Trait PseudoRandomFunction

pub trait PseudoRandomFunction<'a> {
    type KeyHandle;
    type PrfOutputSize: ArrayLength<u8> + ToInt<usize>;
    type Error;

    // Required methods
    fn init(
        &mut self,
        key: &'a dyn PseudoRandomFunctionKey<KeyHandle = Self::KeyHandle>,
    ) -> Result<(), Self::Error>;
    fn update(&mut self, msg: &[u8]) -> Result<(), Self::Error>;
    fn finish(&mut self, out: &mut [u8]) -> Result<usize, Self::Error>;
}

Defines how the KBKDF crate will interact with PRFs This allows the user of this crate to provide their own implementation of a PRF, however, only SP800-108 specified PRFs are allowed in the approved mode of operation. Given that, this crate cannot test for that and assumes that the user is using an approved PRF.

Required Associated Types

type KeyHandle

The type kf key handle the PRF is expecting

type PrfOutputSize: ArrayLength<u8> + ToInt<usize>

The PRF output size

type Error

The error type returned

Required Methods

fn init( &mut self, key: &'a dyn PseudoRandomFunctionKey<KeyHandle = Self::KeyHandle>, ) -> Result<(), Self::Error>

Initializes the pseudo random function

Arguments

• key - The key (K₁)

Returns

Either nothing or an [Error]

Panics

This function is allowed to panic if init is called while already initialized

fn update(&mut self, msg: &[u8]) -> Result<(), Self::Error>

Updates the PRF function

Arguments

• msg - The next message to input into the PRF

Returns

Either nothing or an [Error]

Panics

This function is allowed to panic if update is called before init

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

Finishes the PRF and returns the value in a buffer

Arguments

• out - The result of the PRF

Returns

Either nothing or an [Error]

Panics

This function is allowed to panic if finish is called before init

Implementors