Hash a Password with Argon2 (Tuned Options)

Demonstrates Crypt2.Argon2HashPassword with explicit options: the cost parameters, saltLen (how many random salt bytes to generate when no salt is given), and an optional secret (pepper).

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

// The password should come from a secure source rather than being hard-coded.
let password = "correct horse battery staple".to_string();

// The Argon2 options are the same members as Argon2DeriveKey, except the salt is optional for
// hashing.  When no "salt" is given, a random salt is generated; "saltLen" (default 16, range 8..1024)
// sets how many random bytes to use.
let json = chilkat::JsonObject::new();
let _ = json.update_string("variant", "argon2id");
let _ = json.update_int("memoryCostKb", 131072);
let _ = json.update_int("iterations", 4);
let _ = json.update_int("parallelism", 2);
let _ = json.update_int("saltLen", 16);

// A secret (pepper) and/or ad may be used, but neither is stored in the returned PHC string.  The
// same values must be supplied to Argon2VerifyPassword for the password to verify.
let _ = json.update_string("secret", "application-wide-pepper");
let _ = json.update_string("secretEncoding", "utf-8");

let Ok(phc_hash) = crypt.argon2_hash_password(&password, &json.emit().unwrap_or_default()) else {
    println!("{}", crypt.last_error_text());
    return;
};

println!("{}", phc_hash);