrade to solc^0.5
-    }
   });
 
   context('toEthSignedMessage', function () {
     it('should prefix hashes correctly', async function () {
-      const hashedMessage = web3.sha3(TEST_MESSAGE);
-      (await ecrecovery.toEthSignedMessageHash(hashedMessage)).should.equal(hashMessage(TEST_MESSAGE));
+      (await this.mock.toEthSignedMessageHash(TEST_MESSAGE)).should.equal(toEthSignedMessageHash(TEST_MESSAGE));
     });
   });
 });