(Tcl) Duplicate Java Verify RSA Signature

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

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load ./chilkat.dll

# 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);  
#     }  
# } 

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

set cert [new_CkCert]

set success [CkCert_LoadFromBase64 $cert $base64Certificate]
if {$success == 0} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkCert $cert
    exit
}

set rsa [new_CkRsa]

set success [CkRsa_SetX509Cert $rsa $cert 0]
if {$success == 0} then {
    puts [CkRsa_lastErrorText $rsa]
    delete_CkCert $cert
    delete_CkRsa $rsa
    exit
}

CkRsa_put_EncodingMode $rsa "base64"
set success [CkRsa_VerifyStringENC $rsa $base64DataToBeSigned "sha256" $base64Signature]
if {$success == 0} then {
    puts [CkRsa_lastErrorText $rsa]
    delete_CkCert $cert
    delete_CkRsa $rsa
    exit
}

puts "Signature verified."

delete_CkCert $cert
delete_CkRsa $rsa