childKey method

Implementation

@override
Bip32Slip10Ed25519Blake2b childKey(Bip32KeyIndex index) {
  final isPublic = isPublicOnly;

  if (!isPublic) {
    if (!index.isHardened && !isPublicDerivationSupported) {
      throw Bip32KeyError.notHardenedIndexNotSupported;
    }
    assert(!isPublicOnly);
    final result = keyDerivator.deriveFromSecret(
      parent: privateKey,
      ctx: publicKey,
      index: index,
      type: curveType,
    );

    return Bip32Slip10Ed25519Blake2b(
      keyData: Bip32KeyData(
        chainCode: result.chainCode,
        depth: depth.increase(),
        index: index,
        fingerPrint: fingerPrint,
      ),
      keyNetVer: keyNetVersions,
      privKey: result.key,
      pubKey: null,
    );
  }
  throw Bip32KeyError.publicDerivationNotSupported;
}