Zig Requires Chilkat v11.5.0+

Sign PDF using ARSS (Aruba Remote Signing Service)

See more Signing in the Cloud Examples

Demonstrates how to digitally sign a PDF using the Aruba Remote Signing Service (ARSS). The example loads a local PDF and certificate, configures the ARSS cloud signer credentials, specifies the OTP authentication type with typeOtpAuth, and creates an LTV-enabled signed PDF where the private key remains protected on the Aruba signing server.

Zig

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

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

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

    const pdf = try chilkat.Pdf.init();
    defer pdf.deinit();

    // Load the PDF that will be digitally signed.
    pdf.loadFile("qa_data/pdf/hello.pdf") catch {
        std.debug.print("{s}\n", .{try pdf.getLastErrorText(alloc)});
        return;
    };

    // Signing options are specified in a JSON object.
    const json = try chilkat.JsonObject.init();
    defer json.deinit();

    // Enable LTV (Long-Term Validation).
    // When ltvOcsp is true, OCSP validation information is embedded in the PDF
    // so that signature validation can continue to succeed in the future,
    // even if the original OCSP responder is no longer available.
    json.updateBool("ltvOcsp", true) catch {};

    // Specify the visual appearance of the signature on the PDF page.
    json.updateInt("page", 1) catch {};
    json.updateString("appearance.y", "top") catch {};
    json.updateString("appearance.x", "left") catch {};
    json.updateString("appearance.fontScale", "10.0") catch {};

    // Text lines displayed in the visible signature appearance.
    // Special values such as "cert_cn" and "current_dt" are replaced
    // with the certificate common name and current date/time.
    json.updateString("appearance.text[0]", "Digitally signed by: cert_cn") catch {};
    json.updateString("appearance.text[1]", "current_dt") catch {};
    json.updateString("appearance.text[2]", "This is an LTV-enabled signature.") catch {};

    // Load the signing certificate.
    //
    // The private key is NOT stored locally.  Instead, the private key is
    // stored and protected on the Aruba Remote Signing Service (ARSS).
    //
    // Even though the signing operation will occur remotely, Chilkat still
    // needs the corresponding public certificate locally so that it can
    // construct the CMS/PAdES signature and embed the certificate chain
    // in the signed PDF.
    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;
    };

    // Configure Aruba Remote Signing Service (ARSS) credentials.
    //
    // When SetCloudSigner is called, Chilkat is instructed to perform
    // cryptographic signing operations through the ARSS web service.
    // The PDF is assembled locally, but the actual RSA signature operation
    // is performed remotely using the private key held by Aruba.
    const json_arss = try chilkat.JsonObject.init();
    defer json_arss.deinit();

    // Required.  Indicates that the cloud signing provider is ARSS.
    json_arss.updateString("service", "ARSS") catch {};

    // The ARSS certificate identifier (for example, "AS0").
    // This identifies which remote certificate/private key pair should be used.
    // The remote certificate should correspond to the certificate loaded above.
    json_arss.updateString("certID", "YOUR_ARSS_CERT_ID") catch {};

    // OTP password associated with the Aruba remote-signing account.
    // Depending on the ARSS configuration, an OTP may be required to
    // authorize each signing operation.
    json_arss.updateString("otpPwd", "YOUR_OTP_PWD") catch {};

    // Specifies the OTP authentication environment.
    //
    // Common values are:
    //   "demoprod" - Demo/Test environment
    //   "prod"     - Production environment
    //
    // This value is sent to the ARSS service and determines how the OTP
    // authentication is validated.  The correct value depends on the type
    // of Aruba account and environment that has been provisioned.
    //
    // If signing fails with an authentication-related error, verify that
    // the typeOtpAuth value matches the environment associated with the
    // ARSS account credentials being used.
    json_arss.updateString("typeOtpAuth", "demoprod") catch {};

    // ARSS account username.
    json_arss.updateString("user", "YOUR_ARSS_USERNAME") catch {};

    // ARSS account password.
    json_arss.updateString("userPWD", "YOUR_ARSS_PASSWORD") catch {};

    // Beginning with Chilkat v11.5.0, the ARSS endpoint can be explicitly
    // specified.  This allows the application to target a particular
    // Aruba signing service endpoint when required.
    json_arss.updateString("endpoint", "https://app1.firma-remota.it/ArubaSignerService/webresources/signerservice") catch {};

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

    // Associate the certificate with the PDF object.
    // All subsequent signing operations will use this certificate.
    pdf.setSigningCert(cert) catch {
        std.debug.print("{s}\n", .{try pdf.getLastErrorText(alloc)});
        return;
    };

    // Create the signed PDF.
    //
    // Chilkat performs all PDF processing locally.  When the time comes
    // to generate the cryptographic signature value, Chilkat sends the
    // hash to ARSS, which signs it using the remote private key and returns
    // the signature.  The private key never leaves the Aruba service.
    pdf.signPdf(json, "qa_output/hello_ltv_signed.pdf") catch {
        std.debug.print("{s}\n", .{try pdf.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("The PDF has been successfully cryptographically signed with long-term validation.\n", .{});
}