From a22c5b16bcb5ac208a8b2f609cc1eff9e202f665 Mon Sep 17 00:00:00 2001
From: jxom <7336481+jxom@users.noreply.github.com>
Date: Fri, 22 Nov 2024 07:18:07 +1100
Subject: [PATCH] feat: export `setSignEntropy`

---
 .changeset/ninety-suits-invite.md       | 4 ++--
 src/accounts/index.test.ts              | 1 +
 src/accounts/index.ts                   | 1 +
 src/accounts/utils/sign.ts              | 9 ++++++---
 test/setup.ts                           | 3 ---
 vectors/src/transaction.vectors.test.ts | 3 ---
 6 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/.changeset/ninety-suits-invite.md b/.changeset/ninety-suits-invite.md
index 87ede0700a..21e0bda48e 100644
--- a/.changeset/ninety-suits-invite.md
+++ b/.changeset/ninety-suits-invite.md
@@ -1,5 +1,5 @@
 ---
-"viem": minor
+"viem": patch
 ---
 
-Improved security of signature generation. Resolves #3028.
+Added `setSignEntropy` export to improve security of signature generation.
diff --git a/src/accounts/index.test.ts b/src/accounts/index.test.ts
index bb3be338d6..ae4076eb7d 100644
--- a/src/accounts/index.test.ts
+++ b/src/accounts/index.test.ts
@@ -22,6 +22,7 @@ test('exports utils', () => {
       "mnemonicToAccount",
       "privateKeyToAccount",
       "toAccount",
+      "setSignEntropy",
       "sign",
       "signatureToHex",
       "serializeSignature",
diff --git a/src/accounts/index.ts b/src/accounts/index.ts
index 05506a7c11..8569fc061e 100644
--- a/src/accounts/index.ts
+++ b/src/accounts/index.ts
@@ -55,6 +55,7 @@ export {
   type SignErrorType,
   type SignParameters,
   type SignReturnType,
+  setSignEntropy,
   sign,
 } from './utils/sign.js'
 export {
diff --git a/src/accounts/utils/sign.ts b/src/accounts/utils/sign.ts
index 311170f462..c43db3b0a1 100644
--- a/src/accounts/utils/sign.ts
+++ b/src/accounts/utils/sign.ts
@@ -25,10 +25,13 @@ export type SignReturnType<to extends To = 'object'> =
 
 export type SignErrorType = NumberToHexErrorType | ErrorType
 
-let extraEntropy: Hex | boolean = true
+let extraEntropy: Hex | boolean = false
 
-/** @internal */
-export function setSignEntropy(entropy: Hex | boolean) {
+/**
+ * Sets extra entropy for signing functions.
+ */
+export function setSignEntropy(entropy: true | Hex) {
+  if (!entropy) throw new Error('must be a `true` or a hex value.')
   extraEntropy = entropy
 }
 
diff --git a/test/setup.ts b/test/setup.ts
index 68648b37ab..3b551fbc17 100644
--- a/test/setup.ts
+++ b/test/setup.ts
@@ -5,14 +5,11 @@ 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'
 
 const client = instances.anvilMainnet.getClient()
 
-setSignEntropy(false)
-
 beforeAll(() => {
   setErrorConfig({
     getDocsUrl({ docsBaseUrl, docsPath }) {
diff --git a/vectors/src/transaction.vectors.test.ts b/vectors/src/transaction.vectors.test.ts
index b500e97a81..0acb44ce34 100644
--- a/vectors/src/transaction.vectors.test.ts
+++ b/vectors/src/transaction.vectors.test.ts
@@ -7,9 +7,6 @@ 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'),