(DataFlex) Duplicate Java Verify RSA Signature

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    String sBase64DataToBeSigned
    String sBase64Certificate
    String sBase64Signature
    Variant vCert
    Handle hoCert
    Boolean iSuccess
    Handle hoRsa
    String sTemp1

    // 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);  
    //     }  
    // } 

    Move "Hlp...LE4=" To sBase64DataToBeSigned
    Move "MII...TlQ==" To sBase64Certificate
    Move "I00...pZA==" To sBase64Signature

    Get Create (RefClass(cComChilkatCert)) To hoCert
    If (Not(IsComObjectCreated(hoCert))) Begin
        Send CreateComObject of hoCert
    End
    Get ComLoadFromBase64 Of hoCert sBase64Certificate To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoCert To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get Create (RefClass(cComChilkatRsa)) To hoRsa
    If (Not(IsComObjectCreated(hoRsa))) Begin
        Send CreateComObject of hoRsa
    End

    Get pvComObject of hoCert to vCert
    Get ComSetX509Cert Of hoRsa vCert False To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoRsa To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Set ComEncodingMode Of hoRsa To "base64"
    Get ComVerifyStringENC Of hoRsa sBase64DataToBeSigned "sha256" sBase64Signature To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoRsa To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Signature verified."


End_Procedure