141 lines
5.8 KiB
C
141 lines
5.8 KiB
C
/**
|
|
* \file hkdf.h
|
|
*
|
|
* \brief This file contains the HKDF interface.
|
|
*
|
|
* The HMAC-based Extract-and-Expand Key Derivation Function (HKDF) is
|
|
* specified by RFC 5869.
|
|
*/
|
|
/*
|
|
* Copyright (C) 2018-2019, ARM Limited, All Rights Reserved
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
* not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
* This file is part of mbed TLS (https://tls.mbed.org)
|
|
*/
|
|
#ifndef MBEDTLS_HKDF_H
|
|
#define MBEDTLS_HKDF_H
|
|
|
|
#if !defined(MBEDTLS_CONFIG_FILE)
|
|
#include "mbedtls/config.h"
|
|
#else
|
|
#include MBEDTLS_CONFIG_FILE
|
|
#endif
|
|
|
|
#include "mbedtls/md.h"
|
|
|
|
/**
|
|
* \name HKDF Error codes
|
|
* \{
|
|
*/
|
|
#define MBEDTLS_ERR_HKDF_BAD_INPUT_DATA -0x5F80 /**< Bad input parameters to function. */
|
|
/* \} name */
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/**
|
|
* \brief This is the HMAC-based Extract-and-Expand Key Derivation Function
|
|
* (HKDF).
|
|
*
|
|
* \param md A hash function; md.size denotes the length of the hash
|
|
* function output in bytes.
|
|
* \param salt An optional salt value (a non-secret random value);
|
|
* if the salt is not provided, a string of all zeros of
|
|
* md.size length is used as the salt.
|
|
* \param salt_len The length in bytes of the optional \p salt.
|
|
* \param ikm The input keying material.
|
|
* \param ikm_len The length in bytes of \p ikm.
|
|
* \param info An optional context and application specific information
|
|
* string. This can be a zero-length string.
|
|
* \param info_len The length of \p info in bytes.
|
|
* \param okm The output keying material of \p okm_len bytes.
|
|
* \param okm_len The length of the output keying material in bytes. This
|
|
* must be less than or equal to 255 * md.size bytes.
|
|
*
|
|
* \return 0 on success.
|
|
* \return #MBEDTLS_ERR_HKDF_BAD_INPUT_DATA when the parameters are invalid.
|
|
* \return An MBEDTLS_ERR_MD_* error for errors returned from the underlying
|
|
* MD layer.
|
|
*/
|
|
int mbedtls_hkdf( const mbedtls_md_info_t *md, const unsigned char *salt,
|
|
size_t salt_len, const unsigned char *ikm, size_t ikm_len,
|
|
const unsigned char *info, size_t info_len,
|
|
unsigned char *okm, size_t okm_len );
|
|
|
|
/**
|
|
* \brief Take the input keying material \p ikm and extract from it a
|
|
* fixed-length pseudorandom key \p prk.
|
|
*
|
|
* \warning This function should only be used if the security of it has been
|
|
* studied and established in that particular context (eg. TLS 1.3
|
|
* key schedule). For standard HKDF security guarantees use
|
|
* \c mbedtls_hkdf instead.
|
|
*
|
|
* \param md A hash function; md.size denotes the length of the
|
|
* hash function output in bytes.
|
|
* \param salt An optional salt value (a non-secret random value);
|
|
* if the salt is not provided, a string of all zeros
|
|
* of md.size length is used as the salt.
|
|
* \param salt_len The length in bytes of the optional \p salt.
|
|
* \param ikm The input keying material.
|
|
* \param ikm_len The length in bytes of \p ikm.
|
|
* \param[out] prk A pseudorandom key of at least md.size bytes.
|
|
*
|
|
* \return 0 on success.
|
|
* \return #MBEDTLS_ERR_HKDF_BAD_INPUT_DATA when the parameters are invalid.
|
|
* \return An MBEDTLS_ERR_MD_* error for errors returned from the underlying
|
|
* MD layer.
|
|
*/
|
|
int mbedtls_hkdf_extract( const mbedtls_md_info_t *md,
|
|
const unsigned char *salt, size_t salt_len,
|
|
const unsigned char *ikm, size_t ikm_len,
|
|
unsigned char *prk );
|
|
|
|
/**
|
|
* \brief Expand the supplied \p prk into several additional pseudorandom
|
|
* keys, which is the output of the HKDF.
|
|
*
|
|
* \warning This function should only be used if the security of it has been
|
|
* studied and established in that particular context (eg. TLS 1.3
|
|
* key schedule). For standard HKDF security guarantees use
|
|
* \c mbedtls_hkdf instead.
|
|
*
|
|
* \param md A hash function; md.size denotes the length of the hash
|
|
* function output in bytes.
|
|
* \param prk A pseudorandom key of at least md.size bytes. \p prk is
|
|
* usually the output from the HKDF extract step.
|
|
* \param prk_len The length in bytes of \p prk.
|
|
* \param info An optional context and application specific information
|
|
* string. This can be a zero-length string.
|
|
* \param info_len The length of \p info in bytes.
|
|
* \param okm The output keying material of \p okm_len bytes.
|
|
* \param okm_len The length of the output keying material in bytes. This
|
|
* must be less than or equal to 255 * md.size bytes.
|
|
*
|
|
* \return 0 on success.
|
|
* \return #MBEDTLS_ERR_HKDF_BAD_INPUT_DATA when the parameters are invalid.
|
|
* \return An MBEDTLS_ERR_MD_* error for errors returned from the underlying
|
|
* MD layer.
|
|
*/
|
|
int mbedtls_hkdf_expand( const mbedtls_md_info_t *md, const unsigned char *prk,
|
|
size_t prk_len, const unsigned char *info,
|
|
size_t info_len, unsigned char *okm, size_t okm_len );
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* hkdf.h */
|