(C++) RSA Sign String using Private Key of Certificate Type A3 (smart card / token)

Demonstrates RSA signing a string using the private key of a certificate type A3 (smart card, token).

Note: This is a Windows-only example.

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

void ChilkatSample(void)
    {
    // First get the A3 certificate that was installed on the Windows system.
    CkCertStore certStore;

    const char *thumbprint = "12c1dd8015f3f03f7b1fa619dc24e2493ca8b4b2";

    // This is specific to Windows because it is opening the Windows Current-User certificate store.
    bool bReadOnly = true;
    bool success = certStore.OpenCurrentUserStore(bReadOnly);
    if (success != true) {
        std::cout << certStore.lastErrorText() << "\r\n";
        return;
    }

    // Find the certificate with the desired thumbprint
    // (There are many ways to locate a certificate.  This example chooses to find by thumbprint.)
    CkCert *cert = certStore.FindCertBySha1Thumbprint(thumbprint);
    if (certStore.get_LastMethodSuccess() != true) {
        std::cout << "Failed to find the certificate." << "\r\n";
        return;
    }

    std::cout << "Found: " << cert->subjectCN() << "\r\n";

    CkRsa rsa;

    // Provide the cert's private key
    bool bUsePrivateKey = true;
    success = rsa.SetX509Cert(*cert,bUsePrivateKey);
    delete cert;
    if (success != true) {
        std::cout << rsa.lastErrorText() << "\r\n";
        return;
    }

    // Return the RSA signature in base64 encoded form.
    rsa.put_EncodingMode("base64");

    // Sign the utf-8 byte representation of the string.
    rsa.put_Charset("utf-8");

    // You can also choose other hash algorithms, such as SHA-1.
    const char *sigBase64 = rsa.signStringENC("text to sign","SHA-256");
    if (rsa.get_LastMethodSuccess() != true) {
        std::cout << rsa.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Base64 signature: " << sigBase64 << "\r\n";
    }