(MFC) RSA Sign Using Private Key from .pfx/.p12 to Base64 Signature

See more RSA Examples

Demonstrates how to RSA sign something using a private key loaded from a .pfx/.p12. The RSA signature is returned in Base64 encoded format.

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

See Also: Using MFC CString in Chilkat

#include <CkRsa.h>
#include <CkPfx.h>
#include <CkPrivateKey.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    CkRsa rsa;

    // Load the .pfx/.p12
    CkPfx pfx;
    bool success = pfx.LoadPfxFile("qa_data/pfx/myKey.p12","myPassword");
    if (success != true) {
        strOut.append(pfx.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Get the default private key.
    CkPrivateKey *privKey = pfx.GetPrivateKey(0);
    if (pfx.get_LastMethodSuccess() != true) {
        strOut.append(pfx.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

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

    delete privKey;

    // Get the signature in base64
    rsa.put_EncodingMode("base64");

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

    // Sign the string using the sha256 hash algorithm.
    // Other valid choices are "sha384", "sha512", "sha-1", "md2" and "md5".
    const char *base64Sig = rsa.signStringENC(strData,"sha256");

    strOut.append(base64Sig);
    strOut.append("\r\n");

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


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }