Dart

Duplicate Java Verify RSA Signature

See more RSA Examples

Demonstrates how to duplicate a snippet of Java code that verifies an RSA signature. Dart

import 'package:chilkat/chilkat.dart';

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

  // This example duplicates the following Java code:

  // import com.sun.org.apache.xml.internal.security.utils.Base64;  
  // import java.io.ByteArrayInputStream;  
  // import java.security.PublicKey;  
  // import java.security.Signature;  
  // import java.security.cert.CertificateFactory;  
  // import java.security.cert.X509Certificate;  
  // public class validateSazetak {  
  //   public static void main(String[] args) {  
  //   String signatureAlgorithm = "SHA256withRSA";  
  //   String base64DataToBeSigned = "Hlp...LE4=";  
  //   String base64Certificate = "MII...TlQ==";  
  //   String base64Signature = "I00...pZA==";  
  //   try {  
  //       CertificateFactory cf;  
  //       X509Certificate certificate = null;  
  //       cf = CertificateFactory.getInstance("X.509");  
  //       certificate = (X509Certificate) cf.generateCertificate(new 
  //       ByteArrayInputStream(Base64.decode(base64Certificate)));  
  //        
  //       Signature signature = Signature.getInstance(signatureAlgorithm, "SunRsaSign");  
  //       PublicKey pk = (PublicKey) certificate.getPublicKey();  
  //       signature.initVerify(pk);  
  //        
  //       byte[] hashBytes = Base64.decode(base64DataToBeSigned);  
  //       signature.update(hashBytes);  
  //        
  //       byte[] sigBytes = Base64.decode(base64Signature);  
  //       boolean validity = signature.verify(sigBytes);  
  //       System.out.println("Is valid signature:" + validity);  
  //     } catch (Exception e) {  
  //         System.out.println(e);  
  //     }  
  // } 

  final base64DataToBeSigned = 'Hlp...LE4=';
  final base64Certificate = 'MII...TlQ==';
  final base64Signature = 'I00...pZA==';

  final cert = CkCert();
  try {
    cert.loadFromBase64(base64Certificate);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final rsa = CkRsa();

  try {
    rsa.setX509Cert(cert, false);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  rsa.encodingMode = 'base64';
  try {
    rsa.verifyStringENC(base64DataToBeSigned, 'sha256', base64Signature);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Signature verified.');
}