Rust Requires Chilkat v11.0.0+

About RSA Public/Private Keys

See more RSA Examples

This example provides some additional information for understanding public/private key pairs. In demonstrates how a private key is a superset of the public key. A public key contains the modulus and exponent. The matching private key also contains the modulus and exponent, but also contains the additional private key parts. Rust

let cert = chilkat::Cert::new();

// Load a digital certificate.
if cert.load_from_file("digitalCert.cer").is_err() {
    println!("{}", cert.last_error_text());
    return;
}

// A .cer file does not contain the private key.  It should contain
// the public key...
let pub_key = chilkat::PublicKey::new();
let _ = cert.get_public_key(&pub_key);

// Let's have a look at it (in XML format).
println!("Public Key from Certificate:");
println!("{}", pub_key.get_xml().unwrap_or_default());

// An RSA public key consists of a modulus and exponent.

// An RSA private key includes both the modulus and exponent,
// as well as other "big" numbers: P, Q, D, etc.

// Let's load an RSA private key from a DER-encoded file:
let priv_key = chilkat::PrivateKey::new();

if priv_key.load_any_format_file("PrivateKey.key", "").is_err() {
    println!("{}", priv_key.last_error_text());
    return;
}

// If this private key is the matching half to the public key from
// the certificate, then the modulus and exponent should
// be identical.  (Thus, a "private key" really contains both the public part as well as the private parts...).
println!("Private Key from DER:");
println!("{}", priv_key.get_xml().unwrap_or_default());