Crate xsalsa20poly1305

XSalsa20Poly1305 (a.k.a. NaCl crypto_secretbox1) is an authenticated encryption cipher amenable to fast, constant-time implementations in software, based on the Salsa20 stream cipher (with XSalsa20 192-bit nonce extension) and the Poly1305 universal hash function, which acts as a message authentication code.

This algorithm has largely been replaced by the newer ChaCha20Poly1305 (and the associated XChaCha20Poly1305) AEAD ciphers (RFC 8439), but is useful for interoperability with legacy NaCl-based protocols.

Security Warning

No security audits of this crate have ever been performed, and it has not been thoroughly assessed to ensure its operation is constant-time on common CPU architectures.

Where possible the implementation uses constant-time hardware intrinsics, or otherwise falls back to an implementation which contains no secret-dependent branches or table lookups, however it's possible LLVM may insert such operations in certain scenarios.

Usage

use xsalsa20poly1305::XSalsa20Poly1305;
use aead::{Aead, NewAead, generic_array::GenericArray};

let key = GenericArray::clone_from_slice(b"an example very very secret key.");
let aead = XSalsa20Poly1305::new(key);

let nonce = GenericArray::from_slice(b"extra long unique nonce!"); // 24-bytes; unique
let ciphertext = aead.encrypt(nonce, b"plaintext message".as_ref()).expect("encryption failure!");
let plaintext = aead.decrypt(nonce, ciphertext.as_ref()).expect("decryption failure!");
assert_eq!(&plaintext, b"plaintext message");

Re-exports

pub use aead;

Structs

XSalsa20Poly1305

XSalsa20Poly1305 (a.k.a. NaCl crypto_secretbox) authenticated encryption cipher.

Type Definitions

Tag	Poly1305 tags