Module Hkdf

RFC 5869 specifies a HMAC-based Extract-and-Expand Key Derivation Function (HKDF), which is abstracted over a specific hash function.

module type S = sig ... end
module Make (H : Digestif.S) : S

Given a Hash function, get the HKDF

val extract : hash:Digestif.hash' -> ?salt:string -> string -> string

convenience extract hash salt ikm where the hash has to be provided explicitly

val expand : hash:Digestif.hash' -> prk:string -> ?info:string -> int -> string

convenience expand hash prk info len where the hash has to be provided explicitly