Trait Digest

pub trait Digest {
    type OutputSize: ArrayLength<u8>;

    // Required methods
    fn new() -> Self;
    fn update(&mut self, data: impl AsRef<[u8]>);
    fn chain(self, data: impl AsRef<[u8]>) -> Self
       where Self: Sized;
    fn finalize(self) -> GenericArray<u8, Self::OutputSize>;
    fn finalize_reset(&mut self) -> GenericArray<u8, Self::OutputSize>;
    fn reset(&mut self);
    fn output_size() -> usize;
    fn digest(data: &[u8]) -> GenericArray<u8, Self::OutputSize>;
}

The Digest trait specifies an interface common for digest functions.

It’s a convenience wrapper around Update, FixedOutput, Reset, Clone, and Default traits. It also provides additional convenience methods.

Required Associated Types

type OutputSize: ArrayLength<u8>

Output size for Digest

Required Methods

fn new() -> Self

Create new hasher instance

fn update(&mut self, data: impl AsRef<[u8]>)

Digest data, updating the internal state.

This method can be called repeatedly for use with streaming messages.

fn chain(self, data: impl AsRef<[u8]>) -> Self

where Self: Sized,

Digest input data in a chained manner.

fn finalize(self) -> GenericArray<u8, Self::OutputSize>

Retrieve result and consume hasher instance.

fn finalize_reset(&mut self) -> GenericArray<u8, Self::OutputSize>

Retrieve result and reset hasher instance.

This method sometimes can be more efficient compared to hasher re-creation.

fn reset(&mut self)

Reset hasher instance to its initial state.

fn output_size() -> usize

Get output size of the hasher

fn digest(data: &[u8]) -> GenericArray<u8, Self::OutputSize>

Convenience function to compute hash of the data. It will handle hasher creation, data feeding and finalization.

Example:

println!("{:x}", sha2::Sha256::digest(b"Hello world"));

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<D> Digest for D

where D: Update + FixedOutput + Reset + Clone + Default,

type OutputSize = <D as FixedOutput>::OutputSize