liboqs-rust: Rust bindings for liboqs

crate	crates.io	docs.rs	License
oqs-sys
oqs

liboqs-rust offers two Rust wrappers for the Open Quantum Safe liboqs C library, which is a C library for quantum-resistant cryptographic algorithms.

• The oqs-sys crate compiles and builds liboqs and generates unsafe bindings to the C library.
• The oqs crate offers a Rust-style safe interface to the schemes included in liboqs.

Versioning

Releases up to and including release 0.9.0 of oqs and oqs-sys followed the liboqs versioning 1-on-1. Starting from release 0.9.0, this is no longer guaranteed. These crates will now receive version bumps as necessary. We will include the version number of liboqs that is distributed by liboqs-sys in the version number of liboqs-sys as 0.9.0+liboqs-0.9.0.

Pre-requisites

oqs-sys depends on the liboqs C library. It will build liboqs automatically with the default-enabled vendored feature. See below for more information.

Contents

This crate provides unsafe ffi bindings in the oqs-sys crate, and safe wrappers are offered via the oqs crate. The rendered Rustdoc documentation can be found here

Usage

Update your Cargo.toml and include oqs:

[dependencies]
oqs = "0.9.0"

oqs-sys can be specified equivalently.

Minimal builds

The default-on kems and sigs features turn on all supported KEMs and signature schemes. If you want a smaller build, turn off these default features and opt-in to individual algorithms. Note that if you specify default-features = false, you may also want to re-include the oqs-sys/openssl feature.

Vendored liboqs

By default oqs-sys attempts to find a system-provided version of liboqs and build against it, falling back to vendored from-source build otherwise. You can opt into forcing the vendored build by enabling the vendored feature.

Otherwise, if you want to force using the system-provided liboqs, you can set the LIBOQS_NO_VENDOR=1 environment variable and the build will fail if the library is not found.

Serde support

You can enable serde serialization support by enabling the serde feature on the oqs crate.

std support

The oqs-sys crate does not use std at all. Note that the default features do enable building liboqs with openssl, so use default-features = false.

To make oqs a #![no_std] crate make sure the std feature is disabled. Make sure to also disable the oqs-sys/openssl feature by specifying default-features = false.

As default-features includes the kems and sigs features, consider re-adding them as well. This results into:

[dependencies.oqs]
version = "*"
default-features = false
features = ["sigs", "kems"]

You will probably want to change the random-number generator through the OQS_RAND API offered by oqs-sys.

non_portable feature

If compiled with the non_portable feature, liboqs-sys will not enable CPU feature detection and always use the best implementation on your current platform. This enables support for implementations where feature detection is not functional.

Stack usage

Some algorithms use large amounts of stack space. This means that you may need to specify RUST_MIN_STACK in your environment. This for example affects tests.

Algorithm features

• kems (default): Compile with all KEMs enabled
  • bike
  • classic_mceliece
  • frodokem
  • hqc
  • kyber
  • ntruprime
  • saber
• sigs (default): Compile with all signature schemes enabled
  • dilithium
  • falcon
  • picnic
  • rainbow
  • sphincs: SPHINCS⁺

Running

/// # Example: Some signed KEX
/// This protocol has no replay protection!
///
use oqs::*;
fn main() -> Result<()> {
    let sigalg = sig::Sig::new(sig::Algorithm::Dilithium2)?;
    let kemalg = kem::Kem::new(kem::Algorithm::Kyber512)?;
    // A's long-term secrets
    let (a_sig_pk, a_sig_sk) = sigalg.keypair()?;
    // B's long-term secrets
    let (b_sig_pk, b_sig_sk) = sigalg.keypair()?;

    // assumption: A has (a_sig_sk, a_sig_pk, b_sig_pk)
    // assumption: B has (b_sig_sk, b_sig_pk, a_sig_pk)

    // A -> B: kem_pk, signature
    let (kem_pk, kem_sk) = kemalg.keypair()?;
    let signature = sigalg.sign(kem_pk.as_ref(), &a_sig_sk)?;

    // B -> A: kem_ct, signature
    sigalg.verify(kem_pk.as_ref(), &signature, &a_sig_pk)?;
    let (kem_ct, b_kem_ss) = kemalg.encapsulate(&kem_pk)?;
    let signature = sigalg.sign(kem_ct.as_ref(), &b_sig_sk)?;

    // A verifies, decapsulates, now both have kem_ss
    sigalg.verify(kem_ct.as_ref(), &signature, &b_sig_pk)?;
    let a_kem_ss = kemalg.decapsulate(&kem_sk, &kem_ct)?;
    assert_eq!(a_kem_ss, b_kem_ss);

    Ok(())
}

Limitations and security

liboqs is designed for prototyping and evaluating quantum-resistant cryptography. Security of proposed quantum-resistant algorithms may rapidly change as research advances, and may ultimately be completely insecure against either classical or quantum computers.

We believe that the NIST Post-Quantum Cryptography standardization project is currently the best avenue to identifying potentially quantum-resistant algorithms. liboqs does not intend to "pick winners", and we strongly recommend that applications and protocols rely on the outcomes of the NIST standardization project when deploying post-quantum cryptography.

We acknowledge that some parties may want to begin deploying post-quantum cryptography prior to the conclusion of the NIST standardization project. We strongly recommend that any attempts to do make use of so-called hybrid cryptography, in which post-quantum public-key algorithms are used alongside traditional public key algorithms (like RSA or elliptic curves) so that the solution is at least no less secure than existing traditional cryptography.

Just like liboqs, liboqs-rust is provided "as is", without warranty of any kind. See LICENSE-MIT for the full disclaimer.

License

liboqs-rust is dual-licensed under the MIT and Apache-2.0 licenses.

The included library liboqs is covered by the liboqs license.

Team

The Open Quantum Safe project is led by Douglas Stebila and Michele Mosca at the University of Waterloo.

liboqs-rust was developed by Thom Wiggers at Radboud University.

Support

Financial support for the development of Open Quantum Safe has been provided by Amazon Web Services and the Canadian Centre for Cyber Security.

We'd like to make a special acknowledgement to the companies who have dedicated programmer time to contribute source code to OQS, including Amazon Web Services, Cisco Systems, evolutionQ, IBM Research, and Microsoft Research.

Research projects which developed specific components of OQS have been supported by various research grants, including funding from the Natural Sciences and Engineering Research Council of Canada (NSERC); see the source papers for funding acknowledgments.

Thom Wiggers' contributions before May 2023 were supported by the European Research Council through Starting Grant No. 805031 (EPOQUE).