About RSA Public/Private Keys

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// Needs #include <CkCert.h>
// Needs #include <CkPublicKey.h>
// Needs #include <CkPrivateKey.h>
// Needs #include <CkRsa.h>

    CkString strOut;

    CkCert cert;

    bool success;

    //  Load a digital certificate.
    success = cert.LoadFromFile("digitalCert.cer");
    if (success != true) {
        strOut.append(cert.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkPublicKey *pubKey = 0;

    //  A .cer file does not contain the private key.  It should contain
    //  the public key...
    pubKey = cert.ExportPublicKey();

    //  Let's have a look at it (in XML format).
    strOut.append("Public Key from Certificate:");
    strOut.append("\r\n");
    strOut.append(pubKey->GetXml());
    strOut.append("\r\n");

    //  An RSA public key consists of a modulus and exponent.

    //  An RSA private key includes both the modulus and exponent,
    //  as well as other "big" numbers: P, Q, D, etc.

    //  Let's load an RSA private key from a DER-encoded file:
    CkPrivateKey privKey;

    success = privKey.LoadRsaDerFile("PrivateKey.key");
    if (success != true) {
        strOut.append(privKey.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  If this private key is the matching half to the public key from
    //  the certificate, then the modulus and exponent should
    //  be identical.  (Thus, a "private key" really contains both the public part as well as the private parts...).
    strOut.append("Private Key from DER:");
    strOut.append("\r\n");
    strOut.append(privKey.GetXml());
    strOut.append("\r\n");

    CkRsa rsa;
    success = rsa.UnlockComponent("Anything for 30-day trial.");
    if (success != true) {
        strOut.append(rsa.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  You now realize that the private key really contains both
    //  private and public parts.  Therefore, we may import the private
    //  key and the choose to use either the public or private in our
    //  encrypt/decrypt operations:
    const char * privKeyXml;
    privKeyXml = privKey.getXml();
    success = rsa.ImportPrivateKey(privKeyXml);
    if (success != true) {
        strOut.append(rsa.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }



    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());