RSA Signature with Certificate's Private Key from PFX

Demonstrates how to use a certificate's private key from a PFX file to create an RSA signature.

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C++ Builder Libraries

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

    CkString strOut;

    bool success;

    //  Create an instance of a certificate store object, load a PFX file,
    //  locate the certificate we need, and use it for signing.
    //  (a PFX file may contain more than one certificate.)
    CkCertStore certStore;

    //  The 1st argument is the filename, the 2nd arg is the
    //  PFX file's password:
    success = certStore.LoadPfxFile("chilkat.pfx","test");
    if (success != true) {
        strOut.append(certStore.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkCert *cert = 0;
    cert = certStore.FindCertBySubject("Chilkat Software, Inc.");
    if (cert == 0 ) {
        strOut.append(certStore.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkPrivateKey *pkey = 0;
    pkey = cert->ExportPrivateKey();
    if (pkey == 0 ) {
        strOut.append(cert->lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    const char * pkeyXml;
    //  Get the private key in XML format:
    pkeyXml = pkey->getXml();
    delete pkey;

    CkRsa rsa;

    //  Any string argument automatically begins the 30-day trial.

    success = rsa.UnlockComponent("30-day trial");
    if (success != true) {
        strOut.append("RSA component unlock failed\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Import the private key into the RSA component:
    success = rsa.ImportPrivateKey(pkeyXml);
    if (success != true) {
        strOut.append(rsa.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  This example will sign a string, and receive the signature
    //  in a hex-encoded string.  Therefore, set the encoding mode
    //  to "hex":
    rsa.put_EncodingMode("hex");

    //  If some other non-Chilkat application or web service is going to be verifying
    //  the signature, it is important to match the byte-ordering.
    //  The LittleEndian property may be set to true
    //  for little-endian byte ordering,
    //  or false  for big-endian byte ordering.
    //  Microsoft apps typically use little-endian, while
    //  OpenSSL and other services (such as Amazon CloudFront)
    //  use big-endian.
    rsa.put_LittleEndian(false);

    const char * strData;
    strData = "This is the string to be signed.";

    //  Sign the string using the sha-1 hash algorithm.
    //  Other valid choices are "md2" and "md5".
    const char * hexSig;
    hexSig = rsa.signStringENC(strData,"sha-1");

    strOut.append(hexSig);
    strOut.append("\r\n");

    strOut.append("Success!\r\n");

    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());