(MFC) RSA Signature with Certificate's Private Key from PFX

See more RSA Examples

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

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

See Also: Using MFC CString in Chilkat

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

void ChilkatSample(void)
    {
    CkString strOut;

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

    // 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:
    bool 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 = certStore.FindCertBySubject("Chilkat Software, Inc.");
    if (certStore.get_LastMethodSuccess() == false) {
        strOut.append(certStore.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

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

    delete cert;

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

    CkRsa rsa;

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

    // Encode the signature as a hex string
    rsa.put_EncodingMode("hex");

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

    // Sign the string using the sha-1 hash algorithm.
    // Other valid choices are "sha-256", "md2" and "md5".
    const char *hexSig = rsa.signStringENC(strData,"sha-1");

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

    delete pkey;

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


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }