Trait Kdf 

pub trait Kdf {
    // Required method
    fn derive_key(
        &self,
        secret: &[u8],
        non_secret: &[u8],
        out: &mut [u8],
    ) -> Result<()>;
}

Key Derivation Function.

These functions deterministically produce uniformly random outputs suitable as key material.

It is recommended for types which implement this trait to also implement Default whenever possible.

Required Methods

fn derive_key( &self, secret: &[u8], non_secret: &[u8], out: &mut [u8], ) -> Result<()>

Writes uniformly random data suitable as key material into the entire length of out, derived from the following inputs:

• secret: this is typically a high-entropy input with at least 128-bits of symmetric strength/randomness, but does not have to be uniformly random (e.g. can be the output of a Diffie-Hellman exchange). For KDFs marked Pbkdf, this parameter is allowed to be a password with a lower entropy, but consumers of these traits MUST bound on Pbkdf whenever they are expecting the input to be a password.
• non_secret: this value customizes/personalizes the output and can be used to generate multiple unrelated outputs from the same input. Its secrecy is irrelevant, and it can be published to the world if desired. It maps to an algorithm specific parameter which accomplishes this purpose, sometimes called “salt”, “info”, “context”, or “customization”. See algorithm-specific documentation for the specific input this maps to for the specific impls for a given algorithm. For KDFs marked Pbkdf this is always the salt.

Implementors