/* $OpenBSD: hkdf.h,v 1.2 2018/04/03 13:33:53 tb Exp $ */
/* Copyright (c) 2014, Google Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
module libressl_d.openssl.hkdf;


private static import core.stdc.stdint;
private static import libressl_d.openssl.ossl_typ;
public import libressl_d.openssl.evp;

extern (C):
nothrow @nogc:

/**
 * HKDF computes HKDF (as specified by RFC 5869) of initial keying
 * material |secret| with |salt| and |info| using |digest|, and
 * outputs |out_len| bytes to |out_key|. It returns one on success and
 * zero on error.
 *
 * HKDF is an Extract-and-Expand algorithm. It does not do any key
 * stretching, and as such, is not suited to be used alone to generate
 * a key from a password.
 */
int HKDF(core.stdc.stdint.uint8_t* out_key, size_t out_len, const (libressl_d.openssl.evp.env_md_st)* digest, const (core.stdc.stdint.uint8_t)* secret, size_t secret_len, const (core.stdc.stdint.uint8_t)* salt, size_t salt_len, const (core.stdc.stdint.uint8_t)* info, size_t info_len);

/**
 * HKDF_extract computes a HKDF PRK (as specified by RFC 5869) from
 * initial keying material |secret| and salt |salt| using |digest|,
 * and outputs |out_len| bytes to |out_key|. The maximum output size
 * is |EVP_MAX_MD_SIZE|.  It returns one on success and zero on error.
 */
int HKDF_extract(core.stdc.stdint.uint8_t* out_key, size_t* out_len, const (libressl_d.openssl.evp.env_md_st)* digest, const (core.stdc.stdint.uint8_t)* secret, size_t secret_len, const (core.stdc.stdint.uint8_t)* salt, size_t salt_len);

/**
 * HKDF_expand computes a HKDF OKM (as specified by RFC 5869) of
 * length |out_len| from the PRK |prk| and info |info| using |digest|,
 * and outputs the result to |out_key|. It returns one on success and
 * zero on error.
 */
int HKDF_expand(core.stdc.stdint.uint8_t* out_key, size_t out_len, const (libressl_d.openssl.ossl_typ.EVP_MD)* digest, const (core.stdc.stdint.uint8_t)* prk, size_t prk_len, const (core.stdc.stdint.uint8_t)* info, size_t info_len);