Skip to content

Commit

Permalink
ocb3: use Ocb3 as the type name
Browse files Browse the repository at this point in the history 
Renames `AesOcb3` to `Ocb3`.

Unlike AES-GCM, AES-GCM-SIV, and AES-SIV, in which AES is the de facto
cipher for that mode, OCB is defined in a more cipher-agnostic way
similar to CCM or EAX modes (which, as it were, is reflected in our
choice of crate names).

This renames the type to reflect that, and as it were, match the crate
name as well.
  • Loading branch information
@tarcieri
tarcieri committed Mar 25, 2024
1 parent c2fe6b3 commit eba495c
Show file tree
Hide file tree
Showing 4 changed files with 44 additions and 41 deletions.
8 changes: 7 additions & 1 deletion Cargo.lock
View file

Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.

4 changes: 2 additions & 2 deletions ocb3/README.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,10 +18,10 @@ use aes::Aes128;
use ocb3::{
aead::{Aead, AeadCore, KeyInit, OsRng, generic_array::GenericArray},
consts::U12,
AesOcb3,
Ocb3,
};

type Aes128Ocb3 = AesOcb3<Aes128, U12>;
type Aes128Ocb3 = Ocb3<Aes128, U12>;

let key = Aes128::generate_key(&mut OsRng);
let cipher = Aes128Ocb3::new(&key);
Expand Down
53 changes: 25 additions & 28 deletions ocb3/src/lib.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -80,17 +80,14 @@ mod private {
impl SealedNonceSize for consts::U12 {}
}

/// AES-OCB3: generic over an AES implementation, nonce size, and tag size.
///
/// WARNING: Unless absolutely necessary, prefer the aliases Aes128Ocb3 and
/// Aes256Ocb3.
/// OCB3: generic over a block cipher implementation, nonce size, and tag size.
#[derive(Clone)]
pub struct AesOcb3<Aes, NonceSize = U12, TagSize = U16>
pub struct Ocb3<Cipher, NonceSize = U12, TagSize = U16>
where
NonceSize: self::NonceSize,
TagSize: self::TagSize,
{
cipher: Aes,
cipher: Cipher,
nonce_size: PhantomData<NonceSize>,
tag_size: PhantomData<TagSize>,
// precomputed key-dependent variables
Expand All @@ -104,27 +101,27 @@ where
type SumSize = U16;
type Sum = GenericArray<u8, SumSize>;

impl<Aes, NonceSize, TagSize> KeySizeUser for AesOcb3<Aes, NonceSize, TagSize>
impl<Cipher, NonceSize, TagSize> KeySizeUser for Ocb3<Cipher, NonceSize, TagSize>
where
Aes: KeySizeUser,
Cipher: KeySizeUser,
TagSize: self::TagSize,
NonceSize: self::NonceSize,
{
type KeySize = Aes::KeySize;
type KeySize = Cipher::KeySize;
}

impl<Aes, NonceSize, TagSize> KeyInit for AesOcb3<Aes, NonceSize, TagSize>
impl<Cipher, NonceSize, TagSize> KeyInit for Ocb3<Cipher, NonceSize, TagSize>
where
Aes: BlockSizeUser<BlockSize = U16> + BlockEncrypt + KeyInit + BlockDecrypt,
Cipher: BlockSizeUser<BlockSize = U16> + BlockEncrypt + KeyInit + BlockDecrypt,
TagSize: self::TagSize,
NonceSize: self::NonceSize,
{
fn new(key: &aead::Key<Self>) -> Self {
Aes::new(key).into()
Cipher::new(key).into()
}
}

impl<Aes, NonceSize, TagSize> AeadCore for AesOcb3<Aes, NonceSize, TagSize>
impl<Cipher, NonceSize, TagSize> AeadCore for Ocb3<Cipher, NonceSize, TagSize>
where
NonceSize: self::NonceSize,
TagSize: self::TagSize,
Expand All @@ -134,13 +131,13 @@ where
type CiphertextOverhead = U0;
}

impl<Aes, NonceSize, TagSize> From<Aes> for AesOcb3<Aes, NonceSize, TagSize>
impl<Cipher, NonceSize, TagSize> From<Cipher> for Ocb3<Cipher, NonceSize, TagSize>
where
Aes: BlockSizeUser<BlockSize = U16> + BlockEncrypt + BlockDecrypt,
Cipher: BlockSizeUser<BlockSize = U16> + BlockEncrypt + BlockDecrypt,
TagSize: self::TagSize,
NonceSize: self::NonceSize,
{
fn from(cipher: Aes) -> Self {
fn from(cipher: Cipher) -> Self {
let (ll_star, ll_dollar, ll) = key_dependent_variables(&cipher);

