Dart Requires Chilkat v11.0.0+

Encrypt with Chilkat, Decrypt with OpenSSL

See more OpenSSL Examples

Demonstrates how to RSA encrypt a string using Chilkat, and then shows the corresponding OpenSSL command to RSA decrypt. The OpenSSL command to decrypt is as follows:

openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

Dart

import 'package:chilkat/chilkat.dart';

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

  final rsa = CkRsa();

  // Note: RSA encryption uses the public key.  
  // RSA decryption uses the private key.
  // The reason is that the public key can be freely provided to anybody.  This allows anybody
  // to send an encrypted message to the private key owner, and only the private key owner 
  // can decrypt.
  final key = CkPublicKey();

  // Load an RSA public key from a PEM file:
  try {
    key.loadFromFile('qa_data/pem/VP_Public.pem');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Load the public key into the RSA object.
  try {
    rsa.usePublicKey(key);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final strToEncrypt = '00000000;XYZ2-3BHQ-ABCD-MMVV;6MY1-GHJK-9LRR;0';

  // The LittleEndian property is false by default, but it is set here
  // anyway to show that LittleEndian byte ordering is required for OpenSSL compatibility.
  rsa.littleEndian = false;

  final usePrivateKey = false;
  final encryptedBytes = rsa.encryptString(strToEncrypt, usePrivateKey);
  if (!rsa.lastMethodSuccess) {
    print(rsa.lastErrorText);
    return;
  }

  // The OpenSSL command to decrypt would be this:
  // openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

  final fac = CkFileAccess();
  try {
    fac.writeEntireFile('qa_output/rsa_encrypted.bin', encryptedBytes);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('RSA Encryption Succeeded.');
}