(MFC) Convert ASN.1 to/from Binary DER, XML, and Base64

Demonstrates how to convert ASN.1 from and to any of the following formats: binary DER, Base64, and XML.

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

See Also: Using MFC CString in Chilkat

#include <CkAsn.h>
#include <CkXml.h>

void ChilkatSample(void)
    {
    CkString strOut;

    CkAsn asn;

    bool success;

    //  Begin with loading ASN.1 from a binary DER/BER format file.
    success = asn.LoadBinaryFile("/Users/chilkat/testData/p7b/test.p7b");
    if (success != true) {
        strOut.append(asn.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Convert ASN.1 to XML:
    const char *strXml = asn.asnToXml();
    if (asn.get_LastMethodSuccess() != true) {
        strOut.append(asn.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  The XML returned by AsnToXml will be compact and not pretty-formatted.
    //  Use Chilkat XML to format the XML better:
    CkXml xml;
    success = xml.LoadXml(strXml);
    //  Assuming success for this example..
    //  This is formatted better for human viewing:
    strOut.append(xml.getXml());
    strOut.append("\r\n");

    //  Now get the ASN.1 in base64 format.  Any encoding supported
    //  by Chilkat can be passed, such as "hex", "uu", "quoted-printable", "base32", "modbase64", etc.
    const char *strBase64 = asn.getEncodedDer("base64");

    //  Load the ASN.1 from XML:
    CkAsn asn2;
    success = asn2.LoadAsnXml(xml.getXml());
    if (success != true) {
        strOut.append(asn2.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Load the ASN.1 from an encoded string, such as base64:
    CkAsn asn3;
    success = asn3.LoadEncoded(strBase64,"base64");
    if (success != true) {
        strOut.append(asn3.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }



    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }