//! [Cipher Block Chaining][1] (CBC) mode.

//!

//! <img src="https://raw.githubusercontent.com/RustCrypto/media/26acc39f/img/block-modes/cbc_enc.svg" width="49%" />

//! <img src="https://raw.githubusercontent.com/RustCrypto/media/26acc39f/img/block-modes/cbc_dec.svg" width="49%"/>

//!

//! Mode functionality is accessed using traits from re-exported [`cipher`] crate.

//!

//! # ⚠️ Security Warning: Hazmat!

//!

//! This crate does not ensure ciphertexts are authentic! Thus ciphertext integrity

//! is not verified, which can lead to serious vulnerabilities!

//!

//! # Example

//! ```

//! # #[cfg(feature = "block-padding")] {

//! use aes::cipher::{block_padding::Pkcs7, BlockDecryptMut, BlockEncryptMut, KeyIvInit};

//! use hex_literal::hex;

//!

//! type Aes128CbcEnc = cbc::Encryptor<aes::Aes128>;

//! type Aes128CbcDec = cbc::Decryptor<aes::Aes128>;

//!

//! let key = [0x42; 16];

//! let iv = [0x24; 16];

//! let plaintext = *b"hello world! this is my plaintext.";

//! let ciphertext = hex!(

//!     "c7fe247ef97b21f07cbdd26cb5d346bf"

//!     "d27867cb00d9486723e159978fb9a5f9"

//!     "14cfb228a710de4171e396e7b6cf859e"

//! );

//!

//! // encrypt/decrypt in-place

//! // buffer must be big enough for padded plaintext

//! let mut buf = [0u8; 48];

//! let pt_len = plaintext.len();

//! buf[..pt_len].copy_from_slice(&plaintext);

//! let ct = Aes128CbcEnc::new(&key.into(), &iv.into())

//!     .encrypt_padded_mut::<Pkcs7>(&mut buf, pt_len)

//!     .unwrap();

//! assert_eq!(ct, &ciphertext[..]);

//!

//! let pt = Aes128CbcDec::new(&key.into(), &iv.into())

//!     .decrypt_padded_mut::<Pkcs7>(&mut buf)

//!     .unwrap();

//! assert_eq!(pt, &plaintext);

//!

//! // encrypt/decrypt from buffer to buffer

//! let mut buf = [0u8; 48];

//! let ct = Aes128CbcEnc::new(&key.into(), &iv.into())

//!     .encrypt_padded_b2b_mut::<Pkcs7>(&plaintext, &mut buf)

//!     .unwrap();

//! assert_eq!(ct, &ciphertext[..]);

//!

//! let mut buf = [0u8; 48];

//! let pt = Aes128CbcDec::new(&key.into(), &iv.into())

//!     .decrypt_padded_b2b_mut::<Pkcs7>(&ct, &mut buf)

//!     .unwrap();

//! assert_eq!(pt, &plaintext);

//! # }

//! ```

//!

//! With enabled `alloc` (or `std`) feature you also can use allocating

//! convinience methods:

//! ```

//! # #[cfg(all(feature = "alloc", feature = "block-padding"))] {

//! # use aes::cipher::{block_padding::Pkcs7, BlockDecryptMut, BlockEncryptMut, KeyIvInit};

//! # use hex_literal::hex;

//! # type Aes128CbcEnc = cbc::Encryptor<aes::Aes128>;

//! # type Aes128CbcDec = cbc::Decryptor<aes::Aes128>;

//! # let key = [0x42; 16];

//! # let iv = [0x24; 16];

//! # let plaintext = *b"hello world! this is my plaintext.";

//! # let ciphertext = hex!(

//! #     "c7fe247ef97b21f07cbdd26cb5d346bf"

//! #     "d27867cb00d9486723e159978fb9a5f9"

//! #     "14cfb228a710de4171e396e7b6cf859e"

//! # );

//! let res = Aes128CbcEnc::new(&key.into(), &iv.into())

//!     .encrypt_padded_vec_mut::<Pkcs7>(&plaintext);

//! assert_eq!(res[..], ciphertext[..]);

//! let res = Aes128CbcDec::new(&key.into(), &iv.into())

//!     .decrypt_padded_vec_mut::<Pkcs7>(&res)

//!     .unwrap();

//! assert_eq!(res[..], plaintext[..]);

//! # }

//! ```

//!

//! [1]: https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#CBC

#![no_std]

#![doc(

    html_logo_url = "https://raw.githubusercontent.com/RustCrypto/media/26acc39f/logo.svg",

    html_favicon_url = "https://raw.githubusercontent.com/RustCrypto/media/26acc39f/logo.svg",

    html_root_url = "https://docs.rs/cbc/0.1.2"

)]

#![forbid(unsafe_code)]

#![cfg_attr(docsrs, feature(doc_cfg))]

#![warn(missing_docs, rust_2018_idioms)]

mod decrypt;

mod encrypt;

pub use cipher;

pub use decrypt::Decryptor;

pub use encrypt::Encryptor;

use cipher::generic_array::{ArrayLength, GenericArray};

#[inline(always)]

fn xor<N: ArrayLength<u8>>(out: &mut GenericArray<u8, N>, buf: &GenericArray<u8, N>) {

    for (a, b) in out.iter_mut().zip(buf) {

        *a ^= *b;

    }

}