(MFC) Download and Trust the DigiCert Global Root CA

Demonstrates how to download a root certificate and trust it.

For more information, see https://www.digicert.com/digicert-root-certificates.htm

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

See Also: Using MFC CString in Chilkat

#include <CkHttp.h>
#include <CkBinData.h>
#include <CkCert.h>
#include <CkTrustedRoots.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    // In this example, the URLs for the DigiCert root CA certs are available at this web page:
    // https://www.digicert.com/digicert-root-certificates.htm

    // This example downloads the "DigiCert Global Root G3"
    // Valid until: 15/Jan/2038
    // Serial #: 05:55:56:BC:F2:5E:A4:35:35:C3:A4:0F:D5:AB:45:72
    // Thumbprint: 7E04DE896A3E666D00E687D33FFAD93BE83D349E

    const char *certUrl = "https://dl.cacerts.digicert.com/DigiCertGlobalRootG3.crt";

    CkHttp http;
    CkBinData bdCert;
    bool success = http.DownloadBd(certUrl,bdCert);
    if (success == false) {
        strOut.append(http.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Load it into a Chilkat cert object.
    CkCert cert;
    success = cert.LoadFromBd(bdCert);
    if (success == false) {
        strOut.append(cert.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Examine the common name,serial, and thumbprint:
    strOut.append("CN: ");
    strOut.append(cert.subjectCN());
    strOut.append("\r\n");
    strOut.append("Serial: ");
    strOut.append(cert.serialNumber());
    strOut.append("\r\n");
    strOut.append("Thumbprint: ");
    strOut.append(cert.sha1Thumbprint());
    strOut.append("\r\n");

    // Output from the above:
    // CN: DigiCert Global Root G3
    // Serial: 055556BCF25EA43535C3A40FD5AB4572
    // Thumbprint: 7E04DE896A3E666D00E687D33FFAD93BE83D349E

    // If desired, the certificate can be saved to a local file so it does not need
    // to be downloaded from the website every time.  
    const char *certPath = "qa_data/certs/DigiCertGlobalRootG3.crt";
    success = bdCert.WriteFile(certPath);

    // To load the cert from a file...
    success = cert.LoadFromFile(certPath);

    // Do the following to add the cert to the collection of trusted roots
    // for this application.  (Note:  The trust is not persisted.  Each time the
    // application runs, it should load the cert (from whatever source, whether it is
    // a file, a database,etc.) and do the following:
    CkTrustedRoots troots;

    troots.AddCert(cert);
    troots.Activate();

    strOut.append(cert.subjectCN());
    strOut.append(" is now trusted for this run of this application.");
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }