Zig

Create CMS (PKCS7) Detached MIME Signature

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

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

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

    const mime = try chilkat.Mime.init();
    defer mime.deinit();

    // Load a certificate w/ private key for signing.
    const cert = try chilkat.Cert.init();
    defer cert.deinit();
    cert.loadPfxFile("qa_data/pfx/ecc256_12345.p12", "12345") catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("Cert: {s}\n", .{try cert.getSubjectDN(alloc)});

    // Create a simple MIME message to be signed:
    mime.addHeaderField("Subject", "This is a test") catch {};
    mime.addHeaderField("MyCustomHeader", "abc123") catch {};
    mime.setContentType("text/plain");
    mime.setBody("This is a plain-text body.");

    // Examine the MIME prior to signing:
    std.debug.print("--- MIME prior to signing ---\n", .{});
    std.debug.print("{s}\n", .{try mime.getMime(alloc)});

    // 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.setSigningHashAlg("SHA256");

    // Add a detached signature:
    mime.addDetachedSignature(cert) catch {
        std.debug.print("{s}\n", .{try mime.getLastErrorText(alloc)});
        return;
    };

    // Examine the MIME with detached signature:
    std.debug.print("--- MIME with detached signature ---\n", .{});
    std.debug.print("{s}\n", .{try mime.getMime(alloc)});

    // 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--
}