Rust

Sign a PDF (Simplest Possible Example)

See more PDF Signatures Examples

This example demonstrates how to a sign a PDF using mostly default options in the simplest way possible. Rust

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

let pdf = chilkat::Pdf::new();

// Load a PDF to be signed.
// The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
if pdf.load_file("qa_data/pdf/hello.pdf").is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

// Options for signing are specified in JSON.
let json = chilkat::JsonObject::new();

// In most cases, the signingCertificateV2 and signingTime attributes are required.
let _ = json.update_int("signingCertificateV2", 1);
let _ = json.update_int("signingTime", 1);

// Put the signature on page 1, top left
let _ = json.update_int("page", 1);
let _ = json.update_string("appearance.y", "top");
let _ = json.update_string("appearance.x", "left");

// Use a font scale of 10.0
let _ = json.update_string("appearance.fontScale", "10.0");

// In this example, the appearance of the digital signature will contain three lines:
// 1) The signing certificate's common name
// 2) The current date/time
// 3) Some arbitrary text.
// The keyword "cert_cn" is replaced with the Certificate's Subject Common Name.
// The keyword "current_dt" is replaced with the current date/time.
// Any number of appearance text lines can be added.
let _ = json.update_string("appearance.text[0]", "Digitally signed by: cert_cn");
let _ = json.update_string("appearance.text[1]", "current_dt");
let _ = json.update_string("appearance.text[2]", "The crazy brown fox jumps over the lazy dog.");

// Load the signing certificate. (Use your own certificate.)
let cert = chilkat::Cert::new();
if cert.load_pfx_file("qa_data/pfx/myPdfSigningCert.pfx", "secret").is_err() {
    println!("{}", cert.last_error_text());
    return;
}

// Tell the pdf object to use the certificate for signing.
if pdf.set_signing_cert(&cert).is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

if pdf.sign_pdf(&json, "qa_output/hello_signed.pdf").is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

println!("The PDF has been successfully cryptographically signed.");

// The appearance of the signature appears in Adobe Acrobat as shown here:

// (image:https://example-code.com/images/signature1.jpg/endImage)