Self {
Expand All @@ -156,8 +153,8 @@ where

/// Computes key-dependent variables defined in
/// https://www.rfc-editor.org/rfc/rfc7253.html#section-4.1
fn key_dependent_variables<Aes: BlockSizeUser<BlockSize = U16> + BlockEncrypt>(
cipher: &Aes,
fn key_dependent_variables<Cipher: BlockSizeUser<BlockSize = U16> + BlockEncrypt>(
cipher: &Cipher,
) -> (Block, Block, [Block; L_TABLE_SIZE]) {
let mut zeros = [0u8; 16];
let ll_star = Block::from_mut_slice(&mut zeros);
Expand All @@ -174,9 +171,9 @@ fn key_dependent_variables<Aes: BlockSizeUser<BlockSize = U16> + BlockEncrypt>(
(*ll_star, ll_dollar, ll)
}

impl<Aes, NonceSize, TagSize> AeadInPlace for AesOcb3<Aes, NonceSize, TagSize>
impl<Cipher, NonceSize, TagSize> AeadInPlace for Ocb3<Cipher, NonceSize, TagSize>
where
Aes: BlockSizeUser<BlockSize = U16> + BlockEncrypt + BlockDecrypt,
Cipher: BlockSizeUser<BlockSize = U16> + BlockEncrypt + BlockDecrypt,
TagSize: self::TagSize,
NonceSize: self::NonceSize,
{
Expand Down Expand Up @@ -256,9 +253,9 @@ where
}
}

impl<Aes, NonceSize, TagSize> AesOcb3<Aes, NonceSize, TagSize>
impl<Cipher, NonceSize, TagSize> Ocb3<Cipher, NonceSize, TagSize>
where
Aes: BlockSizeUser<BlockSize = U16> + BlockEncrypt + BlockDecrypt,
Cipher: BlockSizeUser<BlockSize = U16> + BlockEncrypt + BlockDecrypt,
TagSize: self::TagSize,
NonceSize: self::NonceSize,
{
Expand Down Expand Up @@ -410,10 +407,10 @@ where
///
/// Assumes a 96-bit nonce and 128-bit tag.
fn nonce_dependent_variables<
Aes: BlockSizeUser<BlockSize = U16> + BlockEncrypt,
Cipher: BlockSizeUser<BlockSize = U16> + BlockEncrypt,
NonceSize: self::NonceSize,
>(
cipher: &Aes,
cipher: &Cipher,
nn: &Nonce<NonceSize>,
tag_len: u32,
) -> (usize, [u8; 24]) {
Expand Down Expand Up @@ -454,10 +451,10 @@ fn nonce_dependent_variables<
///
/// Assumes a 96-bit nonce and 128-bit tag.
fn initial_offset<
Aes: BlockSizeUser<BlockSize = U16> + BlockEncrypt,
Cipher: BlockSizeUser<BlockSize = U16> + BlockEncrypt,
NonceSize: self::NonceSize,
>(
cipher: &Aes,
cipher: &Cipher,
nn: &Nonce<NonceSize>,
tag_size: u32,
) -> Block {
Expand All @@ -471,9 +468,9 @@ fn initial_offset<
offset.to_be_bytes().into()
}

impl<Aes, NonceSize, TagSize> AesOcb3<Aes, NonceSize, TagSize>
impl<Cipher, NonceSize, TagSize> Ocb3<Cipher, NonceSize, TagSize>
where
Aes: BlockSizeUser<BlockSize = U16> + BlockEncrypt,
Cipher: BlockSizeUser<BlockSize = U16> + BlockEncrypt,
TagSize: self::TagSize,
NonceSize: self::NonceSize,
{
Expand Down
20 changes: 10 additions & 10 deletions ocb3/tests/kats.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@ use aead::{
};
use aes::{Aes128, Aes192, Aes256};
use hex_literal::hex;
use ocb3::{AesOcb3, GenericArray};
use ocb3::{GenericArray, Ocb3};

// Test vectors from https://www.rfc-editor.org/rfc/rfc7253.html#appendix-A
aead::new_test!(rfc7253_ocb_aes, "rfc7253_ocb_aes", Aes128Ocb3);
Expand Down Expand Up @@ -83,15 +83,15 @@ macro_rules! rfc7253_wider_variety {
}

// More types for testing
type Aes192Ocb3 = AesOcb3<Aes192, U12>;
type Aes128Ocb3Tag96 = AesOcb3<Aes128, U12, U12>;
type Aes192Ocb3Tag96 = AesOcb3<Aes192, U12, U12>;
type Aes256Ocb3Tag96 = AesOcb3<Aes256, U12, U12>;
type Aes128Ocb3Tag64 = AesOcb3<Aes128, U12, U8>;
type Aes192Ocb3Tag64 = AesOcb3<Aes192, U12, U8>;
type Aes256Ocb3Tag64 = AesOcb3<Aes256, U12, U8>;
type Aes128Ocb3 = AesOcb3<aes::Aes128, U12>;
type Aes256Ocb3 = AesOcb3<aes::Aes256, U12>;
type Aes192Ocb3 = Ocb3<Aes192, U12>;
type Aes128Ocb3Tag96 = Ocb3<Aes128, U12, U12>;
type Aes192Ocb3Tag96 = Ocb3<Aes192, U12, U12>;
type Aes256Ocb3Tag96 = Ocb3<Aes256, U12, U12>;
type Aes128Ocb3Tag64 = Ocb3<Aes128, U12, U8>;
type Aes192Ocb3Tag64 = Ocb3<Aes192, U12, U8>;
type Aes256Ocb3Tag64 = Ocb3<Aes256, U12, U8>;
type Aes128Ocb3 = Ocb3<aes::Aes128, U12>;
type Aes256Ocb3 = Ocb3<aes::Aes256, U12>;

/// Test vectors from Page 18 of https://www.rfc-editor.org/rfc/rfc7253.html#appendix-A
#[test]
Expand Down

0 comments on commit eba495c

Please sign in to comment.