crypto: use assert instead of directly throwing an error

Fixes: #38302

Author: eladkishon

lib/internal/crypto/diffiehellman.js

@@ -9,6 +9,7 @@ const {
   SafeSet,
 } = primordials;
 
+const assert = require('internal/assert');
 const { Buffer } = require('buffer');
 
 const {
@@ -104,8 +105,8 @@ function DiffieHellman(sizeOrKey, keyEncoding, generator, genEncoding) {
   if (typeof sizeOrKey === 'number')
     validateInt32(sizeOrKey, 'sizeOrKey');
 
-  if (typeof sizeOrKey === 'string' && sizeOrKey.length === 0) {
-      throw new ERR_INVALID_ARG_VALUE('sizeOrKey', sizeOrKey);
+  if (typeof sizeOrKey === 'string') {
+    assert(sizeOrKey.length > 0, 'key must not be empty');
   }
 
   if (keyEncoding && !Buffer.isEncoding(keyEncoding) &&