Struct Context

pub struct Context<const ROUNDS: usize> { /* private fields */ }

Chacha20Poly1305 Incremental Context for Authenticated Data (AAD)

The initial context set the key and nonce, and the authenticated data (if any), then it needs to converted either to a ContextEncryption or ContextDecryption using the Context::to_encryption or Context::to_decryption methods (respectively).

use cryptoxide::chacha20poly1305::Context;

let key : [u8; 16] = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15];
let nonce : [u8; 12] = [1,2,3,4,5,6,7,8,9,10,11,12];
let mut context = Context::<20>::new(&key, &nonce);

// Add incrementally 2 slices of data
context.add_data(b"authenticated");
context.add_data(b"data");

let mut encrypted_input = [0u8; 10+16];
let mut context = context.to_encryption();

// Encrypt incrementally 2 slices and append the encrypted data to the output buffer
context.encrypt(b"hello", &mut encrypted_input[0..5]);
context.encrypt(b"world", &mut encrypted_input[5..10]);

// Finalize the context, and append the tag to the end of the output buffer
let tag = context.finalize();
encrypted_input[10..26].copy_from_slice(&tag.0);

Implementations

impl<const ROUNDS: usize> Context<ROUNDS>

pub fn new(key: &[u8], nonce: &[u8; 12]) -> Self

Create a new context given the key and nonce.

use cryptoxide::chacha20poly1305::Context;

let key : [u8; 16] = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15];
let nonce : [u8; 12] = [1,2,3,4,5,6,7,8,9,10,11,12];
let context = Context::<20>::new(&key, &nonce);

pub fn add_data(&mut self, aad: &[u8])

Add Authenticated Data to the MAC Context

This can be called multiple times

pub fn to_encryption(self) -> ContextEncryption<ROUNDS>

Finish authenticated part and move to the encryption phase

pub fn to_decryption(self) -> ContextDecryption<ROUNDS>

Finish authenticated part and move to the decryption phase

Trait Implementations

impl<const ROUNDS: usize> Clone for Context<ROUNDS>

fn clone(&self) -> Context<ROUNDS>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.