(MFC) Duplicate openssl smime -decrypt -in some_file.dat.enc -binary -inform DER -inkey private.key -out some_file.dat

Demonstrates how to decrypt binary DER that was encrypted using the following openssl command:

openssl smime -encrypt -binary -aes-256-cbc -in some_file.dat -out some_file.dat.enc -outform DER cert.crt

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

See Also: Using MFC CString in Chilkat

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

void ChilkatSample(void)
    {
    CkString strOut;

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

    // Duplicates the following openssl command:
    // openssl smime -decrypt -in hello.txt.enc -binary -inform DER -inkey private.key -out hello.txt

    CkCert cert;
    bool success = cert.LoadFromFile("qa_data/openssl/EE.cer");
    if (success == false) {
        strOut.append(cert.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkBinData bd;
    success = bd.LoadFile("qa_data/openssl/EE.key");
    // Assuming success..

    CkPrivateKey privKey;
    success = privKey.LoadAnyFormat(bd,"");
    if (success == false) {
        strOut.append(privKey.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkCrypt2 crypt;
    success = crypt.SetDecryptCert2(cert,privKey);
    if (success == false) {
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    crypt.put_CryptAlgorithm("PKI");
    success = crypt.CkDecryptFile("qa_data/openssl/hello.txt.enc","qa_output/hello.txt");
    if (success == false) {
        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());

    }