C

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

See more Encryption Examples

_LANGUAGE_ 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. C

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

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

    success = FALSE;

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

    crypt = CkCrypt2_Create();

    // 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));
        CkCrypt2_Dispose(crypt);
        CkCertStore_Dispose(certStore);
        return;
    }

    jsonCN = CkJsonObject_Create();
    CkJsonObject_UpdateString(jsonCN,"CN",signingCertSubject);

    cert = CkCert_Create();
    success = CkCertStore_FindCert(certStore,jsonCN,cert);
    if (success == FALSE) {
        printf("Failed to find certificate by subject common name.\n");
        CkCrypt2_Dispose(crypt);
        CkCertStore_Dispose(certStore);
        CkJsonObject_Dispose(jsonCN);
        CkCert_Dispose(cert);
        return;
    }

    // Tell the crypt component to use this cert.
    success = 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));
        CkCrypt2_Dispose(crypt);
        CkCertStore_Dispose(certStore);
        CkJsonObject_Dispose(jsonCN);
        CkCert_Dispose(cert);
        return;
    }

    success = CkCrypt2_VerifyP7S(crypt,inFile,sigFile);
    if (success == FALSE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCrypt2_Dispose(crypt);
        CkCertStore_Dispose(certStore);
        CkJsonObject_Dispose(jsonCN);
        CkCert_Dispose(cert);
        return;
    }

    printf("Success!\n");


    CkCrypt2_Dispose(crypt);
    CkCertStore_Dispose(certStore);
    CkJsonObject_Dispose(jsonCN);
    CkCert_Dispose(cert);

    }