Struct openssl::hash::Hasher

pub struct Hasher { /* fields omitted */ }

Provides message digest (hash) computation.

Examples

Calculate a hash in one go:

use openssl::hash::{hash, MessageDigest};

let data = b"\x42\xF4\x97\xE0";
let spec = b"\x7c\x43\x0f\x17\x8a\xef\xdf\x14\x87\xfe\xe7\x14\x4e\x96\x41\xe2";
let res = hash(MessageDigest::md5(), data).unwrap();
assert_eq!(&*res, spec);

Supply the input in chunks:

use openssl::hash::{Hasher, MessageDigest};

let data = [b"\x42\xF4", b"\x97\xE0"];
let spec = b"\x7c\x43\x0f\x17\x8a\xef\xdf\x14\x87\xfe\xe7\x14\x4e\x96\x41\xe2";
let mut h = Hasher::new(MessageDigest::md5()).unwrap();
h.update(data[0]).unwrap();
h.update(data[1]).unwrap();
let res = h.finish().unwrap();
assert_eq!(&*res, spec);

Use an XOF hasher (OpenSSL 1.1.1+):

#[cfg(ossl111)]
{
    use openssl::hash::{hash_xof, MessageDigest};

    let data = b"\x41\x6c\x6c\x20\x79\x6f\x75\x72\x20\x62\x61\x73\x65\x20\x61\x72\x65\x20\x62\x65\x6c\x6f\x6e\x67\x20\x74\x6f\x20\x75\x73";
    let spec = b"\x49\xd0\x69\x7f\xf5\x08\x11\x1d\x8b\x84\xf1\x5e\x46\xda\xf1\x35";
    let mut buf = vec![0; 16];
    hash_xof(MessageDigest::shake_128(), data, buf.as_mut_slice()).unwrap();
    assert_eq!(buf, spec);
}

Warning

Don’t actually use MD5 and SHA-1 hashes, they’re not secure anymore.

Don’t ever hash passwords, use the functions in the pkcs5 module or bcrypt/scrypt instead.

For extendable output functions (XOFs, i.e. SHAKE128/SHAKE256), you must use finish_xof instead of finish and provide a buf to store the hash. The hash will be as long as the buf.

Implementations

impl Hasher

pub fn new(ty: MessageDigest) -> Result<Hasher, ErrorStack>

Creates a new Hasher with the specified hash type.

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

Feeds data into the hasher.

pub fn finish(&mut self) -> Result<DigestBytes, ErrorStack>

Returns the hash of the data written and resets the non-XOF hasher.

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

Writes the hash of the data into the supplied buf and resets the XOF hasher. The hash will be as long as the buf.

Trait Implementations

impl Clone for Hasher

fn clone(&self) -> Hasher

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Drop for Hasher

fn drop(&mut self)

Executes the destructor for this type.

impl Write for Hasher

fn write(&mut self, buf: &[u8]) -> Result<usize>

Write a buffer into this writer, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

🔬 This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬 This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

Creates a “by reference” adapter for this instance of Write.

impl Send for Hasher

impl Sync for Hasher