Decrypt P7M using PFX to get MIME

Demonstrates how to decrypt a .p7m (PKCS7) binary file using a certificate and private key from a PFX file. The result of the decryption (in this case) is MIME text that may be loaded into a Chilkat MIME object.

Note: Any type of file or data may be encrypted to produce a .p7m (PKCS7) encrypted file. This example was prompted by a customer needing to decrypt a MIME message. The final step of loading the decrypted text into a MIME object would be skipped if decrypting something other than MIME..

Downloads:

MS Windows Visual C/C++ Libraries

Linux/CentOS C/C++ Libraries

MAC OS X C/C++ Libraries

Solaris C/C++ Libraries

C++ Builder Libraries

FreeBSD C++ Libraries

HP-UX C++ Libraries

BlackBerry QNX C++ Libraries

// Needs #include <CkCrypt2.h>
// Needs #include <CkByteData.h>
// Needs #include <CkMime.h>

    CkString strOut;

    CkCrypt2 crypt;

    //  Any string argument automatically begins the 30-day trial.
    bool success;
    success = crypt.UnlockComponent("30-day trial");
    if (success != true) {
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Read the P7M file into memory.
    CkByteData p7mData;
    success = crypt.ReadFile("encrypted.p7m",p7mData);
    if (success != true) {
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Setup the crypt object:

    //  Indicate that public-key decryption is to be used.
    crypt.put_CryptAlgorithm("pki");

    //  Add a PFX file to allow the crypt object to find
    //  the certificate and private key needed for decryption
    const char * pfxFilePath;
    pfxFilePath = "myPfx.pfx";
    const char * pfxPassword;
    pfxPassword = "secret";
    success = crypt.AddPfxSourceFile(pfxFilePath,pfxPassword);
    if (success != true) {
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Assuming the decrypted data will be text, decrypt to
    //  a string.
    const char * mimeText;
    mimeText = crypt.decryptString(p7mData);
    if (mimeText == 0 ) {
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Note: Chilkat Crypt and Chilkat MIME are separate products.
    //  To use both objects, one would license the "Chilkat Bundle",
    //  which provides licenses to all existing Chilkat products.
    //  This is less expensive than licensing each of the two products separately.

    CkMime mime;

    success = mime.UnlockComponent("Anyting for 30-day trial");
    if (success != true) {
        strOut.append(mime.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Load the MIME text into the MIME object.
    success = mime.LoadMime(mimeText);
    if (success != true) {
        strOut.append(mime.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Save the MIME to a file:
    success = mime.SaveMime("outMime.txt");
    if (success != true) {
        strOut.append(mime.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Success!  Output the MIME text:
    strOut.append(mime.GetMime());
    strOut.append("\r\n");

    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());