(Unicode C++) RSA Signature/Verify with .key and .cer

Demonstrates how to use a .key file (private key) and digital certificate (.cer, public key) to create and verify an RSA signature.

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#include <CkPrivateKeyW.h>
#include <CkRsaW.h>
#include <CkCertW.h>
#include <CkPublicKeyW.h>

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

    CkPrivateKeyW privKey;

    // Load the private key from an RSA .key file:
    bool success = privKey.LoadPemFile(L"privateKey.key");
    if (success != true) {
        wprintf(L"%s\n",privKey.lastErrorText());
        return;
    }

    const wchar_t *privKeyXml = 0;
    // Get the private key in XML format:
    privKeyXml = privKey.getXml();

    CkRsaW rsa;

    // Import the private key into the RSA component:
    success = rsa.ImportPrivateKey(privKeyXml);
    if (success != true) {
        wprintf(L"%s\n",rsa.lastErrorText());
        return;
    }

    // Create the signature as a hex string:
    rsa.put_EncodingMode(L"hex");

    // If some other non-Chilkat application or web service is going to be verifying
    // the signature, it is important to match the byte-ordering.
    // The LittleEndian property may be set to true
    // for little-endian byte ordering, 
    // or false  for big-endian byte ordering.
    // Microsoft apps typically use little-endian, while
    // OpenSSL and other services (such as Amazon CloudFront)
    // use big-endian.
    rsa.put_LittleEndian(false);

    const wchar_t *strData = L"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 wchar_t *hexSig = rsa.signStringENC(strData,L"sha-1");

    wprintf(L"%s\n",hexSig);

    // Load a digital certificate from a .cer file:
    CkCertW cert;

    success = cert.LoadFromFile(L"myCert.cer");
    if (success != true) {
        wprintf(L"%s\n",cert.lastErrorText());
        return;
    }

    CkPublicKeyW *pubKey = 0;

    pubKey = cert.ExportPublicKey();

    // Now verify using a separate instance of the RSA object:
    CkRsaW rsa2;

    // Import the public key into the RSA object:
    success = rsa2.ImportPublicKey(pubKey->getXml());
    if (success != true) {
        wprintf(L"%s\n",rsa2.lastErrorText());
        return;
    }

    delete pubKey;

    // The signature is a hex string, so make sure the EncodingMode is correct:
    rsa2.put_EncodingMode(L"hex");

    // Verify the signature:
    success = rsa2.VerifyStringENC(strData,L"sha-1",hexSig);
    if (success != true) {
        wprintf(L"%s\n",rsa2.lastErrorText());
        return;
    }

    wprintf(L"Success.\n");
    }