Java

Duplicate Java Verify RSA Signature

See more RSA Examples

Demonstrates how to duplicate a snippet of Java code that verifies an RSA signature. Chilkat2 Java

import com.chilkatsoft.chilkat2.Cert;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Rsa;

public class ChilkatExample {

    public static void main(String[] args) {
        // 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);
        //     }
        // }

        String base64DataToBeSigned = "Hlp...LE4=";
        String base64Certificate = "MII...TlQ==";
        String base64Signature = "I00...pZA==";

        Cert cert = new Cert();
        try {
            cert.loadFromBase64(base64Certificate);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        Rsa rsa = new Rsa();

        try {
            rsa.setX509Cert(cert, false);

            rsa.setEncodingMode("base64");
            rsa.verifyStringENC(base64DataToBeSigned, "sha256", base64Signature);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("Signature verified.");
    }
}