(MFC) Extract PKCS7 from MIME and Decrypt

Extracts the base64-encoded PKCS7 body of a MIME message to a file, and then decrypts using Chilkat Crypt2.

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

See Also: Using MFC CString in Chilkat

#include <CkMime.h>
#include <CkCrypt2.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    CkMime mime;

    bool success = mime.LoadMimeFile("c:/aaworkarea/EmailInBytes.txt");
    if (success != true) {
        strOut.append(mime.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    success = mime.SaveBody("c:/aaworkarea/smime.p7m");
    if (success != true) {
        strOut.append(mime.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkCrypt2 crypt;

    success = crypt.AddPfxSourceFile("c:/aaworkarea/my.pfx","pfxPassword");
    if (success == false) {
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Indicate the public-key (PKCS7) encryption/decryption should be used:
    crypt.put_CryptAlgorithm("pki");

    const char *inPath = "c:/aaworkarea/smime.p7m";
    const char *outPath = "c:/aaworkarea/decrypted.dat";

    success = crypt.CkDecryptFile(inPath,outPath);
    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());

    }