C++

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

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

Note: This is a Windows-only example.

C++

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

void ChilkatSample(void)
    {
    bool success = false;

    // 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;
    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.)
    CkJsonObject json;
    json.UpdateString("thumbprint",thumbprint);

    CkCert cert;
    success = certStore.FindCert(json,cert);
    if (success == false) {
        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);
    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";
    }