(MFC) Duplicate OpensSSL to Sign File and Output Binary DER

This example duplicates the following:

openssl smime -sign -in INPUT.xml -signer SIGN.PEM -passin pass:MYPASS -outform der -binary -nodetach -out SIGNED.P7M

Note: Although "smime" is the OpenSSL command, it's not actually producing S/MIME. The arguments "-outform der -binary" indicates that the output is binary DER (i.e. the PKCS7 binary signature). The input can be any type of file: XML, PDF, JPG, ... *anything*...

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

See Also: Using MFC CString in Chilkat

#include <CkCrypt2.h>
#include <CkPem.h>
#include <CkPrivateKey.h>
#include <CkCert.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;

    // Load the PEM containing cert + private key.
    CkPem pem;
    bool success = pem.LoadPemFile("qa_data/pem/myPem.pem","password");
    if (success != true) {
        strOut.append(pem.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkPrivateKey *privkey = pem.GetPrivateKey(0);
    if (pem.get_LastMethodSuccess() != true) {
        strOut.append(pem.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkCert *cert = pem.GetCert(0);
    if (pem.get_LastMethodSuccess() != true) {
        delete privkey;
        strOut.append(pem.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    success = crypt.SetSigningCert2(*cert,*privkey);
    if (success != true) {
        delete privkey;
        delete cert;
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    delete privkey;
    delete cert;

    // Alternatively, we could use a .pfx/.p12 file.
    // (Chilkat also supports other formats/sources for cert/private keys...)
    CkCert certFromP12;
    success = certFromP12.LoadPfxFile("qa_data/p12/myP12.p12","password");
    if (success != true) {
        strOut.append(certFromP12.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // The certificate, when loaded from a .pfx/.p12, will automatically 
    // include the associated private key, assuming it's present in the .p12.
    // We don't have to explicitly provide the private key as in the
    // lines of code above that use the PEM file.
    success = crypt.SetSigningCert(certFromP12);
    if (success != true) {
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Create the opaque signature (PKCS7 binary DER that contains both the signature and original file data).
    success = crypt.CreateP7M("qa_data/infile.anything","qa_output/outfile.p7m");
    if (success != true) {
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

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


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }