pub use chacha20poly1305::ChaCha8Poly1305 as CryptoChaCha8Poly1305;
use chacha20poly1305::{
aead::{array::typenum::Unsigned, AeadCore, AeadInOut, KeyInit, KeySizeUser},
Key,
Nonce,
Tag,
};
pub struct ChaCha8Poly1305(CryptoChaCha8Poly1305);
impl ChaCha8Poly1305 {
pub fn new(key: &[u8]) -> ChaCha8Poly1305 {
let key = Key::try_from(key).expect("CHACHA8_POLY1305 key");
ChaCha8Poly1305(CryptoChaCha8Poly1305::new(&key))
}
pub fn key_size() -> usize {
<CryptoChaCha8Poly1305 as KeySizeUser>::KeySize::to_usize()
}
pub fn nonce_size() -> usize {
<CryptoChaCha8Poly1305 as AeadCore>::NonceSize::to_usize()
}
pub fn tag_size() -> usize {
<CryptoChaCha8Poly1305 as AeadCore>::TagSize::to_usize()
}
pub fn encrypt(&self, nonce: &[u8], plaintext_in_ciphertext_out: &mut [u8]) {
let nonce = Nonce::try_from(nonce).expect("CHACHA8_POLY1305 nonce");
let (plaintext, out_tag) =
plaintext_in_ciphertext_out.split_at_mut(plaintext_in_ciphertext_out.len() - Self::tag_size());
let tag = self
.0
.encrypt_inout_detached(&nonce, &[], plaintext.into())
.expect("CHACHA8_POLY1305 encrypt");
out_tag.copy_from_slice(tag.as_slice())
}
pub fn decrypt(&self, nonce: &[u8], ciphertext_in_plaintext_out: &mut [u8]) -> bool {
let nonce = Nonce::try_from(nonce).expect("CHACHA8_POLY1305 nonce");
let (ciphertext, in_tag) =
ciphertext_in_plaintext_out.split_at_mut(ciphertext_in_plaintext_out.len() - Self::tag_size());
let in_tag = match Tag::try_from(&*in_tag) {
Ok(t) => t,
Err(_) => return false,
};
self.0.decrypt_inout_detached(&nonce, &[], ciphertext.into(), &in_tag).is_ok()
}
}