Module aead 

Authenticated Encryption with Additional Data.

AEAD couples confidentiality and integrity in a single primitive. AEAD algorithms take a key and then can seal and open individual messages. Each message has a unique, per-message nonce and, optionally, additional data which is authenticated but not included in the ciphertext.

No two distinct plaintexts must ever be sealed using the same (key, nonce) pair. It is up to the user of these algorithms to ensure this. For example, when encrypting a stream of messages (e.g. over a TCP socket) a message counter can provide distinct nonces as long as the key is randomly generated for the specific connection and is distinct in each direction.

To implement that example:

use bssl_crypto::aead::{Aead, Aes256Gcm};

let key = bssl_crypto::rand_array();
let aead = Aes256Gcm::new(&key);

let mut message_counter: u64 = 0;
let mut nonce = bssl_crypto::rand_array();
nonce[4..].copy_from_slice(message_counter.to_be_bytes().as_slice());
message_counter += 1;
let plaintext = b"message";
let ciphertext = aead.seal(&nonce, plaintext, b"");

let decrypted = aead.open(&nonce, ciphertext.as_slice(), b"");
assert_eq!(plaintext, decrypted.unwrap().as_slice());

Structs

Aes128Gcm

AES-128 in Galois Counter Mode.

Aes128GcmSiv

AES-128 in GCM-SIV mode (which is different from SIV mode!).

Aes256Gcm

AES-256 in Galois Counter Mode.

Aes256GcmSiv

AES-256 in GCM-SIV mode (which is different from SIV mode!).

Chacha20Poly1305

The AEAD built from ChaCha20 and Poly1305 as described in https://datatracker.ietf.org/doc/html/rfc8439.

InvalidCiphertext

The error type returned when a fallible, in-place operation fails.

XChacha20Poly1305

Chacha20Poly1305 with an extended nonce that makes random generation of nonces safe.

Traits

Aead

Authenticated Encryption with Associated Data (AEAD) algorithm trait.