💬 Join the Matrix chat

dryoc: Don't Roll Your Own Crypto™¹

dryoc is a pure-Rust, general-purpose cryptography library that's hard to misuse. It's based on the excellent libsodium library, but in pure Rust. It also includes protected memory features throughout, which makes it dead simple to build secure, robust, and safe cryptographic software. The original goal of this library was to provide a pure-Rust alternative to libsodium.

The purpose of this project is to provide a pure-Rust, mostly drop-in replacement for libsodium. This library has nearly the same ergonomics as libsodium (referred to in dryoc as the Classic API), such that people familiar with libsodium can use this library nearly interchangeably. While the API is not 100% identical to libsodium, most functions have the same or very similar signatures.

In addition to the Classic API, there's a Rustaceous API which aims to bring an idiomatic Rust implementation of libsodium's core features: public and secret key authenticated cryptography and general-purpose cryptography tools.

Not all features from libsodium are implemented here, either because there exist better implementations in other crates, or because they aren't necessary as part of this crate.

Additionally, this crate provides exceptionally safe cryptography thanks to Rust's safety features. The Rustaceous API is designed designed to make it difficult to shoot yourself in the foot. It's worth noting, however, you certainly can still shoot yourself if you choose (either by leaking private data, using insecure hardware, OPSEC issues, etc).

For example usage, refer to the official docs or the integration tests.

Features

• 100% pure Rust, no hidden C libraries
• mostly free of unsafe code²
• Hard to misuse, helping you avoid common costly cryptography mistakes
• Many libsodium features implemented with both Classic and Rustaceous API
• Protected memory handling (mprotect() + mlock(), along with Windows equivalents) on stable Rust for Unix and Windows targets, enabled by default with the protected feature
• Serde support (with features = ["serde"])
• wincode support for direct binary serialization of Rustaceous box types (with features = ["wincode"])
• Portable SIMD implementations on nightly, with features = ["simd_backend", "nightly"]:
  • Blake2b (used by generic hashing, password hashing, and key derivation)
  • Argon2 block mixing (used by password hashing)
  • Salsa20 (used by XSalsa20-Poly1305 secretbox)
  • Poly1305 (used by one-time authentication and secret boxes), except on AArch64 where dryoc keeps the soft backend because the portable-SIMD path is slower there
• curve25519-dalek (used by public/private key functions) selects its own serial or x86_64 vector backend at build time
• SHA2 (used by sealed boxes) includes SIMD implementation for AVX2
• ChaCha20 (used by streaming interface) includes SIMD implementations for NEON, AVX2, and SSE2

Rust version

dryoc uses the Rust 2024 edition and requires Rust 1.89 or newer, as declared by rust-version in Cargo.toml.

Rust 2024 reserves gen as a keyword. Prefer generation APIs such as Key::generate(). Existing gen APIs remain available through raw identifier syntax, such as Key::r#gen(), for compatibility and will be deprecated in a future release.

The simd_backend and nightly features enable dryoc's portable SIMD backends. CPU-specific dependency backends and local benchmarking may also benefit from target-specific RUSTFLAGS:

• For AVX2 set RUSTFLAGS=-Ctarget-cpu=haswell -Ctarget-feature=+avx2
• For SSE2 set RUSTFLAGS=-Ctarget-feature=+sse2
• For NEON set RUSTFLAGS=-Ctarget-feature=+neon
• For local Apple Silicon benchmarks, use RUSTFLAGS=-Ctarget-cpu=native. NEON is part of the AArch64 macOS baseline target, so adding -Ctarget-feature=+neon is not expected to change native results.

The Curve25519 backend is selected by curve25519-dalek, not by dryoc's simd_backend feature.

Poly1305 is a special exception on AArch64: even with simd_backend and nightly enabled, dryoc uses the soft Poly1305 backend because profiling shows the portable-SIMD implementation is slower on that architecture.

Note that eventually this project will converge on portable SIMD implementations for all the core algos which will work across all platforms supported by LLVM, rather than relying on hand-coded assembly or intrinsics, but this is a work in progress.

See BENCHMARKS.md for side-by-side software and SIMD benchmark results.

Optional serialization

Enable serde to derive serde::Serialize and serde::Deserialize for supported data structures.

Enable wincode to derive wincode::SchemaWrite and wincode::SchemaRead for supported Rustaceous box types, including DryocBox and DryocSecretBox, plus AEAD boxes and envelopes from dryocaead.

