crypto: don't crash X509ToObject on error

Use MaybeLocal::ToLocal and don't crash X509ToObject on error.

PR-URL: nodejs/node#25717
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

Author: davidben

src/node_crypto.cc

@@ -1556,24 +1556,27 @@ static void AddFingerprintDigest(const unsigned char* md,
   }
 }
 
+
 static MaybeLocal<Object> ECPointToBuffer(Environment* env,
                                           const EC_GROUP* group,
                                           const EC_POINT* point,
-                                          point_conversion_form_t form) {
+                                          point_conversion_form_t form,
+                                          const char** error) {
   size_t len = EC_POINT_point2oct(group, point, form, nullptr, 0, nullptr);
   if (len == 0) {
-    env->ThrowError("Failed to get public key length");
+    if (error != nullptr) *error = "Failed to get public key length";
     return MaybeLocal<Object>();
   }
   MallocedBuffer<unsigned char> buf(len);
   len = EC_POINT_point2oct(group, point, form, buf.data, buf.size, nullptr);
   if (len == 0) {
-    env->ThrowError("Failed to get public key");
+    if (error != nullptr) *error = "Failed to get public key";
     return MaybeLocal<Object>();
   }
   return Buffer::New(env, buf.release(), len);
 }
 
+
 static Local<Object> X509ToObject(Environment* env, X509* cert) {
   EscapableHandleScope scope(env->isolate());
   Local<Context> context = env->context();
@@ -4474,6 +4477,7 @@ void ECDH::GetPublicKey(const FunctionCallbackInfo<Value>& args) {
   ECDH* ecdh;
   ASSIGN_OR_RETURN_UNWRAP(&ecdh, args.Holder());
 
+  const EC_GROUP* group = EC_KEY_get0_group(ecdh->key_.get());
   const EC_POINT* pub = EC_KEY_get0_public_key(ecdh->key_.get());
   if (pub == nullptr)
     return env->ThrowError("Failed to get ECDH public key");
@@ -4482,10 +4486,11 @@ void ECDH::GetPublicKey(const FunctionCallbackInfo<Value>& args) {
   uint32_t val = args[0].As<Uint32>()->Value();
   point_conversion_form_t form = static_cast<point_conversion_form_t>(val);
 
-  MaybeLocal<Object> buf =
-      ECPointToBuffer(env, EC_KEY_get0_group(ecdh->key_.get()), pub, form);
-  if (buf.IsEmpty()) return;
-  args.GetReturnValue().Set(buf.ToLocalChecked());
+  const char* error;
+  Local<Object> buf;
+  if (!ECPointToBuffer(env, group, pub, form, &error).ToLocal(&buf))
+    return env->ThrowError(error);
+  args.GetReturnValue().Set(buf);
 }
 
 
@@ -5088,9 +5093,11 @@ void ConvertKey(const FunctionCallbackInfo<Value>& args) {
   uint32_t val = args[2].As<Uint32>()->Value();
   point_conversion_form_t form = static_cast<point_conversion_form_t>(val);
 
-  MaybeLocal<Object> buf = ECPointToBuffer(env, group.get(), pub.get(), form);
-  if (buf.IsEmpty()) return;
-  args.GetReturnValue().Set(buf.ToLocalChecked());
+  const char* error;
+  Local<Object> buf;
+  if (!ECPointToBuffer(env, group.get(), pub.get(), form, &error).ToLocal(&buf))
+    return env->ThrowError(error);
+  args.GetReturnValue().Set(buf);
 }