Expand description
HMAC-based Extract-and-Expand Key Derivation Function.
HKDF is specified in RFC 5869.
In most situations, it is best to use extract_and_expand to do both the
HKDF-Extract and HKDF-Expand as one atomic operation. It is only necessary
to use the separate expand and extract functions if a single derived
PRK (defined in RFC 5869) is used more than once.
Salts have type hmac::SigningKey instead of &[u8] because they are
frequently used for multiple HKDF operations, and it is more efficient to
construct the SigningKey once and reuse it. Given a digest algorithm
digest_alg and a salt salt: &[u8], the SigningKey should be
constructed as hmac::SigningKey::new(digest_alg, salt).
Functions
Fills out with the output of the HKDF-Expand operation for the given
inputs.
The HKDF-Extract operation.
Fills out with the output of the HKDF Extract-and-Expand operation for
the given inputs.