tacet-macros

Proc macros for timing side-channel tests.

This crate provides the timing_test! and timing_test_checked! macros for tacet. You typically don't need to depend on this crate directly.

Installation

The macros are included when you enable the macros feature on tacet (enabled by default):

[dev-dependencies]
tacet = "0.1"

Usage

timing_test!

Returns Outcome for pattern matching on all four variants:

use tacet::{timing_test, Outcome};

let outcome = timing_test! {
    baseline: || [0u8; 32],
    sample: || rand::random::<[u8; 32]>(),
    measure: |input| {
        my_crypto_function(&input);
    },
};

match outcome {
    Outcome::Pass { leak_probability, .. } => {
        println!("No leak: {:.1}%", leak_probability * 100.0);
    }
    Outcome::Fail { exploitability, .. } => {
        panic!("Timing leak detected: {:?}", exploitability);
    }
    Outcome::Inconclusive { reason, .. } => {
        println!("Inconclusive: {:?}", reason);
    }
    Outcome::Unmeasurable { recommendation, .. } => {
        println!("Skipped: {}", recommendation);
    }
}

timing_test_checked!

Same as timing_test! but panics on Fail:

use tacet::{timing_test_checked, Outcome};

// Panics if timing leak detected
let outcome = timing_test_checked! {
    baseline: || [0u8; 32],
    sample: || rand::random::<[u8; 32]>(),
    measure: |input| {
        constant_time_eq(&secret, &input);
    },
};

Custom Oracle Configuration

use tacet::{timing_test, TimingOracle, AttackerModel};

let outcome = timing_test! {
    oracle: TimingOracle::for_attacker(AttackerModel::SharedHardware)
        .pass_threshold(0.01)
        .fail_threshold(0.99),
    baseline: || [0u8; 32],
    sample: || rand::random::<[u8; 32]>(),
    measure: |input| operation(&input),
};

Syntax

timing_test! {
    // Optional: oracle configuration (defaults to AdjacentNetwork)
    oracle: TimingOracle::for_attacker(AttackerModel::AdjacentNetwork),

    // Required: baseline input generator
    baseline: || fixed_input,

    // Required: sample input generator
    sample: || random_input(),

    // Required: operation to measure
    measure: |input| operation(&input),
}

Documentation

• API Documentation
• Main crate
• GitHub Repository

License

MPL-2.0