(MFC) SII Chile - FRMT Signature Computation and Add to XML

Compute the FRMT signature and add to the XML. This is the RSA signature of the SHA-1 digest of the "flattened" DD element.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkXml.h>
#include <CkStringBuilder.h>
#include <CkPrivateKey.h>
#include <CkRsa.h>

void ChilkatSample(void)
    {
    CkString strOut;

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // Also see:  Compute the FRMA Signature and Add to XML

    CkXml xml;

    // Load the unsigned XML that contains the following:

    // <DTE version="1.0">
    //   <Documento ID="F60T33">
    //         <TED version="1.0">
    //             <DD>
    // 		...
    //                 <CAF version="1.0">
    //                     <DA>
    // 			...
    //                     </DA>
    //                     <FRMA algoritmo="SHA1withRSA">...</FRMA>
    //                 </CAF>
    //                 ...
    //             </DD>
    //             ... The FRMT will be added here in another example ...
    //         </TED>
    //   </Documento>
    // </DTE>

    bool success = xml.LoadXmlFile("qa_data/xml_dsig/sii_cl/test_1.xml");
    if (success == false) {
        strOut.append("Failed to load initial XML file.");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Get a reference to the "DD" element
    CkXml *ddXml = xml.FindChild("Documento|TED|DD");
    if (xml.get_LastMethodSuccess() == false) {
        strOut.append("Failed to find DD element");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  We need to get the "flattened" DD XML where:
    //    - No whitespace between elements.
    //    - The 5 pre-defined entities are converted.
    //    - The text is encoded in the ISO-8859-1 character set (Latin-1), 
    CkStringBuilder sbFlattened;
    ddXml->put_EmitCompact(true);
    ddXml->put_EmitXmlDecl(false);
    ddXml->GetXmlSb(sbFlattened);

    // Compute the SHA-1 message digest of the iso-8859-1 byte representation, 
    // and sign it with our RSA private key, getting the result in base64 format.

    CkPrivateKey privKey;
    success = privKey.LoadAnyFormatFile("qa_data/rsa/rsaPrivKey_pkcs8.pem","");
    if (success == false) {
        strOut.append(privKey.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkRsa rsa;
    rsa.ImportPrivateKeyObj(privKey);

    rsa.put_EncodingMode("base64");
    rsa.put_Charset("iso-8859-1");
    const char *sig = rsa.signStringENC(sbFlattened.getAsString(),"sha1");

    // Add the FRMT signature element to the XML.
    xml.UpdateChildContent("Documento|TED|FRMT",sig);
    xml.UpdateAttrAt("Documento|TED|FRMT",true,"algoritmo","SHA1withRSA");

    delete ddXml;

    // See what we have:
    xml.put_EmitCompact(false);
    xml.put_EmitXmlDecl(true);
    strOut.append(xml.getXml());
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }