Xbase++

Duplicate Java Verify RSA Signature

See more RSA Examples

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

LOCAL nSuccess
LOCAL cBase64DataToBeSigned
LOCAL cBase64Certificate
LOCAL cBase64Signature
LOCAL oCert
LOCAL oRsa

nSuccess := 0

//  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);  
//      }  
//  } 

cBase64DataToBeSigned := "Hlp...LE4="
cBase64Certificate := "MII...TlQ=="
cBase64Signature := "I00...pZA=="

oCert := CreateObject("Chilkat.Cert")
nSuccess := oCert:LoadFromBase64(cBase64Certificate)
IF (nSuccess == 0)
    ? oCert:LastErrorText
    oCert:destroy()
    RETURN
ENDIF

oRsa := CreateObject("Chilkat.Rsa")

nSuccess := oRsa:SetX509Cert(oCert, 0)
IF (nSuccess == 0)
    ? oRsa:LastErrorText
    oCert:destroy()
    oRsa:destroy()
    RETURN
ENDIF

oRsa:EncodingMode := "base64"
nSuccess := oRsa:VerifyStringENC(cBase64DataToBeSigned, "sha256", cBase64Signature)
IF (nSuccess == 0)
    ? oRsa:LastErrorText
    oCert:destroy()
    oRsa:destroy()
    RETURN
ENDIF

? "Signature verified."

oCert:destroy()
oRsa:destroy()