NoxTLS for Rust

A pure Rust TLS/DTLS workspace for embedded and host systems.
Built for deterministic behavior, portable integrations, and modern cryptography.

Website: https://noxtls.com
Issues: https://github.com/argenox/noxtls-rs/issues

Why NoxTLS Rust?

NoxTLS Rust is built for teams that need Rust-native TLS/DTLS support with predictable resource use.

• Small and portable crate design
• Deterministic crypto and protocol behavior
• Embedded-friendly no_std + alloc support
• Configurable transport adapters (embedded-io, embedded-io-async, tokio)
• X.509 parsing, validation, and PEM tooling

Features and cryptography

Protocols (TLS / DTLS)

• TLS 1.3 and DTLS 1.3 — handshake, record layer, resumption and early-data policy hooks, OCSP stapling support, and QUIC-style packet protection helpers for HTTP/3-style stacks.
• TLS 1.2 and DTLS 1.2 — ECDHE-RSA with AES-128-GCM or AES-256-GCM (IANA 0xC02F / 0xC030).

Negotiated cipher suites

Key exchange and signatures (TLS 1.3)

• Groups: X25519, P-256 (secp256r1), ML-KEM-768 (standalone and hybrid with X25519).
• Signature algorithms: ECDSA with P-256, RSA-PSS (SHA-256 / SHA-384), Ed25519, ML-DSA-65.

noxtls-crypto primitive suite

The noxtls-crypto crate supplies the underlying algorithms used by TLS and by tooling examples:

• Digests and KDF: SHA-256 / SHA-384 / SHA-512, SHA-3, SHAKE-256, HMAC, HKDF, TLS 1.2 PRF helpers; SHA-1 where legacy verification requires it.
• Symmetric: AES-GCM, ChaCha20-Poly1305, and additional AES / ARIA / Camellia modes (CBC, CCM, CTR, CFB, OFB, XTS, and more).
• Public-key: RSA (OAEP, PKCS#1 v1.5, PSS), P-256 ECDH and ECDSA, X25519, Ed25519, ML-KEM, ML-DSA.
• Randomness: HMAC-DRBG (SHA-256).

Legacy or hazardous algorithms (for example DES, RC4, X448, and some relaxed RSA key-generation paths) are gated behind the hazardous-legacy-crypto Cargo feature and are off by default.

Certificates and PKIX

• noxtls-x509 — X.509 parsing, chain validation, hostname checks, CSR and CRL handling (see examples/ for PEM/DER workflows).
• noxtls-pem — PEM envelope encoding and decoding shared across the stack.

Optional integrations

• provider-psa — offload signing, decryption, derivation, and AEAD to a PSA-style backend while keeping the same protocol API.
• Transport adapters — embedded-io, embedded-io-async, and Tokio (noxtls-io, enabled from noxtls).

Getting started

Use noxtls from crates.io

The noxtls crate is published on crates.io. Browse the API on docs.rs/noxtls.

Add it to your project:

cargo add noxtls

Or pin a version in Cargo.toml (use the version you intend to ship against; this repository’s workspace is currently 0.2.12):

[dependencies]
noxtls = "0.2.12"

Defaults: the crate enables std and alloc by default for typical host applications. For no_std builds, disable default features and opt in explicitly:

[dependencies]
noxtls = { version = "0.2.12", default-features = false, features = ["alloc"] }

Common Cargo features (see crates/noxtls/Cargo.toml for the complete list):

Import protocol types from the crate root, for example:

use noxtls::{Connection, TlsVersion, CipherSuite};

For end-to-end TLS/DTLS and certificate examples, use this repo’s examples/ (below) and the hosted guides at rsdocs.noxtls.com.

Clone this repository

git clone https://github.com/argenox/noxtls-rs.git
cd noxtls-rs

Build and test

cargo check --workspace
cargo test --workspace

Run examples (from a clone)

cargo run -p noxtls --example tls_client
cargo run -p noxtls --example parse_certificate
cargo run -p noxtls --example noxtls-rs -- dgst --alg sha256 --text "hello"

See examples/README.md for the full command list.

Workspace crates

Crates in crates/:

Documentation

• Docs site: https://rsdocs.noxtls.com
• Local docs server:

cd docs
npm install
npm run docs:sync
npm run start

• Versioned docs (like NoxTLS C): snapshots live under docs/versioned_docs/version-* and are listed in docs/versions.json. When you ship a release, add an entry to docs/changelog.json, then from docs/ run npm run docs:snapshot -- X.Y.Z (runs docs:sync then docusaurus docs:version X.Y.Z). Commit the updated versioned_docs/, versioned_sidebars/, and versions.json. Set lastVersion in docs/docusaurus.config.js to the newest published doc version.

• Record-layer integration notes: docs/TLS13_RECORD_POLICY.md

• DTLS policy knobs: docs/DTLS13_OPERATIONAL_POLICY.md

Formatting and linting

cargo fmt --all
cargo clippy --workspace --all-targets

Local validation

Run the full local gate that mirrors CI, release/docs consistency checks, thumbv6m-none-eabi Embassy-oriented checks, and the Docusaurus build:

./scripts/validate-local.ps1

On Unix-like shells:

./scripts/validate-local.sh

Useful flags:

• -SkipDocs / --skip-docs skips the Docusaurus install/build steps.
• -SkipThumbv6m / --skip-thumbv6m skips embedded target checks when the target is not installed locally.
• -SkipTests / --skip-tests skips cargo test --workspace.
• -FreshDocsInstall / --fresh-docs-install forces npm ci before the docs build.

Licensing

This project follows a dual-license model:

• GPLv2 for open-source usage
• Commercial license for proprietary usage

See LICENSE.md and COPYING.md.
Commercial licensing: info@argenox.com.