Dart Requires Chilkat v11.0.0+

Duplicate openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

See more RSA Examples

Demonstrates how to duplicate the creation of an RSA signature produced by this OpenSSL command:

openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example assumes the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  final pkey = CkPrivateKey();

  // Load the private key from an RSA PEM file:
  pkey.loadPemFile('myKey.pem');

  final rsa = CkRsa();

  // Import the private key into the RSA component:
  try {
    rsa.usePrivateKey(pkey);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // OpenSSL uses BigEndian byte ordering:
  rsa.littleEndian = false;

  // The resulting signature will be a Base64 string:
  rsa.encodingMode = 'base64';

  // For simplicity, we're not loading
  // the data to be signed from a file.  We are instead simply
  // using a literal string value.  
  final strData = 'This is the text to be signed.';

  // Hash the input using MD5, and then sign the hash:
  // Other valid hash algorithm choices are "md2" and "sha-1".
  final base64Sig = rsa.signStringENC(strData, 'md5');

  print(base64Sig);

  print('Success!');
}