mbedtls/3rdparty/everest/include/everest/x25519.h
2019-08-19 13:37:46 +01:00

191 lines
6.1 KiB
C

/*
* ECDH with curve-optimized implementation multiplexing
*
* Copyright 2016-2018 INRIA and Microsoft Corporation
* 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_X25519_H
#define MBEDTLS_X25519_H
#ifdef __cplusplus
extern "C" {
#endif
#define MBEDTLS_ECP_TLS_CURVE25519 0x1d
#define MBEDTLS_X25519_KEY_SIZE_BYTES 32
/**
* Defines the source of the imported EC key.
*/
typedef enum
{
MBEDTLS_X25519_ECDH_OURS, /**< Our key. */
MBEDTLS_X25519_ECDH_THEIRS, /**< The key of the peer. */
} mbedtls_x25519_ecdh_side;
/**
* \brief The x25519 context structure.
*/
typedef struct
{
unsigned char our_secret[MBEDTLS_X25519_KEY_SIZE_BYTES];
unsigned char peer_point[MBEDTLS_X25519_KEY_SIZE_BYTES];
} mbedtls_x25519_context;
/**
* \brief This function initializes an x25519 context.
*
* \param ctx The x25519 context to initialize.
*/
void mbedtls_x25519_init( mbedtls_x25519_context *ctx );
/**
* \brief This function frees a context.
*
* \param ctx The context to free.
*/
void mbedtls_x25519_free( mbedtls_x25519_context *ctx );
/**
* \brief This function generates a public key and a TLS
* ServerKeyExchange payload.
*
* This is the first function used by a TLS server for x25519.
*
*
* \param ctx The x25519 context.
* \param olen The number of characters written.
* \param buf The destination buffer.
* \param blen The length of the destination buffer.
* \param f_rng The RNG function.
* \param p_rng The RNG context.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX error code on failure.
*/
int mbedtls_x25519_make_params( mbedtls_x25519_context *ctx, size_t *olen,
unsigned char *buf, size_t blen,
int( *f_rng )(void *, unsigned char *, size_t),
void *p_rng );
/**
* \brief This function parses and processes a TLS ServerKeyExchange
* payload.
*
*
* \param ctx The x25519 context.
* \param buf The pointer to the start of the input buffer.
* \param end The address for one Byte past the end of the buffer.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX error code on failure.
*
*/
int mbedtls_x25519_read_params( mbedtls_x25519_context *ctx,
const unsigned char **buf, const unsigned char *end );
/**
* \brief This function sets up an x25519 context from an EC key.
*
* It is used by clients and servers in place of the
* ServerKeyEchange for static ECDH, and imports ECDH
* parameters from the EC key information of a certificate.
*
* \see ecp.h
*
* \param ctx The x25519 context to set up.
* \param key The EC key to use.
* \param side Defines the source of the key: 1: Our key, or
* 0: The key of the peer.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX error code on failure.
*
*/
int mbedtls_x25519_get_params( mbedtls_x25519_context *ctx, const mbedtls_ecp_keypair *key,
mbedtls_x25519_ecdh_side side );
/**
* \brief This function derives and exports the shared secret.
*
* This is the last function used by both TLS client
* and servers.
*
*
* \param ctx The x25519 context.
* \param olen The number of Bytes written.
* \param buf The destination buffer.
* \param blen The length of the destination buffer.
* \param f_rng The RNG function.
* \param p_rng The RNG context.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX error code on failure.
*/
int mbedtls_x25519_calc_secret( mbedtls_x25519_context *ctx, size_t *olen,
unsigned char *buf, size_t blen,
int( *f_rng )(void *, unsigned char *, size_t),
void *p_rng );
/**
* \brief This function generates a public key and a TLS
* ClientKeyExchange payload.
*
* This is the second function used by a TLS client for x25519.
*
* \see ecp.h
*
* \param ctx The x25519 context.
* \param olen The number of Bytes written.
* \param buf The destination buffer.
* \param blen The size of the destination buffer.
* \param f_rng The RNG function.
* \param p_rng The RNG context.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX error code on failure.
*/
int mbedtls_x25519_make_public( mbedtls_x25519_context *ctx, size_t *olen,
unsigned char *buf, size_t blen,
int( *f_rng )(void *, unsigned char *, size_t),
void *p_rng );
/**
* \brief This function parses and processes a TLS ClientKeyExchange
* payload.
*
* This is the second function used by a TLS server for x25519.
*
* \see ecp.h
*
* \param ctx The x25519 context.
* \param buf The start of the input buffer.
* \param blen The length of the input buffer.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX error code on failure.
*/
int mbedtls_x25519_read_public( mbedtls_x25519_context *ctx,
const unsigned char *buf, size_t blen );
#ifdef __cplusplus
}
#endif
#endif /* x25519.h */