Zig
Sign PDF for ICP-Brasil

Sign a PDF to create a signed PDF compliant with the ICP-Brasil Digital Signature Standard Conformity Checker. (Verificador de Conformidade do Padrão de Assinatura Digital ICP-Brasil)
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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.

    // The signed PDF produced by this example should be verifiable at https://validar.iti.gov.br/
    const pdf = try chilkat.Pdf.init();
    defer pdf.deinit();

    // Load a PDF to be signed.
    // The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
    pdf.loadFile("qa_data/pdf/hello.pdf") catch {
        std.debug.print("{s}\n", .{try pdf.getLastErrorText(alloc)});
        return;
    };

    const json = try chilkat.JsonObject.init();
    defer json.deinit();

    // Define the appearance and location of the signature.
    json.updateInt("page", 1) catch {};
    json.updateString("appearance.y", "bottom") catch {};
    json.updateString("appearance.x", "middle") catch {};
    json.updateString("appearance.fontScale", "9.0") catch {};
    json.updateString("appearance.text[0]", "Digitally signed by: cert_cn") catch {};
    json.updateString("appearance.text[1]", "current_dt") catch {};
    json.updateString("appearance.image", "document-accepted") catch {};
    json.updateString("appearance.imagePlacement", "left") catch {};
    json.updateString("appearance.imageOpacity", "100") catch {};

    // Add the CMS options required for ICP-Brasil
    json.updateInt("contentType", 1) catch {};
    json.updateInt("messageDigest", 1) catch {};
    json.updateInt("signingCertificateV2", 1) catch {};
    json.updateBool("ltvOcsp", true) catch {};

    // Listed here are the currently existing profiles. (Chilkat will add additional ICP Brasil policy profiles in future versions as new ones are created.)
    // See https://www.gov.br/iti/pt-br/assuntos/repositorio/artefatos-de-assinatura-digital for more information.
    //
    // PA_AD_RA_v1_1 --> 2.16.76.1.7.1.5.1.1
    // PA_AD_RA_v1_2 --> 2.16.76.1.7.1.5.1.2
    // PA_AD_RA_v2_0 --> 2.16.76.1.7.1.5.2
    // PA_AD_RA_v2_1 --> 2.16.76.1.7.1.5.2.1
    // PA_AD_RA_v2_2 --> 2.16.76.1.7.1.5.2.2
    // PA_AD_RA_v2_3 --> 2.16.76.1.7.1.5.2.3
    // PA_AD_RA_v2_4 --> 2.16.76.1.7.1.5.2.4

    // PA_AD_RB_v1_1 --> 2.16.76.1.7.1.1.1.1
    // PA_AD_RB_v2_0 --> 2.16.76.1.7.1.1.2
    // PA_AD_RB_v2_1 --> 2.16.76.1.7.1.1.2.1
    // PA_AD_RB_v2_2 --> 2.16.76.1.7.1.1.2.2
    // PA_AD_RB_v2_3 --> 2.16.76.1.7.1.1.2.3

    // PA_AD_RC_v1_1 --> 2.16.76.1.7.1.4.1.1
    // PA_AD_RC_v2_0 --> 2.16.76.1.7.1.4.2
    // PA_AD_RC_v2_1 --> 2.16.76.1.7.1.4.2.1
    // PA_AD_RC_v2_2 --> 2.16.76.1.7.1.4.2.2
    // PA_AD_RC_v2_3 --> 2.16.76.1.7.1.4.2.3

    // PA_AD_RT_v1_1 --> 2.16.76.1.7.1.2.1.1
    // PA_AD_RT_v2_0 --> 2.16.76.1.7.1.2.2
    // PA_AD_RT_v2_1 --> 2.16.76.1.7.1.2.2.1
    // PA_AD_RT_v2_2 --> 2.16.76.1.7.1.2.2.2
    // PA_AD_RT_v2_3 --> 2.16.76.1.7.1.2.2.3

    // PA_AD_RV_v1_1 --> 2.16.76.1.7.1.3.1.1
    // PA_AD_RV_v2_0 --> 2.16.76.1.7.1.3.2
    // PA_AD_RV_v2_1 --> 2.16.76.1.7.1.3.2.1
    // PA_AD_RV_v2_2 --> 2.16.76.1.7.1.3.2.2
    // PA_AD_RV_v2_3 --> 2.16.76.1.7.1.3.2.3

    // PA_PAdES_AD_RA_v1_0 --> 2.16.76.1.7.1.14.1
    // PA_PAdES_AD_RA_v1_1 --> 2.16.76.1.7.1.14.1.1
    // PA_PAdES_AD_RA_v1_2 --> 2.16.76.1.7.1.14.1.2
    // PA_PAdES_AD_RB_v1_0 --> 2.16.76.1.7.1.11.1
    // PA_PAdES_AD_RB_v1_1 --> 2.16.76.1.7.1.11.1.1
    // PA_PAdES_AD_RC_v1_0 --> 2.16.76.1.7.1.13.1
    // PA_PAdES_AD_RC_v1_1 --> 2.16.76.1.7.1.13.1.1
    // PA_PAdES_AD_RC_v1_2 --> 2.16.76.1.7.1.13.1.2
    // PA_PAdES_AD_RT_v1_0 --> 2.16.76.1.7.1.12.1
    // PA_PAdES_AD_RT_v1_1 --> 2.16.76.1.7.1.12.1.1

    // Set the policy profile name
    // ---------------------------------------------------
    // Note: On 24-May-2024, I was informed that adding the "policyId.profile"
    // causes the PDF signature to fail validation at https://validar.iti.gov.br/
    // Perhaps something changed in the years since this example was originally written and tested to be working.
    // You may need to omit the "policyId.profile".
    // ---------------------------------------------------
    json.updateString("policyId.profile", "PA_PAdES_AD_RB_v1_1") catch {};

    // Load the signing certificate. (Use your own certificate.)
    // Note: If loading from a smart card, call LoadFromSmartcard instead, and make sure to use Chilkat v9.5.0.88 or later.
    const cert = try chilkat.Cert.init();
    defer cert.deinit();
    cert.loadPfxFile("qa_data/pfx/myPdfSigningCert.pfx", "pfx_password") catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        return;
    };

    // Tell the pdf object to use the certificate for signing.
    pdf.setSigningCert(cert) catch {
        std.debug.print("{s}\n", .{try pdf.getLastErrorText(alloc)});
        return;
    };

    pdf.signPdf(json, "qa_output/hello_signed.pdf") catch {
        std.debug.print("{s}\n", .{try pdf.getLastErrorText(alloc)});
        return;
    };

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