#![cfg(feature = "aags")]
use crate::Error;
use aes_gcm_siv::{
aead::{Aead, KeyInit},
Aes256GcmSiv, Nonce,
};
const KEY_OFFSET: usize = 32;
const KEY_LEN: usize = 32;
const NONCE_SIZE: usize = 12;
const MIN_DATA_LEN: usize = 17;
#[inline]
pub fn encrypt(master_key: &[u8; 64], plaintext_bytes: &[u8]) -> Result<Vec<u8>, Error> {
if plaintext_bytes.is_empty() {
return Err(Error::EmptyPlaintext);
}
let key_slice = &master_key[KEY_OFFSET..KEY_OFFSET + KEY_LEN];
let key: &[u8; 32] = key_slice.try_into().unwrap();
let cipher = Aes256GcmSiv::new(key.into());
let nonce = Nonce::from([0u8; NONCE_SIZE]);
cipher
.encrypt(&nonce, plaintext_bytes)
.map_err(|_| Error::EncryptionFailed)
}
#[inline]
pub fn decrypt(master_key: &[u8; 64], data: &[u8]) -> Result<Vec<u8>, Error> {
if data.len() < MIN_DATA_LEN {
return Err(Error::PayloadTooShort);
}
let key_slice = &master_key[KEY_OFFSET..KEY_OFFSET + KEY_LEN];
let key: &[u8; 32] = key_slice.try_into().unwrap();
let cipher = Aes256GcmSiv::new(key.into());
let nonce = Nonce::from([0u8; NONCE_SIZE]);
cipher
.decrypt(&nonce, data)
.map_err(|_| Error::DecryptionFailed)
}