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Unicode C

Create CMS (PKCS7) Detached MIME Signature

Demonstrates how to add a CMS detached signature to MIME.

Chilkat Unicode C Downloads

Unicode C
#include <C_CkMimeW.h>
#include <C_CkCertW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkMimeW mime;
    HCkCertW cert;

    success = FALSE;

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

    mime = CkMimeW_Create();

    //  Load a certificate w/ private key for signing.
    cert = CkCertW_Create();
    success = CkCertW_LoadPfxFile(cert,L"qa_data/pfx/ecc256_12345.p12",L"12345");
    if (success != TRUE) {
        wprintf(L"%s\n",CkCertW_lastErrorText(cert));
        CkMimeW_Dispose(mime);
        CkCertW_Dispose(cert);
        return;
    }

    wprintf(L"Cert: %s\n",CkCertW_subjectDN(cert));

    //  Create a simple MIME message to be signed:
    CkMimeW_AddHeaderField(mime,L"Subject",L"This is a test");
    CkMimeW_AddHeaderField(mime,L"MyCustomHeader",L"abc123");
    CkMimeW_putContentType(mime,L"text/plain");
    CkMimeW_SetBody(mime,L"This is a plain-text body.");

    //  Examine the MIME prior to signing:
    wprintf(L"--- MIME prior to signing ---\n");
    wprintf(L"%s\n",CkMimeW_getMime(mime));

    //  The MIME prior to signing looks like this:

    //  Subject: This is a test
    //  MyCustomHeader: abc123
    //  Content-Type: text/plain; format=flowed
    //  
    //  This is a plain-text body.

    //  Use SHA256 as the hash algorithm in the CMS signature.
    CkMimeW_putSigningHashAlg(mime,L"SHA256");

    //  Add a detached signature:
    success = CkMimeW_AddDetachedSignature(mime,cert);
    if (success == FALSE) {
        wprintf(L"%s\n",CkMimeW_lastErrorText(mime));
        CkMimeW_Dispose(mime);
        CkCertW_Dispose(cert);
        return;
    }

    //  Examine the MIME with detached signature:
    wprintf(L"--- MIME with detached signature ---\n");
    wprintf(L"%s\n",CkMimeW_getMime(mime));

    //  Content-Type: multipart/signed; boundary="----=_NextPart_6e3_c655_9641494d.b4f00501";
    //   protocol="application/x-pkcs7-signature";
    //   micalg=sha256
    //  
    //  ------=_NextPart_6e3_c655_9641494d.b4f00501
    //  Subject: This is a test
    //  MyCustomHeader: abc123
    //  Content-Type: text/plain; format=flowed
    //  
    //  This is a plain-text body.
    //  ------=_NextPart_6e3_c655_9641494d.b4f00501
    //  Content-Transfer-Encoding: base64
    //  Content-Type: application/x-pkcs7-signature; name="smime.p7s"
    //  Content-Disposition: attachment; filename="smime.p7s"
    //  
    //  MIID7AYJKoZIhvcNAQcCoIID3TCCA9kCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
    //  ggJxMIICbTCCAhOgAwIBAgIJAJuS2kgOoyr+MAkGByqGSM49BAEwWzELMAkGA1UEBhMCQVUxEzAR
    //  BgNVBAgTClNvbWUtU3RhdGUxITAfBgNVBAoTGEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEUMBIG
    //  A1UEAxMLZWNjMjU2LXRlc3QwHhcNMTYwODIzMTU0OTM5WhcNNDQwMTA4MTU0OTM5WjBbMQswCQYD
    //  VQQGEwJBVTETMBEGA1UECBMKU29tZS1TdGF0ZTEhMB8GA1UEChMYSW50ZXJuZXQgV2lkZ2l0cyBQ
    //  dHkgTHRkMRQwEgYDVQQDEwtlY2MyNTYtdGVzdDBZMBMGByqGSM49AgEGCCqGSM49AwEHA0IABARy
    //  Hd86A7+qQ4DlIfKynZaFGdGLpkU3GlQwqaVD6GIJg3QIDhaWEksYtZ9OWjNHn9a6+i/P9o5/NrdI
    //  SP0VWDWjgcAwgb0wHQYDVR0OBBYEFGmd2DfK4c3VBTVn8ebKH2BTmRicMIGNBgNVHSMEgYUwgYKA
    //  FGmd2DfK4c3VBTVn8ebKH2BTmRicoV+kXTBbMQswCQYDVQQGEwJBVTETMBEGA1UECBMKU29tZS1T
    //  dGF0ZTEhMB8GA1UEChMYSW50ZXJuZXQgV2lkZ2l0cyBQdHkgTHRkMRQwEgYDVQQDEwtlY2MyNTYt
    //  dGVzdIIJAJuS2kgOoyr+MAwGA1UdEwQFMAMBAf8wCQYHKoZIzj0EAQNJADBGAiEAhuiwGy0lZKtK
    //  LA13Ffc8AMTK7NsePPSfs0clXlZUR78CIQDXsJXpYsJ7tlTeockrK+6099sG/gGFTRPiQYU8juyf
    //  LzGCAT8wggE7AgEBMGgwWzELMAkGA1UEBhMCQVUxEzARBgNVBAgTClNvbWUtU3RhdGUxITAfBgNV
    //  BAoTGEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEUMBIGA1UEAxMLZWNjMjU2LXRlc3QCCQCbktpI
    //  DqMq/jANBglghkgBZQMEAgEFAKBpMBgGCSqGSIb3DQEJAzELBgkqhkiG9w0BBwEwHAYJKoZIhvcN
    //  AQkFMQ8XDTIyMDUwODE0MzM1NFowLwYJKoZIhvcNAQkEMSIEIMvNpYuymLvF68aFFe+l3NEQTdkB
    //  7T8U6/j+Y5FgDlIUMAoGCCqGSM49BAMCBEYwRAIgQ6migEn3Le9ciIVUP/qc2JZAJZWjpulJXY9Q
    //  IZJ3XK0CIGZwpLOgiv7ES8958hqT9a/q7aPc1xmkaZHtsat/k+Ki
    //  
    //  ------=_NextPart_6e3_c655_9641494d.b4f00501--


    CkMimeW_Dispose(mime);
    CkCertW_Dispose(cert);

    }