Dart

Export a Private Key as DER into a BinData

Demonstrates the Chilkat PrivateKey.GetPkcsBd method, which exports the key as DER into a BinData. The first argument selects PKCS #1 (true) versus PKCS #8 (false), the second is the password (empty for unencrypted), and the third is the BinData that receives the bytes.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: This is the in-memory binary export — the raw DER bytes land in a BinData ready to hash, encrypt, or hand to another API without a temporary file. One method covers several cases: the boolean picks the traditional (PKCS #1) versus modern (PKCS #8) structure, and a nonempty password produces an encrypted PKCS #8 export (with the cipher from Pkcs8EncryptAlg). Source any password securely.

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Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // Load a private key to export.
  final privKey = CkPrivateKey();
  try {
    privKey.loadPemFile('qa_data/private.pem');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // The key password is not hard-coded in a real application; obtain it from an interactive
  // prompt, environment variable, or a secrets vault.
  final password = 'myKeyPassword';

  // Export the key as DER into a BinData.  The 1st argument selects PKCS #1 (true) versus PKCS #8
  // (false); the 2nd is the password (empty string for an unencrypted export); the 3rd is the
  // BinData that receives the DER bytes.
  final usePkcs1 = false;
  final bd = CkBinData();
  try {
    privKey.getPkcsBd(usePkcs1, password, bd);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Exported ${bd.numBytes} DER bytes.');
}