Function orion::default::hkdf

pub fn hkdf(
    salt: &[u8], 
    input: &[u8], 
    info: &[u8]
) -> Result<[u8; 32], UnknownCryptoError>

HKDF-HMAC-SHA512.

About:

The output length is set to 32, which makes the derived key suitable for use with AES256.

Parameters:

• salt: Salt value
• input: Input keying material
• info: Optional context and application specific information (can be a zero-length string)

See RFC for more information.

Exceptions:

An exception will be thrown if:

• The length of the salt is less than 16 bytes.

Security:

Salts should always be generated using a CSPRNG. The gen_rand_key function in util can be used for this. The recommended length for a salt is 16 bytes as a minimum. HKDF is not suitable for password storage.

Example:

use orion::default;
use orion::utilities::util;

let mut salt = [0u8; 32];
util::gen_rand_key(&mut salt).unwrap();
let data = "Some data.".as_bytes();
let info = "Some info.".as_bytes();

let hkdf = default::hkdf(&salt, data, info).unwrap();