strobe-rs

This is a relatively barebones, no_std implementation of the Strobe protocol framework in pure Rust. It is intended to be used as a library to build other protocols and frameworks. This implementation currently only supports Keccak-f[1600] as the internal permutation function, which is the largest possible block size, so big deal.

Example

A simple program that encrypts and decrypts a message:

use strobe_rs::{SecParam, Strobe};

fn main() {
    let mut rx = Strobe::new(b"correctnesstest", SecParam::B256);
    let mut tx = Strobe::new(b"correctnesstest", SecParam::B256);

    rx.key(b"the-combination-on-my-luggage", false);
    tx.key(b"the-combination-on-my-luggage", false);

    let mut msg = b"Attack at dawn".to_vec();
    rx.send_enc(msg.as_mut_slice(), false);

    // Rename for clarity. `msg` has been encrypted in-place.
    let mut ciphertext = msg;

    tx.recv_enc(ciphertext.as_mut_slice(), false);

    // And back again.
    let round_trip_msg = ciphertext;

    assert_eq!(&round_trip_msg, b"Attack at dawn");
}

Features

Default features flags: [none]

Feature flag list:

• std - Implements std::error::Error for AuthError.
• serialize_secret_state - Implements serde's Serialize and Deserialize traits for the Strobe struct. SECURITY NOTE: Serializing Strobe state outputs security sensitive data that MUST be kept private. Treat the data as you would a private encryption/decryption key.

For info on how to omit or include feature flags, see the cargo docs on features.

MSRV

The current minimum supported Rust version (MSRV) is 1.51.0 (2021-03-25).

Tests

To run tests, execute

cargo test --all-features

This includes known-answer tests, which test against JSON-encoded test vectors in the kat/ directory. To verify these test vectors against the reference Python implementation, cd into kat/, run python2 verify_test_vector.py and follow the included instructions.

Benchmarks

To benchmark, run

cargo bench

This will produce a summary with plots in target/crieteron/report/index.html. These won't be very interesting, since almost every function in STROBE has the same runtime.

TODO

• Contribute an asm impelmentation of Keccak-f[1600] to tiny-keccak and expose a feature flag that lets strobe-rs users choose which implementation they prefer.

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE)
• MIT license (LICENSE-MIT)

at your option.

Warning

This code has not been audited in any sense of the word. Use at your own discretion.