Function std::hkdf_extract

#include <std/crypto/hkdf.h> source

generic<H: BlockHash> void hkdf_extract(
    H fresh,
    []const unsigned char salt,
    []const unsigned char ikm,
    []unsigned char prk,
)

PRK = HMAC-Hash(salt, IKM), digest_size() bytes into 'prk'. An empty salt is the all-zero string of digest_size() bytes (RFC 5869 §2.2).