| /* |
| * 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 */ |