BIP32 derivePath different privatekey in nodejs and dart(flutter) (same mnemonic) - node.js

Question

Hello i'm have some problem with BIP32
i use BIP32 library in nodejs and dart(flutter)
in dart(flutter) BIP32 derivePath show different privatekey but not of all mnemonic is just incorrect some mnemonic
in 1000 mnemonic different privatekey 1-2 mnemonic
below is dart derivePath,,
what is inccorect in this code:
Help me pls.
BIP32 derivePath(String path) {
final regex = new RegExp(r"^(m\/)?(\d+'?\/)*\d+'?$");
if (!regex.hasMatch(path)) throw new ArgumentError("Expected BIP32 Path");
List<String> splitPath = path.split("/");
if (splitPath[0] == "m") {
if (parentFingerprint != 0) throw new ArgumentError("Expected master, got child");
splitPath = splitPath.sublist(1);
print("splitPath: "+ splitPath);
}
print("splitPath: "+ splitPath);
return splitPath.fold(this, (BIP32 prevHd,String indexStr) {
int index;
if (indexStr.substring(indexStr.length - 1) == "'") {
index = int.parse(indexStr.substring(0, indexStr.length - 1));
return prevHd.deriveHardened(index);
} else {
index = int.parse(indexStr);
return prevHd.derive(index);
}
});
}
BIP32 derive(int index) {
if (index > UINT32_MAX || index < 0) throw new ArgumentError("Expected UInt32");
final isHardened = index >= HIGHEST_BIT;
Uint8List data = new Uint8List(37);
if (isHardened) {
if (isNeutered()) {
throw new ArgumentError("Missing private key for hardened child key");
}
data[0] = 0x00;
data.setRange(1, 33, privateKey);
data.buffer.asByteData().setUint32(33, index);
} else {
data.setRange(0, 33, publicKey);
data.buffer.asByteData().setUint32(33, index);
}
final I = hmacSHA512(chainCode, data);
final IL = I.sublist(0, 32);
final IR = I.sublist(32);
if (!ecc.isPrivate(IL)) {
return derive(index + 1);
}
BIP32 hd;
if (!isNeutered()) {
final ki = ecc.privateAdd(privateKey, IL);
if (ki == null) return derive(index + 1);
hd = BIP32.fromPrivateKey(ki, IR, network);
} else {
final ki = ecc.pointAddScalar(publicKey, IL, true);
if (ki == null) return derive(index + 1);
hd = BIP32.fromPublicKey(ki, IR, network);
}
hd.depth = depth + 1;
hd.index = index;
hd.parentFingerprint = fingerprint.buffer.asByteData().getUint32(0);
return hd;
}
BIP32 deriveHardened(int index) {
if (index > UINT31_MAX || index < 0) throw new ArgumentError("Expected UInt31");
return this.derive(index + HIGHEST_BIT);
}

Answer 1

OK can solved this problem problem occur in the ecuve function bytes is less than 32 bytes just padding 0 in the left equal 32 bytes just solved it !