timelock_round_trip/
timelock_round_trip.rs

1//! Full encrypt → store-header → decrypt round-trip using the timelock API.
2//!
3//! Demonstrates:
4//!   - Deriving an encryption key from an explicit time (`params = None` → `_at` path)
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 (`params = Some(header)` → `_now` path)
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    timelock, 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 = timelock(
40        Some(cadence.clone()),
41        Some(lock_time),
42        Some(TimePrecision::Hour),
43        Some(TimeFormat::Hour24),
44        Some(salts.clone()),
45        Some(kdf),
46        None,   // params = None → _at (encryption) path
47    )
48    .expect("encryption-side key derivation failed");
49
50    println!("enc_key[:8] = {:02x?}", &enc_key.as_bytes()[..8]);
51
52    // Pack every setting — including salts and KDF params — into a compact header.
53    // This header goes into the ciphertext in plaintext; nothing here is secret.
54    let header = pack(
55        TimePrecision::Hour,
56        TimeFormat::Hour24,
57        &cadence,
58        salts,
59        kdf,
60    );
61
62    // ── Decryption side ───────────────────────────────────────────────────────
63    // Load `header` from the ciphertext and call timelock() at the matching
64    // time slot with params = Some(header).
65    println!("Deriving decryption key from system clock…");
66    let dec_key = timelock(
67        None, None, None, None, None, None,
68        Some(header),   // params = Some → _now (decryption) path
69    )
70    .expect("decryption-side key derivation failed");
71
72    println!("dec_key[:8] = {:02x?}", &dec_key.as_bytes()[..8]);
73
74    // ── Verdict ───────────────────────────────────────────────────────────────
75    if enc_key.as_bytes() == dec_key.as_bytes() {
76        println!("\nKeys match ✓  — running on a Tuesday at 18:xx");
77    } else {
78        println!("\nKeys differ — not running on a Tuesday at 18:xx (expected outside that window)");
79    }
80}
timelock_round_trip/timelock_round_trip.rs

timelock_round_trip/
timelock_round_trip.rs
