From 3bd16c3cc6988263e55a70d12b09c62a815937cf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tobias=20Nie=C3=9Fen?= <tniessen@tnie.de>
Date: Mon, 14 Aug 2023 15:01:43 +0000
Subject: [PATCH] crypto: remove default encoding from DiffieHellman

getDefaultEncoding() always returns 'buffer' in Node.js 20.

In diffiehellman.js, this value is always used as input to either
toBuf(), encode(), or getArrayBufferOrView(). All of these functions
treat any falsy encoding just like 'buffer', so we can safely remove the
calls to getDefaultEncoding().

Refs: https://github.com/nodejs/node/pull/47182
---
 lib/internal/crypto/diffiehellman.js | 20 +-------------------
 1 file changed, 1 insertion(+), 19 deletions(-)

diff --git a/lib/internal/crypto/diffiehellman.js b/lib/internal/crypto/diffiehellman.js
index 3f52e78d7a3036..59bbf8ff71233c 100644
--- a/lib/internal/crypto/diffiehellman.js
+++ b/lib/internal/crypto/diffiehellman.js
@@ -51,7 +51,6 @@ const {
 
 const {
   getArrayBufferOrView,
-  getDefaultEncoding,
   jobPromise,
   toBuf,
   kHandle,
@@ -97,10 +96,6 @@ function DiffieHellman(sizeOrKey, keyEncoding, generator, genEncoding) {
     keyEncoding = false;
   }
 
-  const encoding = getDefaultEncoding();
-  keyEncoding = keyEncoding || encoding;
-  genEncoding = genEncoding || encoding;
-
   if (typeof sizeOrKey !== 'number')
     sizeOrKey = toBuf(sizeOrKey, keyEncoding);
 
@@ -148,7 +143,6 @@ DiffieHellmanGroup.prototype.generateKeys =
 
 function dhGenerateKeys(encoding) {
   const keys = this[kHandle].generateKeys();
-  encoding = encoding || getDefaultEncoding();
   return encode(keys, encoding);
 }
 
@@ -158,9 +152,6 @@ DiffieHellmanGroup.prototype.computeSecret =
     dhComputeSecret;
 
 function dhComputeSecret(key, inEnc, outEnc) {
-  const encoding = getDefaultEncoding();
-  inEnc = inEnc || encoding;
-  outEnc = outEnc || encoding;
   key = getArrayBufferOrView(key, 'key', inEnc);
   const ret = this[kHandle].computeSecret(key);
   if (typeof ret === 'string')
@@ -175,7 +166,6 @@ DiffieHellmanGroup.prototype.getPrime =
 
 function dhGetPrime(encoding) {
   const prime = this[kHandle].getPrime();
-  encoding = encoding || getDefaultEncoding();
   return encode(prime, encoding);
 }
 
@@ -186,7 +176,6 @@ DiffieHellmanGroup.prototype.getGenerator =
 
 function dhGetGenerator(encoding) {
   const generator = this[kHandle].getGenerator();
-  encoding = encoding || getDefaultEncoding();
   return encode(generator, encoding);
 }
 
@@ -197,7 +186,6 @@ DiffieHellmanGroup.prototype.getPublicKey =
 
 function dhGetPublicKey(encoding) {
   const key = this[kHandle].getPublicKey();
-  encoding = encoding || getDefaultEncoding();
   return encode(key, encoding);
 }
 
@@ -208,13 +196,11 @@ DiffieHellmanGroup.prototype.getPrivateKey =
 
 function dhGetPrivateKey(encoding) {
   const key = this[kHandle].getPrivateKey();
-  encoding = encoding || getDefaultEncoding();
   return encode(key, encoding);
 }
 
 
 DiffieHellman.prototype.setPublicKey = function setPublicKey(key, encoding) {
-  encoding = encoding || getDefaultEncoding();
   key = getArrayBufferOrView(key, 'key', encoding);
   this[kHandle].setPublicKey(key);
   return this;
@@ -222,7 +208,6 @@ DiffieHellman.prototype.setPublicKey = function setPublicKey(key, encoding) {
 
 
 DiffieHellman.prototype.setPrivateKey = function setPrivateKey(key, encoding) {
-  encoding = encoding || getDefaultEncoding();
   key = getArrayBufferOrView(key, 'key', encoding);
   this[kHandle].setPrivateKey(key);
   return this;
@@ -251,15 +236,12 @@ ECDH.prototype.generateKeys = function generateKeys(encoding, format) {
 ECDH.prototype.getPublicKey = function getPublicKey(encoding, format) {
   const f = getFormat(format);
   const key = this[kHandle].getPublicKey(f);
-  encoding = encoding || getDefaultEncoding();
   return encode(key, encoding);
 };
 
 ECDH.convertKey = function convertKey(key, curve, inEnc, outEnc, format) {
   validateString(curve, 'curve');
-  const encoding = inEnc || getDefaultEncoding();
-  key = getArrayBufferOrView(key, 'key', encoding);
-  outEnc = outEnc || encoding;
+  key = getArrayBufferOrView(key, 'key', inEnc);
   const f = getFormat(format);
   const convertedKey = _ECDHConvertKey(key, curve, f);
   return encode(convertedKey, outEnc);