(C) Encrypt File using X.509 Certificate using AES in CBC Mode

Demonstrates how to encrypt a file using an X.509 Certificate's public key, where the underlying bulk encryption algorithm is 128-bit AES in CBC mode. (The underlying bulk encryption algorithm can be specified to be other algorithms/strengths.)

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#include <C_CkCrypt2.h>
#include <C_CkCert.h>

void ChilkatSample(void)
    {
    HCkCrypt2 crypt;
    HCkCert cert;
    BOOL success;

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

    crypt = CkCrypt2_Create();

    //  Use public-key cryptography for encryption.
    CkCrypt2_putCryptAlgorithm(crypt,"pki");

    //  Get an X.509 certificate to use for encrypting.
    //  Note: Chilkat provides many different ways of loading a certificate, from many different formats,
    //  or if on Windows, from the installed certificates on the system.
    //  This example simply loads a certificate from a file.
    //  Also, for encryption, only the public key is needed.  Digital certificates embed the public key
    //  within the X.509 format itself.  Therefore, if you have a certificate, you also have the public key.
    cert = CkCert_Create();
    success = CkCert_LoadFromFile(cert,"qa_data/certs/testCert.cer");
    if (success != TRUE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkCrypt2_Dispose(crypt);
        CkCert_Dispose(cert);
        return;
    }

    success = CkCrypt2_SetEncryptCert(crypt,cert);
    if (success != TRUE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCrypt2_Dispose(crypt);
        CkCert_Dispose(cert);
        return;
    }

    //  Indicate the underlying bulk encryption algorithm to be used:
    CkCrypt2_putPkcs7CryptAlg(crypt,"aes");
    CkCrypt2_putKeyLength(crypt,128);

    //  Note: When doing public-key encryption the underlying bulk symmetric cipher mode will always be CBC. (at least with Chilkat...)

    //  There's one last option that could be set.  If is the RSA encryption encryption/padding scheme.
    //  By default, RSAES_PKCS1-V1_5 is used.  If desired, the OaepPadding property could be set to TRUE to
    //  use RSAES_OAEP.  (We'll leave it set at the default value of FALSE)
    CkCrypt2_putOaepPadding(crypt,FALSE);

    //  Everything is specified.  Now just encrypt...
    //  The output is PKCS7 in binary DER format.
    success = CkCrypt2_CkEncryptFile(crypt,"qa_data/hamlet.xml","qa_output/hamlet.p7");
    if (success != TRUE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCrypt2_Dispose(crypt);
        CkCert_Dispose(cert);
        return;
    }

    printf("Finished.\n");


    CkCrypt2_Dispose(crypt);
    CkCert_Dispose(cert);

    }