(MFC) Export Digital Certificate's Public Key

The ExportPublicKey method can be called to get a certificate's public key. It can then be saved to any of a number of formats: (1) OpenSSL DER, (2) OpenSSL PEM, (3) RSA DER, (4) XML.

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

See Also: Using MFC CString in Chilkat

#include <CkCert.h>
#include <CkPublicKey.h>

void ChilkatSample(void)
    {
    CkString strOut;

    CkCert cert;

    // LoadFromFile will load virtually any certificate format file.
    // It will auto-recognize the format and load appropiately.
    bool success = cert.LoadFromFile("/Users/chilkat/testData/cer/chilkat.cer");
    if (success != true) {
        strOut.append(cert.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Get the public key:
    CkPublicKey *pubkey = 0;

    pubkey = cert.ExportPublicKey();
    if (cert.get_LastMethodSuccess() == false) {
        strOut.append(cert.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Save to various formats:
    success = pubkey->SaveOpenSslDerFile("/Users/chilkat/testData/pubkeys/chilkat_openSsl.der");
    if (success != true) {
        strOut.append(pubkey->lastErrorText());
        strOut.append("\r\n");
        delete pubkey;
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    success = pubkey->SaveOpenSslPemFile("/Users/chilkat/testData/pubkeys/chilkat_openSsl.pem");
    if (success != true) {
        strOut.append(pubkey->lastErrorText());
        strOut.append("\r\n");
        delete pubkey;
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    success = pubkey->SaveRsaDerFile("/Users/chilkat/testData/pubkeys/chilkat_rsa.der");
    if (success != true) {
        strOut.append(pubkey->lastErrorText());
        strOut.append("\r\n");
        delete pubkey;
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    success = pubkey->SaveXmlFile("/Users/chilkat/testData/pubkeys/chilkat.xml");
    if (success != true) {
        strOut.append(pubkey->lastErrorText());
        strOut.append("\r\n");
        delete pubkey;
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    delete pubkey;
    strOut.append("Public key exported to all file formats.");
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }