(Lianja) Duplicate Java Verify RSA Signature

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

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// 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);  
//     }  
// } 

lcBase64DataToBeSigned = "Hlp...LE4="
lcBase64Certificate = "MII...TlQ=="
lcBase64Signature = "I00...pZA=="

loCert = createobject("CkCert")
llSuccess = loCert.LoadFromBase64(lcBase64Certificate)
if (llSuccess = .F.) then
    ? loCert.LastErrorText
    release loCert
    return
endif

loRsa = createobject("CkRsa")

llSuccess = loRsa.SetX509Cert(loCert,.F.)
if (llSuccess = .F.) then
    ? loRsa.LastErrorText
    release loCert
    release loRsa
    return
endif

loRsa.EncodingMode = "base64"
llSuccess = loRsa.VerifyStringENC(lcBase64DataToBeSigned,"sha256",lcBase64Signature)
if (llSuccess = .F.) then
    ? loRsa.LastErrorText
    release loCert
    release loRsa
    return
endif

? "Signature verified."


release loCert
release loRsa