(MFC) Sign String to create a CAdES-T Signature

This example will sign a string to create a CAdEST-T signature.

Note: This example requires Chilkat v9.5.0.78 or greater.

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

See Also: Using MFC CString in Chilkat

#include <CkCrypt2.h>
#include <CkCert.h>
#include <CkJsonObject.h>
#include <CkBinData.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    CkCrypt2 crypt;

    // This example will use the certificate + private key currently inserted into a smartcard reader.
    CkCert cert;

    // If we wish to provide the smartcard PIN (otherwise the user will be prompted by the operating system).
    cert.put_SmartCardPin("000000");
    bool success = cert.LoadFromSmartcard("");
    if (success != true) {
        strOut.append(cert.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Note: It is also possible to use certs from .pfx/.p12, .pem, or other sources such as 
    // pre-installed Windows certificates.

    success = crypt.SetSigningCert(cert);

    // Use SHA-256 rather than the default of SHA-1
    crypt.put_HashAlgorithm("sha256");

    // Create JSON that tells Chilkat what signing attributes to include:
    CkJsonObject attrs;
    attrs.UpdateBool("contentType",true);
    attrs.UpdateBool("signingTime",true);
    attrs.UpdateBool("messageDigest",true);
    attrs.UpdateBool("signingCertificateV2",true);

    // A CAdES-T signature is one that includes a timestampToken created by an online TSA (time stamping authority).
    // We must include the TSA's URL, as well as a few options to indicate what is desired.
    // Except for the TSA URL, the options shown here are typically what you would need.
    attrs.UpdateBool("timestampToken.enabled",true);
    attrs.UpdateString("timestampToken.tsaUrl","https://freetsa.org/tsr");
    attrs.UpdateBool("timestampToken.addNonce",false);
    attrs.UpdateBool("timestampToken.requestTsaCert",true);
    attrs.UpdateString("timestampToken.hashAlg","sha256");

    crypt.put_SigningAttributes(attrs.emit());

    const char *strToSign = "THIS IS MY ID";

    CkBinData bd;
    bd.AppendString(strToSign,"utf-8");

    // This creates the CAdES-T signature.  During the signature creation, it
    // communicates with the TSA to get a timestampToken.
    // The contents of bd are signed and replaced with the CAdES-T signature (which embeds the original content).
    success = crypt.OpaqueSignBd(bd);
    if (success != true) {
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Get the signature in base64 format:
    strOut.append(bd.getEncoded("base64_mime"));
    strOut.append("\r\n");

    // Or save the signature to a file.
    bd.WriteFile("qa_output/cades-t_sample.p7m");

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


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }