Function pack 

pub fn pack(
    precision: TimePrecision,
    format: TimeFormat,
    cadence: &TimeLockCadence,
    salts: TimeLockSalts,
    kdf_params: KdfParams,
) -> TimeLockParams

Pack TimePrecision, TimeFormat, and a TimeLockCadence reference into a compact TimeLockParams for ciphertext header storage.

Only the variant identity of cadence is recorded — the actual day, weekday, or month values are intentionally discarded.

Example

let salts = TimeLockSalts::generate();
let kdf   = KdfPreset::Balanced.params();
let p = pack(
    TimePrecision::Minute,
    TimeFormat::Hour24,
    &TimeLockCadence::DayOfWeek(Weekday::Tuesday),
    salts,
    kdf,
);
// p.time_precision == 2, p.time_format == 1, p.cadence_variant == 1

Examples found in repository

examples/timelock_round_trip.rs (lines 54-60)

fn main() {
    // ── Encryption side ───────────────────────────────────────────────────────
    // Generate fresh salts.  Salts are NOT secret — store them in plaintext
    // alongside the ciphertext so the decryption side can reproduce the key.
    let salts = TimeLockSalts::generate();

    // Use a deliberately fast preset so the example finishes quickly.
    // In production use KdfPreset::Balanced or stronger.
    let kdf = KdfPreset::Balanced.params();

    // Lock to any Tuesday at 18:00 (hour-precision window = the full 18:00–18:59 block).
    let cadence   = TimeLockCadence::DayOfWeek(Weekday::Tuesday);
    let lock_time = TimeLockTime::new(18, 0).unwrap();

    println!("Deriving encryption key (this may take a few seconds)…");
    let enc_key = timelock(
        Some(cadence.clone()),
        Some(lock_time),
        Some(TimePrecision::Hour),
        Some(TimeFormat::Hour24),
        Some(salts.clone()),
        Some(kdf),
        None,   // params = None → _at (encryption) path
    )
    .expect("encryption-side key derivation failed");

    println!("enc_key[:8] = {:02x?}", &enc_key.as_bytes()[..8]);

    // Pack every setting — including salts and KDF params — into a compact header.
    // This header goes into the ciphertext in plaintext; nothing here is secret.
    let header = pack(
        TimePrecision::Hour,
        TimeFormat::Hour24,
        &cadence,
        salts,
        kdf,
    );

    // ── Decryption side ───────────────────────────────────────────────────────
    // Load `header` from the ciphertext and call timelock() at the matching
    // time slot with params = Some(header).
    println!("Deriving decryption key from system clock…");
    let dec_key = timelock(
        None, None, None, None, None, None,
        Some(header),   // params = Some → _now (decryption) path
    )
    .expect("decryption-side key derivation failed");

    println!("dec_key[:8] = {:02x?}", &dec_key.as_bytes()[..8]);

    // ── Verdict ───────────────────────────────────────────────────────────────
    if enc_key.as_bytes() == dec_key.as_bytes() {
        println!("\nKeys match ✓  — running on a Tuesday at 18:xx");
    } else {
        println!("\nKeys differ — not running on a Tuesday at 18:xx (expected outside that window)");
    }
}