Trait Digest 

pub trait Digest: Clone {
    const BLOCK_LEN: usize;
    const OUTPUT_LEN: usize;

    // Required methods
    fn new() -> Self;
    fn update(&mut self, data: &[u8]);
    fn finalize_into(self, out: &mut [u8]);
    fn finalize_reset(&mut self, out: &mut [u8]);
    fn zeroize(&mut self);

    // Provided method
    fn digest(data: &[u8]) -> Vec<u8>  { ... }
}

Minimal trait for fixed-output hash functions that can back HMAC.

SHA-1 and SHA-2 implementations behind this trait are Merkle-Damgard style hashes, so their raw outputs inherit the usual length-extension caveat. Use Hmac<H> for keyed authentication, or prefer SHA-3 / SHAKE when you specifically want sponge-based hashing semantics.

Required Associated Constants

const BLOCK_LEN: usize

Byte-oriented block size used by the Merkle-Damgard or sponge API.

For SHA-3, this is the Keccak rate in bytes, which is the block size used by HMAC with the SHA-3 family.

const OUTPUT_LEN: usize

Digest size in bytes.

Required Methods

fn new() -> Self

Create a fresh hashing state.

fn update(&mut self, data: &[u8])

Absorb more input bytes.

fn finalize_into(self, out: &mut [u8])

Finalize the hash into out.

The default one-shot digest(...) helper below allocates. Prefer the concrete types’ inherent digest(...) methods when you know the hash at compile time and want a fixed-size array.

fn finalize_reset(&mut self, out: &mut [u8])

Finalize in place and wipe the internal state.

This exists primarily so keyed constructions such as Hmac<H> can consume intermediate hash state without leaving key-derived chaining values behind in memory.

fn zeroize(&mut self)

Best-effort zeroization of the internal state.

Provided Methods

fn digest(data: &[u8]) -> Vec<u8>

Convenience helper for one-shot hashing.

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 Digest for Md5

const BLOCK_LEN: usize = 64

const OUTPUT_LEN: usize = 16

impl Digest for Ripemd160

const BLOCK_LEN: usize = 64

const OUTPUT_LEN: usize = 20

impl Digest for Sha1

const BLOCK_LEN: usize = 64

const OUTPUT_LEN: usize = 20

impl Digest for Sha224

const BLOCK_LEN: usize = 64

const OUTPUT_LEN: usize = 28

impl Digest for Sha256

const BLOCK_LEN: usize = 64

const OUTPUT_LEN: usize = 32

impl Digest for Sha384

const BLOCK_LEN: usize = 128

const OUTPUT_LEN: usize = 48

impl Digest for Sha512

const BLOCK_LEN: usize = 128

const OUTPUT_LEN: usize = 64

impl Digest for Sha512_224

const BLOCK_LEN: usize = 128

const OUTPUT_LEN: usize = 28

impl Digest for Sha512_256

const BLOCK_LEN: usize = 128

const OUTPUT_LEN: usize = 32

impl Digest for Sha3_224

const BLOCK_LEN: usize = 144

const OUTPUT_LEN: usize = 28

impl Digest for Sha3_256

const BLOCK_LEN: usize = 136

const OUTPUT_LEN: usize = 32

impl Digest for Sha3_384

const BLOCK_LEN: usize = 104

const OUTPUT_LEN: usize = 48

impl Digest for Sha3_512

const BLOCK_LEN: usize = 72

const OUTPUT_LEN: usize = 64