(MFC) Get Certificate User Principal Name (UPN)

See more Certificates Examples

Demonstrates how to get a certificate's UPN from the SAN (Subject Alternative Name). Most certificates do not have a UPN. This example only applies to those certificates that have a User Principal Name.

Note: This example requires Chilkat v9.5.0.90 or greater due to fixes made in getting the UPN from the SAN.

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

See Also: Using MFC CString in Chilkat

#include <CkCert.h>
#include <CkXml.h>

void ChilkatSample(void)
    {
    CkString strOut;

    CkCert cert;

    bool success = cert.LoadFromFile("qa_data/certs/sample.cer");
    if (success == false) {
        strOut.append(cert.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkXml xml;
    xml.LoadXml(cert.subjectAlternativeName());
    strOut.append(xml.getXml());
    strOut.append("\r\n");

    // A certificate with a User Principal Name in the SAN might have this:

    // <SubjectAltName>
    //     <rfc822Name>joe@example.com</rfc822Name>
    //     <name type="oid" oid="1.3.6.1.4.1.311.20.2.3">joe@example.com</name>
    // </SubjectAltName>

    // The OID 1.3.6.1.4.1.311.20.2.3 is for the User Principal Name.
    const char *upn = xml.chilkatPath("/A/name,oid,1.3.6.1.4.1.311.20.2.3|*");
    if (xml.get_LastMethodSuccess() == false) {
        strOut.append("No user principle name.");
        strOut.append("\r\n");
    }
    else {
        strOut.append("User Principle Name = ");
        strOut.append(upn);
        strOut.append("\r\n");
    }



    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }