Struct Aez

pub struct Aez { /* private fields */ }

AEZ encryption scheme.

Implementations

impl Aez

pub fn new(key: &[u8]) -> Self

Create a new AEZ instance.

The key is expanded using Blake2b, according to the AEZ specification.

If you provide a key of the correct length (48 bytes), no expansion is done and the key is taken as-is.

pub fn encrypt( &self, nonce: &[u8], associated_data: &[&[u8]], tau: u32, data: &[u8], ) -> Vec<u8>

Encrypt the given data.

This is a convenience function that allocates a fresh buffer of the appropriate size and copies the data.

Parameters:

• nonce – the nonce to use. Each nonce should only be used once, as re-using the nonce (without chaning the key) will lead to the same ciphertext being produced, potentially making it re-identifiable.
• associated_data – additional data to be included in the integrity check. Note that this data will not be contained in the ciphertext, but it must be provided on decryption.
• tau – number of bytes (not bits) to use for integrity checking. A value of tau = 16 gives 128 bits of security. Passing a value of 0 is valid and leads to no integrity checking.
• data – actual data to encrypt. Can be empty, in which case the returned ciphertext provides a “hash” that verifies the integrity of the associated data will be

Returns the ciphertext, which will be of length data.len() + tau.

pub fn encrypt_vec( &self, nonce: &[u8], associated_data: &[&[u8]], tau: u32, data: &mut Vec<u8>, )

Encrypts the data in the given Vec.

This function extends the vector with enough space to hold tau bytes of authentication data. Afterwards, the vector will hold the ciphertext.

If tau == 0, the vector will not be expanded.

The parameters are the same as for Aez::encrypt.

pub fn encrypt_inplace( &self, nonce: &[u8], associated_data: &[&[u8]], tau: u32, buffer: &mut [u8], )

Encrypts the data inplace.

This function will overwrite the last tau bytes of the given buffer with the authentication block before encrypting the data.

If the buffer is smaller than tau, this function panics.

pub fn encrypt_buffer( &self, nonce: &[u8], associated_data: &[&[u8]], input: &[u8], output: &mut [u8], )

Encrypts the data in the given buffer, writing the output to the given output buffer.

This function will infer tau from the size difference between input and output. If the output is smaller than the input, this funcion will panic.

The nonce and associated_data parameters are the same as for Aez::encrypt.

pub fn decrypt( &self, nonce: &[u8], associated_data: &[&[u8]], tau: u32, data: &[u8], ) -> Option<Vec<u8>>

Decrypts the given ciphertext.

This is a convenience function that returns an owned version of the plaintext. If the original buffer may be modified, you can use Aez::decrypt_inplace to save an allocation.

Parameters:

• nonce, associated_data and tau are as for Aez::encrypt.
• data – the ciphertext to decrypt.

Returns the decrypted content. If the integrity check fails, returns None instead. The returned vector has length data.len() - tau.

pub fn decrypt_inplace<'a>( &self, nonce: &[u8], associated_data: &[&[u8]], tau: u32, data: &'a mut [u8], ) -> Option<&'a [u8]>

Decrypt the given buffer in-place.

Returns a slice to the valid plaintext subslice, or None.

The parameters are the same as for Aez::decrypt.