Struct MacCtx 

pub struct MacCtx { /* private fields */ }

Stateful MAC context (EVP_MAC_CTX*).

!Clone — use fork() to duplicate mid-stream state. All stateful operations require &mut self.

Implementations

impl MacCtx

pub fn new(alg: &MacAlg) -> Result<Self, ErrorStack>

Create a new (uninitialised) MAC context from an algorithm descriptor.

Call MacCtx::init with a key before feeding data.

Errors

pub fn init( &mut self, key: &[u8], params: Option<&Params<'_>>, ) -> Result<(), ErrorStack>

Initialise (or re-initialise) with a key and optional parameters.

key is always copied into the MAC context by EVP_MAC_init. HMAC additionally pads the key into IPAD/OPAD. The copy is unavoidable.

Errors

pub fn update(&mut self, data: &[u8]) -> Result<(), ErrorStack>

Feed data into the ongoing MAC computation.

Errors

pub fn finish(&mut self, out: &mut [u8]) -> Result<usize, ErrorStack>

Finalise the MAC and write into out.

out must be at least self.mac_size() bytes. Returns the number of bytes written.

Errors

pub fn finish_xof(&mut self, out: &mut [u8]) -> Result<(), ErrorStack>

Finalise with variable-length XOF output (KMAC-128, KMAC-256).

Errors

pub fn mac_size(&self) -> usize

Expected MAC output length in bytes. Available after init.

pub fn fork(&self) -> Result<MacCtx, ErrorStack>

Fork the current mid-stream state into a new context (EVP_MAC_CTX_dup).

Named fork (not clone) to signal this is a potentially expensive deep copy.

Errors

Trait Implementations

impl Drop for MacCtx

fn drop(&mut self)

Executes the destructor for this type.

impl Send for MacCtx