(Unicode C++) Sign JSON (or any Text) to Create a Detached PKCS7 Signature

Demonstrates how to sign JSON or any string using a certificate + private key from a .p12/.pfx to create a detached PKCS7 signature. (A detached signature is one that does not embed the original signed data.)

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#include <CkCrypt2W.h>
#include <CkCertW.h>
#include <CkByteData.h>

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

    CkCrypt2W crypt;

    CkCertW cert;
    bool success = cert.LoadPfxFile(L"qa_data/pfx/cert_test123.pfx",L"test123");
    if (success != true) {
        wprintf(L"%s\n",cert.lastErrorText());
        return;
    }

    // Tell the crypt component to use this cert.
    success = crypt.SetSigningCert(cert);
    if (success != true) {
        wprintf(L"%s\n",crypt.lastErrorText());
        return;
    }

    crypt.put_HashAlgorithm(L"sha256");

    // By default, all the certs in the chain of authentication are included in the signature.
    // If desired, we can choose to only include the signing certificate:
    crypt.put_IncludeCertChain(false);

    // Create the detached signature, which does NOT contain the original data.
    // To create a PKCS7 signature that contains the original data, see CAdES Sign JSON
    crypt.put_Charset(L"utf-8");
    CkByteData detachedSig;
    const wchar_t *stringToSign = L"{ \"abc\": 123}";
    success = crypt.SignString(stringToSign,detachedSig);
    if (crypt.get_LastMethodSuccess() == false) {
        wprintf(L"%s\n",crypt.lastErrorText());
        return;
    }

    // Verify the signature against the original data.
    bool verified = crypt.VerifyString(stringToSign,detachedSig);
    if (verified == false) {
        wprintf(L"%s\n",crypt.lastErrorText());
        return;
    }

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