Type Alias XChaCha20

pub type XChaCha20 = StreamCipherCoreWrapper<XChaChaCore<U10>>;

XChaCha is a ChaCha20 variant with an extended 192-bit (24-byte) nonce.

The construction is an adaptation of the same techniques used by XChaCha as described in the paper “Extending the Salsa20 Nonce”, applied to the 96-bit nonce variant of ChaCha20, and derive a separate subkey/nonce for each extended nonce:

https://cr.yp.to/snuffle/xsalsa-20081128.pdf

No authoritative specification exists for XChaCha20, however the construction has “rough consensus and running code” in the form of several interoperable libraries and protocols (e.g. libsodium, WireGuard) and is documented in an (expired) IETF draft:

https://tools.ietf.org/html/draft-arciszewski-xchacha-03

Aliased Type

struct XChaCha20 { /* private fields */ }

Implementations

impl<T> StreamCipherCoreWrapper<T>

where T: StreamCipherCore, <T as BlockSizeUser>::BlockSize: IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>, <<T as BlockSizeUser>::BlockSize as IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>>::Output: NonZero,

pub fn get_core(&self) -> &T

Return reference to the core type.

pub fn from_core(core: T) -> StreamCipherCoreWrapper<T>

Return reference to the core type.

Trait Implementations

impl<T> Clone for StreamCipherCoreWrapper<T>

where T: Clone + BlockSizeUser, <T as BlockSizeUser>::BlockSize: IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>, <<T as BlockSizeUser>::BlockSize as IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>>::Output: NonZero,

fn clone(&self) -> StreamCipherCoreWrapper<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Default for StreamCipherCoreWrapper<T>

where T: Default + BlockSizeUser, <T as BlockSizeUser>::BlockSize: IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>, <<T as BlockSizeUser>::BlockSize as IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>>::Output: NonZero,

fn default() -> StreamCipherCoreWrapper<T>

Returns the “default value” for a type.

impl<T> IvSizeUser for StreamCipherCoreWrapper<T>

where T: IvSizeUser + BlockSizeUser, <T as BlockSizeUser>::BlockSize: IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>, <<T as BlockSizeUser>::BlockSize as IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>>::Output: NonZero,

type IvSize = <T as IvSizeUser>::IvSize

Initialization vector size in bytes.

fn iv_size() -> usize

Return IV size in bytes.

impl<T> KeyInit for StreamCipherCoreWrapper<T>

where T: KeyInit + BlockSizeUser, <T as BlockSizeUser>::BlockSize: IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>, <<T as BlockSizeUser>::BlockSize as IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>>::Output: NonZero,

fn new( key: &GenericArray<u8, <StreamCipherCoreWrapper<T> as KeySizeUser>::KeySize>, ) -> StreamCipherCoreWrapper<T>

Create new value from fixed size key.

fn new_from_slice(key: &[u8]) -> Result<Self, InvalidLength>

Create new value from variable size key.

impl<T> KeyIvInit for StreamCipherCoreWrapper<T>

where T: KeyIvInit + BlockSizeUser, <T as BlockSizeUser>::BlockSize: IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>, <<T as BlockSizeUser>::BlockSize as IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>>::Output: NonZero,

fn new( key: &GenericArray<u8, <StreamCipherCoreWrapper<T> as KeySizeUser>::KeySize>, iv: &GenericArray<u8, <StreamCipherCoreWrapper<T> as IvSizeUser>::IvSize>, ) -> StreamCipherCoreWrapper<T>

Create new value from fixed length key and nonce.

fn new_from_slices(key: &[u8], iv: &[u8]) -> Result<Self, InvalidLength>

Create new value from variable length key and nonce.

impl<T> KeySizeUser for StreamCipherCoreWrapper<T>

where T: KeySizeUser + BlockSizeUser, <T as BlockSizeUser>::BlockSize: IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>, <<T as BlockSizeUser>::BlockSize as IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>>::Output: NonZero,

type KeySize = <T as KeySizeUser>::KeySize

Key size in bytes.

fn key_size() -> usize

Return key size in bytes.

impl<T> StreamCipher for StreamCipherCoreWrapper<T>

where T: StreamCipherCore, <T as BlockSizeUser>::BlockSize: IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>, <<T as BlockSizeUser>::BlockSize as IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>>::Output: NonZero,

fn try_apply_keystream_inout( &mut self, data: InOutBuf<'_, '_, u8>, ) -> Result<(), StreamCipherError>

Apply keystream to inout data.

fn try_apply_keystream( &mut self, buf: &mut [u8], ) -> Result<(), StreamCipherError>

Apply keystream to data behind buf.

fn apply_keystream_inout(&mut self, buf: InOutBuf<'_, '_, u8>)

Apply keystream to inout data.

fn apply_keystream(&mut self, buf: &mut [u8])

Apply keystream to data in-place.

fn apply_keystream_b2b( &mut self, input: &[u8], output: &mut [u8], ) -> Result<(), StreamCipherError>

Apply keystream to data buffer-to-buffer.

impl<T> StreamCipherSeek for StreamCipherCoreWrapper<T>

where T: StreamCipherSeekCore, <T as BlockSizeUser>::BlockSize: IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>, <<T as BlockSizeUser>::BlockSize as IsLess<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, B0>, B0>>>::Output: NonZero,

fn try_current_pos<SN>(&self) -> Result<SN, OverflowError>

where SN: SeekNum,

Try to get current keystream position

fn try_seek<SN>(&mut self, new_pos: SN) -> Result<(), StreamCipherError>

where SN: SeekNum,

Try to seek to the given position

fn current_pos<T>(&self) -> T

where T: SeekNum,

Get current keystream position

fn seek<T>(&mut self, pos: T)

where T: SeekNum,

Seek to the given position