(MFC) RSA Sign with PKCS8 Encrypted Key

See more RSA Examples

Demonstrates how to load a private key from an encrypted PKCS8 file and create an RSA digital signature.

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

See Also: Using MFC CString in Chilkat

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

void ChilkatSample(void)
    {
    CkString strOut;

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

    CkPrivateKey pkey;

    // Load the private key from an RSA PEM file:
    bool success = pkey.LoadPkcs8EncryptedFile("privateKey.key","myPassword");

    const char *pkeyXml = 0;
    // Get the private key in XML format:
    pkeyXml = pkey.getXml();

    CkRsa rsa;

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

    // Return the signature in hex
    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 "md2", "sha256", "sha384", "sha512",  and "md5".
    const char *hexSig = rsa.signStringENC(strData,"sha-1");

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


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }