(Go) Duplicate Java Verify RSA Signature

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

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

    // 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);  
    //     }  
    // } 

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

    cert := chilkat.NewCert()
    success := cert.LoadFromBase64(base64Certificate)
    if success == false {
        fmt.Println(cert.LastErrorText())
        cert.DisposeCert()
        return
    }

    rsa := chilkat.NewRsa()

    success = rsa.SetX509Cert(cert,false)
    if success == false {
        fmt.Println(rsa.LastErrorText())
        cert.DisposeCert()
        rsa.DisposeRsa()
        return
    }

    rsa.SetEncodingMode("base64")
    success = rsa.VerifyStringENC(base64DataToBeSigned,"sha256",base64Signature)
    if success == false {
        fmt.Println(rsa.LastErrorText())
        cert.DisposeCert()
        rsa.DisposeRsa()
        return
    }

    fmt.Println("Signature verified.")

    cert.DisposeCert()
    rsa.DisposeRsa()