(Node.js) Create CMS (PKCS7) Detached MIME Signature

Demonstrates how to add a CMS detached signature to MIME.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

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

    var mime = new chilkat.Mime();

    // Load a certificate w/ private key for signing.
    var cert = new chilkat.Cert();
    var success = cert.LoadPfxFile("qa_data/pfx/ecc256_12345.p12","12345");
    if (success !== true) {
        console.log(cert.LastErrorText);
        return;
    }

    console.log("Cert: " + cert.SubjectDN);

    // Create a simple MIME message to be signed:
    mime.AddHeaderField("Subject","This is a test");
    mime.AddHeaderField("MyCustomHeader","abc123");
    mime.ContentType = "text/plain";
    mime.SetBody("This is a plain-text body.");

    // Examine the MIME prior to signing:
    console.log("--- MIME prior to signing ---");
    console.log(mime.GetMime());

    // 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.
    mime.SigningHashAlg = "SHA256";

    // Add a detached signature:
    success = mime.AddDetachedSignature(cert);
    if (success == false) {
        console.log(mime.LastErrorText);
        return;
    }

    // Examine the MIME with detached signature:
    console.log("--- MIME with detached signature ---");
    console.log(mime.GetMime());

    // 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--

}

chilkatExample();