Project status

The following libsodium features are currently implemented, or awaiting implementation. This list has been reviewed against libsodium 1.0.22:

• Public-key cryptography (crypto_box_*) libsodium link
• Secret-key cryptography (crypto_secretbox_*) libsodium link
• Curve25519 point*scalar multiplication (crypto_scalarmult*) libsodium link
• Zeroing memory (sodium_memzero) with zeroize libsodium link
• Generating random data (randombytes_buf) libsodium link
• Encrypted streams (crypto_secretstream_*) libsodium link
• XChaCha20-Poly1305-IETF AEAD (crypto_aead_xchacha20poly1305_ietf_*) libsodium link
• Memory locking (sodium_mlock, sodium_munlock, sodium_mprotect_*) libsodium link
• Encrypting related messages (sodium_increment) libsodium link
• Generic hashing (crypto_generichash_*) libsodium link
• Secret-key authentication (crypto_auth*) libsodium link
• One-time authentication (crypto_onetimeauth_*) libsodium link
• Sealed boxes (crypto_box_seal*) libsodium link
• Key derivation (crypto_kdf_*) libsodium link
• Key exchange (crypto_kx_*) libsodium link
• Public-key signatures (crypto_sign_*) libsodium link
• Ed25519 to Curve25519 (crypto_sign_ed25519_*) libsodium link
• SHA-512 hashing (crypto_hash_sha512_*) libsodium link
• Short-input hashing (crypto_shorthash) libsodium link
• Password hashing (crypto_pwhash_*) libsodium link

The following libsodium features are either incomplete, not exposed as public APIs, or not implemented; you may find equivalent functionality in other crates:

• AEAD constructions beyond XChaCha20-Poly1305-IETF, including AEGIS-128L/256, AES256-GCM, and ChaCha20-Poly1305
• XChaCha20-Poly1305 box and secretbox variants (crypto_box_curve25519xchacha20poly1305_*, crypto_secretbox_xchacha20poly1305_*)
• HKDF key derivation variants (crypto_kdf_hkdf_sha256_*, crypto_kdf_hkdf_sha512_*)
• SHA-2/SHA-3 hash variants beyond SHA-512 (crypto_hash_sha256_*, crypto_hash_sha3256_*, crypto_hash_sha3512_*)
• Extendable-output functions (crypto_xof_shake*, crypto_xof_turboshake*), added in libsodium 1.0.21
• Key encapsulation (crypto_kem_*, crypto_kem_mlkem768_*, crypto_kem_xwing_*), added in libsodium 1.0.22
• Direct HMAC authentication variants (crypto_auth_hmacsha256_*, crypto_auth_hmacsha512_*, crypto_auth_hmacsha512256_*)
• Signature secret-key extraction helpers (crypto_sign_ed25519_sk_to_seed, crypto_sign_ed25519_sk_to_pk)
• Deterministic random data for reproducible tests (randombytes_buf_deterministic)
• Short-input hash variants beyond SipHash-2-4 with 64-bit output (crypto_shorthash_siphashx24_*)
• IP address encryption (crypto_ipcrypt_*, sodium_ip2bin, sodium_bin2ip), added in libsodium 1.0.21
• Helpers, padding, and constant-time verify utilities (sodium_*, crypto_verify_*)
• Standalone stream cipher APIs (crypto_stream_*; use the salsa20 or chacha20 crates directly instead)
• Advanced features:
  • Keccak-f[1600] core permutation (crypto_core_keccak1600_*)
  • Scrypt (crypto_pwhash_scryptsalsa208sha256_*; use the scrypt crate directly instead)
  • Finite field and group arithmetic (crypto_core_ed25519_*, crypto_core_ristretto255_*; try the curve25519-dalek crate)
  • Ed25519 and Ristretto255 scalar multiplication variants (crypto_scalarmult_ed25519_*, crypto_scalarmult_ristretto255_*)

Stargazers over time

Other NaCl-related Rust implementations worth mentioning

• sodiumoxide
• crypto_box

Footnotes

1. Not actually trademarked. ↩

2. The protected memory features described in the [protected] mod are available on Unix and Windows targets with the default protected feature. Unsupported targets do not expose the protected-memory API. These features require custom memory allocation, system calls, and pointer arithmetic, which are unsafe in Rust. Some optional SIMD code, including dependency-provided SIMD implementations and small internal helpers, may contain unsafe code. In particular, many SIMD implementations are considered "unsafe" due to their use of assembly or intrinsics, however without SIMD-based cryptography you may be exposed to timing attacks. The in-crate unsafe inventory includes fixed-size byte views, optional wincode schema impls for Rustaceous boxes and AEAD envelopes, BLAKE2b parameter byte views, protected memory guarded heap buffers and OS protection calls, and Salsa20 SIMD unaligned in-place and buffer-to-buffer XOR. See the rustdoc unsafe code summary for the full non-test unsafe inventory in this crate. ↩