Rust Requires Chilkat v11.0.0+

RSASSA-PSS Sign String to Create Base64 PCKS7 Signature

See more Digital Signatures Examples

Signs a string to create a PKCS7 signature in the base64 encoding. The signature algorithm is RSASSA-PSS with SHA256. Rust

let mut success = false;

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

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

// Get a digital certificate with private key from a .pfx
// (Chilkat has many different ways to provide a cert + private key for siging.
// Using a PFX is just one possible option.)
let pfx = chilkat::Pfx::new();
success = pfx.load_pfx_file("qa_data/rsassa-pss/privatekey.pfx", "PFX_PASSWORD").is_ok();
if !success {
    println!("{}", pfx.last_error_text());
    return;
}

// Get the certificate to be used for signing.
// (The typical case for a PFX is that it contains a cert with an associated private key,
// as well as other certificates in the chain of authentication.  The cert with the private
// key should be in the first position at index 0.)

let cert = chilkat::Cert::new();
success = pfx.cert_at(0, &cert).is_ok();
if !success {
    println!("{}", pfx.last_error_text());
    return;
}

let _ = crypt.set_signing_cert(&cert);

// Indicate that RSASSA-PSS with SHA256 should be used.
crypt.set_signing_alg("pss");
crypt.set_hash_algorithm("sha256");

crypt.set_encoding_mode("base64");

// Sign a string and return the base64 PKCS7 detached signature
let original_text = "This is a test".to_string();
let pkcs7sig = crypt.sign_string_enc(&original_text).unwrap_or_default();
println!("Detached Signature:");
println!("{}", pkcs7sig);

// This signature looks like this:
// MIIG5wYJKoZIhvcNAQcCoIIG2DCCBtQCAQExDzANBgl .. YToLqEwTdU87ox5g7rvw==

// The ASN.1 of the signature can be examined by browsing to https://lapo.it/asn1js/ ,
// then copy-and-paste the Base64 signature into the form and decode..

// The signature can be verified against the original data like this:
success = crypt.verify_string_enc(&original_text, &pkcs7sig).is_ok();
println!("Signature verified: {}", success);
success = crypt.verify_string_enc("Not the original text", &pkcs7sig).is_ok();
println!("Signature verified: {}", success);

// Now we'll create an opaque signature (the opposite of a detached signature). 
// An opaque signature is a PKCS7 message that contains both the original data and
// the signature.  The verification process extracts the original data.
let opaque_sig = crypt.opaque_sign_string_enc(&original_text).unwrap_or_default();
println!("Opaque Signature:");
println!("{}", opaque_sig);

// The ASN.1 of the signature can be examined by browsing to https://lapo.it/asn1js/ ,
// then copy-and-paste the Base64 signature into the form and decode..

// We can verify and extract the original data:
let Ok(orig_txt) = crypt.opaque_verify_string_enc(&opaque_sig) else {
    println!("Signature verification failed.");
    println!("{}", crypt.last_error_text());
    return;
};

println!("Signature verified.");
println!("Extracted text:{}", orig_txt);