Rust

Create CMS Signed File (PDF) with Multiple Signing Certificates

See more Digital Signatures Examples

Demonstrates how to sign a file by adding multiple signatures (multiple certificates). This example signs a PDF file to produce an output file that is a CMS signature wrapping the original PDF. (Note: This is different than modifying a PDF by injecting a signature into the PDF file format.)

Note: This example requires Chilkat v9.5.0.83 or greater.

Rust

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

let crypt = chilkat::Crypt2::new();

// ------------ This example requires Chilkat v9.5.0.83 or greater.

let cert1 = chilkat::Cert::new();
if cert1.load_pfx_file("qa_data/pfx/cert_test123.pfx", "test123").is_err() {
    println!("{}", cert1.last_error_text());
    return;
}

let cert2 = chilkat::Cert::new();
if cert2.load_pfx_file("qa_data/pfx/test_secret.pfx", "secret").is_err() {
    println!("{}", cert2.last_error_text());
    return;
}

// ------------ This example requires Chilkat v9.5.0.83 or greater.

// Tell the crypt component to use both certificates for signing. 
// When we create the signature, it will be signed by both certificates.
if crypt.add_signing_cert(&cert1).is_err() {
    println!("{}", crypt.last_error_text());
    return;
}

if crypt.add_signing_cert(&cert2).is_err() {
    println!("{}", crypt.last_error_text());
    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.set_cades_enabled(true);

crypt.set_hash_algorithm("sha256");

// We can sign any type of file, creating a .p7s as output.
// The .p7s contains the signature and also embeds the data of the file that is signed.
let in_file = "qa_data/pdf/sample.pdf".to_string();
let p7s_file = "qa_output/sample.pdf.p7s".to_string();

// Create the CAdES-BES attached signature, which contains the original data.
// Note: Chilkat's function naming is not accurate.  CreateP7M creates a PKCS7 signature where the signed file
// is contained within the signature.  CreateP7S creates a detached PKCS7 signature where the signed file
// is NOT contained within the signature.  We want the data to be contained in the signature, therefore
// we call CreateP7M even though we are naming our output file .p7s.
if crypt.create_p7_m(&in_file, &p7s_file).is_err() {
    println!("{}", crypt.last_error_text());
    return;
}

// Verify the .p7s file and extract the original file from the .p7s. 
let extracted_to_file_path = "qa_output/sample.pdf".to_string();
if crypt.verify_p7_m(&p7s_file, &extracted_to_file_path).is_err() {
    println!("{}", crypt.last_error_text());
    return;
}

println!("Success!");