PureBasic

Create CMS (PKCS7) Detached MIME Signature

Demonstrates how to add a CMS detached signature to MIME. PureBasic

IncludeFile "CkCert.pb"
IncludeFile "CkMime.pb"

Procedure ChilkatExample()

    success.i = 0

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

    mime.i = CkMime::ckCreate()
    If mime.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Load a certificate w/ private key for signing.
    cert.i = CkCert::ckCreate()
    If cert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkCert::ckLoadPfxFile(cert,"qa_data/pfx/ecc256_12345.p12","12345")
    If success <> 1
        Debug CkCert::ckLastErrorText(cert)
        CkMime::ckDispose(mime)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    Debug "Cert: " + CkCert::ckSubjectDN(cert)

    ; Create a simple MIME message to be signed:
    CkMime::ckAddHeaderField(mime,"Subject","This is a test")
    CkMime::ckAddHeaderField(mime,"MyCustomHeader","abc123")
    CkMime::setCkContentType(mime, "text/plain")
    CkMime::ckSetBody(mime,"This is a plain-text body.")

    ; Examine the MIME prior to signing:
    Debug "--- MIME prior to signing ---"
    Debug CkMime::ckGetMime(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.
    CkMime::setCkSigningHashAlg(mime, "SHA256")

    ; Add a detached signature:
    success = CkMime::ckAddDetachedSignature(mime,cert)
    If success = 0
        Debug CkMime::ckLastErrorText(mime)
        CkMime::ckDispose(mime)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; Examine the MIME with detached signature:
    Debug "--- MIME with detached signature ---"
    Debug CkMime::ckGetMime(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--


    CkMime::ckDispose(mime)
    CkCert::ckDispose(cert)


    ProcedureReturn
EndProcedure