This crate contains generic implementation of [block cipher modes of
operation][1].
Note that this crate implements only modes which require padding. For CTR,
CFB and OFB modes (i.e. modes which transsform block ciphers into stream
ciphers) see crates in the [RustCrypto/stream-ciphers][2] repository.
# Usage example
```
#[macro_use] extern crate hex_literal;
extern crate aes_soft as aes;
extern crate block_modes;
use block_modes::{BlockMode, Cbc};
use block_modes::block_padding::Pkcs7;
use aes::Aes128;
// create an alias for convinience
type Aes128Cbc = Cbc;
# fn main() {
let key = hex!("000102030405060708090a0b0c0d0e0f");
let iv = hex!("f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff");
let plaintext = b"Hello world!";
let cipher = Aes128Cbc::new_var(&key, &iv).unwrap();
// buffer must have enough space for message+padding
let mut buffer = [0u8; 32];
// copy message to the buffer
let pos = plaintext.len();
buffer[..pos].copy_from_slice(plaintext);
let ciphertext = cipher.encrypt(&mut buffer, pos).unwrap();
assert_eq!(ciphertext, hex!("1b7a4c403124ae2fb52bedc534d82fa8"));
// re-create cipher mode instance
let cipher = Aes128Cbc::new_var(&key, &iv).unwrap();
let mut buf = ciphertext.to_vec();
let decrypted_ciphertext = cipher.decrypt(&mut buf).unwrap();
assert_eq!(decrypted_ciphertext, plaintext);
# }
```
With an enabled `std` feature (which is enabled by default) you can use
`encrypt_vec` and `descrypt_vec` methods:
```
# #[macro_use] extern crate hex_literal;
# extern crate aes_soft as aes;
# extern crate block_modes;
#
# use block_modes::{BlockMode, Cbc};
# use block_modes::block_padding::Pkcs7;
# use aes::Aes128;
#
# // create an alias for convinience
# type Aes128Cbc = Cbc;
#
# fn main() {
# let key = hex!("000102030405060708090a0b0c0d0e0f");
# let iv = hex!("f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff");
# let plaintext = b"Hello world!";
let cipher = Aes128Cbc::new_var(&key, &iv).unwrap();
let ciphertext = cipher.encrypt_vec(plaintext);
assert_eq!(ciphertext, hex!("1b7a4c403124ae2fb52bedc534d82fa8"));
let cipher = Aes128Cbc::new_var(&key, &iv).unwrap();
let decrypted_ciphertext = cipher.decrypt_vec(&ciphertext).unwrap();
assert_eq!(decrypted_ciphertext, plaintext);
# }
```
[1]: https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation
[2]: https://github.com/RustCrypto/stream-ciphers