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

#include <C_CkCrypt2.h>
#include <C_CkByteData.h>
#include <C_CkMime.h>

void ChilkatSample(void)
    {
    HCkCrypt2 crypt;
    BOOL success;
    HCkByteData p7mData;
    const char * pfxFilePath;
    const char * pfxPassword;
    const char * mimeText;
    HCkMime mime;

    crypt = CkCrypt2_Create();

    //  Any string argument automatically begins the 30-day trial.

    success = CkCrypt2_UnlockComponent(crypt,"30-day trial");
    if (success != TRUE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        return;
    }

    //  Read the P7M file into memory.
    p7mData = CkByteData_Create();
    success = CkCrypt2_ReadFile(crypt,"encrypted.p7m",p7mData);
    if (success != TRUE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        return;
    }

    //  Setup the crypt object:

    //  Indicate that public-key decryption is to be used.
    CkCrypt2_putCryptAlgorithm(crypt,"pki");

    //  Add a PFX file to allow the crypt object to find
    //  the certificate and private key needed for decryption

    pfxFilePath = "myPfx.pfx";

    pfxPassword = "secret";
    success = CkCrypt2_AddPfxSourceFile(crypt,pfxFilePath,pfxPassword);
    if (success != TRUE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        return;
    }

    //  Assuming the decrypted data will be text, decrypt to
    //  a string.

    mimeText = CkCrypt2_decryptString(crypt,p7mData);
    if (mimeText == 0 ) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        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.

    mime = CkMime_Create();

    success = CkMime_UnlockComponent(mime,"Anyting for 30-day trial");
    if (success != TRUE) {
        printf("%s\n",CkMime_lastErrorText(mime));
        return;
    }

    //  Load the MIME text into the MIME object.
    success = CkMime_LoadMime(mime,mimeText);
    if (success != TRUE) {
        printf("%s\n",CkMime_lastErrorText(mime));
        return;
    }

    //  Save the MIME to a file:
    success = CkMime_SaveMime(mime,"outMime.txt");
    if (success != TRUE) {
        printf("%s\n",CkMime_lastErrorText(mime));
        return;
    }

    //  Success!  Output the MIME text:
    printf("%s\n",CkMime_getMime(mime));

    CkCrypt2_Dispose(crypt);
    CkByteData_Dispose(p7mData);
    CkMime_Dispose(mime);

    }