timelock_round_trip/
timelock_round_trip.rs

1//! Full encrypt → store-header → decrypt round-trip using the timelock API.
2//!
3//! Demonstrates:
4//!   - Building a [`TimelockBuilder`] for the encryption path (`::encrypt()`)
5//!   - Packing all settings (precision, format, cadence, salts, KDF params) into a
6//!     self-contained [`TimeLockParams`] header for plaintext storage in the ciphertext
7//!   - Re-deriving the key from the live system clock with [`TimelockBuilder::decrypt`]
8//!
9//! Run with:
10//! ```sh
11//! cargo run --example timelock_round_trip --features encryption
12//! ```
13//!
14//! If you run this at exactly the right minute the keys will match.  Because
15//! `TimePrecision::Minute` is used the window is 60 seconds wide — any run
16//! within the same minute as the lock-time will succeed.
17
18use toolkit_zero::encryption::timelock::{
19    TimelockBuilder, pack,
20    TimeLockCadence, TimeLockSalts, TimeLockTime,
21    TimePrecision, TimeFormat, KdfPreset, Weekday,
22};
23
24fn main() {
25    // ── Encryption side ───────────────────────────────────────────────────────
26    // Generate fresh salts.  Salts are NOT secret — store them in plaintext
27    // alongside the ciphertext so the decryption side can reproduce the key.
28    let salts = TimeLockSalts::generate();
29
30    // Use a deliberately fast preset so the example finishes quickly.
31    // In production use KdfPreset::Balanced or stronger.
32    let kdf = KdfPreset::Balanced.params();
33
34    // Lock to any Tuesday at 18:00 (hour-precision window = the full 18:00–18:59 block).
35    let cadence   = TimeLockCadence::DayOfWeek(Weekday::Tuesday);
36    let lock_time = TimeLockTime::new(18, 0).unwrap();
37
38    println!("Deriving encryption key (this may take a few seconds)…");
39    let enc_key = TimelockBuilder::encrypt()
40        .cadence(cadence.clone())
41        .time(lock_time)
42        .precision(TimePrecision::Hour)
43        .format(TimeFormat::Hour24)
44        .salts(salts.clone())
45        .kdf(kdf)
46        .derive()
47        .expect("encryption-side key derivation failed");
48
49    println!("enc_key[:8] = {:02x?}", &enc_key.as_bytes()[..8]);
50
51    // Pack every setting — including salts and KDF params — into a compact header.
52    // This header goes into the ciphertext in plaintext; nothing here is secret.
53    let header = pack(
54        TimePrecision::Hour,
55        TimeFormat::Hour24,
56        &cadence,
57        salts,
58        kdf,
59    );
60
61    // ── Decryption side ───────────────────────────────────────────────────────
62    // Load `header` from the ciphertext and call TimelockBuilder::decrypt at the
63    // matching time slot.  All settings are read from the header automatically.
64    println!("Deriving decryption key from system clock…");
65    let dec_key = TimelockBuilder::decrypt(header)
66        .derive()
67        .expect("decryption-side key derivation failed");
68
69    println!("dec_key[:8] = {:02x?}", &dec_key.as_bytes()[..8]);
70
71    // ── Verdict ───────────────────────────────────────────────────────────────
72    if enc_key.as_bytes() == dec_key.as_bytes() {
73        println!("\nKeys match ✓  — running on a Tuesday at 18:xx");
74    } else {
75        println!("\nKeys differ — not running on a Tuesday at 18:xx (expected outside that window)");
76    }
77}
timelock_round_trip/timelock_round_trip.rs

timelock_round_trip/
timelock_round_trip.rs
