feat: add entropy to sign - resolves #3028

.changeset/ninety-suits-invite.md

@@ -0,0 +1,5 @@
+---
+"viem": minor
+---
+
+Improved security of signature generation. Resolves #3028.

site/pages/op-stack/guides/deposits.md

@@ -193,7 +193,7 @@ import { publicClientL2 } from './config'
 
 // Build parameters for the transaction on the L2.
 const args = await publicClientL2.buildDepositTransaction({
-  mint: parseEther('1')
+  mint: parseEther('1'),
   to: account.address,
 })
 ```
@@ -265,7 +265,7 @@ import { account, publicClientL2, walletClientL1 } from './config'
 
 // Build parameters for the transaction on the L2.
 const args = await publicClientL2.buildDepositTransaction({
-  mint: parseEther('1')
+  mint: parseEther('1'),
   to: account.address,
 })
 
@@ -350,7 +350,7 @@ import {
 
 // Build parameters for the transaction on the L2.
 const args = await publicClientL2.buildDepositTransaction({
-  mint: parseEther('1')
+  mint: parseEther('1'),
   to: account.address,
 })
 
@@ -432,7 +432,7 @@ import {
 
 // Build parameters for the transaction on the L2.
 const args = await publicClientL2.buildDepositTransaction({
-  mint: parseEther('1')
+  mint: parseEther('1'),
   to: account.address,
 })
 
@@ -519,7 +519,7 @@ import {
 
 // Build parameters for the transaction on the L2.
 const args = await publicClientL2.buildDepositTransaction({
-  mint: parseEther('1')
+  mint: parseEther('1'),
   to: account.address,
 })
 

src/accounts/utils/sign.ts

@@ -25,6 +25,13 @@ export type SignReturnType<to extends To = 'object'> =
 
 export type SignErrorType = NumberToHexErrorType | ErrorType
 
+let extraEntropy: Hex | boolean = true
+
+/** @internal */
+export function setSignEntropy(entropy: Hex | boolean) {
+  extraEntropy = entropy
+}
+
 /**
  * @description Signs a hash with a given private key.
  *
@@ -38,7 +45,11 @@ export async function sign<to extends To = 'object'>({
   privateKey,
   to = 'object',
 }: SignParameters<to>): Promise<SignReturnType<to>> {
-  const { r, s, recovery } = secp256k1.sign(hash.slice(2), privateKey.slice(2))
+  const { r, s, recovery } = secp256k1.sign(
+    hash.slice(2),
+    privateKey.slice(2),
+    { lowS: true, extraEntropy },
+  )
   const signature = {
     r: numberToHex(r, { size: 32 }),
     s: numberToHex(s, { size: 32 }),

src/zksync/formatters.ts

@@ -81,7 +81,9 @@ export const formatters = {
           return {
             blockNumber: hexToBigInt(l2ToL1Log.blockHash),
             blockHash: l2ToL1Log.blockHash,
-            l1BatchNumber: l2ToL1Log.l1BatchNumber ? hexToBigInt(l2ToL1Log.l1BatchNumber) : null,
+            l1BatchNumber: l2ToL1Log.l1BatchNumber
+              ? hexToBigInt(l2ToL1Log.l1BatchNumber)
+              : null,
             transactionIndex: hexToBigInt(l2ToL1Log.transactionIndex),
             shardId: hexToBigInt(l2ToL1Log.shardId),
             isService: l2ToL1Log.isService,

test/setup.ts

@@ -5,6 +5,7 @@ import { cleanupCache, listenersCache } from '~viem/utils/observe.js'
 import { promiseCache, responseCache } from '~viem/utils/promise/withCache.js'
 import { socketClientCache } from '~viem/utils/rpc/socket.js'
 
+import { setSignEntropy } from '../src/accounts/utils/sign.js'
 import { setErrorConfig } from '../src/errors/base.js'
 import * as instances from './src/anvil.js'
 
@@ -19,6 +20,7 @@ beforeAll(() => {
     },
     version: '[email protected]',
   })
+  setSignEntropy(false)
   vi.mock('../src/errors/utils.ts', () => ({
     getContractAddress: vi
       .fn()

vectors/src/transaction.vectors.test.ts

@@ -7,6 +7,9 @@ import { signTransaction } from '../../src/accounts/utils/signTransaction.js'
 import { parseTransaction } from '../../src/index.js'
 import { serializeTransaction } from '../../src/utils/transaction/serializeTransaction.js'
 import { readGzippedJson } from '../utils.js'
+import { setSignEntropy } from '../../src/accounts/utils/sign.js'
+
+setSignEntropy(false)
 
 const transactions_ = await readGzippedJson(
   join(import.meta.dir, './transaction.json.gz'),