Function evercrypt::hkdf::hkdf

pub fn hkdf(
    mode: Mode, 
    salt: &[u8], 
    ikm: &[u8], 
    info: &[u8], 
    okm_len: usize
) -> Vec<u8>

HKDF using hash function mode, salt, input key material ikm, info, and output length okm_len. Calls extract and expand with the given input. Returns the key material in a vector of length okm_len.