Zig

Create CAdES p7m using AWS KMS to Sign in the Cloud

See more Signing in the Cloud Examples

Demonstrates how to create a CAdES p7m, using AWS KMS. The signing of the hash happens in the Cloud on AWS KMS. Everything else regarding the creation of CAdES happens locally within Chilkat.

Note: This example requires Chilkat v9.5.0.96 or greater.

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.

    // Load the certificate used for signing.  The certificate's private key is stored in AWS KMS
    // However, we still need the certificate locally (without private key).
    const cert = try chilkat.Cert.init();
    defer cert.deinit();
    cert.loadFromFile("qa_data/certs/myCert.cer") catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        return;
    };

    // Here's a screenshot showing the key ID of a private key in AWS KMS:
    // (image:https://example-code.com/images/aws_kms.jpg/endImage)

    // To sign using AWS KMS,
    // add the following lines of code to specify your AWS authentication credentials,
    // and the ID of the KMS private key.
    const json_aws_kms = try chilkat.JsonObject.init();
    defer json_aws_kms.deinit();
    // Set the "service" equal to "aws_kms" to tell Chilkat to use AWS KMS for signing.
    json_aws_kms.updateString("service", "aws_kms") catch {};
    json_aws_kms.updateString("access_key", "ACCESS_KEY") catch {};
    json_aws_kms.updateString("secret_key", "SECRET_KEY") catch {};
    // Make sure to specify the correct region for your case.
    json_aws_kms.updateString("region", "us-west-2") catch {};
    // In the above screenshot, our key ID is "187012e8-008f-4fc7-b100-5efe6146dff2".  You will use your key ID.
    json_aws_kms.updateString("key_id", "187012e8-008f-4fc7-b100-5efe6146dff2") catch {};

    try cert.setCloudSigner(json_aws_kms);

    const crypt = try chilkat.Crypt2.init();
    defer crypt.deinit();

    crypt.setSigningCert(cert) catch {
        std.debug.print("{s}\n", .{try crypt.getLastErrorText(alloc)});
        return;
    };

    // The CadesEnabled property applies to all methods that create PKCS7 signatures.
    // To create a CAdES-BES signature, set this property equal to true.
    crypt.setCadesEnabled(true);

    crypt.setHashAlgorithm("sha256");

    const signed_attrs = try chilkat.JsonObject.init();
    defer signed_attrs.deinit();
    signed_attrs.updateInt("contentType", 1) catch {};
    signed_attrs.updateInt("signingTime", 1) catch {};
    signed_attrs.updateInt("messageDigest", 1) catch {};
    signed_attrs.updateInt("signingCertificateV2", 1) catch {};
    crypt.setSigningAttributes(try signed_attrs.emit(alloc));

    // You can sign any type of file..
    const input_xml_path = "qa_data/e-Invoice.xml";
    const output_p7m_path = "qa_output/signed.p7m";

    // Create the CAdES-BES attached signature, which contains the original data.
    // Chilkat will build the .p7m locally, but will (internally) use ARSS
    // to do the RSA signing remotely.
    crypt.createP7M(input_xml_path, output_p7m_path) catch {
        std.debug.print("{s}\n", .{try crypt.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("Success.\n", .{});
}