Use Certificate and Private Key PEM Files to Create a Digital Signature

Demonstrates how to load a digital certificate from a PEM file, load it's corresponding private key from a PEM file, save the private key to a key container (if necessary), link the certificate to the key container, and use it to create a digital signature.

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

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

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

    cert = CkCert_Create();

    //  Load the cert from a PEM file;
    CkCert_LoadFromFile(cert,"cert.pem");

    pkey = CkPrivateKey_Create();

    //  Load the private key from an RSA PEM file:
    CkPrivateKey_LoadPemFile(pkey,"pkey_rsa.pem");

    success = CkCert_SetPrivateKey(cert,pkey);
    if (success != TRUE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        return;
    }

    //  Use Chilkat Crypt (a non-freeware component) to create
    //  a digital signature using the certificate w/ private key:
    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;
    }

    //  Tell the crypt component to use this cert.
    CkCrypt2_SetSigningCert(crypt,cert);

    //  A PKCS7 signature for any type of file content can be created:
    success = CkCrypt2_CreateP7S(crypt,"license.rtf","license.p7s");
    if (success == FALSE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        return;
    }

    printf("%s\n",CkCrypt2_lastErrorText(crypt));

    //  Verify and restore the original file:
    CkCrypt2_SetVerifyCert(crypt,cert);

    success = CkCrypt2_VerifyP7S(crypt,"license.rtf","license.p7s");
    if (success == FALSE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        return;
    }

    printf("Success!\n");



    CkCert_Dispose(cert);
    CkPrivateKey_Dispose(pkey);
    CkCrypt2_Dispose(crypt);

    }