Sign a File to Create a .p7s (Detached Signature)

C example to create a detached signature file (.p7s) for any type file. The signature can be verified by calling VerifyP7S and passing the original filename and the .p7s filename.

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

void ChilkatSample(void)
    {
    HCkCrypt2 crypt;
    BOOL success;
    const char * signingCertSubject;
    const char * pfxFilename;
    const char * pfxPassword;
    HCkCertStore certStore;
    HCkCert cert;
    const char * inFile;
    const char * sigFile;

    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;
    }

    //  Use a digital certificate and private key from a PFX file (.pfx or .p12).

    signingCertSubject = "Acme Inc";

    pfxFilename = "/Users/chilkat/testData/pfx/acme.pfx";

    pfxPassword = "test123";

    certStore = CkCertStore_Create();
    success = CkCertStore_LoadPfxFile(certStore,pfxFilename,pfxPassword);
    if (success != TRUE) {
        printf("%s\n",CkCertStore_lastErrorText(certStore));
        return;
    }

    cert = CkCertStore_FindCertBySubjectCN(certStore,signingCertSubject);
    if (cert == 0 ) {
        printf("Failed to find certificate by subject common name.\n");
        return;
    }

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

    //  We can sign any type of file, creating a .p7s as output:

    inFile = "/Users/chilkat/testData/pdf/sample.pdf";

    sigFile = "/Users/chilkat/testData/p7s/sample.p7s";

    success = CkCrypt2_CreateP7S(crypt,inFile,sigFile);
    if (success == FALSE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCert_Dispose(cert);
        return;
    }

    success = CkCrypt2_VerifyP7S(crypt,inFile,sigFile);
    if (success == FALSE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCert_Dispose(cert);
        return;
    }

    CkCert_Dispose(cert);

    printf("Success!\n");

    CkCrypt2_Dispose(crypt);
    CkCertStore_Dispose(certStore);

    }